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.
Parts of a typical laparoscopic instrument.
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.
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.
Laparoscopic atraumatic graspers. (Reproduced with permission from Stryker Endoscopy.)
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.
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.
Laparoscopic traumatic graspers (left) and scissors (right). (Reproduced with permission from Stryker Endoscopy.)
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.
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.
A. Hulka uterine manipulator. B. A balloon-type uterine manipulator. The deflated balloon tip is inserted into the endometrial cavity. The balloon is inflated to hold the stiff manipulator in place.
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.
Cohen cannula. This device is used in conjunction with a separate tenaculum. The tenaculum is placed horizontally on the anterior cervical lip. A. The narrow cephalad tip of the cannula fits into the endocervical canal. The conical head abuts the external cervical os and limits insertion into the endometrial cavity. B. The caudad portion contains a crossbar into which the ratcheted handle of the cervical tenaculum fits.
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.
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.
Suction-irrigator. Inset: Irrigator tip.
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.
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.
Endoscopic sac during progressing stages of deployment.
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 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 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.
A-C. Laparoscopic monopolar tools. D and E. Bipolar tools. (Reproduced with permission from Stryker Endoscopy.) F. Laparoscopic Harmonic scalpel. (Reproduced with permission from Ethicon.)
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.
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).
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).
Acessa system for myolysis. Reproduced with permission of Halt Medical.
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.
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.
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.
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.
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.