The continent ileostomy has an interesting history. It began as a revolutionary concept and technique, only to fall out of routine use because of technical issues and ultimately a better alternative: the ileal pouch–anal anastomosis (IPAA). Indications for a continent ileostomy still exist, although the operation is now rarely performed. It has undergone multiple modifications, is technically demanding, and is associated with a relatively high need for revisions. However, patients with a continent ileostomy often go to great lengths not to lose their pouch, even if this means traveling long distances to one of the ever-dwindling number of surgeons skilled in pouch management and being willing to undergo major revisions and repairs.
In this chapter we will discuss the evolution of the continent ileostomy, the technique as it currently stands, indications, contraindications, and common complications and their management. We will also outline the management of urgent problems for persons unfamiliar with these pouches.
Evolution of the Continent Ileostomy
In 1952, Brian Brooke revolutionized the end ileostomy by simply everting the mucosa of the ileum and suturing it to the skin. This technique resolved the major and at times debilitating problem of “ileostomy dysfunction” caused by ileal serositis. Despite this advance, there was still a strong incentive to find an alternative to the end ileostomy, which entails a major change in lifestyle and body image and is difficult for patients to accept. In addition, early stoma appliances were quite rudimentary and both less comfortable and more prone to fail than they are today. At this time the discipline of stoma therapy, started by Turnbull and Gill, was still in its infancy.
During the 1960s, Nils Kock of the University of Goteborg, Sweden, developed a technique to create a continent intestinal reservoir. He presented this work at the 26th Annual Meeting of the Central Surgical Association in Chicago, Illinois, on February 21, 1969. Kock described the cases of five patients in whom he detubularized and reconfigured the distal ileum to make a low-pressure U-shaped pouch, a corner of which was opened onto the abdomen ( Fig. 40-1 ). Continence relied upon making “the ileostomy canal through the abdominal wall narrow and oblique through the rectus muscle in order to obtain sufficient closing of the outlet of the reservoir.” Advantages compared with a conventional ileostomy included placement of a flush stoma much lower in the abdomen where it was easy to conceal, without the need to wear an appliance.
Despite the initial promise of this pouch, it soon became clear that the continence mechanism was inadequate. Kock modified his design by adding an efferent limb to the pouch and creating a one-way nipple valve by intussusception of part of the efferent limb into the pouch ( Fig. 40-2 ). This modification was a great improvement, but over time it became apparent that the valve was prone to sliding or slipping. Subsequent modifications to stabilize the valve took one of two approaches: modifications of the basic design to better fix the valve, or modifications of the pouch design itself to make a valve less susceptible to slipping.
Techniques to Better Fix the Valve
The valve has an inherent tendency to slip because peristalsis promotes undoing of the intussusception. Initially the intussusception was held in place by sutures passed through both segments of intussuscepted bowel, avoiding the mesentery. Later, the use of a noncutting linear or TX stapler replaced this technique and has proved more effective. The following additional maneuvers help hold the intussuscepted bowel in place:
Use of sclerosing agents on its serosa (e.g., tetracycline powder)
Scarifying its serosa with cautery to cause an inflammatory reaction
Carefully stripping the peritoneum from the mesentery of the bowel making up the valve
Debulking or defatting a thick mesentery
Placing sutures around the fundus of the pouch at the exit conduit
Use of a mesh collar at the exit conduit (effective but abandoned because it led to fistula formation)
The most important modification seems to have been attaching the valve to the pouch wall. Initially sutures were used, but the use of another row of staples, as described by Fazio and Tjandra in 1992, is most effective.
Pouch Design Modifications
The first major modification to the basic Kock design was described by Barnett in 1987. He constructed an isoperistaltic valve and then wrapped a segment of bowel contiguous with the pouch around the exit conduit as it left the pouch ( Fig. 40-3 ). A T pouch was described by Kaiser in 2002, based on one used by his urology colleagues. A nonintussuscepted valve mechanism was created by anchoring and opening an isolated bowel segment into a serosa-lined trough formed by the base of two adjacent ileal segments that constitute the pouch ( Fig. 40-4 ). These pouches have their advocates but do not seem to be any easier to create technically or to give results superior to the most current modification of the original design.
Current Indications and Contraindications
The most common indication for a continent ileostomy is the need for a proctocolectomy in someone who is not a candidate for an IPAA but wishes to avoid a conventional Brooke ileostomy. IPAA may be impossible either for practical reasons (such as poor anal sphincter function) or technical reasons (such as lack of pouch reach or a prior proctocolectomy including the anus). A failed IPAA can also be converted to a continent ileostomy if it can be mobilized from the pelvis without too much damage.
Obesity is a relative contraindication to a continent ileostomy because the fatty mesentery causes issues with valve creation and passage of the exit conduit through the widened abdominal wall is difficult. Patients need a certain level of dexterity, cognitive function, and motivation to adequately use and care for the pouch. As with the IPAA, it should not be performed in a person with co-existing small bowel Crohn disease, although colonic and anal Crohn disease may not be a contraindication. Prior loss of a significant amount of small bowel is also a relative contraindication because a pouch will use another 50 to 70 cm of bowel, and if the pouch were to fail and need to be removed, this loss could be significant. Finally, the procedure should not be performed by a surgeon who lacks experience in the management of common complications (Box 40-1 ).