bladder is gently separated from the underlying lower uterine segment with blunt or sharp dissection within this vesicouterine space (Fig. 30-3). This bladder lap creation efectively 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.
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.
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 ield.
he relection 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 FIGURE 30-3 Cross section shows blunt dissection of the bladder of the uterus to edge of peritoneum is elevated, and the expose the lower uterine segment.
FIGURE 30-4 The myometrium is incised with shallow strokes to avoid cutting the fetal head.
FIGURE 30-5 After entering the uterine cavity, the incision is extended laterally with fingers or with bandage scissors (inset).
Some surgeons do not create a bladder lap. The main advantage is a shorter skin incision-to-delivery time. However, data supporting this practice are limited (O'Neill, 2014; Tuuli, 2012).
Uterine Incision. The uterus is entered through the lower uterine segment. Digital palpation to find the physiological border between irmer 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 inger 30-5). Some evidence also supports widening the lower-uterine-segment incision instead with ingers pulling in opposition in a cephalocaudad direction (Cromi, 2008; Xodo, 2016).