Parastomal hernia is the most frequent complication following the construction of a colostomy or an ileostomy, occurring in up to 50 percent of patients. A parastomal hernia is a type of incisional hernia that allows protrusion of abdominal contents through the abdominal wall defect created during ostomy formation (image 1). It should be recognized that, unlike a hernia development in a surgical incision for which the fundamental problem is healing between tissues that have been approximated, ostomy creation introduces an abdominal wall defect, the trephine, for which no healing is expected. A parastomal hernia forms as the trephine is continually stretched by the forces tangential to its circumference .
The construction of an ostomy and the management of patients with an ileostomy or colostomy are reviewed separately. (See "Surgical principles of ostomy construction" and "Management of patients with a colostomy or ileostomy".)
EPIDEMIOLOGY AND RISK FACTORS
The reported incidence of parastomal hernia varies widely and is related the type of ostomy constructed, the duration of follow-up after ostomy construction, and the definition used to identify parastomal hernia. The incidence of parastomal hernia is reported as ranging from 0 to 50 percent, depending upon the type of ostomy [2-12]. One review found the following rates of parastomal hernia formation :
●End-ileostomy – 1.8 to 28.3 percent
●End-colostomy – 4.0 to 48.1 percent