Incision and Closure
Abdominal incisions provide access to the abdominal and pelvic organs. The planned procedure and the patient’s medical and surgical history guide decisions about the location, type, and length of abdominal incisions. This chapter focuses on open techniques for abdominal entry. Surgeons should choose the incision that combines the best exposure and least patient discomfort and risk.
General abdominal examination (Table 1.4.1)
A bimanual pelvic examination can assist with decisions regarding incision type and location by providing information about uterine size, mobility, tenderness, and the presence and character of adnexal masses.
IMAGING AND OTHER DIAGNOSTICS
Prior to cesarean delivery, ultrasound can confirm fetal presentation and placental location.
If there is concern for morbidly adherent placenta on ultrasound, magnetic resonance imaging (MRI) of the abdomen and pelvis may provide more detailed information about placental invasion.
Additional imaging may be warranted to determine the location of unusual anatomy or foreign bodies if indicated by patient history. For example, adnexal masses can be reasonably assessed with pelvic 2D and 3D ultrasound and Doppler, and computerized tomography (CT) or MRI scan can be employed in evaluating other pelvic conditions such as appendicitis.
The ideal abdominal incision is that which ensures adequate surgical exposure for the necessary procedure while minimizing postoperative complications.
The rationale for the type and location of the incision should be a part of the informed consent discussion owing to differences in cosmetic outcomes.
The need for additional instruments or retractors based on patient habitus or pathology is determined during the preoperative examination. For example, surgeons may request a pannus retractor to improve access to the lower abdomen when the patient is obese. Intra-abdominal visualization may be improved in some instances with the AlexisTM retractor, which has two rigid plastic rings that are available in different sizes, connected by a sheath of plastic. These disposable devices tend to retract the entire length of the incision equally and therefore may provide improved exposure in some circumstances over handheld or metal self-retaining retractors. For improved operating room (OR) efficiency, special instrumentation should be requested in advance of the procedure date.
Table 1.4.1 General Abdominal Examination
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Abdominal entry for most obstetric surgeries can be performed under regional, general, or in rare and exceptional circumstances, local anesthesia. The mode of anesthesia is dependent on patient presentation, acuity of the surgery, degree of urgency, and the skill of the anesthesiologist.
Ideally, operating facilities ensure adequate space for the surgeon, assistant, anesthesiologist, and ancillary staff, including neonatal teams if needed. The surgical suite should be equipped with appropriate medications and supplies to handle emergencies such as postpartum hemorrhage and complications of the newborn.
The dorsal supine position with a leftward tilt is common during abdominal procedures on obstetric patients. This tilt improves maternal cardiac output and uteroplacental perfusion by reducing uterine compression on the aorta and inferior vena cava.
The low lithotomy position provides several advantages, especially when the risk of bleeding is high. This position allows for an additional surgeon to be directly at the operative site, visualization and quantification of vaginal blood loss, urethral access for cystoscopy or stent placement, and for intraoperative placement of transvaginal instruments or intrauterine devices (e.g., tamponade balloon) if needed.
Abdominal entry is accomplished using either open or laparoscopic methods. Gestational age, body habitus, patient history, and anticipated pathology drive decisions regarding the type of abdominal incision and the placement of laparoscopic ports. See Chapter 3.6 for laparoscopic approach.
Familiarity with the anterior abdominal wall anatomy is key when considering abdominal entry.
The anterior abdominal wall musculature includes the vertically oriented rectus abdominis and pyramidalis muscles, and the transversely oriented external and internal oblique, and transverse abdominis (Figure 1.4.1) muscles. The vertical muscles are responsible for motion and posture, whereas the transverse muscles provide most of the support strength of the anterior abdominal wall.
Blood flow to the anterior abdominal wall is through vessels that originate primarily from the external iliac, femoral, and anterior thoracic arteries (Figure 1.4.2). The mid-abdomen is supplied by the epigastric arteries, and the lateral abdomen by the musculophrenic and the superficial and deep circumflex iliac arteries. In addition, a rich network of anastomoses distributes blood to the abdominal wall.
Nerves of the anterior abdominal wall include the thoracoabdominal, iliohypogastric, and ilioinguinal nerves (Figure 1.4.3). Lateral vertical incisions may cause damage to branches of the thoracoabdominal nerves. Creation and repair of wide transverse incisions may disrupt or tether the iliohypogastric or ilioinguinal nerve. Knowledge of the anatomy of these nerves is important because injury to them can result in chronic pain or sensation changes to the mons and/or labia majora. The use of port closure devices can be associated with nerve entrapment resulting in similar symptoms depending on the distribution of the involved nerve.
Surgical planning requires consideration of potential anatomic changes related to pregnancy. Diastasis recti caused by the gravid uterus is a common finding during pregnancy. In women with prior pelvic surgeries, it is important to be alert for adherent muscles, fascia, or intraperitoneal adhesions. Patients with a history of herniorrhaphy may have a length of mesh at the site, in which case preoperative consultation with a general surgeon may be beneficial. During the late second and third trimesters, the umbilicus loses its usefulness as a landmark for the aortic bifurcation. The location of the uterine fundus and lateral borders, if not clearly palpable, should be identified by ultrasound prior to placing laparoscopic ports or creating incisions for procedures other than cesarean delivery.
Although the advantages of transverse incisions include cosmesis and strength over vertical incisions, they are not always feasible. Vertical incisions are associated with less postoperative pain and reduced blood loss as compared to the transverse option; however, the reduction in local perfusion may be associated with poorer wound healing (1). Body habitus, uterine size, need for exposure, potential need for upper abdominal exploration, and surgical history all influence the direction and type of laparotomy incision used in obstetric patients (Figure 1.4.4).
Procedures and Techniques
Pfannenstiel (Tech Figure 1.4.1)
The cosmetic results of the Pfannenstiel incision are generally preferred over vertical incisions. The incision is made with a scalpel 2 to 3 cm above the cephalad edge of the pubic symphysis and spans ˜8 to 10 cm with a slightly cephalad curve to the ends. The length can be altered depending on the amount of exposure needed.
The subcutaneous adipose layer is opened in a transverse fashion using either the scalpel or electrocautery. Both Camper and Scarpa fascia are incised and separated for the entire length of the incision until reaching the anterior rectus sheath. The superficial epigastric vessels can be displaced by a retractor or coagulated to avoid bleeding.
The anterior rectus sheath is then sharply incised in the midline and extended bilaterally from the midline in a transverse curvilinear fashion using a knife or electrocautery. The fascia at this level is comprised of two layers of aponeuroses, one from the external oblique and the second from the internal oblique muscles fused with the transverse abdominis. Blunt dissection under the fascia separates the anterior sheath from the underlying rectus muscles. Lateral dissection of one layer at a time with either curved Mayo scissors or electrocautery allows identification of perforating vessels that can be transected with electrocautery.
Next, the rectus muscles are separated from the overlying fascia. The superior edge of the fascia is elevated cephalad with two Kocher clamps and using countertraction the rectus muscles are separated from the fascia bluntly. Using the index finger, the muscle can be gently separated from the midline rectus sheath raphe on either side by running the finger up both sides of the raphe in a cephalad direction. The exposed midline raphe can then be incised with scissors or
electrocautery to separate the muscles from the fascia. More extensive lateral separation of the muscle from the fascia is frequently unnecessary, and this prevents tearing of perforating vessels and unneeded bleeding. Sweeping the finger laterally under the fascial edge to separate a large area of muscle is generally not needed and is not advised as this can easily tear vessels that then retract and bleed at a later time. In women who have had prior abdominal surgery, separation of the muscle from the fascia and the midline raphe may need to be performed sharply or with cautery secondary to scar and adhesions, which will reduce tissue trauma and blood loss. Care must be taken to avoid lateral perforating vessels during this step. The same technique is repeated to separate the rectus muscles at the inferior fascial edge as needed. The rectus muscles are then separated from each other in the midline. This step is accomplished bluntly or with aid of a hemostat in women without a history of abdominal surgery, but sharp dissection may be required in patients with prior surgeries.
The peritoneum is entered at the cephalad apex of the incision to avoid bladder injury. Entry is accomplished sharply using Metzenbaum scissors or bluntly in patients without adhesion. The peritoneal opening is then extended sharply superiorly and inferiorly. Sharp dissection in the inferior direction is completed cautiously to avoid bladder dome injury. To extend the peritoneum further, the inferior portion of the peritoneum can be thinned into layers. Placing one finger on the internal surface of the peritoneum and tenting upward helps in the identification of translucent areas and prevention of bladder injuries.
Surgical reapproximation of the parietal peritoneum is optional at the time of abdominal wall closure. If the surgeon opts to close this layer, a rapidly absorbable suture is sufficient. For fascial closure, a synthetic absorbable suture such as polyglactin 910 or polyglycolic acid in a running fashion provides adequate strength during the period of wound healing. Both long half-life absorbable suture (polydioxanone, polyglyconate) and permanent (polypropylene) sutures are appropriate when women have had prior surgery, for vertical incisions, or when there are risk factors for herniation (e.g., obesity, chronic cough, diabetes, or steroid use). Both the anterior and posterior layers of the fascia are included during closure of Pfannenstiel incisions. The subcutaneous layer should be closed when >2 cm deep using continuous or interrupted technique. Surgeons may also consider closing this layer to decrease tension on a subcutaneous skin closure when the incision is <2 cm deep if needed. Skin can be closed with a continuous subcutaneous suture or with staples.
A Pfannenstiel offers limited exposure compared to other incisions. Rapid conversion to a Maylard or Cherney incision (see below) may be challenging and owing to vascular supply, blood loss may be greater than when compared to a vertical incision (1,2,3,4,5,6).
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