CHAPTER 41: Minimally Invasive Surgery Fundamentals

Minimally invasive surgery (MIS) is characteristically performed through a small incision or no incision, and visualization is provided by endoscopes. Both laparoscopy and hysteroscopy are considered in this category. With laparoscopy, small abdominal incisions provide access to introduce an endoscope and surgical instruments into the abdomen. To increase operative space, a pneumoperitoneum is created. As such, laparoscopy provides a minimally invasive option for women undergoing intraabdominal gynecologic surgery. And, with its technology improvements, almost all major intraabdominal gynecologic procedures can now be performed with MIS.

Hysteroscopy uses an endoscope and uterine cavity distending medium to provide an internal view of the endometrial cavity. This tool permits both the diagnosis and operative treatment of intrauterine pathology.

In theory, laparoscopic surgery differs from laparotomy only by its mode of access to the operative field. However, inherent qualities can make some surgical steps more difficult. These include indirect palpation of tissue, counterintuitive motion, a finite number of ports for abdominal access, restricted movement, and replacement of normal 3-dimensional (3-D) vision by 2-dimensional (2-D) video images. In appropriately selected patients, the trade-off is a faster recovery, improved cosmesis, less postoperative pain, diminished adhesion formation, and at least equivalent surgical results (Ellström, 1998; Falcone, 1999; Lundorff, 1991; Mais, 1996; Nieboer, 2009). The decision to perform laparoscopy is based on several parameters. Primary among these are patient factors, availability of appropriate instrumentation, and surgeon skill.

Patient Factors

Laparoscopy using a pneumoperitoneum is contraindicated in very few clinical conditions, but these include acute glaucoma, retinal detachment, increased intracranial pressure, and some types of ventriculoperitoneal shunts. Thus, laparoscopy is appropriate for many, although modifications are warranted for certain clinical situations. Several are discussed subsequently.

Prior Surgeries

With laparoscopy, adhesive disease increases the risk of visceral and vascular injury during abdominal entry. Adhesions are also associated with higher conversion rates to laparotomy because long and tedious adhesiolysis may be completed by some surgeons more quickly with open surgical dissection techniques. Thus, during preoperative physical examination, a surgeon notes the location of previous surgical scars and ascertains the risk of possible intraabdominal adhesive disease (Table 41-1). Similarly, a history of endometriosis, pelvic inflammatory disease, or radiation treatment may predispose to adhesions. In addition, abdominal wall hernias or hernia repairs and any reparative mesh are identified and avoided during trocar insertion. If abnormal findings are found during this preoperative evaluation, plans for an alternative entry site are considered.

Laparoscopic Physiology

Compared with traditional open laparotomy, laparoscopy produces several distinct cardiovascular and pulmonary physiologic changes. These result mainly from: (1) absorption across the peritoneum and into circulation of carbon dioxide (CO₂) used for insufflation, (2) increased intraabdominal pressure created by the pneumoperitoneum, and (3) head-down Trendelenburg positioning. These changes are typically tolerated by those in generally good health but may be less so in those with cardiovascular or pulmonary compromise. Thus for patient safety, surgeons should be familiar with these physiologic alterations.

During laparoscopy, a pneumoperitoneum is created, in most cases with CO₂. Absorption of this gas across the peritoneum can lead to systemic CO₂ accumulation and hypercarbia. In turn, hypercarbia produces sympathetic stimulation that raises systemic and pulmonary vascular resistance and increases blood pressure. If hypercarbia is not cleared by compensatory ventilation, acidemia develops. From this, direct myocardial contractility depression and decreased cardiac output can follow (Ho, 1995; Reynolds, 2003; Sharma, 1996). Hypercarbia can also lead to tachycardia and arrhythmia. Less commonly, bradycardia can stem from vagal stimulation. This may follow pelvic organ manipulation, cervical stretching during uterine manipulator placement, or peritoneal stretching during pneumoperitoneum creation.

Insufflation of any gas elevates intraabdominal pressure. This increased pressure decreases flow in the inferior vena cava, causes blood pooling in the legs, and raises venous resistance. In sum, venous return to the heart is decreased, and thereby cardiac output is lowered. Increased intraabdominal pressure can also directly lower splanchnic blood flow.

Intraoperative pulmonary function may be challenged during laparoscopy. First, the diaphragm is displaced upward by intraabdominal pressure from the pneumoperitoneum. This can be accentuated by organs also being pushed cephalad against the diaphragm during Trendelenburg positioning. Moreover, insufflation pressures stiffen the diaphragm and chest wall. Together, these alterations lead to higher required airway pressures to achieve adequate mechanical ventilation. Also, as the diaphragm moves up, lung volume and functional residual capacity are diminished, which in turn reduces the reserve volume for oxygenation. Moreover, this lung volume decline favors a tendency for the lung to collapse, leading to atelectasis. This can create ventilation and perfusion mismatching and an increased alveolar-arterial oxygen gradient. In sum, all of these factors favor poorer oxygenation.

Urinary output commonly is diminished during laparoscopy. This may result from the lowered cardiac output, decreased splanchnic blood flow, direct renal parenchymal compression, or the release of renin, aldosterone, or antidiuretic hormone. Together, these lessen renal blood flow, reduce glomerular filtration rate, and diminish urine output. Importantly, renal function returns to normal following pneumoperitoneum decompression (Demyttenaere, 2007).

Health Conditions

Several coexistent medical disorders are particularly relevant when considering laparoscopy. These include cardiac and pulmonary disease, intestinal obstruction, hemoperitoneum and hemodynamic instability, and pregnancy. As just described, in those with severe cardiac or pulmonary disease, elevated intra­abdominal pressures and steep Trendelenburg positioning may not be tolerated, as they decrease venous return and pulmonary reserve. Unfortunately, with laparoscopy, these techniques are often required for adequate visualization and instrument manipulation. In addition, CO₂ is used to distend the abdomen during laparoscopy. As noted, it is absorbed across the peritoneum into circulation, and hypercarbia may follow. Accordingly, in those with pulmonary or cardiovascular limitations, lowering intraabdominal pressures and flattening the degree of Trendelenburg are advantageous.

For a clinically stable patient with hemoperitoneum, laparoscopy is not contraindicated. Thus, ruptured ectopic pregnancies or a ruptured bleeding ovarian cyst may be treated via MIS. Although an unstable patient was previously considered a contraindication to laparoscopic surgery, many skilled surgeons feel they can safely and quickly enter the abdomen laparoscopically. That said, the lowered venous return and cardiac output must be factored into the decision to select laparoscopy for such patients.

Concurrent intestinal obstruction and its associated bowel distention may increase risks for bowel injury during abdominal entry. In these situations, open entry to gain initial abdominal access may be beneficial. However, ischemic bowel may be poorly served by pneumoperitoneum-related diminished splanchnic blood flow.

Obesity

In the past, obesity had been considered a relative contraindication for gynecologic laparoscopy. First, adequate ventilation may be difficult. In general, obese patients display reduced lung compliance that is proportional to their body mass index (BMI). Moreover, abdominal wall adiposity lowers abdominal wall compliance, which in turn elevates the pneumoperitoneum pressure required for surgery. Also, fattier omentum and mesenteric fat add to the bulk forced against the diaphragm in Trendelenburg position. Other limitations include a thick subcutaneous layer that encumbers laparoscopic instrument motion. It can also hinder abdominal entry, and trocar tunneling during insertion is common. Just patient girth relative to surgeon arm length may limit instrument manipulation.

As possible fixes, placement of an extra ancillary port for adequate manipulation of omentum and bowel out of the operative field can be helpful. Coordination with the anesthesia team to find a comfortable degree of Trendelenburg for both successful operative manipulations and adequate ventilation is essential. Longer “bariatric” instruments can overcome many length limitations.

As a result, with a skilled surgeon, obese patients may actually benefit from MIS. In studies, healthy obese patients experience less pain, quicker recovery, and fewer postoperative complications such as wound infections and postoperative ileus after laparoscopy compared with laparotomy (Eltabbakh, 1999, 2000; Scribner, 2002). That said, certain operative parameters may be adversely affected in obese patients undergoing laparoscopy compared with normal-weight patients. Higher conversion rates to laparotomy, longer operating times, and longer hospitalizations have been noted (Chopin, 2009; Heinberg, 2004; Thomas, 2006). However, this has not been found by all investigators, and overall outcomes may be superior to an open abdominal approach (Camanni, 2010; O’Hanlan, 2003; Shah, 2015).

Pregnancy

Nonurgent conditions identified during pregnancy may often be delayed and addressed postpartum. However, laparoscopy may be performed during any trimester. Thus, familiarity with the superimposed physiologic changes of pregnancy can improve maternal and fetal safety (O’Rourke, 2006; Reynolds, 2003).

Perioperatively, a wedge can be placed beneath the mother’s back on the right to create a left-lateral tilt and displace the uterus. For second- or third-trimester pregnancies, this can minimize the decreased venous return that results from pneumoperitoneum and from an enlarged uterus compressing pelvic veins and inferior vena cava. Also, rates of venous thromboembolism (VTE) are increased during pregnancy due to gestational hypercoagulability. Placing sequential compression stockings can help lower this risk.

Intraoperatively, steps involve avoiding placement of intracervical uterine manipulators, limiting insufflation pressures to 10 to 15 mm Hg, maintaining maternal end-tidal CO₂ levels between 32 and 34 mm Hg, moving trocar placement appropriately cephalad to avoid puncture of the gravid uterus, and limiting uterine manipulation (Pearl, 2011). Of note, the routine use of perioperative prophylactic tocolytics is not recommended in these cases. However, pre- and postoperative fetal heart rate assessment and contraction monitoring for more advanced gestations are typically implemented.

Underlying Pathology

For adnexal masses, myomectomy, and supracervical hysterectomy, operative planning must address appropriate specimen removal. As discussed later, options include endoscopic bags, morcellation, colpotomy, or minilaparotomy incisions. To guide selection, specimen size and the risks for occult malignancy and abdominal tumor seeding are assessed. Importantly, for masses that are known or strongly suspected to be malignant, laparoscopy is avoided if patient outcome could be compromised by specimen rupture, seeding, or morcellation or by incomplete resection or staging.

Facility Factors

In addition to patient factors, a surgeon must also consider environmental factors. The availability of appropriate anesthesia care, surgical nursing, support staff, and proper instrumentation influences procedure selection. Advanced operative laparoscopy is a coordinated team effort that requires multiple simultaneous activities, overseen and directed by the surgeon.

Prophylaxis

Randomized clinical trials have demonstrated that prophylactic antibiotics significantly reduce postoperative infectious morbidity rates following abdominal or vaginal hysterectomy. During laparoscopic hysterectomy, the vagina is similarly opened. Thus, preoperative antibiotics are recommended, and selection can be aided by American College of Obstetricians and Gynecologists guidelines (2014) found in Table 39-6. Antibiotics are generally given at the induction of anesthesia. For other types of laparoscopic procedures, data do not support antibiotic prophylaxis for clean surgical cases, that is, those that do not enter the vagina, bowel, or urinary tract (Chap. 3).

For thromboprophylaxis, the same principles used for other abdominal surgeries are applied to laparoscopic cases (American College of Obstetricians and Gynecologists, 2013). Specific to laparoscopy, pneumoperitoneum pressure may decrease venous return from the lower extremities (Caprini, 1994; Ido, 1995). Thus, for those in whom VTE prophylaxis is planned, preventative measures are administered early and prior to anesthesia induction. A complete list of VTE prophylaxis and guidelines for its use can be found in Table 39-8.

Preoperative Bowel Preparation

The benefits of routine mechanical bowel preparation are debatable, and thus plans for bowel preparation are individualized (Chap. 39). If the risk of bowel injury and stool spillage is increased because of pelvic adhesions or advanced endometriosis, then bowel preparation may limit fecal contamination at the surgical site. Moreover, if proctosigmoidoscopy is planned, an appropriate bowel preparation allows adequate visualization.

Anesthesia Selection

Laparoscopy can be completed using general or regional anesthesia. In most cases, general anesthesia with endotracheal intubation is selected to provide: (1) adequate patient comfort, (2) controlled ventilation to correct hypercarbia, (3) muscle relaxation, (4) airway protection from regurgitation due to increased intraabdominal pressures, and (5) orogastric tube placement. Some studies suggest that injection of local anesthesia at port sites may diminish postoperative pain (Einarsson, 2004).

Consent

Laparoscopy itself is usually associated with little associated morbidity. Of major complications, the most common is organ injury caused by puncture or by electrosurgical tools and is described later. If these occur or if surgery is hindered by bleeding or adhesions, conversion to laparotomy may be necessary. Overall, this risk of conversion is low, and logically, rates decline as surgeon experience accrues.

Minor complications of laparoscopy occur more frequently. These may include wound infection or hematoma, subcutaneous emphysema from CO₂ infiltration, vulvar edema, and postoperative peritoneal irritation from retained intraabdominal CO₂. Irritation stems from conversion of CO₂ to carbonic acid, which can be a direct irritant.

Puncture Injuries

Because sharp tools are used during laparoscopic entry, vessels and abdominal organs may be punctured. Risk factors have been identified and include intraabdominal adhesions, insufficient gastric emptying, full bladder, insufficient pneumoperitoneum, poor muscle relaxation, thin patient habitus, and unsuitable angle or force of tool insertion. As discussed later, several authors advocate an open entry method as a means to help lower puncture injury rates (Catarci, 2001; Hasson, 2000; Long, 2008).

Organ Injury

The organ most frequently injured during laparoscopy is bowel, and rates of 0.6 and 1.6 per 1000 cases are reported (Chapron, 1999; Harkki-Siren, 1997). Women with previous laparotomy have a higher incidence of abdominal adhesions and are at greatest risk for this complication.

Unfortunately, bowel injury sustained during laparoscopy is often missed intraoperatively. For example, in an observational study by Chandler and coworkers (2001), nearly 50 percent of both small- and large-bowel injuries were unrecognized for 24 hours or longer. Typically, these patients present with fever, abdominal pain, nausea, and vomiting within 48 hours of surgery (Li, 1997).

In laparoscopic cases, decompression of the stomach with an orogastric tube prior to obtaining laparoscopic access can lower the stomach puncture risk. Moreover, in those with suspected abdominal adhesive disease, several preventative steps can help avoid bowel injury. These include: (1) introduction of a microlaparoscope to scout for adhesions, (2) preoperative sonography using the visceral slide test to exclude bowel adhered to the anterior abdominal wall, and (3) an alternative site for primary trocar entry, for example in the left hypochondrium (Palmer point), rather than at the umbilicus.

Bladder puncture is uncommon with laparoscopy. Bladder decompression prior to and during surgery and careful placement of secondary trocars under direct visualization will prevent many injuries. However, with increased rates of laparoscopic hysterectomy, rates of bladder and ureteral damage have concurrently risen. These occur at the same surgical steps associated with urinary tract injury during abdominal hysterectomy.

Vascular or Nerve Injury

Major vascular injury associated with laparoscopy is rare and typically results during primary trocar insertion. Puncture rates are cited as 0.09 to 5 per 1000 cases, and characteristically, the terminal aorta, inferior vena cava, and iliac vessels, particularly the right common iliac artery, may be injured (Bergqvist, 1987; Catarci, 2001; Nordestgaard, 1995). Rarely, air embolism from gas insufflation following vessel puncture may occur.

Although infrequent, a significant number of deaths result from large vessel injury (Baadsgaard, 1989; Munro, 2002). Prevention may include use of the open entry technique or awareness of the angle and force of trocar entry. Despite these steps, if a large vessel is punctured, the wounding instrument is not removed because it may act as a vascular plug. Moreover, this tool is held stable to avoid extending the laceration. In most cases, laparotomy, direct manual pressure on the vessel, steps for hemodynamic resuscitation, and notification of a vascular surgeon should follow expeditiously.

In contrast, if the inferior epigastric artery is injured, several simple techniques can control hemorrhage. First, bipolar electrosurgical coagulation of the bleeding site may suffice in many cases. If this fails to control bleeding, a 14F Foley catheter can be threaded through the cannula of the wounding trocar or through the defect created by this trocar. The Foley balloon then is inflated and pulled upward to create direct pressure against the posterior surface of the anterior abdominal wall. At the skin surface, a Kelly clamp is placed perpendicular across the Foley catheter and parallel to the skin to hold the balloon firmly in place. The balloon and catheter can be removed approximately 12 hours later. Alternatively, sutures can be placed that traverse the skin, abdominal wall, and peritoneum; arch under the bleeding vessel; and exit the abdomen to directly ligate the vessel (Fig. 41-1). Similarly, the Carter-Thomason tool can be used to ligate both ends of this vessel.

Nerve injury can follow in patients placed for extended periods in the dorsal lithotomy position with arms abducted. From this, injury to the common peroneal, femoral, lateral femoral cutaneous, obturator, sciatic, and ulnar nerves and to the brachial plexus is possible (Barnett, 2007). Specific injuries and prevention are described in Chapter 40. Attention paid to patient position and surgery duration prevent many of these complications.

Thermal Injury

Accidental burns may follow direct instrument contact or stray electric current. Fortunately, the risk of this complication is low. Prevention steps include keeping instrument tips within the visual field when electric current is applied, strict instrument maintenance to identify insulation defects, employment of bipolar coagulation or harmonic energy for hemostasis when feasible, and use of lower-voltage (cutting) current whenever possible to reduce the applied voltage (Wu, 2000).

Incisional Hernia

Incisional hernias are a potential long-term consequence of laparoscopy. The incidence approximates 1 percent but may rise in the future with increased use of larger trocars for operative laparoscopy and single-port umbilical techniques. Approximately one fourth of hernias are umbilical, and the remainder develop at secondary trocar sites (Lajer, 1997).

A major risk for incisional hernia is use of large trocars measuring ≥10 mm in diameter or port sites from which larger specimens are extracted. Preventatively, smaller trocar use when possible and fascial closure of larger trocars wound sites is advocated. The use of trocars with conical rather than pyramidal tips can also lower this incidence (Leibl, 1999). Finally, peritoneal tissue is ideally not drawn into the superficial layers of the wound when removing the cannulas (Boughey, 2003; Montz, 1994).

Trocar-site Metastasis

Rates of trocar-site cancer metastasis are low, and this complicates the clinical course of approximately 1 percent of patients in whom gynecologic malignancy is identified. Similarly, port-site seeding of other tissues such as endometriosis has been reported. Metastases are more frequent with ovarian cancer than other malignancies, and higher rates are seen with more advanced disease (Abu-Rustum, 2004; Childers, 1994; Zivanovic, 2008). Although most trocar-site metastases are associated with advanced stages of disease, metastasis has followed surgery for tumors of low malignant potential. As a result, the steps of laparoscopy itself have been evaluated as a risk for tumor spread to the trocar sites (Ramirez, 2004). Currently, no evidence-based consensus addresses prevention of this complication. Thus, the careful tissue extraction techniques described on page 896 are encouraged.

Operating Equipment

In laparoscopy, tool movement is limited compared with laparotomy, secondary to instrument angle restrictions and fixed ports (Berguer, 2001). Thus, room organization is essential, and equipment is positioned before the procedure begins. Also preoperatively, all instruments are checked and tested to confirm proper functioning.

Although equipment positioning may vary based on surgeon preference, the following is suggested to optimize efficiency and safety. The operating room table is centered in the room, and surgical lights lie directly above the operative field. Prior to surgery, this bed is checked to ensure it moves up and down and into steep Trendelenburg position. Obese patients may require a larger bariatric operating table.

Video monitors may be fixed to the ceiling with articulating arms or may be placed on portable stands. One monitor may suffice for simple procedures, however, two monitors provide easy viewing by the surgeon and assistant. When operating in the pelvis, the monitor is placed directly in front of the surgeon, and the surgeon, forearm-instrument axis, and video monitor are aligned in a straight line. Thus, placement of the video monitor for most gynecologic surgeries is near the patient’s upper thigh (Fig. 41-2). For best surgeon ergonomics, monitor height is 10 to 20 degrees below eye level to prevent neck strain (van Det, 2009). Also, surgeons stand an appropriate distance and height relative to the operating table such that their arms are slightly abducted, their shoulders are inwardly rotated, and their elbows are extended from 90 to 120 degrees. This positioning can minimize surgeon fatigue. The scrub technician and Mayo stand generally are positioned on the side of the primary surgeon near the patient’s leg. Here, instruments can be easily passed to both surgeons. The Mayo stand is organized with frequently used handheld instruments.

A dedicated cabinet or “tower” houses the laparoscopic light source, gas insufflator, and image capture equipment. The tower is positioned on the side opposite the primary surgeon such that he or she has an unobstructed view of equipment display panels. All insufflation tubing, camera, and light cords ideally exit the operating field from the same direction and connect to the equipment tower. Similarly, electrosurgical equipment and pedals are organized so that all these cords are aligned in one direction to reach a separate cart that houses these electrosurgical units. Pedals are oriented appropriately for the primary surgeon to comfortably reach without adjusting his body or moving his eyes from the monitor.

Patient Positioning

This is another essential component of safe laparoscopy. Following anesthesia induction, a patient is placed in low dorsal lithotomy position with the legs in booted support stirrups (see Fig. 41-2). To aid proper leg positioning, the stirrup brackets, which holster the stirrups, are attached to the table at the level of the patient hips. To prevent femoral nerve injury, the hips are positioned without sharp flexion or marked abduction or external hip rotation. The knees are not flexed more than 90 degrees and are appropriately positioned and padded to avoid common peroneal nerve compression. To avert slipping when in steep Trendelenburg position and to minimize lower back pressure, a patient can be placed directly on an antiskid material such as egg-crate or gel pad. With these, patient skin directly contacts the padding (Klauschie, 2010; Lamvu, 2004). If uterine manipulation is needed, the buttocks are placed slightly past the edge of the table.

Patient arms are tucked to the side in military position. This allows improved patient access and prevents upper extremity hyperextension, which can result in brachial plexus injury. The arms may be tucked using an extended draw sheet, which is placed under the gel pad. This relationship limits arm slippage, which can generate pressure against the brachial plexus. Even in obese patients, the use of antiskid material and arm tucking is useful in preventing slippage for long periods in steep Trendelenburg position (Klauschie, 2010). The arms are padded to avert compression of the ulnar and median nerves. Fingertips are facing the thighs, well-padded, and positioned away from the moving foot of the bed to prevent unintentional amputation. During arm positioning, finger oxygen monitors and intravenous access should not be dislodged.

Shoulder braces are padded brackets that are placed on the cephalic side of the operating room bed and arch around to the patient’s acromion. Their goal is to brace the shoulder and prevent the head from slipping off the bed when in Trendelenburg position. If shoulder braces are required, we recommend tucking the arms in addition to using well-padded braces. However, due to the risk of nerve injury, the use of shoulder braces in general should be limited. Specifically, brachial plexus injury complicates 0.16 percent of gynecologic laparoscopic procedures. When shoulder braces are used, compression over the acromion may apply pressure that stretches the plexus. Moreover, lateral compression by braces may compress the humerus against the plexus. Both predispose to brachial plexus injury (Romanowski, 1993).

Instrument Anatomy

Successful laparoscopic surgery relies on the use of appropriate surgical instruments. Most surgeons have designated preferences for certain types of graspers, dissectors, and cutting instruments. Many of these have been adapted and modified for laparoscopic surgery and undergo frequent updates. Moreover, new designs further aid retraction and dissection, thereby increasing the number of procedures that can be performed laparoscopically.

The components of a laparoscopic instrument include the hand grip, shaft, jaw, and tip (Fig. 41-3). In general, an instrument tip’s diameter is concordant with its shaft diameter, and standard sizes fit through 5-mm or 10-mm diameter cannulas. Additionally, 3-mm, 8-mm, and 15-mm instrument diameters are available for many tips. The tip defines instrument function. Jaws may be double action or single action. With a single-action jaw, one tip is fixed, lies in the same axis as the shaft, and offers greater stability during the action performed. Double-action jaws have tips that move synchronously, and this jaw offers a wider angle in which to perform its function. Some jaws are now modified by a compression feature that allows full-length scissor blades to secure the tissue in the tip crux and then cut tissue with greater stability and precision.

Important instrument qualities are comfort and ease of use, which stem primarily from the hand grip shape, the instrument length, and its locking capability. Most laparoscopic instruments have a standard 33-cm length. Due to the popularity of bariatric MIS, extended instruments are now available for procedures in obese patients. Specifically, long Veress needles and trocars and longer instrument shaft lengths offer improved manipulation through a thickened pannus. Although permitting better access, these longer instruments are often more difficult to manipulate due to altered operating angles caused by the extended length.

In the hand grip, a locking feature allows a surgeon to hold tissue without maintaining constant pressure against the grip. This decreases hand fatigue. The ability to rotate an instrument tip 360 degrees is now preferred. This versatility allows access to additional anatomic spaces and decreases the need for uncomfortable surgeon hand or arm rotation.

Disposable versus Reusable

Many laparoscopic instruments are available in both reusable and disposable forms, each having its own advantages. The main advantage to reusable instruments is lowered expense. Analyses demonstrate that disposable instruments add significant cost compared with reusable ones (Campbell, 2003; Morrison, 2004). The main advantage to disposable instruments is the consistent tool sharpness and avoidance of lost instrument parts. For example, dull scissors may lead to longer operating times and ineffectual surgical technique. Corson and associates (1989) showed that reusable trocars, although sharpened at regular intervals, still required twice the force for entry compared with disposable trocars. As a compromise, modified trocar systems combine the strength of these two features. Namely, the cannula is reusable, whereas a disposable inner trocar offers a consistently sharper tip.

Manipulators

Atraumatic Manipulators

During laparoscopic surgery, abdominopelvic organs may be elevated, retracted, or placed on tension (Fig. 41-4). Most current instrument designs have incorporated safety considerations to minimize organ trauma yet allow effective manipulation. Of these, the blunt probe has an end that is modified to decrease the perforation risk to retracted tissues. It is used for exploration and retraction and is a preferred tool during diagnostic laparoscopy. Most blunt probes are stainless steel and are conductive of electric current. However, disposable probes constructed of nonconductive materials are available.

Graspers are divided into two main categories, atraumatic and those with toothed or serrated tips. Atraumatic graspers are used for exploration, gentle traction, and delicate tissue handing. The 5-mm diameter is a popular size, although 3-mm and 10-mm sizes are available. Most of these graspers have a double-action jaw, and the hand grip is typically nonlocking. Their gradually tapering curved tip permits the surgeon to define and separate tissue planes and is generally preferred for blunt dissection.

The Maryland clamp is an example of a curved blunt tip used for dissection and grasping. It compares to the pean, hemostat, or munion, which are used in open surgery. Additionally, it can double as a needle driver if needed. Although technically considered atraumatic, this clamp may crush delicate tissues such as the fallopian tube or bowel.

The alligator clamp is a blunt grasper with a long, wide tip that handles delicate tissues with minimal crush-injury risk. It is useful for manipulating bowel, larger vessels, or reproductive organs or for exploration of vascular compartments that may be easily punctured or lacerated. However, its ability to retract tissues under tension is limited due to its atraumatic characteristics.

The Babcock clamp is another atraumatic tip that handles delicate tissues with minimal crushing. Its surgical role is similar to that in open techniques. However, as with the alligator clamp, its ability to retract or grasp during applied tension is poor due to slippage.

Ideally, all of these clamps are included in a general laparoscopic surgical tray for most laparoscopic procedures. Figure 41-4 shows additional tips with similar characteristics. As seen, some tips have window openings and are described as fenestrated. These are useful for tissue elevation or retraction or for passing sutures during vessel ligation.

Traumatic Graspers

Graspers with tips that are serrated or toothed are used in procedures that involve resection and tissue approximation (Fig. 41-5). Generally, such tissues are placed on tension, and a strong hold is required. In addition, a locking hand grip is typically preferred to keep grasped tissues secured. Most of these instruments have double-action jaws to allow a wide tissue purchase. In situations in which greater grip and tension strength is required, however, a tip with a single-action jaw and locking hand grip may be preferred.

Toothed graspers have teeth at their tip’s end. These are superior for tissue manipulation but function poorly as graspers for sutures or needles. One example is the laparoscopic tenaculum. Single-tooth and double-tooth tenaculums are both available and effectively hold and retract dense, heavy tissue. The single-tooth tenaculum usually has a double-action jaw, whereas the double-tooth tenaculum is available with either a single- or double-action jaw. Both usually offer a locking hand grip. A tenaculum is traumatic and thus is generally used only on tissue to be resected or repaired. One common use is to grasp and remove tissue during morcellation.

The cobra grasper is a toothed instrument with a double-action jaw. It has short teeth on each side and is excellent for tissue retraction due to its strong grip strength. It is considered a traumatic grasper and is not used on delicate tissues.

Some of the toothed instruments are designed with less traumatic teeth and are selected when less tissue crushing is desired. For example, ovarian biopsy forceps provide adequate grasp with minimal tissue crushing. An appropriate setting might be ovarian cyst resection and subsequent ovarian repair. An Allis grasper has blunter teeth for grasping and holding tissue during resection. However, it provides less gripping strength than the cobra.

Serrated graspers are considered traumatic but are less damaging than toothed graspers. They offer a secure grip with minimal tissue damage and generally are used in repairs or tissue approximation. Because of their variety, a surgeon should be familiar with their grips and tissue effects to select the one that best fits the planned procedure. Serrated graspers may be fenestrated or nonfenestrated, may offer a locking hand grip, and may have single-action or double-action jaws.

A corkscrew tip probe is frequently used for marked retraction of more solid masses such as leiomyomas. It offers superior grip and strength but is limited by the trauma created as it is screwed into the tissue to be held. Additionally, surgeons are mindful of the tip location when advancing it, as the downward force required to spiral the corkscrew tip may inadvertently perforate adjacent tissues. Despite this risk, this tool can be invaluable when manipulating solid, bulky leiomyomas or uteri.

Newer, small, 2-mm and 3-mm accessory manipulators have a trocar built around the instrument shaft. These can be placed percutaneously to augment surgical manipulation yet leave only a tiny residual abdominal wall scar. Of the two available designs, one is fully disposable and the other is reusable.

Uterine Manipulators

These devices were originally designed to offer manipulation of the uterus to create tension, expand operating space, or improve access to specific parts of the pelvis. The Hulka and the Sargis uterine manipulators are reusable stainless steel instruments that contain the following: a stiff blunt tip for insertion into the endocervical canal, a toothed tip that affixes to the cervical lip for stabilization, and a handle for vaginal placement (Fig. 41-6). For these manipulators, the cervix should to be patent to allow entry into the lower uterine cavity.

Uterine manipulators have become increasingly versatile and offer additional functions. The Cohen cannula manipulator has a hard-rubber conical tip with a patent cannula for dye injection into the uterus, such as with chromotubation (Fig. 41-7). For placement, a single-tooth tenaculum is placed on the anterior cervical lip. The manipulator’s conical tip wedges firmly against the cervix and thereby minimizes retrograde dye egress back through the os. The distal end of the Cohen manipulator then articulates with the crossbar that extends between the tenaculum’s finger rings. Although commonly used, its range of motion is hindered by its straight shaft. Thus, the ability to dramatically flex a uterus anteriorly or posteriorly may be limited. The Rubin cannula manipulator is similar, with the same disadvantages. Greater flexion may be offered by the Hayden and Valtchev uterine manipulators. These have tip options, either conical or longer blunt intrauterine probes, which attach to a wristed joint at the distal end of the instrument shaft. This joint permits improved anteflexion and retroflexion. All of the manipulators just described affix to the cervical lip for stability. Thus, the risk of cervical trauma, although usually minimal, is disadvantageous.

Disposable uterine manipulators such as the Harris-Kronner Uterine Manipulator Injector (HUMI) or the Zinnati Uterine Manipulator Injector (ZUMI) also have a cannula for introducing dye to assess uterine and tubal patency (see Fig. 41-6). Rather than affixing to the cervix, an intracavitary balloon at the manipulator’s uterine end is expanded similar to a Foley balloon once the manipulator is placed. This prevents the device from dislodging. Due to the length and firmness of the material used, these devices are advantageous for oversized uteri.

At times, a vaginal sponge stick is a practical manipulator for elevation and identification of pelvic structures. This may be selected by an advanced surgeon who wishes to eliminate the manipulator or chosen in cases in which the uterine fundus is absent. Last, newer manipulator designs have emerged to complement laparoscopic hysterectomy and are illustrated in Chapter 44.

Scissors

These are integral to most laparoscopic procedures and are available in reusable and disposable models. Scissor tips vary depending on the type of dissection or resection needed (see Fig. 41-5). Scissors preferred for dissection commonly have a curved, somewhat blunted, tip that tapers similar to Metzenbaum scissors. This shape allows a surgeon to use standard techniques for tissue separation and resection with minimal trauma to the surrounding tissues (Chap. 40). These curved blades may be smooth or slightly serrated. A serrated edge tends to hold tissue and minimize slippage prior to cutting. A smooth blade is preferred for sharp dissection, such as with adhesiolysis.

Straight scissors also come with smooth or serrated blades. They are used more for cutting and are less desired for dissection. Many straight scissors are designed with a single-action jaw, and some surgeons feel this offers better control.

Hooked scissors have a rounded, blunt tip and hooked blades. When initially approximated, the blades close around the tissue without cutting and then cut from the tip toward the hinge. This offers a controlled transection and is useful for partial transection of tissues. Moreover, its design allows a surgeon to confirm optimum placement before cutting. This type of scissors is commonly used for suture cutting.

Suction and Irrigation Devices

Successful laparoscopy requires a clear visual field. Thus, an effective and efficient suction and irrigation system is integral to procedures that require fluid or smoke removal (Fig. 41-8). Older systems were extremely slow and thereby prolonged operative time or failed to adequately clear a field with brisk bleeding. Newer motorized systems provide faster irrigation and evacuation, and motors usually have two speeds, which can be manually adjusted. The suction tips are available in 3-, 5-, and 10-mm diameters, thereby tailoring instrument capability to the clinical setting. The latest generation systems also permit additional instruments to be placed through the hollow suction tip for concurrent monopolar electrosurgery. Newer models also have attachments to fluid management systems to monitor infused and extracted volumes.

When using a suction irrigation system, all of the suction holes are ideally submerged in the fluid to be removed. This avoids inadvertent insufflation gas removal, which then collapses the operative field. Additionally, the probe may cause suction damage to viscera, especially delicate structures such as tubal fimbria and bowel epiploica. To avoid damage, suction is used when there is a safe distance from vulnerable structures and with the assistance of another instrument to move these structures away from the suction tip.

Tissue Extraction

Morcellators

These tools cut excised tissues into smaller pieces, which can then be extracted. Available morcellators use either thin cutting blades or pulsatile kinetic energy. Bladed morcellators consist of a hollow large-bore shaft that contains razorlike blades to shave tissues into thin strips. One of these, the Storz Rotocut, is reusable but houses disposable stainless steel blades that are efficient in cutting through dense masses. Although bulkier and heavier than others, it is among the fastest and most effective. The Lina Morcellator has a built-in battery pack, is slower but more ergonomic, and is disposable. The MOREsolution morcellator offers a 2-cm-diameter blade, which is currently the largest and may be helpful for large masses. Another device, the Gynecare Morcellex, is currently unavailable due to a voluntary suspension of worldwide sales. Each mechanical morcellator has its advantages, and familiarity with these allows selection of the most suitable instrument for a given tissue.

Another morcellator, the PKS PlasmaSORD Bipolar Morcellator, is bladeless. Instead, it uses plasma kinetic energy, which is a form of pulsatile bipolar energy. It works well for hysterectomy and myomectomy specimen morcellation. However, it produces a large smoke plume, which reduces visibility and thereby increases operative time. Accordingly, cases with larger specimens may have extended operative times with this instrument compared with bladed instruments. However, no randomized studies support the superiority of one morcellator over another.

Endoscopic Retrieval Pouches

Endoscopic bags for tissue retrieval vary in size and vinyl strength. Some are free-standing sacs designed for manual introduction into the abdominal cavity through cannulas and are preferred for larger and denser masses. Once loaded, the sac is simply lifted through an appropriately sized abdominal wall incision.

Other types are manufactured as pouches attached to support arms at the end of a laparoscopic shaft to create a self-contained unit. As shown in Figure 41-9, the support arms open the sac. Once the mass is bagged, the arms and pouch are retracted and removed through the cannula. The cannula is then removed, bringing the bag to the incision where it is extracted. With either sac type, if a specimen does not compress or cannot be drained, the incision may require enlargement.

Self-retaining Retractors

Designed to complement MIS, nonmetal self-retaining retractors consist of two equal-sized plastic rings connected by a cylindrical plastic sheath. One ring collapses into a canoe shape that can be threaded through the incision and into the abdomen. Once inside the abdomen, it springs again into its circular form. The second ring remains exteriorized. Between these rings, the plastic sheath spans the thickness of the abdominal wall. To hold the retractor in place, a surgeon everts the exterior ring multiple times until the plastic sheath is tight against the skin and subcutaneous layers. This form creates 360-degree retraction. These disposable retractors maximize incision size because of their circular shape and by eliminating thick metal retractor blades within the wound opening. Brands include the Alexis and Mobius retractors, and available sizes range from extra small to extra large. In some studies, these retractors provide wound protection and lower wound infection rates (Horiuchi, 2007; Reid, 2010).

For MIS cases, these devices offer several functions. First, they retract minilaparotomy incisions to aid large specimen removal. Moreover, certain procedures, such as laparoscopic myomectomy, can also be completed through these incisions (Section 44-8). Second, concern about tissue dissemination has prompted development of retrieval bags that are coupled with these self-retaining retractors. For this, the retrieval bag is initially placed into the abdomen. The bag containing the excised specimen is then brought to the surface and is fanned open outside and around the minilaparatomy incision. The self-retaining circular retractor is then placed into the bag’s interior and simultaneously opened within the incision. This creates a closed environment in which the specimen can be sharply morcellated manually with scissor or knife. Long-term data on safety and efficacy of this enclosed approach are not yet available.

Energy Systems in Minimally Invasive Surgery

Understanding principles and correct use of electrosurgical instruments is essential to safe laparoscopy. The same principles of electrosurgery in open surgery apply to laparoscopy (Chap. 40). However, special considerations are necessary in a closed, minimally invasive environment. For example, the entire length of an instrument may extend past a surgeon’s visual field, thus risking unintended electrosurgical burns. Fortunately, advances in instrumentation mitigate many of the physical constraints inherent to MIS.

Monopolar Electrosurgery

Monopolar instruments may be useful for tissue cutting, dissection, vaporization, and desiccation. Delivery of this energy is usually through scissors or needle point tip. Of these, monopolar scissors coagulate tissues within its jaws prior to incision. This is typically used for thin tissues and small vessels. In addition, closed blade tips can act simultaneously to cut tissue and achieve hemostasis. Monopolar energy delivered though a needle point tip is used for functions ranging from ovarian drilling to development of peritoneal planes during hydrodissection.

Unintended thermal injuries form the main risk with this energy type. With monopolar instruments, insulation failures, direct coupling, or capacitative coupling may each result in unintended, potentially serious electrosurgical burns. First, insulation failures are breaches in an instrument’s insulation. This break provides an alternate pathway for current flow. When a monopolar instrument is activated, electric current may travel from the electrode through the insulation breach and discharge to any tissue in contact with this breach. This current flow may cause thermal damage to surrounding visceral and vascular structures without the surgeon ever being aware. Accordingly, before electrosurgical tools are used, systematic inspection should look for insulation cracks throughout their length, for aberrant or loose cord connections, and for assurance that a grounding pad is correctly placed on the patient.

Another monopolar effect is direct coupling, which occurs when an activated electrode contacts another metal object—either intentionally or unintentionally. This technique is frequently used during open surgery to achieve hemostasis of small vessels, such as when the electrosurgical blade tip is touched to a hemostat around a small vessel. However, in laparoscopy, unintentional direct coupling may occur when a metal instrument or object (such as a metal cannula) contacts an active monopolar instrument and thus provides an alternate and undesired current flow to surrounding viscera.

Another hazard with monopolar instruments is the risk of capacitative coupling. A capacitor is defined as two conductors separated by a nonconducting medium. During laparoscopy, an “inadvertent capacitor” can be created when a conductive active electrode (e.g., monopolar scissors) is surrounded by a nonconducting medium (insulation around the scissors) and is placed through another conductive medium (a metal cannula). This capacitor creates an electrostatic field between the two conductors. When current is activated through one of the conductors, this in turn will induce a current in the second conductor. Capacitative coupling occurs when this system discharges current into other surrounding conductive material. In the case of an all-metal cannula, current can be dissipated throughout the abdominal wall. With hybrid cannula systems, in which a metal cannula is anchored by a plastic sleeve or collar, the capacitor that is created has no place to discharge. Stray current can then exit to adjacent tissue that is in contact with the metal portion of the cannula, thereby damaging nearby vascular or visceral structures. This risk can be reduced by avoiding hybrid cannulas and by selecting bipolar instruments. Moreover, the addition of an integrated shield on the electrode shaft of some monopolar instruments, which monitors for stray current, can prevent this complication.

Bipolar Electrosurgery

Bipolar energy is mainly used in laparoscopy for tissue desiccation and hemostasis. Many types of bipolar forceps are available for various uses (Fig. 41-10). The 3-mm paddle forceps are used for tubal coagulation during sterilization procedures. Flat-tip forceps desiccate larger vessels and tissue pedicles. Fine-tip, “microbipolar” forceps aid hemostasis near or on vulnerable structures such as the ureter, bowel, and fallopian tubes. Burns are less of a concern with bipolar energy because the currents used are typically lower. Currents, for the most part, also stay confined between the two closely approximated electrodes.

For hemostasis, energy is delivered to denature collagen and elastin in vessel walls and thus seal the vessel. During this process, the bipolar device uniformly compresses the tissue and provides internal monitoring to adjust energy delivery. When evaluating these devices, important considerations include thermal spread, ability to provide desired tissue effects, consistency of results, time required to achieve results, plume produced, and maximum vessel diameter that can be securely sealed (Lamberton, 2008; Newcomb, 2009).

Currently used advanced bipolar devices such as the LigaSure, Plasmakinetic (PK) Gyrus, and Enseal are multifunctional tools that can be used for both tissue desiccation and dissection. Each of these devices employs a low voltage to deliver energy to tissue and carry impedance feedback to the electrosurgical unit to locally regulate thermal tissue effects. These adaptations allow for reduced collateral injury from thermal spread, an improved tissue seal, less plume production, and diminished tissue sticking. Whereas the LigaSure delivers a continuous bipolar radiofrequency waveform, the PK delivers energy in a pulsed waveform. The Enseal system has a temperature-controlled feedback mechanism at its tip, which “locally” modulates energy delivery.

Ultrasonic Energy

The Harmonic scalpel, also known as an ultrasonic scalpel, uses ultrasonic energy, which is converted to mechanical energy at the active blade. Seen as the lower blade in Figure 41-10F, the active blade vibrates to deliver high-frequency ultrasonically generated frictional force, whereas the inactive upper arm holds tissues in apposition against the active blade. Alternatively, the active blade may be used alone. Either cutting or coagulating effects can be achieved, and a balance between these two is created by controlling several factors: power levels, tissue tension, blade sharpness, and application time. Higher power level, greater tissue tension, and a sharp blade will lead to cutting. Lower power, decreased tissue tension, and a blunt blade will create slower cutting and greater hemostasis. Limitations of the Harmonic scalpel include limited ability to coagulate vessels larger than 5 mm and the requirement for the surgeon to balance the factors listed above (Bubenik, 2005; Lamberton, 2008).

Laser Energy

Lasers were widely used in laparoscopy in the 1980 through 1990s and include the CO₂, argon, KTP (potassium titanyl phosphate), the Nd-YAG (neodymium:yttrium-aluminum-garnet) lasers. These are generally used through an operative channel on the laparoscope or via a separate port. These lasers can cut, coagulate, and vaporize tissues and are employed for lysis of adhesions, tubal surgery, and endometriosis fulguration or resection. In the hands of skilled surgeons, lasers offer precision and control with minimal effect on surrounding tissue. Thus, a laser is able to work near or over sensitive structures such as bowel, bladder, ureters, and vessels. Disadvantages are its learning curve, expense, lack of portability, and smoke production.

Laparoscopic Leiomyoma Ablation

Myolysis describes leiomyoma puncture by energy-based probes that incite tissue necrosis and subsequent shrinkage. Of these, bipolar energy and cryoablation have been used with varying degrees of success and thus have not gained widespread popularity with gynecologic surgeons.

The Acessa procedure instead uses monopolar energy combined with ultrasound guidance through laparoscopic instrumentation (Fig. 41-11). For this, a special ultrasound probe is placed during laparoscopy through a 10-mm lower abdominal port and directly contacts the uterus to localize myomas. This allows better myoma visualization by permitting views from several angles. A thick radiofrequency needle is inserted through a separate abdominal wall puncture site and then punctures each tumor serially under sonographic guidance. Once the needle is inserted into a myoma, a deployable electrode array housed within the needle is expanded within the tumor to deliver the destructive energy. Real-time laparoscopic and sonographic surveillance confirm that the electrodes remain within the mass. The outpatient Acessa procedure is typically performed in the operating suite with general anesthesia. Postoperative oral narcotics or nonsteroidal antiinflammatory drugs (NSAIDs) provide sufficient postoperative analgesia for most women (Galen, 2013).

With this approach, early evidence shows improved patient symptoms and a reintervention rate of 11 percent at 3 years (Berman, 2014). Other long-term data regarding outcomes are lacking, but current ongoing studies will add information.

Laparoscopic Optics

Laparoscope Construction

Successful MIS requires excellent visual acuity provided by high-intensity light sources and laparoscopes with focused lenses. The modern-day rod lens system contains a series of lenses that are the diameter of the laparoscope cylinder. At the periphery of each lens are small scalloped grooves that permit light-carrying fibers to reach the endoscope end. This provides a well-lit image and minimal distortion. Uniquely, the space between lenses is filled with small, tightly packed glass rods. These rods fit exactly, which make them self-aligning to require no other structural support. Appropriate curvature and coatings to the rod ends and optimal glass type permit superb image quality—even with cylinder tubes measuring only 1 mm in diameter.

In addition to its main cylinder, a laparoscope contains an eyepiece, to which a camera can be affixed. The camera usually is an attachable springed plastic cap that can be clipped onto the eyepiece. The main cylinder also has an adapter on its exterior to attach the light-source cable. Laparoscope diameters range from 0.8 to 15 mm. In general, greater diameters offer superior optics but require a larger incision. This trade-off typically dictates laparoscope selection for a given procedure.

Differing from traditional straight-shaft endoscopes, operative laparoscopes have an eyepiece that branches off at a 45- or 90-degree angle from the straight operative shaft. This permits tools to be placed through the operative shaft, which are then seen by the endoscope. Instruments used are generally longer than instruments typically placed in accessory ports. Most instruments are 45 cm, which is considered bariatric length. Lasers are also frequently placed through the operative shaft and can allow for precise energy application.

Angles of View

Similar to hysteroscopes and cystoscopes, laparoscopes vary in their angle of view. The most common are 0-, 30-, and 45-degree laparoscopes, and each offers a different view of the peritoneal cavity. A 0-degree endoscope offers a forward view and is preferred by most gynecologists. This laparoscope is used in most diagnostic procedures or simple surgeries involving biopsies, simple adhesiolysis, and excision of small masses or organs such as an ovary, fallopian tube, or appendix.

In contrast, angled-view endoscopes provide a lateral and larger field of view. These are useful during cases with more complicated pathology such as dense adhesions that obstruct the traditional forward view. For example, during difficult dissection in which multiple instruments are in action, an angled-view laparoscope offers a panoramic view at a distance. This provides a surgical field in which all instruments in use can be seen.

Angled-view endoscopes also allow a lateral view of pathology. For example, if an angled-view laparoscope is placed at one pelvic sidewall and is directed to the opposite sidewall, a surgeon is provided a large lateral visual operating space. Moreover, angled views are valuable along the sides of organs. With a large myomatous uterus, it may be challenging to identify the uterine artery and cardinal ligaments. An angled-view laparoscope permits a surgeon to “slide” along the lateral border of the uterus to reach these. Similar benefits are gained when operating in small spaces such as in the deep pelvis or space of Retzius.

Clearly, the 0-degree laparoscope is easier to master. However, the advantages for advanced procedures warrant the time needed to operate using an oblique view. Importantly, during orienting with an angled-view laparoscope, when the field of view is directed downward, the light cord attached to the endoscope is positioned up. Conversely, if the view is upward, the light cord will be positioned down. To maintain orientation when changing viewing polarity, the camera buttons remain facing upward, while the light cord rotates in relation to it.

Flexible Laparoscopes

The tips of these special laparoscopes are able to bend to a greater degree. As such, they can travel into smaller spaces or around corners. Whereas traditional fiberoptic laparoscopes contain fiber bundles that run the length of the endoscope, these flexible endoscopes house a camera chip at their end to transmit images as electrical signals. This results in less image distortion. This concept has also provided the option of dual camera technology, which uses two camera chips at the tip. As benefits, optics and opportunities for more advanced procedures are improved. Some newer models afford a 3-D view and are used for single-port laparoscopic approaches, in which there is traditionally less maneuverability.

Lighting

Light is transmitted through the laparoscope from a light source via the light cable. Originally, endoscopic light was provided by incandescent lightbulbs, which produced little light and transmitted increased heat. Currently, a cold light source is used and provides a more intense beam. The term “cold light” describes the dissipation of heat along the length of the cable. Cold light sources use halogen, xenon, or halide modalities for the lamps. Despite heat dissipation, the light source still creates a hot tip at the distal laparoscope end. Thus, prolonged exposure of the tip to surgical drapes, patient skin, or internal organs is avoided. Thermal injuries have resulted from such exposure.

Light cables connect the light source to the endoscope. Of these, two types are available: fiberoptic and fluid filled. The fiberoptic cable contains multiple coaxial quartz fibers that transmit light with relatively little heat conduction. However, these cables suffer from fiber breakage and need to be serviced often. In contrast, fluid-filled cables transmit more light and conduct more heat than the fiber cables. They are stiffer and have decreased maneuverability. This coupled with difficulty in sterilization may make this type less preferred.

Once attached to a camera and light source, most laparoscopes must be adjusted to a “true white” to ensure that the colors in the viewing field are accurate. This is called white balancing and is performed at the procedure’s beginning.

One modern approach to MIS uses robotic assistance, and most abdominal gynecologic procedures can be completed with this technique. Similar to laparoscopy, robotic surgery uses abdominal ports to introduce instruments and a pneumoperitoneum to expand the operative field. One positive difference is the miniaturized and wristed articulating instrument tips that allow successful completion of complex procedures in tight operating spaces. The instrument tips mimic those used in open surgery and in laparoscopy and include graspers, needle drivers, and cutting instruments. Advanced video technology within an 8-mm laparoscope provides a high-definition and magnified view.

Of disadvantages, tactile feedback is lost with robotic surgery and forces a surgeon to use visual cues. This is a learned skill that carries a significant learning curve. However, surgeons experienced in advanced laparoscopic techniques adapt more quickly. Other disadvantages include extended initial set-up time needed during each case, physician training costs, and robot and instrument expenses.

Robot

Currently, the only commercially available robot is the da Vinci system. As shown in Figure 41-12, one or two surgeon consoles are used to control robot arm movement. A separate cart stands at the surgical bedside and serves as the base for the four robotic arms. Of these arms, one controls the laparoscope, whereas the other arms hold robotic instruments. Procedures are performed using two or three of the instrument arms according to the procedure’s needs and surgeon’s preference. The second surgeon console is generally used for training. If port sites in addition to the basic four are needed, an assistant surgeon can also work at the patient bedside through one or two traditional laparoscopic accessory ports. These are generally placed in the right or left upper quadrants. Typically, 5- to 15-mm trocars are used for the accessory port(s), depending on the instruments required for a given procedure.

During port placement, initial abdominal entry and subsequent accessory trocars are inserted similar to laparoscopy. Port placement for robotic surgery is unique in that ports must be placed with a minimum intervening distance of 8 cm. This keeps the robot arms from colliding with each other and with any accessory ports. As shown in Figure 41-13, the level of the laparoscope’s port depends on the procedure, the complexity of the pathology, and previous patient surgeries. Importantly, a black ring around the cannula marks the depth to which a trocar is inserted. Insertion to this depth is essential to provide the robot arms the correct fulcrum to function optimally and lessens port-site tissue trauma.

Of newer modifications, reduced-port robotic surgery uses microtip percutaneous instruments to minimize the number of 8-mm ports. Its advantage is yet to be proven with randomized trials. As another modification, the Food and Drug Administration (FDA) has approved instrumentation for single-site robotic surgery for certain gynecologic procedures. A fuller discussion of single-site laparoscopy is found on page 894.

Patient Selection

When selecting a robotic approach, both patient and procedure characteristics are considered. First, procedures that are currently performed efficiently by conventional laparoscopy should not be replaced by robotic surgery (American College of Obstetricians and Gynecologists, 2015). Rather, this modality is an alternative to laparotomy and thus may offer the patient a more rapid recovery and decreased postoperative morbidity. Second, patients chosen for this technique should be able to withstand conventional laparoscopic physiologic changes discussed earlier. As with laparoscopy, a high patient BMI may limit the robotic approach but is not a contraindication and must have the joint effort of the anesthesiologist.

Anterior Abdominal Wall

The laparoscopic view of pelvic anatomy may differ slightly from laparotomy due to the effects of pneumoperitoneum, Trendelenburg positioning, and the translation of a 3-D reality into a 2-D image on the monitor.

When planning abdominal entry, key structures of the anterior abdominal wall are considered to avert neurovascular complications. Key landmarks include the umbilicus, anterior superior iliac spine, and pubic symphysis. Especially in the obese patient in whom a large pannus may alter anatomic relationships, bony landmarks are used to plan safe port placement.

The umbilicus is generally located at the level of the L3-L4 vertebrae, although it may lie above or below depending on habitus. In most patients, the aorta bifurcates at the union of L4-L5 vertebrae (Nezhat, 1998). However, in obese patients, the umbilicus tends to be caudal to this aortic bifurcation. In all patients, the left common iliac vein crosses the midline approximately 3 to 6 cm caudal to the aortic bifurcation, and the umbilicus is always cephalad to this point. The umbilicus is more caudal in heavier women. In normal-weight supine patients, these structures are considered during initial trocar entry at the umbilicus as they lie approximately 6 cm deep to the base of the umbilicus and may be closer in thinner patients (Hurd, 1992).

Accessory ports are placed under direct visualization of important anatomic structures including the bladder, bowel, and the inferior (deep) and superficial epigastric vessels. The inferior epigastric artery travels along the lateral third of the posterior surface of the rectus abdominis muscle and should be visualized intraperitoneally, running lateral to the medial umbilical ligaments (see Fig. 41-13). The superficial epigastric artery, a branch of the femoral artery, travels in the subcutaneous tissue in a path similar to that of the inferior epigastric vessels. The superficial epigastric artery may be identified by transillumination of the anterior abdominal wall with the laparoscope. Although it cannot be visualized, nerve supply of the anterior abdominal wall is also considered to avoid trauma during trocar placement. Both the ilioinguinal and iliohypogastric nerves can be lacerated during ancillary port placement. Steps to limit injury to these nerves and vessels are described on page 895.

Retroperitoneal Structures

Along the anterior abdominal wall, five prominent ligaments lie beneath the peritoneum and can be seen laparoscopically. These superficial intraperitoneal landmarks run cephalad to caudad and may be used to identify key anatomic structures in the retroperitoneum (Fig. 41-14). In the midline, the median umbilical ligament traverses from the bladder dome to the umbilicus and is the obliterated urachus.

Lateral to this lie the medial umbilical folds, which cover the obliterated umbilical arteries. Identification of the medial umbilical ligament is essential in the setting of a frozen pelvis and can provide access to the internal iliac artery. For this, the medial umbilical ligament is followed underneath the round ligament, through the broad ligament, to the superior vesicle artery, and finally to the internal iliac artery.

Running laterally to the medial umbilical folds and to the round ligaments are the lateral umbilical folds. These folds are formed by peritoneum overlying the inferior epigastric vessels before they enter the rectus sheath. Direct intraperitoneal visualization of the lateral umbilical folds will prevent injury to these vessels during port placement.

In the pelvic retroperitoneum, laparoscopy usually allows easy direct identification of the ureter and vessels of the pelvic sidewall. Moreover, the course of the pelvic ureter traveling from the pelvic brim, along the pelvic sidewall, and lateral to the cervix should routinely be appreciated with every laparoscopy to ensure normal peristalsis and caliber. To avoid injury to the ureter, its course is frequently confirmed during adnexal surgery, hysterectomy, and cases with adhesive disease.

The choice of entry site and method is influenced by factors that include body habitus, prior surgery, risk of encountering adhesive disease, intended procedure, surgeon skill, and the site, size, and type of pathology. Nearly half of all laparoscopic complications occur during abdominal entry, and nearly one quarter of these are undetected until the postoperative period (Bhoyrul, 2001; Chandler, 2001). Thus, entry carefully factors the above variables. Each of the methods discussed below may be beneficial in different situations, but all have potential risks. It has not been established which entry method is safest.

Umbilical Entry

The umbilicus is the most frequent entry site, although the left upper quadrant and subxiphoid area are others. The umbilicus is preferred for primary trocar placement because the subcutaneous and preperitoneal tissue layers are thinnest at the fused umbilical plate. Thus, the transumbilical approach is the shortest distance to the abdominal cavity, even in obese patients. From a cosmetic standpoint, the umbilical fossa also conceals the port-site scar.

Laparoscopic entry can be performed with an open or closed technique. With closed entry, either a Veress needle or laparoscopic trocar is used to pierce the fascia and peritoneum to gain abdominal entry. Closed entry techniques offer quick access to the abdominal cavity with a low risk of injury (Bonjer, 1997; Catarci, 2001). With open entry, the fascia is grasped with Allis clamps or peans and surgically incised. The peritoneum is then grasped and opened. Some authors advocate an open entry method as a way to lower puncture injury rates. However, metaanalyses fail to show that any of the following techniques are superior to the others (Ahmad, 2008; Vilos, 2007).

Closed Entry

During laparoscopic entry, surgeons appropriately assess patient habitus and their physical relationship to the supine patient. To diminish the downward thrust when placing the Veress needle and trocars, a surgeon adjusts the table height and uses a short stepstool if necessary. The aorta and its bifurcation lie beneath the umbilicus. To maximize the distance between the puncturing instrument and these vessels and avert vascular injury, premature Trendelenburg positioning is avoided, and the patient should lie flat. Moreover, to minimize visceral puncture during abdominal entry, the surgeon should empty the patient’s bladder and confirm with the anesthesiologist that an orogastric tube has emptied the stomach. Palpation over these areas can confirm adequate decompression. The sacral promontory and aorta are also palpated, and a Veress needle or trocar with a length sufficient to reach the peritoneal cavity is selected. Finally, once all equipment is checked and correctly connected, the surgeon confirms with the anesthesiologist that the patient is fully paralyzed to prevent involuntary patient movement during abdominal entry.

Veress Needle Entry

The goal of this closed technique is to first create a pneumoperitoneum with a 14-gauge Veress needle. Once a pneumoperitoneum is created, the fascia and peritoneum are then secondarily punctured with a trocar. The pneumoperitoneum serves to tense the peritoneum and increases the distance of the viscera and retroperitoneal structures from the trocar entering the abdominal wall. These ideally help lower the risk of puncture injury during trocar insertion.

With all the closed methods, a skin incision appropriate to the trocar size is created, usually at the umbilicus. The incision can be either horizontal or vertical, is placed centrally within the umbilicus, and can be made with a no. 11 or 15 blade. Skin hooks or Allis clamps can aid in everting the umbilicus.

To begin, a Veress needle tip pierces through the fascia and peritoneum and enters the intraabdominal cavity to allow its insufflation with CO₂. During both Veress and trocar placement, many surgeons recommend abdominal wall elevation, either manually or with instruments such as towel clips (Fig. 41-15). A study using computed tomography images revealed that up to 8 cm can be added between the incision and retroperitoneum by elevation with towel clips (Shamiyeh, 2009). Abdominal wall elevation also provides a controlled countertension to the downward thrust of the Veress needle and subsequent trocar during insertion.

The Veress needle has a spring-loaded obturator (Fig. 41-16). As the device contacts the fascia, the obturator is pushed back, and the needle pierces the fascia and peritoneum. As soon as the tip enters the abdominal cavity, the obturator springs forward to prevent the needle from injuring abdominal viscera.

Prior to insertion, the Veress needle is checked for patency by flushing saline through the needle. The spring mechanism is also confirmed to function appropriately. The patient and operating table are flat, and the anterior abdominal wall is elevated. The Veress needle is inserted at a 45- to 90-degree angle depending on patient habitus and abdominal wall thickness. In patients with a normal BMI, angling the needle at a 45-degree angle permits abdominal entry yet minimizes the risk of great vessel injury (Fig. 41-17). With the Veress needle angled toward the hollow of the pelvis in the midline, there is a sensation of two “pops” as the tip of the needle penetrates the fascia and then the peritoneum. As shown in the figure, in overweight and obese individuals, smaller insertion angles are needed to successfully enter the abdomen.

Entry failures with this method usually stem from Veress needle tip placement into the preperitoneal space (Fig. 41-18). Flow of gas through the needle creates an extraperitoneal insufflation. This gaseous dissection of the peritoneum away from the anterior abdominal wall hinders the trocar in piercing the peritoneum. Instead, the trocar further stretches and pushes the peritoneum internally. Fortunately, this problem can often be overcome by a second attempt with the Veress needle above the umbilicus or by switching to an open entry technique (Fig. 41-19).

Preperitoneal insertion of the Veress needle is common and can lead to abandonment of the laparoscopic procedure. Thus, confirmation of correct needle placement in the peritoneal cavity is essential. For confirmation, a 10-mL syringe containing 5 mL of saline is attached to the hub of the inserted Veress needle. With aspiration, air bubbles should be seen in the syringe. If blood or bowel contents are aspirated, concern for vascular or visceral injury should be high. In these cases, the needle is left in place to help localize the puncture site and act as a vascular plug as discussed on page 877.

After aspiration, saline is easily injected with no resistance. The surgeon should be unable to reaspirate this saline, which has dispersed into the abdominal cavity. Similarly, a hanging drop test can be used. With this, a few drops of saline are placed on the external open end of the Veress needle. If the needle tip is correctly inserted, the fluid drops disappear into the negative pressure of the abdominal cavity. If incorrect entry is suspected, the needle is withdrawn and checked for patency. Moving the Veress needle from side to side is avoided at this stage. Such movement can create rents in the omentum or injure bowel.

Once correct placement is confirmed by these methods, the CO₂ insufflation tubing can be attached to the needle. A low-volume flow of CO₂ is selected, and initial intraabdominal pressure recordings should be <8 mm Hg while the abdominal wall is manually lifted. If the pressure is elevated, the needle is immediately removed. The initial pressure is the most sensitive measurement of correct intraperitoneal Veress needle placement (Vilos, 2007). With the needle correctly inserted, pressure and gas flow may be increased. Simultaneously, the electronic insufflator parameters are closely monitored to ensure a steady increase in the pressure and continued flow. If the intraperitoneal pressure rises rapidly prior to insufflation of 1.5 to 2 L of gas, one again is concerned for preperitoneal insufflation.

During insufflation, the abdomen is observed for a uniform distention and dullness to percussion over the liver. Since the total volume required to appropriately insufflate an abdomen will vary depending on patient habitus, intraperitoneal pressure, rather than total volume of gas, is used to determine adequate peritoneal insufflation. During normal insufflation, pressures should not exceed 20 mm Hg. Such elevated pressure can lead to hemodynamic and pulmonary compromise. When an intraperitoneal pressure of 20 mm Hg is achieved, the Veress needle may be withdrawn, and the pneumoperitoneum should assist safe primary trocar insertion. This transiently elevated intraabdominal pressure provides a volumetric countertension for primary trocar insertion. However, once the primary trocar is inserted, the insufflation pressure is dropped to <15 mm Hg, or to the lowest pressure that allows the planned procedure to be adequately visualized and safely performed.

Although data from multiple studies are conflicting, it has been proposed that the use of humidified CO₂ for insufflation through out a case may have advantages. These include decreased postoperative pain, improved visualization from less lens fogging, and in animal studies, less de novo adhesion formation (Farley, 2004; Ott, 1998; Peng, 2009; Sammour, 2008).

Primary Trocar Placement

Once adequate insufflation is achieved, the primary trocar may then be placed. Trocars are used gain access to the abdominal cavity. First-generation trocars consist of a hollow, long, slender cannula that sheaths an inner obturator. Trocars typically range from 5 to 12 mm in diameter, and their tips may be conical, pyramidal, or blunt (Fig. 41-20).

Conical trocars are smooth except for their more pointed tip and have no cutting edges. They split the fascia rather than cut it and thus are preferred by some to lower risks of postoperative hernia formation and vessel injury (Hurd, 1995; Leibl, 1999). However, they require more penetration force to insert. In contrast, pyramidal trocars have sharp edges and tip and as a result, cut the fascia as they are inserted into the abdomen.

In the 1980s, trocars with retractable shields were introduced. Similar to the concept used with the Veress needle, a hollow plastic retractable shield covers the trocar tip both before and after the trocar pierces the abdominal wall. In this manner, the cutting edge is exposed only during its passage through the fascia. Despite theoretical advantages to these shielded trocars in preventing organ injury, studies have failed to show superiority of this design (Fuller, 2003).

Initial trocar entry is a blind procedure and is completed with the patient still supine and flat. The Veress needle is removed, and the trocar’s tip is placed in the umbilical incision. The trocar handle is cupped in the palm of the dominant hand, and the same hand’s index finger is extended along the trocar shaft to splint the trocar from too deep of insertion. The angle of trocar insertion should mirror that of the Veress needle. The anterior abdominal wall is elevated. With control and minimal downward force, the trocar punctures the fascia and underlying peritoneum and enters the abdominal cavity. After insertion, the trocar obturator is removed, and the cannula may be advanced slightly to ensure adequate placement into the peritoneal cavity. At this point, the laparoscope is inserted through the umbilical cannula to visually confirm safe and atraumatic entry.

VersaStep System

Similar to the Veress needle method, a VersaStep System may be used. This consists of a stretchable nylon sheath over a disposable Veress needle (Fig. 41-21). The first step of insertion is identical to Veress needle insertion and peritoneal insufflation. Once insufflation is complete, the Veress needle is removed, leaving the nylon sheath in situ. A trocar with a blunt inner obturator is inserted into the nylon sheath. Downward, gradual continuous pressure by the trocar causes the nylon sheath to stretch and accommodate as the trocar is advanced. The obturator is then removed, leaving only the nylon sheath and cannula as the operative port. The benefit of this system is that only a blunt trocar is used, thus potentially diminishing traumatic injuries from a cutting blade. Also, the conical dilator may create a smaller fascial defect.

Optical Access Trocar Entry

To reduce bowel injury risk at the time of primary trocar insertion, optical trocars were developed. These devices, in essence, combine the laparoscope and trocar into one tool. Importantly, the laparoscope should be focused once it is housed within the trocar and prior to insertion. During use, the optical trocar transmits images of the abdominal wall layers to the television monitor. These layers then are pierced under direct visualization by trocar tip advancement. If choosing an umbilical entry, the layers visualized, in sequence, should be the subcutaneous fat, the linea alba (fascia), preperitoneal fat, and peritoneum.

Optical entry methods can be used with and without the prior establishment of pneumoperitoneum. Despite the theoretical advantage of this type of trocar, major organ injury still has been reported. Moreover, no large studies have established its clinical superiority over other entry techniques (Sharp, 2002).

Direct Trocar Entry

Because of entry failures associated with preperitoneal insufflation, a direct trocar entry method may be preferred (Copeland, 1983; Dingfelder, 1978). For this, the abdominal wall is elevated and directly pierced with a trocar without prior insufflation. Comparative studies between Veress needle and direct trocar techniques show lower rates of entry failure with the direct method (Byron, 1993; Clayman, 2005; Gunenc, 2005). Moreover, investigators note comparable or lower associated minor complication rates with the direct entry method.

Open Umbilical Entry

To lower puncture injury rates with closed entry methods, an open entry technique was described by Hasson (1971, 1974). For this, a 1- to 2-cm transverse skin incision at the lower edge of the umbilicus is made while applying tension with fine-toothed forceps to its lateral borders. Skin edges are retracted laterally, and the subcutaneous layer is divided to expose the linea alba. This fascia is lifted and everted upward with two Allis clamps (Fig. 41-22). A 0.5- to 1-cm incision with scalpel or scissors then transects the fascia. The Allis clamps are repositioned, one on each free fascial edge.

A hemostat or finger is used to bluntly open the peritoneum, and the end of an S-retractor is placed into the abdomen. The abdominal portion of the retractor is used to elevate the abdominal wall and shield the underlying organs as a stitch of 0-gauge delayed-absorbable suture is placed parallel on one side of the fascial opening (Fig. 41-23). This suture is not tied. This suturing step is repeated on the opposite fascial edge.

The distal, blunt end of the Hassan trocar then is inserted into the incision. The fascial tag sutures are pulled firmly upward and threaded into the suture holders found on either side of the cannula’s proximal end (Fig. 41-24). The blunt obturator is removed, and the laparoscope is threaded through the cannula.

In a retrospective review of more than 5000 open entry procedures, Hasson and associates (2000) noted that minor and medium-risk complications developed at a rate of 0.5 percent. Moreover, in studies comparing open and closed techniques, open methods showed lower rates of entry failure and organ injury (Bonjer, 1997; Merlin, 2003). Open entry is recommended by many surgeons for patients with prior abdominal surgery, for those following a closed technique entry failure, for those with a large cystic mass, and for pediatric or pregnant patients (Madeb, 2004). This technique, however, is not foolproof, and organ injury, mainly bowel, has been described (Magrina, 2002). Typically, this method of entry takes longer than closed entry, and the pneumoperitoneum can be difficult to maintain in some cases due to air escape around the cannula.

Alternative Entry Sites

Anterior Abdominal Wall

At times, the umbilicus may be unsuitable for initial abdominal entry, and surgeons should develop comfort with entry at an alternative site. Of concerns, adhesive disease may tether bowel beneath the umbilicus and is suspected in women with prior intraabdominal surgery, infection, endometriosis, or malignancy (see Table 42-1). Similarly, surgical mesh placed during umbilical herniorrhaphy is also linked with adhesive disease, and entry at this site may also disrupt the hernia repair. Nonumbilical entry can also avoid inadvertent trauma to or rupture of a large intraabdominal mass or gravid uterus.

Nonumbilical anterior abdominal wall entry has been described at various locations. The left upper quadrant is most common, but the subxiphoid area is another. Both have the advantage of providing working ports at these sites once safe entry is achieved.

Of these, left upper quadrant entry is simple, has a low risk of complications, and usually is free of adhesions (Agarwala, 2005; Howard, 1997; Palmer, 1974). Although left upper quadrant access may be obtained at either Palmer point or the ninth intercostal space, the easy accessibility of Palmer point makes this a favored site. Palmer point is located 3 cm below the left costal margin in the midclavicular line. Organs in close proximity to this point are the stomach, left lobe of the liver, spleen, and retroperitoneal structures, which may be as close as 1.5 cm (Giannios, 2009; Tulikangas, 2000).

For entry at Palmer point, one ensures that the stomach is emptied using suction with an orogastric or nasogastric tube. Palpating the area will ensure adequate emptying and exclude incidental splenomegaly. A skin incision adequate for trocar insertion is made at Palmer point. With anterior abdominal wall elevation, the Veress needle is inserted in the skin incision at an angle slightly less than 90 degrees and is directed caudad to avoid liver injury. Initial intraabdominal pressure of <10 mm Hg indicates correct intraperitoneal placement. Once adequate insufflation is obtained, the Veress needle may be removed and a trocar inserted. Alternatively, direct trocar entry may be performed at Palmer point as well. We favor an optical access trocar to permit each layer of the anterior abdominal wall to be seen as it is penetrated (Vellinga, 2009). For this, the anterior abdominal wall is elevated, and the trocar with laparoscope is placed into the skin incision. The trocar is directed at a 90-degree angle. During insertion, one should observe the following in sequence: subcutaneous fat, outer fascial layer, muscle layer, inner fascial layer, peritoneum, and finally, abdominal organs. Remember that above the level of the arcuate line, posterior rectus sheath fascia is present and is the inner fascial layer.

Natural Orifice Transluminal Endoscopic Surgery

This method uses existing natural orifices such as the vagina, stomach, bladder, and rectum to access the peritoneum. In addition, a transuterine approach has been described. Although infrequently used in current practice, interest is renewed in laparoscopic access through the posterior fornix. Proposed advantages of this method are improved access to organs, better cosmesis from elimination of an external scar, shorter hospitalizations, and possibly less postoperative pain and fewer postoperative complications.

Single-port Access Laparoscopy

Single-incision surgery is a laparoscopic approach in which a sole 2- to 3-cm incision accommodates a single larger port that concurrently houses multiple instruments. It is also known as single-incision laparoscopic surgery (SILS), laparoendoscopic single-site surgery (LESS), and single-port access (SPA). The proposed advantages of this method are improved cosmesis from a single port, which is usually buried in the umbilicus, and possibly faster return to normal activity. This is balanced against the longer incision that potentially has greater risks for postoperative pain, wound infection or dehiscence, and later incisional hernia. Moreover, single-incision surgery is technically more challenging than conventional laparoscopy due to instrument crowding at a single port, limited visualization, and loss of instrument triangulation (Uppal, 2011). Triangulation describes instruments converging on a focal point from lateral angles of origin. These angles create opposing forces, which are essential for effective tissue retraction, dissection, and resection. However, SPA has grown in popularity with advances in articulating instruments and flexible-tip endoscopes, which help deal with some of these challenges.

For laparoscopic SPA, several ports are popular. The SILS port (Covidien) is limited to umbilical placement and may not be suitable for large pathology that encroaches on the umbilicus. The Gelpoint (Applied Medical) may be inserted almost anywhere on the abdominal wall due to the variable depth of its self-retaining sheath attached between the two rigid loops (Fig. 41-25). Moreover, the gel dome lacks preset silos for the trocars, and thus allows any size trocar to be inserted in individualized groupings.

For robotic SPA, the Single Site port (da Vinci) is placed in the umbilicus and contains cannulas for the curved trocars used in this approach. This system is limited by the required port placement but offers an alternative for suitable candidates. Instrument choices and movement are more limited. For example, the traditional wristed models are not offered, but the longer curved trocars may offer sufficient triangulation.

Gasless Laparoscopy

This variation of traditional laparoscopy addresses the physiologic disadvantages of pneumoperitoneum just described. With this method, an abdominal wall lift device elevates the abdominal wall to create the laparoscopic working space, and thus no gas is required. Additional advantages include the sustained visualization after colpotomy or with continuous suctioning. Despite advantages, drawbacks are a “tent-shaped” operating space, additional required incisions, and time needed for the lift device assembly. These currently limit its routine use, but gasless laparoscopy may still have value in high-risk patients with cardiorespiratory diseases (Cravello, 1999; Goldberg, 1997; Negrin Perez, 1999).

Accessory Port Placement

Once primary abdominal access is achieved, additional operative ports are needed to insert instruments. The number, location, and size of these cannulas will vary depending on the tools required and the laparoscopic procedure. For additional port placement, the patient is placed in Trendelenburg position to displace bowel from the pelvis and provide an unobstructed view. Ancillary trocars are always placed under direct laparoscopic visualization to minimize the puncture risk to anterior abdominal wall vessels or abdominal viscera. The camera is generally driven by the first assistant or in some cases by the second assistant to free two surgeons’ hands for the actual operative tasks.

Appropriate ancillary port site selection is a key step in operative planning. Correct placement permits triangulation. Poorly placed ports may create instrument angles that lead to ineffective movement, surgeon fatigue, and iatrogenic complications. Of sites, the suprapubic midline site is most frequently used. Prior to trocar insertion, the bladder is emptied, and the trocar is placed after identification of both the bladder and the urachus. For operative laparoscopy, placement of two lower quadrant ports lateral to the inferior epigastric vessels is also common. Their sites are individualized according to patient anatomy and pathology. Generally, larger pelvic masses require more cephalad placement.

During accessory port placement, transillumination of the anterior abdominal wall is useful to avoid puncture of the superficial epigastric vessels. In this process, the laparoscope, within the abdominal cavity, is placed directly against the peritoneal surface of the anterior wall. This light is seen externally as a red circular glow, and the superficial epigastric arteries are seen as dark vessels traversing it.

Unfortunately, the inferior epigastric arteries lie deep to the rectus abdominis muscle and are poorly seen with transillumination. These arteries, however, can be seen by direct laparoscopic visualization in most cases (Fig. 41-26) (Hurd, 2003). Also, anatomic landmarks can be used to limit vessel puncture risks. For example, Epstein and coworkers (2004) noted that the main stem of the inferior epigastric artery can be avoided if trocars are inserted within the lateral third of the distance between the midline and anterior superior iliac spine (ASIS). Rahn and colleagues (2010) noted that the inferior epigastric vessels were 3.7 cm from the midline at the level of the ASIS and were always lateral to the rectus abdominis muscle at a level 2 cm superior to the pubic symphysis.

Ideally, port placement will also minimize the risk of ilioinguinal and iliohypogastric nerve injury. Most injuries to these nerves and to the inferior epigastric vessels can be averted by placing the accessory ports superior to the ASIS and >6 cm from the abdomen’s midline (Rahn, 2010). Once all ports are positioned, the planned procedure is begun.

Tissue Extraction

Near the end of many MIS procedures, safe tissue extraction is an essential step. However, port-site seeding and inadvertent dissemination of both benign and malignant tissue during specimen fragmentation and extraction are risks. Several studies have described peritoneal leiomyomatosis, parasitic myomas, and de novo endometriosis following power morcellation of uteri and myomas (Kho, 2009; Milad, 2013; Sepilian, 2003). Moreover, morcellation of occult cancer may worsen patient prognosis. This may be particularly likely with uterine sarcoma, which has been a topic of debate (Park, 2011; Pritts, 2015).

Alternatives to power morcellation are varied. First, through minilaparatomy incisions ranging from 1 to 4 cm, myomas and uteri may be brought to the anterior abdominal wall (Fig. 44-8). Here, they can be hand morcellated with a scalpel or scissors and extracted (Alessandri, 2006; Panici, 2005).

Second, posterior colpotomy is safe and effective to open the cul-de-sac for bulky tissue removal (Ghezzi, 2012). As shown in Figure 41-27, a posterior colpotomy is created similar to that for vaginal hysterectomy. Namely, the cervix is lifted upward, and the vagina of the posterior fornix is stretched outward and downward to create tension. Curved Mayo scissors then incise the intervening vaginal wall and peritoneum to enter the abdomen via the posterior cul-de-sac. Once entry is confirmed, vaginal retractors can be placed for exposure. Alternatively, posterior colpotomy can be completed during laparoscopy. As Figure 41-28 illustrates, the uterosacral ligaments and ureters are first identified. A wide, blunt vaginal probe is inserted to elevate, accentuate, and stretch the posterior vaginal fornix for incision. Using an energy-based device, the vaginal wall is incised below the level of the cervix and between the uterosacral ligaments to create the posterior colpotomy incision. Whether through this opening or a minilaparatomy, the addition of a tissue retrieval bag during tissue extraction can create a closed environment for morcellation (Fig. 41-29). This reduces the risk of inadvertent tissue dissemination during fragmentation, although long-term safety data are needed.

A third method, enclosed power morcellation, is still being studied. For this, a large endoscopic bag that can house the insufflation gas, conform to the abdominal cavity, and flatten against the intraperitoneal organs is introduced through a laparoscopic port. In the abdomen, it is unfolded to allow the specimen and gas to be contained. Depending on the pathology, the bag may be exteriorized through one abdominal port or incision, or may function during morcellation simply as a liner that catches any disseminated tissue (Einarsson, 2014). Following morcellation, the gas is released, and bag and tissue fragments are removed. Limitations of currently available retrieval bags involve the pouch size, the working aperture diameter, tensile strength, and permeability (Cohen, 2014).

Abdominal Entry Closure

The intraabdominal pressure produced by the pneumoperitoneum has an excellent hemostatic effect. Thus, at the end of cases, sites of potential bleeding are evaluated under a reduced pressure. A portion of the pneumoperitoneum is allowed to escape, and the intraabdominal pressure gauge is reset to 7 or 8 mm Hg. Vessels that need sealing will be seen and treated prior to procedure completion.

With surgery completed, CO₂ insufflation is halted, and the gas tubing is disconnected from the primary cannula. The gas ports on all cannulas are opened to deflate the abdominal cavity. To prevent diaphragmatic irritation from retained CO₂, manual pressure is placed on the abdomen to help expel remaining gas. Next, cannulas are removed under laparoscopic visualization. This allows evaluation for bleeding from punctured vessels that may have been tamponaded by the cannula or the pneumoperitoneum. These sites and other potential bleeding sites are reinspected as the pneumoperitoneum diminishes. Additionally, visualization prevents herniation of bowel or omentum up through the cannula track and into the anterior abdominal wall. Once all secondary cannulas are out, the laparoscope and then the primary cannula are removed.

Many surgeons recommend reapproximation of fascial defects at port sites to prevent anterior abdominal wall hernia formation. Although closure of the fascial defect does not obviate the risk of hernia formation, in general, most surgeons close ancillary ports sites ≥10 mm. The fascia can be closed by direct visualization with the assistance of S-retractors. The fascia is grasped with Allis clamps and then reapproximated with interrupted stitches of 0-gauge delayed-absorbable suture. Also, several laparoscopic closure devices (Carter-Thomason, EndoClose, and neoClose devices) are available. With these, fascial defects are reapproximated during direct laparoscopic visualization.

Skin incisions are closed with a subcuticular stitch of 4-0 gauge delayed-absorbable suture. Alternatively, the skin may be closed with cyanoacrylate tissue adhesive (Dermabond) or with skin tape (Steri-Strip Elastic) plus benzoin tincture (Chap. 40).

Open Entry Incision Closure

During removal of the Hasson trocar, sutures originally placed in the fascia are unthreaded from the cannula. Each of these sutures then is brought to the midline of the incision, and square knots are tied to close the fascial defect. The skin is reapproximated in a similar manner to that just described with closed abdominal entry.

Tissue Approximation

Suturing Tools

Following tissue excision, reapproximation with suture is often needed. Subsequent knot tying may be performed using either inside the body, intracorporeal, or outside the body, extracorporeal, techniques. For these skills, a learning curve demands a time investment, not only in the operating room, but also with box trainers or simulators. Some newer devices can make these essential steps of surgery less challenging. Typically, selection is based on the procedure planned, surgeon preference, and reapproximation goals.

Needles for MIS suturing must pass through the placed ports. For this, the suture is grasped approximately 1 cm from the needle swage and passed through an appropriately sized cannula. Thus, the needle type chosen will depend on the size of available cannulas. One option, the ski needle, can pass through a narrow cannula (Fig. 41-30). Straight Keith needles can also be easily passed through cannulas of any size. However, their wide, flat arcs prohibit their use in tight anatomic spaces, which require a needle with a fuller arc. Conventional needle shapes and sizes often require higher-diameter ports.

Needle driver styles are also varied and are curved or straight and have either a smooth or finely serrated inner surface (Fig. 41-31). Driver tips are tapered to limit tissue trauma. They also have a single-action jaw to provide a stable needle grasp. To assist with needle grasping, some driver tips are designed to guide the needle into a correct driving position. Termed self-righting, these drivers may be less desirable for suturing in difficult-to-reach anatomic spaces. Here, the needle may need to be grasped by the driver at an oblique angle to achieve correct suture placement. Other needle driver features include a coaxial (rotating) handle and a locking grip. These hold the needle in place yet decrease hand strain. With suturing, the needle driver is held in the dominant hand, while the nondominant hand holds a tissue grasper. Alternatively, some surgeons prefer to use a second needle driver in the nondominant hand. This assists in grasping the tissue, retrieving the needle or sutures from the dominant hand, and providing countertraction when needed.

Disposable suturing devices render needle drivers unnecessary for tissue approximation. The Endo Stitch is a 10-mm- diameter instrument with a double-action jaw. A short, straight needle juts at a right angle from the inner surface of one tip. As the instrument tips are closed, the needle passes through the desired tissue. Then, with the tips still closed and with the flip of a handle toggle, the detachable needle is released from the first tip and reanchors at a right angle into the opposite tip. Instruments containing delayed-absorbable, barbed, or nonabsorbable suture are available. Also, the LSI suturing device is a 5-mm instrument with a hooked tip that passes a straight needle through the tissue. Both suturing tools have benefits and limitations, and familiarity with both is advantageous.

Sutures are broadly categorized as: (1) absorbable, delayed-absorbable, and permanent, (2) as monofilament or braided, (3) as natural or synthetic, and (4) as barbed or unbarbed. Suture selection depends primarily on the characteristics of tissues to be approximated and on the functional goals of reapproximation. Importantly, compared with traditional surgery, laparoscopic knot tying creates increased friction and suture fraying, and time between knot throws is longer. Thus, greater tensile strength and increased memory become more valued suture traits. For example, synthetic delayed-absorbable suture offers high tensile strength, less tissue reactivity, greater knot reliability, and easy handling for either intracorporeal or extracorporeal knot tying. Of filament types, although monofilament suture passes more smoothly through tissues, braided suture ties more easily and breaks less frequently. Last, the most common absorbable suture is catgut. However, compared with delayed-absorbable suture, this material provides less tensile strength and less knot security. Accordingly, catgut is less popular for MIS. If used, intracorporeal knot tying is generally preferred due to the significant fraying that occurs with this suture during extracorporeal tying.

For laparoscopy, narrow sutures in the 2-0 and 3-0 gauge range are preferred. This diameter provides suitable tensile strength to prevent suture breakage. Yet, it is thin enough to limit scarring from foreign-body reaction and to harbor fewer bacteria compared with thicker suture. However, for some procedures, such as vaginal cuff closure, the greater tensile strength provided by a 0-gauge suture is required.

Barbed sutures offer the unique ability to maintain tensile pressure on a continuous suture line. With this synthetic suture, multiple barbs are evenly spaced around the suture’s outer surface (Fig. 41-32). These barbs flatten as they pass through the tissues to be approximated but flare out once through to the other side. These flared barbs prevent suture from slipping back through the approximated tissues. As a result, the tissues remain joined with evenly distributed tissue tension (Greenberg, 2008). By its design, this suture obviates the need for knot tying. Available barbed-suture products include Quill, Stratafix, and V-Loc sutures.

Barbed suture may be uni- or bidirectional, and these differ in the direction that suturing can proceed. Unidirectional suture has a small preformed loop at the tail end, which serves as the knot for that end of the suture line. Suturing moves from the looped end in the other direction. Bidirectional suture has needles at each end. Suturing begins at the incision midpoint and can then progress in both directions along the incision. With either suture type, the tissue is approximated by cinching the final suture line or placing a suture loop in the opposite direction. No final knot is needed to secure the suture line, which is held in place by the barbs. Alternatively, an anchoring hemostatic clip may be placed to secure the suture line end. In general, barbed suture may be advantageous for myometrial reapproximation during laparoscopic myomectomy or for vaginal cuff closure during total laparoscopic hysterectomy. At completion of the running suture line, the suture is cut short to avoid puncture of adjacent tissue by a barb.

Knots

The length of suture will depend on the proposed suturing and knot tying. In general, 6 to 8 cm is needed for intracorporeal knot tying, and 24 to 36 cm for extracorporeal tying. Longer lengths are required for running stitches and for complicated knots compared with simple interrupted stitches.

Once tissues are approximated, the suture is tied by the intracorporeal or extracorporeal technique and then trimmed. Of the two, intracorporeal tying has a steeper learning curve because the surgeon must use laparoscopic instruments rather than fingers to loop the suture (Fig. 41-33). Extracorporeal knot tying is simpler for most surgeons because the suture is looped with fingers as in traditional tying. Each formed knot throw is then guided through a laparoscopic cannula and cinched with a knot pusher to create the knot (Fig. 41-34). Of suture types, stronger braided suture is preferred if the knot pusher is used because suture fraying is a side effect of this technique. Another disadvantage of extracorporeal knot tying compared with intracorporeal methods is that it often causes more tissue tension and can tear delicate tissues.

As an alternative to manual knot tying, disposable clips can be placed at the end of a suture line for security. Specifically, a hemoclip is a titanium V-shaped clip with arms that can be squeezed together during application. These clips were originally designed to compress vessels for hemostasis and are available in various sizes. At the end of a running suture line, hemoclips can also be placed across the suture tail to prevent stitch unraveling. If used for this purpose, two clips are advisable. More recent developments include the Lapra-Ty. This has a locking clip made of delayed-absorbable polydioxanone, which is also used in the suture brand PDS. Its ability to be absorbed and its lock are advantages, whereas its need for a 11- to 12-mm port may be disadvantageous in some settings. Also, these ties are only approved to anchor suture diameters greater than 4-0 gauge. Another option is the 5-mm Ti-KNOT instrument. With this disposable device, a special titanium clip is placed around a single or a double strand of suture. With any of these alternatives to laparoscopic knot tying, the cost may be justified by the time saved in the operating room.

Stapling

In gynecologic surgery, vascular tissue is typically ligated first and then transected. Ligation may be achieved with electrosurgical tools described earlier, with stapling devices, or with suture loops. Linear staplers are mainly used for achieving anastomoses as in bowel surgery and are not frequently employed for gynecologic procedures. When selected in gynecologic laparoscopic surgery, they are chiefly used to ligate vascular pedicles, such as the infundibulopelvic ligament. Once fired, the stapler lays down three staggered double rows of staples while dividing tissue in between.

The staplers are available in 35- or 45-cm lengths and contain an end called the “anvil,” which houses the staple cartridges. Vascular cartridges apply staples that are 1 mm high when closed. Tissue cartridges apply those that are 1.5 mm when closed and are suitable for thicker pedicles. Stapling provides hemostasis and gentle handling of tissue, which should lead to less necrosis and better healing.

Newer models have added articulating and rotating capabilities at the jaw. These attributes permit stapling at an angle. Most staples are titanium. However, newer angled staplers for the vaginal cuff use delayed-absorbable material such as Polyglactin 910 for their staples. A main limitation to stapler use is generally the price of the device and cartridges, which can be costly compared with suture. However, if operating time is reduced, these costs can be negligible.

Suture Loops

Preformed suture loops, such as the Endoloop, may also be used to ligate tissue pedicles (Fig. 41-35). This instrument has a length of suture housed within a stiff, 5-mm-diameter rod and has a pretied loop at the end. The loop is guided around the intended tissue pedicle by the stiff rod and then is cinched like a noose. The rod tip, similar to an index finger during manual knot tying, adds pressure to secure the knot in place. Loops of absorbable, delayed-absorbable, and permanent suture are available. Other types of knots that are pretied loops include the Roeder knot, Meltzer knot, and Tayside knot. These currently are not as popular as the square knot.

Laparoscopic Dissection Techniques

Pelvic adhesions are often lysed to reestablish normal anatomy and complete planned surgery. Some situations require the use of sharp dissection, especially if adhesions are not amenable to blunt tissue separation. For cutting fine adhesions, the tissue band may be placed on gentle stretch using an atraumatic grasper or blunt probe. Curved scissors with a dissecting tip or an energy modality (monopolar, bipolar, or harmonic) are frequently used.

If denser adhesions are found, they are divided in layers to prevent injury to adjacent adhered organs. Traction and countertraction aid in tissue plane identification. As the surgeon begins to separate tissues with tension, the plane of attachment may be identified, and the scissor tips create a small incision (Fig. 40-11). The tip is then eased between the tissue layers to create an opening by spreading the blades outward. The initial snip carries the risk of injury to the underlying viscera or vessel and is made as shallow as possible. The use of energy sources in these situations is generally discouraged, as thermal injury may have a wider effect that may not be readily apparent. Conversely, a sharp cut is easier to identify and repair intraoperatively. The scissors used may be curved or straight depending on the contour of the pelvic organs. Once a plane is developed, wider and deeper strokes are used to complete tissue dissection.

Hydrodissection is another technique often used in MIS. With this, normal saline or other irrigation fluid is injected under pressure to separate tissue planes. For example, peritoneal endometriosis can be lifted and excised with greater ease and less trauma to retroperitoneal structures. Other uses include resection of cysts from an ovary, removal of ectopic products from a fallopian tube, or separation of tissue planes that might be obscured or in close proximity to vascular spaces or bowel. As shown in Figure 41-36, an atraumatic grasper lifts the tissue at the junction point, and a needle tip is inserted with the bevel away from the structure to be protected. Irrigation fluid is injected and creates a balloon effect. Depending on the location, 5 to 30 mL of fluid is instilled. A suction-irrigation system also is helpful for this technique. With this instrument, once the peritoneum is incised, the suction tip is insinuated into the opening. Fluid is forced to gently separate the tissue planes (Fig. 44-4.2). Often, hydrodissection allows a surgeon to identify natural planes that might otherwise be obscured.

Hemostasis

As tissue planes are developed, bleeding is variably encountered. Requirements for vessel sealing differ according to vessel diameters. For small vessels, spot coagulation is suitable, and a monopolar tool is satisfactory and mimics the electrosurgical blade (Bovie) use in open procedures. For larger vessels, the bipolar or Harmonic technologies are preferred. Of these, the Harmonic grasper coagulates or denatures the vessel tissue and can seal vessels up to 5 mm in diameter. Advanced bipolar technologies achieve vessel sealing by desiccation and can effectively seal vessels ranging from 5 to 7 mm in diameter. When choosing a modality, the thermal spread of a device is considered. Last, microbipolar probes and needle-tip monopolar probes are useful for delicate tissues such as the fallopian tubes. The thermal spread is minimal, and the tip sizes are optimal for the small but friable vessels.

Liquid topical hemostatic agents have also gained popularity and have been adapted for laparoscopic use (Table 40-5). When using a laparoscopic adaptor, a portion of the matrix may remain in the applicator cannula. Thus, to avoid retained and thus wasted sealant, a surgeon flushes the cannula following initial matrix application. For this, a plunger is included in many sealant kits, or a syringe filled with air may be used to force matrix through the cannula and onto the desired tissue. Alternatively, an oxidized regenerated cellulose fabric sheet (Surgicel) can be used.

Patient Evaluation

Hysteroscopy allows an endoscopic view of the endometrial cavity and tubal ostia for both the diagnosis and operative treatment of intrauterine pathology. The role of hysteroscopy in modern gynecology has expanded rapidly with development of more effective hysteroscopic instruments and smaller endoscopes, bringing many procedures into the office. Indications for hysteroscopy vary and include evaluation and in some cases, treatment of infertility, recurrent miscarriage, abnormal uterine bleeding, amenorrhea, and retained foreign bodies. With hysteroscopic techniques, abnormal bleeding can be treated with endometrial ablation, polypectomy, or submucous myomectomy. Infertility may be improved with resection of intrauterine adhesions or a septum. Additionally, obstructed tubal ostia may be unblocked or dilated. Alternatively, for those seeking sterilization, hysteroscopic tubal occlusion can serve as an effective and safe method of contraception.

Because the indications for hysteroscopy are varied, patient evaluations for specific disorders are discussed in their respective chapters. More generally, continuing pregnancy is an absolute contraindication to hysteroscopy and should be excluded with serum or urine β-human chorionic gonadotropin testing prior to surgery. In addition, cervicitis or pelvic infection is treated prior to hysteroscopy, and screening for Neisseria gonorrhoeae and Chlamydia trachomatis in those with risk factors is prudent (Table 1-1). For those with abnormal bleeding and significant risks for endometrial cancer, preoperative endometrial Pipelle sampling is reasonable as seeding of the peritoneal cavity with cancer cells has been noted following hysteroscopy (Chap. 8).

If diagnostic hysteroscopy is planned to locate and remove a foreign body, preoperative imaging is recommended, usually with transvaginal sonography. For example, in some cases, an intrauterine device (IUD) or retained fetal bone may have perforated the uterine wall, lie predominantly outside the uterus, and thus be best removed by laparoscopy.

Consent

The risk of complications for women undergoing hysteroscopy is low and cited at less than 1 to 3 percent (Hulka, 1993; Jansen, 2000; Propst, 2000). Complications are similar to those associated with dilatation and curettage and include uterine perforation, inability to sufficiently dilate the cervix, hemorrhage, cervical laceration, and postoperative endometritis. In addition, because either gas or liquid medium is required to distend the endometrial cavity during hysteroscopy, gas venous embolism and excessive intravascular fluid absorption are risks discussed later. In general, complication rates increase with the length and complexity of the procedure planned.

In the event of uterine perforation during hysteroscopy, diagnostic laparoscopy may be indicated for evaluation of the surrounding pelvic organs. Thus, patients are additionally consented and aware of the possible need for laparoscopy.

Patient Preparation

Infectious and venous thromboembolic (VTE) complications following hysteroscopic surgery are rare. Accordingly, preoperative antibiotics or VTE prophylaxis is typically not required (American College of Obstetricians and Gynecologists, 2013, 2014).

Endometrial Thickness

In premenopausal women, hysteroscopy is ideally performed in the early proliferative phase of the menstrual cycle, when the endometrium is relatively thin. This allows small masses to be identified and easily removed. Alternatively, agents that induce endometrial atrophy such as progestins, combination oral contraceptives, or gonadotropin-releasing hormone (GnRH) agonists have been administered individually prior to an anticipated surgery. Although these effectively thin the endometrium, many of these agents have disadvantages including expense, adverse side effects, and surgical delay while atrophy ensues.

Cervical Dilatation

For operative hysteroscopy, dilatation of the cervix is typically required to insert an 8- to 10-mm hysteroscope or resectoscope. To ease dilatation and lower the risk of uterine perforation, cervical preparation is considered. Misoprostol (Cytotec), a synthetic prostaglandin E₁ analogue, may be administered orally the night before and if desired, again the morning of surgery to aid cervical softening. Commonly used dosing options include 200 or 400 μg vaginally or 400 μg orally once 12 to 24 hours prior to surgery. Common side effects include cramping, uterine bleeding, or nausea. Thus, the need for softening is balanced against these side effects, especially bleeding that might limit endoscopic visualization.

If cervical stenosis is encountered intraoperatively, smaller caliber tools, such as a lacrimal duct probe, may be guided into the external cervical os to define the canal path. In these situations, transabdominal sonography may be helpful when done simultaneously with dilatation to help ensure proper placement (Christianson, 2008). Also, injection of intracervical dilute vasopressin can diminish the force required for cervical dilation (Phillips, 1997). Because the onset of action is rapid, this is especially helpful if stenosis was not anticipated preoperatively. As a potent vasoconstrictor, however, vasopressin is ideally avoided in those with serious hypertension and cardiovascular disease.

Rigid Hysteroscope

Hysteroscopy requires a hysteroscope, light source, uterine distention medium, and, in many cases, a video camera system. Most hysteroscopes consists of a 3- to 4-mm-diameter endoscope surrounded by an outer sheath. Smaller diameter hysteroscopes have been developed, although their use is limited by their decreased field of view and lower light intensity. Hysteroscopes are broadly classified as diagnostic or operative. Diagnostic hysteroscopes offer a small diameter, which provides an adequate endometrial cavity view yet requires minimal if any cervical dilatation. Operative hysteroscopes have sheaths that increase the overall diameter and necessitate cervical dilation in most cases. Thus, cases requiring operative hysteroscopes are best managed under general or regional anesthesia in the operating room for patient comfort and safety.

Individual endoscopes offer specific angles of view. Although 0- through 70-degree angles (0, 12, 25, 30, and 70 degrees) are available, a 0- or 12-degree hysteroscope allows the easiest orientation within the uterine cavity for most procedures (Fig. 41-37). The 12-, 25-, 30-, and 70-degree angles provide additional lateral views, which are often required for complex operative procedures. There are also devices that have 90- to 110-degree angles of view, although these are infrequently used.

In general, the light source system used in hysteroscopy is the same type as for laparoscopy. However, the intensity is typically less than for most laparoscopic procedures. During assembly of the hysteroscope at the beginning of the procedure, the light source attaches directly to the endoscope.

An outer sheath surrounds the endoscope and directs fluid, and in some cases instruments, to the endometrial cavity. In directing fluid flow, sheaths are constructed to allow either unidirectional or bidirectional flow of distending media. Sheaths that allow continuous flow, that is, bidirectional inflow and outflow circulation of the distention medium, are most valuable in cases in which bleeding or large fluid volume deficits are expected (Fig. 41-38). This circulation helps clear blood from the operative field and assists with fluid volume deficit calculation. The type of tubing attached to the hysteroscope sheath is dictated by the fluid management system.

In operative hysteroscopes, the outer sheath also allows the use of semirigid, rigid, and flexible instruments. The basic set that will suffice for most cases includes biopsy forceps, grasping forceps, and scissors. Of these, biopsy forceps are somewhat sharp and cuplike. Grasping forceps permit removal of tissue or foreign bodies and may be toothed. Last, scissors can lyse adhesions, resect masses, or excise an intrauterine septum. Generally 5F in diameter and 34 to 40 cm long, these instruments are much smaller than the instruments used with the resectoscope. None of these requires special distention media or energy. Flexible electrodes used to vaporize tissue may also be passed through this sheath.

Bettochi Hysteroscope

This small, 4-mm-diameter rigid operative hysteroscope has a 5F (1.67 mm) operating channel that provides diagnostic and operative capability. Additionally, the hysteroscope diameter is oblong rather than circular, which conforms to the cervical canal’s configuration (Bradley, 2009). Biopsy forceps, monopolar and bipolar electrosurgical scissors, bipolar needle-like tip, or delivery devices for transcervical sterilization can easily pass through this hysteroscope’s working channel. The flow sheath has a small diameter yet permits sufficient flow to avoid compromised optical quality. These hysteroscopes are available in 0-degree and angled views.

Flexible Hysteroscope

These hysteroscopes have tips that can deflect over a range of 120 to 160 degrees. Although their optical view is less clear than that with rigid hysteroscopes, they offer easy maneuverability within irregularly shaped endometrial cavities. This can be helpful when tubal access is required or during lysis of adhesions. Additionally, flexible hysteroscopes cause less intraoperative pain than rigid ones and may benefit office procedures (Unfried, 2001).

Resectoscope

If resection of intrauterine tissues is planned, a resectoscope may be used. This tool consists of inner and outer sheaths. The inner sheath houses a 3- to 4-mm-diameter endoscope and a channel for fluid medium inflow. The 8- to 10-mm outer sheath contains an electrosurgical resection loop and allows fluid egress from the uterus through a series of small holes near the sheath’s distal end. By means of a spring mechanism, the resection loop can be extended and then retracted to shave off contacted ­tissues. Through its central cannula, larger instruments that are ­energy-based for tissue resection can also be passed. These include the roller bar, roller ball, vaporizing electrodes (monopolar, bipolar, laser), hot scalpel, and motorized morcellator.

Hysteroscopic Morcellator

For resection of polyps, submucosal leiomyomas, septa, or synechiae, a hysteroscopic morcellator may be chosen. Hysteroscopic morcellators offer different tips depending on tissue type. For polyp resection, a rakelike tip is used. For resection of firmer tissue, a cutting tip is selected. Both tips contain a mechanized blade that fragments tissue. These tips are attached to a hollow cannula that evacuates the tissue fragments by suction to a collection receptacle. The morcellator fits through the working channel of a 9-mm or greater operative hysteroscopic cannula.

Because the anterior and posterior uterine walls lie in apposition, a distention medium is required to expand the endometrial cavity for viewing. Fluid media include saline, and low-viscous fluids, such as sorbitol, mannitol, and glycine solutions (Table 41-2). Historically, carbon dioxide was used for diagnostic hysteroscopy but is infrequently employed today. Each group has distinct advantages and properties. To expand the cavity, intrauterine pressures of these media must reach 45 to 80 mm Hg. Rarely is more than 100 mm Hg required. Moreover, because for most women, mean arterial pressure approximates 100 mm Hg, higher pressures can result in increased intravasation of media into the patient’s circulation to create fluid volume overload.

Carbon Dioxide

This gaseous distention medium, when used under pressure, tends to flatten the endometrium and provides excellent visibility. A continuous flow is necessary to replace any gas lost through the tubes, and typically flow rates of 40 to 50 mL/min are adequate. Rates higher than 100 mL/min are associated with increased risks for gas embolism and therefore discouraged. Specialized hysteroscopic machines, which limit maximum flow rates, should be used. Importantly, because laparoscopic insufflating machines can permit flow rates >1000 mL/min, these should not be used for hysteroscopy.

Disadvantages to CO₂ include its tendency, when mixed with blood or mucus, to form visually obstructive gas bubbles. Accordingly, prior to hysteroscope insertion, blood and mucus are carefully removed from the cervical os with a dry swab (Sutton, 2006). Similarly, use of CO₂ with thermal energy sources is avoided as smoke production prohibits adequate viewing. Because of these limitations, CO₂ is best used in cases in which minimal bleeding is anticipated, such as diagnostic hysteroscopy. The most serious complication associated with CO₂ use is venous gas embolism and is discussed on page 905.

Fluid Media

Bleeding is common with operative hysteroscopy procedures. Thus rather than CO₂, fluid media are typically selected because of their optical clarity and ability to mix with blood. The main risk of fluid distention media, however, involves increased fluid absorption and circulatory fluid volume overload. Volume overload may develop with any of the fluid media and results from various mechanisms. As examples, absorption across the endometrium, intravasation through surgically opened venous channels, and spill from the fallopian tubes with absorption by the peritoneum have all been suggested. Therefore, clinical settings in which procedures are long, increased distention pressures are used, or large tissue areas are resected all carry a greater risk.

Fluid distention media can be divided according to their viscosity and electrolyte status. In general, low-viscosity fluids are used in modern hysteroscopy. An appropriate medium is selected based on its compatibility with electrosurgical instrumentation.

Low-viscosity Electrolyte Fluids

Normal saline and lactated Ringer solutions are isotonic, electrolyte fluids. They are readily available in the operating room and are frequently used for diagnostic hysteroscopy. However, these fluids cannot be used with monopolar electrosurgery. Specifically, these solutions conduct current; thus, dissipate the energy; and thereby render the instrument useless.

These electrolyte-containing, isotonic fluids have lower associated risks of hyponatremia compared with hypoosmolar fluids, described in the next section. Still, rapid absorption can lead to pulmonary edema. In general, when using isotonic medium in a healthy patient, a surgeon should consider terminating the procedure when the fluid deficit nears 2500 mL (American Association of Gynecologic Laparoscopists, 2013; American College of Obstetricians and Gynecologists, 2011).

Low-viscosity, Electrolyte-poor Fluids

Of other available media, 1.5-percent glycine, 3-percent sorbitol, and 5-percent mannitol are all low-viscosity, electrolyte-poor fluids. Because they are nonconducting, these media are used for electrosurgery involving monopolar instruments. Unfortunately, these fluids can create volume overload with concurrent development of hyponatremia and hypoosmolality and the potential for cerebral edema and death (American College of Obstetricians and Gynecologists, 2011). Mechanistically, sorbitol is a six-carbon sugar and is metabolized following absorption. This effectively leaves free water in the intravascular space. Normal serum sodium levels are 135 to 145 mEq/L, and levels significantly below this may lead to seizure followed by respiratory arrest. In addition, hypokalemia and hypocalcemia can often develop concurrently. Five-percent mannitol, also a six-carbon sugar, is isoosmolar and so has diuretic properties but does not lead to serum osmolality changes (American Association of Gynecologic Laparoscopists, 2013).

In cases in which large fluid volume deficits are calculated, measurement of serum electrolyte levels is warranted. If a serum sodium level lower than 125 mEq/L is reached, postoperative care should be continued in a critical care setting. Treatment includes stimulation of diuresis with furosemide (Lasix), 20 to 40 mg given intravenously. Correction of hyponatremia is achieved with 3-percent sodium chloride, administered at a rate of 0.5 to 2 mL/kg/hr. In those with acute neurologic symptoms, 3-percent saline can instead be given in a 100-mL infusion over 30 minutes and repeated an additional two times if needed (Nagler, 2014; Verbalis, 2013). The goal of therapy is to reach a serum sodium level of 135 mEq/L within 24 hours. Overcorrection is avoided to prevent additional cerebral effects (Nagler, 2014; Verbalis, 2013). Consultation with an internal medicine specialist may be helpful.

To assist with intraoperative fluid volume calculation, most operative hysteroscopes contain continuous flow systems that allow fluid deficits to be calculated. Calculation of deficits is performed every 15 minutes during procedures. If a procedure has the potential for larger deficits, a Foley catheter is also warranted for urine output monitoring. Moreover, an ongoing communication with participating anesthesia staff regarding large fluid deficits is prudent. If deficits of a hypotonic solution reach 1000 mL, a surgeon should consider procedure termination, measure electrolytes, and give diuretics as indicated (American Association of Gynecologic Laparoscopists, 2013). At the end of every hysteroscopic procedure, a final deficit is determined, and this value is recorded in the operative note.

Hysteroscopic Electrosurgery

Many widely used hysteroscopic tissue resection or desiccation techniques rely on monopolar current. Because current is dissipated and is thus ineffective in electrolyte solutions, these techniques have typically required nonelectrolyte solutions such as sorbitol, mannitol, and glycine. However, as just discussed, these media can be associated with hyponatremia if fluid volume overload develops.

Alternatively, bipolar electrosurgery systems (Versapoint Bipolar Electrosurgery System and Karl Storz bipolar resectoscope) allow use of traditional hysteroscopic tools in a saline solution. The Versapoint system has attachments that include a loop resecting electrode and multiedged vaporizing electrode. There are also ball, spring, and twizzle tips that can be employed for vaporization, desiccation, and cutting. The Karl Storz resectoscope (22F) has a cutting loop, ball tip, and pointed coagulation electrode attachments.

Uterine Perforation

In addition to fluid overload, uterine perforation or bleeding may complicate hysteroscopy. The uterus may be perforated during uterine sounding, cervical dilatation, or hysteroscopic procedures. Fundal perforations created by sounds, dilators, or hysteroscopes can be managed conservatively, as the myometrium will typically contract around these defects. In contrast, lateral perforation may perforate the broad ligament or injure larger pelvic vessels; posterior perforation may injure the rectum; and those caused by electrosurgical tools may cause organ laceration or burn. Diagnostic laparoscopy is indicated in these cases. Similarly, anterior perforations should prompt cystoscopy to evaluate associated bladder injury.

Gas Embolization

If vessels are opened during cervical dilation or during endometrial or myometrial disruption, gas under pressure can be forced into the vasculature. Any undissolved portion can reach the lungs. CO₂ is many times more soluble in plasma than is room air, and it typically dissolves sufficiently during transit from the pelvis (Corson, 1988). As a result, pulmonary embolism is rare in diagnostic hysteroscopic cases using CO₂ (Brandner, 1999). In contrast, room air is poorly soluble in blood, and embolization can lead to rapid cardiovascular collapse. Signs and symptoms include chest pain, dyspnea, and hypotension. Anesthesia staff may note decreased end-tidal CO₂ levels, oxygen desaturation, dysrhythmias, or a “mill wheel” murmur (Groenman, 2008). To manage this emergency, the patient is placed in the left lateral decubitus position with the head tilted downward. This aids movement of the air from the right outflow tract to the apex of the right ventricle, where the embolus may be aspirated (American College of Obstetricians and Gynecologists, 2011).

Surgeons can minimize the risk of gas embolism by avoiding Trendelenburg positioning of the patient during hysteroscopy, ensuring that air bubbles are purged from all tubing prior to introduction of the hysteroscope into the uterus, maintaining intrauterine pressures <100 mm Hg, minimizing the effort needed to dilate the cervix, avoiding deep myometrial resections, and limiting multiple removals and reinsertions of the hysteroscope in and out of the uterine cavity.

Hemorrhage

Heavy bleeding may develop during or following resection procedures. Although hysteroscopic electrosurgical electrodes may be used to contact and coagulate smaller vessels, these may be less effective for larger ones. If heavy bleeding is encountered and is refractory to electrosurgical coagulation, termination of the procedure may be indicated. A Foley catheter balloon can be placed into the endometrial cavity and inflated incrementally with 5 to 10 mL of saline until moderate resistance to catheter tension is noted. An attached collection bag can be used to document blood loss and bleeding cessation. After several hours, the catheter may be removed.