Abdominal Wall Hernias


Obturator hernias

are very rare hernias that occur predominantly in thin, older women and are difficult to diagnose. Patients classically present with bowel obstruction and focal tenderness on rectal examination. Pain along the medial aspect of the thigh with medial thigh rotation, known as the Howship-Romberg sign, results from obturator nerve compression and, when present, may aid in the clinical diagnosis of an obturator hernia.

 B .Treatment and operative management

Small epigastric, umbilical, obturator, and spigelian hernias may be repaired primarily. Most incisional hernias and lumbar and obturator hernias require the use of prosthetic mesh because of their size, the often poor quality of surrounding tissue, and high recurrence rates after primary repair.

OPEN HERNIA REPAIR

The principles for ventral hernia repair include dissection and identification of all defects and repair with nonabsorbable sutures placed in healthy tissue. Most sizable incisional hernias are now repaired with some type of mesh prosthesis that should be anchored by nonabsorbable sutures placed in healthy fascial tissue several centimeters beyond the margins of the defect. The mesh should be durable and well tolerated by the patient, with a low risk for infection. A variety of mesh products are available for repair, including polypropylene, polytetrafluoroethylene (PTFE, Gore-Tex), and a composite mesh of polypropylene and PTFE. Several newer composite mesh products (Table 26-1) with absorbable barriers coating polypropylene or polyester mesh are available to minimize tissue attachment to intraabdominal structures. Nonsynthetic products available for closure of defects (Table 26-2) in contaminated fields include AlloDerm, which is a decellularized human skin preparation that acts as a matrix for tissue ingrowth, and Surgisis, which is a porcine small intestine submucosa product that also promotes tissue ingrowth. One should try to avoid placing polypropylene mesh in direct contact with the intestine because of the risk of adhesion formation and fistulization. Rarely, in patients with massive incisional defects and loss of domain of intestinal contents, preoperative pneumoperitoneum can be used to stretch the abdominal wall to provide sufficient autogenous tissue for repair. Peritoneal insufflation of air (500 to 1,000 mL/day for 5 to 10 days) may allow primary closure when not otherwise possible and may obviate the need for a prosthetic graft.

TABLE 26-1 Characteristics of Mesh Used for Inguinal Hernia Repair
Marlexa (heavyweight) Prolene softb (midweight) Ultraprob (lightweight)
Material Polypropylene Polypropylene Polypropylene, poliglecaprone
Weight (g/m2) 95 45 28
Pore size (mm) 0.6 2.4 4
Burst strength (newtons) 1,218 590 576
Stiffness (newtons/cm) 59.1 49.1 43.2
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