The colostomy construction technique depends on whether the goal is decompression or diversion.Ongoing surveillance of the remaining colon is necessary but often overlooked in patients with colostomies.
A decompressing colostomy vents the distal and proximal bowel limbs while maintaining continuity between the limbs. A blowhole is used for massively dilated colon. The anterior wall of the transverse colon is sewn in two layers to the abdominal fascia and the skin. Typically, blowhole colostomies are reserved for patient palliation.
Diverting colostomies, such as end-colostomy and mucous fistula, are used following distal resection or perforation so that the distal limb is completely separated from the fecal stream. All colostomies are matured in the operating room. If a stoma rod is used, it is removed 1 week after surgery.
Complications of colostomies include necrosis, stricture, and herniation. If the stoma becomes dusky, an anoscope is inserted. If necrosis does not extend below the fascia, it can be observed safely; otherwise, urgent revision is performed. Parastomal hernias are repaired only if they prevent application of a stomal appliance or cause small-bowel obstruction; these can be approached locally, although definitive treatment generally entails relocation of the stoma to a different site. Laparoscopic parastomal hernia repair has also been described.
Colostomy closure is not a trivial procedure, with a reported morbidity rate of 20 to 30% (bleeding, anastomotic leak, abscess) and a mortality rate of 3%. Tagging the rectal stump with long, nonabsorbable sutures and mobilizing the splenic flexure during the initial resection and placing preoperative ureteral stents can facilitate reanastomosis. Placement of adhesion barriers at the time of initial exploratory laparotomy may reduce adhesions enough to allow laparoscopic colostomy closure.