With minor variations, surgical performance of cesarean delivery is comparable worldwide. Most steps are founded on evidence-based data, and these have been reviewed by Dahlke and associates (2013). As with all surgery, a clear understanding of relevant anatomy is essential, and this is described and illustrated in Chapter 2 (Anterior Abdominal Wall).
In obstetrics, a suprapubic transverse incision or a midline vertical one is chosen for laparotomy. Transverse abdominal entry is by either Pfannenstiel or Maylard incisions. Of all these, the Pfannenstiel incision is selected most frequently for cesarean delivery.
Transverse incisions follow Langer lines of skin tension. Thus, compared with vertical ones, Pfannenstiel incisions offer superior cosmesis and lower incisional hernia rates. Use of the Pfannenstiel incision, however, is often discouraged for cases in which a large operating space is essential or in which access to the upper abdomen may be needed. With transverse incisions, because of the layers created during incision of the internal and external oblique aponeuroses, purulent fluid can collect between these. Therefore, some favor a midline vertical incision for cases with high infection risks. Emergent entry is typically faster with vertical incision during primary and repeat cesarean delivery (Wylie, 2010). Last, neurovascular structures, which include the ilioinguinal and iliohypogastric nerves and superficial and inferior epigastric vessels, are often encountered with transverse incisions. Logically, bleeding, wound hematoma, and neurological disruption may more frequently complicate these incisions compared with vertical ones. The best incision for the morbidly obese parturient is unclear (Smid, 2016). As discussed in Chapter 48 (Bariatric Surgery), our preference with very obese women is a periumbilical midline vertical incision.
The Maylard incision differs mainly from the Pfannenstiel in that the bellies of the rectus abdominis muscle are transected horizontally to widen the operating space. It is technically more difficult due to its required muscle cutting and isolation and ligation of the inferior epigastric arteries, which lie laterally to these muscle bellies.
Once access is gained, metal handheld retractors provide exposure for hysterotomy. A few small randomized studies have evaluated postcesarean wound infection rates with a disposable plastic barrier retractor (Alexis-O). Results showing benefit are contradictory (Hinkson, 2016; Scolari Childress, 2016; Theodoridis, 2011).
With the Pfannenstiel incision, the skin and subcutaneous tissue are incised using a low, transverse, slightly curvilinear incision. This is made at the level of the pubic hairline, which is typically 3 cm above the superior border of the symphysis pubis. The incision is extended laterally sufficiently to accommodate delivery—12 to 15 cm is typical.
Sharp dissection is continued through the subcutaneous layer to the fascia. The superficial epigastric vessels can usually be identified halfway between the skin and fascia, several centimeters from the midline, and are coagulated. If lacerated, these may be suture ligated with 3–0 plain gut suture or coagulated with an electrosurgical blade.
The fascia is then incised sharply at the midline. The anterior abdominal fascia is typically composed of two visible layers, the aponeurosis from the external oblique muscle and a fused layer containing aponeuroses of the internal oblique and transverse abdominis muscles. Ideally, the two layers are individually incised during lateral extension of the fascial incision. The inferior epigastric vessels usually lie outside the lateral border of the rectus abdominis muscle and beneath the fused aponeuroses of the internal oblique and transverse abdominis muscles. Thus, although infrequently required, extension of the fascial incision further laterally may cut these vessels. With extension, these vessels are best identified and coagulated or ligated to prevent bleeding and vessel retraction.
Once the fascia is incised, the inferior fascial edge is grasped with Kocher clamps and elevated by an assistant as the operator separates the fascial sheath from the underlying rectus abdominis muscle either bluntly or sharply until the superior border of the symphysis pubis is reached. Next, the superior fascial edge is grasped and again, separation of fascia from the rectus muscle is completed. Blood vessels coursing between the sheath and muscles are clamped, cut, and ligated, or they are coagulated with an electrosurgery blade. Meticulous hemostasis is imperative to lower rates of incisional hematoma and infection. The fascial separation progresses cephalad and laterally to create a semicircular area above the transverse incision with a radius of approximately 8 cm. This will vary depending on fetal size. The rectus abdominis and pyramidalis muscles are then separated in the midline, first superiorly and then inferiorly, by sharp and blunt dissection to expose the transversalis fascia and peritoneum.
The transversalis fascia and preperitoneal fat are bluntly dissected away to reach the underlying peritoneum. The peritoneum near the upper end of the incision is opened carefully, either bluntly or by elevating it with two hemostats placed approximately 2 cm apart. This upper site lowers cystotomy risks. The tented fold of peritoneum between the clamps is examined and palpated to ensure that omentum, bowel, or bladder is not adjacent. The peritoneum is then incised. The peritoneal incision is extended superiorly to the upper pole of the fascial dissection and downward to just above the peritoneal reflection over the bladder. Importantly, in women with prior intraabdominal surgery, including cesarean delivery, omentum or bowel may be adhered to the undersurface of the peritoneum. In women with obstructed labor, the bladder may be pushed cephalad almost to the level of the umbilicus.
Midline Vertical Incision
This incision begins 2 to 3 cm above the superior margin of the symphysis. It should sufficiently long to allow fetal delivery, and 12 to 15 cm is typical. Sharp or electrosurgical blade dissection through the subcutaneous layers ultimately exposes the anterior rectus sheath. A small opening is made sharply with scalpel in the upper half of the linea alba. Placement here helps avoid potential cystotomy. Index and middle fingers are placed beneath the fascia to elevate it, and the fascial incision is extended first superiorly and then inferiorly with scissors. Midline separation of the rectus muscles and pyramidalis muscles and peritoneal entry are similar to those with the Pfannenstiel incision.
Most often, the lower uterine segment is incised transversely as described by Kerr in 1921. Occasionally, vertical incision confined solely to the lower uterine segment may be elected (Krönig, 1912). In contrast, a classical incision begins as a low-vertical incision, which is then extended cephalad into the active portion of the uterine corpus. Last, a fundal or even posterior incision may be selected for cases with placental accrete syndromes.
Low Transverse Cesarean Incision
For most cesarean deliveries, this incision is preferred. Compared with a classical incision, it is easier to repair, causes less incision-site bleeding, and promotes less bowel or omentum adherence to the myometrial incision. Located in the inactive segment, it also is less likely to rupture during a subsequent pregnancy.
Before any hysterotomy, the surgeon palpates the fundus to identify degrees of uterine rotation. The uterus may be rotated so that one round ligament is more anterior and closer to the midline. In such cases, the uterus can be manually reoriented and held to permit centering of the incision. This avoids incision extension into and laceration of the adjacent uterine artery. A moist sponge may be used to pack protruding bowel away from the operative field.
The reflection of peritoneum at the upper margin of the bladder and overlying the lower uterine segment is grasped in the midline with forceps and incised transversely with scissors (Fig. 30-1). Following this initial incision, scissors are inserted between peritoneum and lower uterine segment. Open scissors are pushed laterally from the midline on each side. This transverse peritoneal incision extends almost the full length of the lower uterine segment. As the lateral margin on each side is approached, the scissors are directed slightly cephalad (Fig. 30-2). The lower edge of peritoneum is elevated, and the bladder is gently separated from the underlying lower uterine segment with blunt or sharp dissection within this vesicouterine space (Fig. 30-3). This bladder flap creation effectively moves the bladder away from the planned hysterotomy site. It also helps prevent bladder laceration if an unintended inferior hysterotomy extension occurs during fetal delivery.
The loose peritoneum above the bladder reflection is grasped with forceps and incised with Metzenbaum scissors.
This peritoneal edge is elevated and incised laterally.
Cross section shows blunt dissection of the bladder off the uterus to expose the lower uterine segment.
In general, this caudad separation of bladder does not exceed 5 cm and usually is less. However, in instances in which cesarean hysterectomy is planned or anticipated, extended caudad dissection is recommended to aid total hysterectomy and decrease the risk of cystotomy.
Some surgeons do not create a bladder flap. The main advantage is a shorter skin incision-to-delivery time. However, data supporting this practice are limited (O’Neill, 2014; Tuuli, 2012).
The uterus is entered through the lower uterine segment. Digital palpation to find the physiological border between firmer upper segment myometrium and the more flexible lower segment can guide placement. The bladder flap incision can also serve as a guide, and a hysterotomy site near this line is often selected.
For women with advanced or complete cervical dilatation, the hysterotomy is placed relatively higher. Failure to adjust increases the risk of lateral extension of the incision into the uterine arteries. It may also lead to incision of the cervix or vagina rather than the lower uterine segment. Such incisions into the cervix can distort postoperative cervical anatomy.
The uterus can be incised by various techniques. Each is initiated by using a scalpel to transversely incise the exposed lower uterine segment for 1 to 2 cm in the midline (Fig. 30-4). Repetitive shallow strokes avoid fetal laceration. As the myometrium thins, a fingertip can then bluntly enter the uterine cavity. Once the uterus is opened, the hysterotomy is lengthened by simply spreading the incision, using lateral and slightly upward pressure applied with each index finger (Fig. 30-5). Some evidence also supports widening the lower-uterine-segment incision instead with fingers pulling in opposition in a cephalocaudad direction (Cromi, 2008; Xodo, 2016).
The myometrium is incised with shallow strokes to avoid cutting the fetal head.
After entering the uterine cavity, the incision is extended laterally with fingers or with bandage scissors (inset).
Alternatively, if the lower uterine segment is thick and unyielding, cutting laterally and then slightly upward with bandage scissors will lengthen the incision. Importantly, when scissors are used, the index and midline fingers of the nondominant hand should be insinuated beneath the myometrium and above fetal parts to prevent fetal laceration. Comparing blunt and sharp expansion of the initial uterine incision, blunt stretch is associated with fewer unintended incision extensions, shorter operative time, and less blood loss. However, the rates of infection and need for transfusion do not differ (Asıcıoglu, 2014; Saad, 2014).
The uterine incision is made large enough to allow delivery of the fetus without tearing into the uterine vessels that course along the lateral uterine margins. If the placenta is encountered in the incision line, it must be either detached or incised. Placental function is thereby compromised, and thus delivery is performed expeditiously.
At times, a low transverse hysterotomy is selected but provides inadequate room for delivery. In such instances, one corner of the hysterotomy incision is extended cephalad into the contractile portion of the myometrium—a J incision. If this is completed bilaterally, a U incision is formed. Last, some prefer instead to extend in the midline—a T incision. As expected, each has higher intraoperative blood loss (Boyle, 1996; Patterson, 2002). Moreover, as these extend into the contractile portion, a trial of labor is more likely to be complicated by uterine rupture in future pregnancies.
In a cephalic presentation, a hand is slipped into the uterine cavity between the symphysis and fetal head. The head is elevated gently with the fingers and palm through the incision. Once the head enters the incision, delivery may be aided by modest transabdominal fundal pressure (Fig. 30-6).
Delivery of the fetal head.
After a long labor with cephalopelvic disproportion, the fetal head may be tightly wedged in the birth canal. Release of an impacted fetal head raises the risk of hysterotomy extension, of associated blood loss, and of fetal skull fracture. In this situation, there are three considerations for delivery. First, a “push” method may be used. With this, upward pressure exerted by a hand in the vagina by an assistant will help to dislodge the head and allow its delivery above the symphysis. If this is anticipated, a patient in frog-leg position may allow easier vaginal access.
Second, as an alternative, a “pull” method grasps the fetal legs to bring them through the hysterotomy. The fetus is then delivered by traction as one would complete a breech extraction. Support for this latter approach comes only from small randomized trials and retrospective cohort studies (Berhan, 2014; Jeve, 2016; Nooh, 2017). A low vertical hysterotomy incision, which will give more room for the “pull” technique, may be selected. If a low transverse incision has already been made, then this can be extended to a J-, U-, or T-incision as previously discussed.
The third method is use of the “fetal pillow,” which is a distensible intravaginal balloon that when inflated, elevates the fetal head. The device is available outside the United States, but evidence for its efficacy is limited (Safa, 2016; Seal, 2016).
Conversely, in women without labor, the fetal head may be unmolded and without a leading cephalic point. The round head may be difficult to lift through the uterine incision in a relatively thick lower segment that is unattenuated by labor. In such instances, either forceps or a vacuum device may be used to deliver the fetal head (Fig. 30-7).
A. The first cesarean forceps blade is placed. B. Slight upward and outward traction is used to lift the head through the incision.
After head delivery, a finger should be passed across the fetal neck to determine whether it is encircled by one or more umbilical cord loops. If present, these are slipped over the head. The head is rotated to an occiput transverse position, which aligns the fetal bisacromial diameter vertically. The sides of the head are grasped with two hands, and gentle downward traction is applied until the anterior shoulder enters the hysterotomy incision (Fig. 30-8). Next, by upward movement, the posterior shoulder is delivered. During delivery, abrupt or powerful force is avoided to avert brachial plexus injury. With steady outward traction, the rest of the body then readily follows. Gentle fundal pressure may aid this.
The anterior (A) and then the posterior (B) shoulder are delivered.
With some exceptions, current American Heart Association neonatal resuscitation recommendations eschew suctioning immediately following birth, even with meconium present (Wyckoff, 2015). A fuller discussion of this and delayed umbilical cord clamping is found in Chapter 27 (Delivery of the Shoulders). The umbilical cord is clamped, and the newborn is given to the team member who will conduct resuscitative efforts as needed.
Comparing elective cesarean under neuraxial anesthesia and spontaneous vaginal deliveries, studies show that the need for neonatal resuscitation is not practically significant between the two (Atherton, 2006; Gordon, 2005; Jacob, 1997). The American Academy of Pediatrics and the American College of Obstetricians and Gynecologists (2017) recommend that “a qualified person who is skilled in neonatal resuscitation should be in the delivery room.” At Parkland Hospital, pediatric nurse practitioners attend uncomplicated, scheduled cesarean deliveries. Notably, as anticipated neonatal risks rise, so too should the resuscitative skills of the attendants (Wyckoff, 2015).
To promote breastfeeding, the American College of Obstetricians and Gynecologists (2017b) recommends skin-to-skin contact between newborn and mother in the delivery room. Although most randomized trials focus on vaginal birth, several small studies support such contact following cesarean delivery, and this our practice (Moore, 2016; Stevens, 2014).
After birth, an intravenous infusion containing two ampules or 20 units of oxytocin per liter of crystalloid is infused at 10 mL/min. Some prefer higher infusion dosages, however, nondilute boluses are avoided because of associated hypotension (Roach, 2013). Once the uterus contracts satisfactorily, the rate can be reduced. An alternative is carbetocin—a longer-acting oxytocin derivative that is not available in the United States—that provides suitable, albeit more expensive, hemorrhage prophylaxis (Jin, 2016). Ergot-alkaloids are second-tier agents and carry hypertensive side effects. Carboprost, a 15-methyl derivative of prostaglandin F2α, is another second-tier agent used to treat uterine atony. Some but certainly not all studies indicate that misoprostol appears to perform similarly to oxytocin (Chaudhuri, 2014; Conde-Agudelo, 2013). Finally, some recommend the use of tranexamic acid added to a standard oxytocin infusion to decrease blood loss (Simonazzi, 2016; Wang, 2015). Its antifibrinolytic action and effects on thromboembolism rates in pregnant surgical patients are unclear. Larger trials are needed before widespread use. Additional discussions of all these agents are found in Chapter 41 (Risk Factors).
The uterine incision is observed for any vigorously bleeding sites. These should be quickly clamped with Pennington or ring forceps. Although some surgeons may prefer manual removal of the placenta, spontaneous delivery prompted by some cord traction may reduce the risk of operative blood loss and infection (Anorlu, 2008; Baksu, 2005). Fundal massage may begin as soon as the fetus is delivered to hasten placental separation and delivery (Fig. 30-9).
Placenta bulging through the uterine incision as the uterus contracts. A hand gently massages the fundus to help aid spontaneous placental separation.
Immediately after delivery and quick gross inspection of the placenta, the uterine cavity is suctioned and wiped out with a gauze sponge to remove avulsed membranes, vernix, and clots. In the past, double-gloved fingers or ring forceps placed through the hysterotomy incision were used to dilate an ostensibly closed cervix. This practice does not reduce infection rates from potential hematometra and is not recommended (Kirscht, 2017; Liabsuetrakul, 2011).
After placental delivery, the uterus is lifted through the incision and onto the draped abdominal wall, and the fundus is covered with a moistened laparotomy sponge. We favor this and believe a relaxed, atonic uterus can be recognized quickly and massage applied. Incision and bleeding points are more easily visualized and repaired, especially if there have been extensions. Adnexal exposure is superior, and thus, tubal sterilization is easier. Instead, some clinicians prefer to close the hysterotomy with the uterus in situ. Comparing these two approaches, febrile morbidity, pain, and blood loss are not significantly different (Walsh, 2009; Zaphiratos, 2015).
Before hysterotomy closure, previously clamped large vessels may be ligated separately or incorporated within the running incision closure. IUD insertion, if planned, is completed prior to hysterotomy closure (Chap. 38, Progestin Implants). One angle of the uterine incision is grasped to stabilize and maneuver the incision. The uterine incision is then closed with one or two layers of continuous 0- or no. 1 absorbable suture (Fig. 30-10). Chromic catgut suture is used by many, but some prefer synthetic delayed-absorbable polyglactin 910 (Vicryl). In subsequent pregnancy, neither suture type has been shown superior by mitigating against greater rates of adverse pregnancy outcomes such as uterine incision rupture (CORONIS Collaborative Group, 2016). Single-layer closure is typically faster and is not associated with higher rates of infection or transfusion (CAESAR Study Collaborative Group, 2010; Dodd, 2014; Roberge, 2014). Moreover, most studies observed that the number of layers does not significantly affect complication rates in the next pregnancy (Chapman, 1997; CORONIS Collaborative Group, 2016; Durnwald, 2003; Roberge, 2011).
The cut edges of the uterine incision are approximated with a running, locking suture.
At Parkland Hospital, we use a one-layer uterine closure with chromic catgut. The initial suture is placed just beyond one angle of the uterine incision. A continuous, locking suture line for hemostasis is then performed, with each suture penetrating the full thickness of the myometrium. The suture line then extends to a point just beyond the opposite incision angle. If approximation is not satisfactory after a single layer or if bleeding sites persist, then more sutures are required. Either another layer of running suture is placed to achieve approximation and hemostasis, or individual bleeding sites can be secured with targeted figure-of-eight or mattress stitches.
Traditionally, the peritoneum in the anterior cul-de-sac is approximated with a continuous 2–0 chromic catgut suture line. Multiple randomized trials suggest that omission of this step causes no postoperative complications (Grundsell, 1998; Irion, 1996; Nagele, 1996). If tubal sterilization is to be performed, it is completed as described in Chapter 39 (Puerperal Tubal Sterilization).
Following cesarean delivery, adhesions commonly form within the vesicouterine space or between the anterior abdominal wall and uterus. And, with each successive pregnancy, the percentage of affected women and adhesion severity rise (Morales, 2007; Tulandi, 2009). Adhesions can significantly lengthen incision-to-delivery time and total operative time (Rossouw, 2013; Sikirica, 2012). Although occurring infrequently, rates of cystotomy and bowel injury are also increased because of adhesive disease (Rahman, 2009; Silver, 2006).
Intuitively, scarring can be reduced by handling tissues delicately, achieving hemostasis, and minimizing tissue ischemia, infection, and foreign-body reaction. Most recent data on short- and long-term outcomes show no benefit to peritoneal closure (CAESAR Study Collaborative Group, 2010; CORONIS Collaborative Group, 2013, 2016; Kapustian, 2012). Similarly, most studies show no benefit from placement of an adhesion barrier at the hysterotomy site (Edwards, 2014; Kiefer, 2016).
Any laparotomy sponges are removed, and the paracolic gutters and cul-de-sac are gently suctioned of blood and amnionic fluid. Some surgeons irrigate the gutters and cul-de-sac, especially in the presence of infection or meconium. Routine irrigation in low-risk women, however, leads to greater intraoperative nausea but not to lower postoperative infection rates (Eke, 2016; Viney, 2012).
Prior to abdominal closure, correct sponge and instrument counts are verified. The rectus abdominis muscle bellies are allowed to fall into place. With significant diastasis, the rectus muscles may be approximated with one or two figure-of-eight sutures of 0 or no. 1 chromic gut suture. The overlying rectus fascia is closed by a continuous, nonlocking technique with a delayed-absorbable suture. In patients with a higher risk for infection, there may be theoretical value in selecting a monofilament suture here rather than braided material.
The subcutaneous tissue usually need not be closed if it is less than 2 cm thick. With thicker layers, however, closure is recommended to minimize seroma and hematoma formation, which can lead to wound infection and/or disruption (Bohman, 1992; Chelmow, 2004). One recent metaanalysis found lower rates of seroma formation and of developing any wound complication with closure, but hematoma and wound infection rates were unaffected (Pergialiotis, 2017). Addition of a subcutaneous drain does not prevent significant wound complications (Hellums, 2007; Ramsey, 2005).
Skin is closed with a running subcuticular stitch of 4–0 delayed-absorbable suture, with adhesive glue, or with staples. In comparison, final cosmetic results and infection rates appear similar, skin suturing takes longer, but wound separation rates are higher with metal staples (Basha, 2010; Figueroa, 2013; Mackeen, 2014a, 2015). Poliglecaprone 25 (Monocryl) or polyglactin 910 (Vicryl) are both suitable (Tuuli, 2016b). Outcomes with 2-octyl cyanoacrylate adhesive (Dermabond) were equivalent to sutures for Pfannenstiel incisions (Daykan, 2017; Siddiqui, 2013). A sterile thin abdominal wound dressing is sufficient. In morbidly obese women, application of a prophylactic negative-pressure device atop the closed skin incision to prevent seroma and subsequent infection does not appear to lower wound complication rates (Hussamy, 2018; Smid, 2017).
Joel-Cohen and Misgav Ladach Techniques
The Pfannenstiel-Kerr technique just described has been used for decades. More recently, Joel-Cohen and Misgav Ladach techniques have been added (Holmgren, 1999). These differ from traditional Pfannenstiel-Kerr entry mainly by their initial incision placement and greater use of blunt dissection.
The Joel-Cohen technique creates a straight 10-cm transverse skin incision 3 cm below the level of the anterior superior iliac spines (Oloffson, 2015). The subcutaneous tissue layer is opened sharply 2 to 3 cm in the midline. This is carried down, without lateral extension, to the fascia. A small transverse incision is made in the fascia, and curved Mayo scissors are pushed laterally on each side and beneath intact subcutaneous fat to incise the fascia. With this incision completed, an index finger from each hand is inserted between the rectus abdominis muscle bellies and beneath the fascia. One finger is moved cranially and the other caudally, in opposition, to separate the bellies and further open the fascial incision. Then, a finger from each hand hooks under each belly to stretch the muscles laterally. The peritoneum is entered sharply, and this incision is sharply extended cephalocaudad. Entry with the Misgav Ladach technique differs in that the peritoneum is entered bluntly (Holmgren, 1999).
Modifications to the Joel-Cohen method abound. For emergency delivery, we begin along a line somewhat lower on the abdomen. For speed, we extend the fascial incision bluntly by hooking index fingers in the fascial incision’s lateral angles and pulling laterally (Hofmeyr, 2009; Oloffson, 2015). Index fingers insinuated between the rectus bellies then move cephalocaudad in opposition to stretch the incision. Blunt index-finger dissection enters the peritoneum, and again, cranial and caudad opposing stretch opens this layer. Last, all the layers of the abdominal wall are grasped manually and pulled laterally in opposition to further open the operating space.
These techniques have been associated with shorter operative times and with lower rates of intraoperative blood loss and postoperative pain (Mathai, 2013). They may, however, prove difficult for women with anterior rectus fibrosis and peritoneal adhesions (Bolze, 2013).
Classical Cesarean Incision
This incision is usually avoided because it encompasses the active upper uterine segment and thus is prone to rupture with subsequent pregnancies. Some indications stem from difficulty in exposing or safely entering the lower uterine segment. For example, a densely adhered bladder from previous surgery is encountered; a leiomyoma occupies the lower uterine segment; the cervix has been invaded by cancer; or massive maternal obesity precludes safe access to the lower uterine segment. A classical incision is also preferred for placenta previa with anterior implantation, especially those complicated by placenta accrete syndromes. In extreme cases of this, the typical classical hysterotomy may be placed even higher in the uterine body or posteriorly to avoid the placenta. As such, fetuses with cephalic presentation are then delivered in a manner similar to total breech extraction (Chap. 28, Total Breech Extraction).
In other instances, fetal indications dictate the need. Transverse lie of a large fetus, especially if the membranes are ruptured and the shoulder is impacted in the birth canal, usually necessitates a classical incision. A fetus presenting as a back-down transverse lie is particularly difficult to deliver through a transverse uterine incision. In instances when the fetus is very small and breech, a classical incision may be preferable (Osmundson, 2013). In such cases, the poorly developed lower uterine segment provides inadequate space for the manipulations required for breech delivery. Or, less commonly, the small fetal head may become entrapped by a contracting uterine fundus following membrane rupture. Last, with multiple fetuses, a classical incision again may provide suitable room for extraction of fetuses that may be malpositioned or preterm (Osmundson, 2015).
Uterine Incision and Repair
A vertical uterine incision is initiated with a scalpel beginning as low as possible and preferably within the lower uterine segment (Fig. 30-11). If adhesions, insufficient exposure, a tumor, or placenta percreta preclude development of a bladder flap, then the incision is made above the level of the bladder. Once the uterus is entered with a scalpel, the incision is extended cephalad with bandage scissors until it is long enough to permit delivery of the fetus. With scissor use, the fingers of the nondominant hand are insinuated between the myometrium and fetus to prevent fetal laceration. As the incision is opened, numerous large vessels that bleed profusely are commonly encountered within the myometrium. The remainder of fetal and placental delivery mirrors that with a low transverse hysterotomy.
An initial small vertical hysterotomy incision is made in the lower uterine segment. Fingers are insinuated between the myometrium and fetus to avoid fetal laceration. Scissors extend the incision cephalad as needed for delivery. (Reproduced with permission from Johnson DD: Cesarean delivery. In Yeomans ER, Hoffman BL, Gilstrap LC III, et al (eds): Cunningham and Gilstrap’s Operative Obstetrics, 3rd ed. New York, McGraw-Hill Education, 2017.)
For incision closure, one method employs a layer of 0- or no. 1 chromic catgut with a running stitch to approximate the deeper length of the incision (Fig. 30-12). The outer layer of myometrium is then closed along its length with similar suture and with a running suture line. To achieve good approximation and to prevent the suture from tearing through the myometrium, it is helpful to have an assistant compress the uterus on each side of the wound toward the midline as each stitch is placed.
Classical incision closure. The deeper half (left) and superficial half (middle) of the incision are closed in a running fashion. The serosa is then closed (right). (Reproduced with permission from Johnson DD: Cesarean delivery. In Yeomans ER, Hoffman BL, Gilstrap LC III, et al (eds): Cunningham and Gilstrap’s Operative Obstetrics, 3rd ed. New York, McGraw-Hill Education, 2017.)