OSTOMIAS

Indications To defunctionalize bowel. Protection of distal anastomosis. Relief of obstruction.

Contraindications Absolute None. Relative Carcinomatosis precluding mobilization of bowel. Morbid obesity such that mesentery or stoma cannot reach the skin surface.

Informed Consent Expected Benefits Decompression of bowel obstruction. Protection of distal anastomosis to allow healing with decreased risk of intra-abdominal sepsis. Relative Risks Bleeding. Intra-abdominal abscess. Wound infection. Parastomal hernia. Need for ostomy revision secondary to stenosis or ischemia.

Equipment Standard general surgery set for major gastrointestinal surgery.

Patient Preparation Nasogastric tube in cases of perforation or obstruction. Resuscitation to correct any fluid and electrolyte abnormalities. Perioperative antibiotics and additional doses in the event operative time is prolonged. No bowel preparation is necessary for small bowel procedures. Preoperative evaluation and marking of optimal stoma position by an enterostomal therapist.

Patient Positioning The patient should be supine.

Procedure Loop Colostomy Figure 21–1: When ostomy is performed for diversion of the fecal stream due to distal obstruction, the dilated colon may be decompressed with a needle or catheter attached to wall suction. The collapsed bowel is easier to manipulate, and there is decreased risk of injury and perforation. Figure 21–2: An incision is made along the apex of the selected loop of bowel to prepare for stoma creation on the antimesenteric wall of the bowel. Figure 21–3: The cut edges of the bowel are everted and interrupted sutures are placed using full-thickness bites of colon wall and subdermal bites of skin. A rod or red rubber catheter may be placed under the loop of colon being brought up; however, this step is not necessary and may interfere with placement of the ostomy appliance. Figure 21–1 Figure 21–2 Figure 21–3 End Ileostomy Figure 21–4A: For creation of an end ileostomy, a circular incision approximately 2.5 cm in diameter is made overlying the rectus muscle. Figure 21–4B: Blunt dissection is used to divide the soft tissue to the level of the fascia. A cruciate incision is made in the fascia and carried 2 cm in both directions. The rectus muscle fibers are split using the clamps and retractors. Figure 21–4C: The posterior sheath is opened with a cruciate incision sufficient to permit passage of two fingers. Figure 21–4D, E: The small bowel is brought through this fascial opening using a Babcock clamp until 5 cm of ileum protrudes above the surface, with care taken to avoid twisting the mesentery. Four Brooke-type sutures are then placed to evert the bowel. These are created by placing interrupted sutures through the full-thickness of the cut bowel edge, a seromuscular bite through the bowel wall at the level of the skin, and finally a subdermal skin bite. These sutures are placed in four quadrants avoiding the mesentery. The sutures are tied down, thus everting the bowel edges and elevating the lumen above the skin. Additional interrupted sutures from the cut edge of the bowel to the dermis may be placed in between the four Brooke-type sutures. Figure 21–4A–E Loop Ileostomy Figure 21–5A-D: An ileal loop is brought out through the abdominal wall (Figure 21–5A) and an incision is extended to roughly 80% of the circumference of the distal limb (Figure 21–5B). The cut edge is everted over the proximal limb and secured with interrupted sutures (Figures 21–5C, D). This results in elevation of the proximal limb of the stoma and leaves the defunctionalized or distal limb flush with the skin surface. Figure 21–5A–D

Postoperative Care Stoma may appear dusky with edema during the first postoperative week. Enterostomal therapists can assist with patient education about appliance care as well as treatment of any peristomal skin irritation.

Potential Complications Skin irritation from gastrointestinal contents. Ostomy retraction (common in obese patients). Mechanical obstruction due to an overly tight fascial closure around the stoma. Parastomal hernia. Prolapse. Fistula. Stenosis (may be treated with careful dilation). Necrosis of the ostomy due to ischemia (requires reoperation for resection).

Pearls and Tips For ease of appliance changes, optimal selection of a stoma site on flat skin, avoiding skin folds, prior scars, and bony prominences, is critical. Also avoid placement in the "belt line" or waistline area. Avoid fecal contamination to prevent postoperative infection and incisional hernia. Ensure an adequate blood supply to the stoma by noting the color of the bowel and pulsatile flow of terminal arterial branches at bowel ends following division. Ensure that the stoma is not rendered ischemic by an overly small opening in the abdominal wall at the level of the fascia. To create a tension-free stoma, ensure sufficient mobility of the bowel to easily reach the abdominal wall. Avoid twisting or kinking of the bowel and mesentery as the bowel is brought through the abdominal wall. Handle the bowel gently when suturing the ostomy to prevent ischemia, necrosis, and leak. Expect some amount of postoperative bowel wall edema. Avoid excessive manipulation of the bowel ends with the forceps to prevent further edema and bruising.

References Souba WW, Fink MP, Jurkovich GJ, et al, eds. ACS Surgery, Principles and Practice. New York, NY: WebMD Professional Publishing; 2006. Zollinger RM Jr, Zollinger RM Sr. Zollinger's Atlas of Surgical Operations, 8th ed. New York, NY: McGraw-Hill; 2002.