Chapter 35: Abdominal Wall, Omentum, Mesentery, and Retroperitoneum

Key Points

• There are differences in the anatomic structure in the rectus sheath above and below the arcuate line. Below the arcuate line, all the lateral fascial layers combine and travel anteriorly forming the anterior rectus sheath and leaving the posterior aspect of the lower portion of the rectus muscles without an aponeurotic covering. Above the arcuate line, the posterior rectus sheath is formed by a portion of the internal oblique aponeurosis and the transversus abdominus sheath, and the anterior rectus sheath is formed by the remaining fibers of the internal oblique and the external oblique aponeuroses.

• Two randomized trials have found that closure of midline incisions with small fascial stitches of five to eight mm length and five mm width is beneficial in preventing incisional hernias of the abdominal wall.

• Primary repair of ventral incisional hernias results in high recurrence rates, and repair utilizing other methods, including prosthetic mesh and component separation, are preferred techniques of repair.

• Laparoscopic incisional hernia repair results in similar recurrence rates and wound infections, compared to open repair. Laparoscopic repair may result in a faster recovery and shorter hospitalization; however, there may be an increase in bowel injury when compared to an open repair.

• Desmoid tumors should be monitored for asymptomatic patients as there is a possibility of spontaneous regression. For patients with rapidly growing or symptomatic tumors resection is recommended. If complete pathologic resection is not achievable without significant morbidity, more modest resection is recommended along with treatment with adjuvant therapies.

• The omentum provides an immunogenic and fibrotic response to foreign stimuli, allowing the abdomen to wall off infections preventing diffuse peritonitis.

• The role of surgery in the treatment of sclerosing mesenteritis is minimal and is most often undertaken to obtain tissue for diagnosis. Most cases should be treated medically with surgical interventions reserved for cases of bowel obstruction and ischemia.

• Surgical interventions for retroperitoneal fibrosis include obtaining tissue for pathologic diagnosis, relieving ureteral obstructions via ureterolysis or ureteral stenting, and relieving vascular obstructions via endovascular stenting of affected vessels. Most cases are treated successfully with the use of steroids.