Leading article Ileal pouch-anal anastomosis for Crohn’s disease

Over the past 10 years ileal pouch-anal anastomosis has become the operation of choice for most patients with ulcerative colitis. Although pouch surgery in ulcerative colitis does have a moderate complication rate, so do the alternatives of proctocolectomy and ileostomy. The very real advantage of avoiding a stoma along with the inherent curability of ulcerative colitis by excisional surgery help to explain the attractiveness of this operation. In Crohn’s disease the situation is notably diVerent as the condition is not curable by surgery, and all operations in Crohn’s disease are followed by a higher complication rate and fairly frequent recurrence. Indeed, recurrence is often seen when a permanent stoma is avoided and an anastomosis constructed. Patients with Crohn’s disease are just as averse to a stoma as those with ulcerative colitis, and so for very good reasons stomas are often avoided even though both patient and doctor are well aware that this puts the patient at increased risk of recurrence and further surgery. Thus, it would be standard practice to oVer a patient with terminal ileal Crohn’s disease right hemicolectomy and some patients with large bowel Crohn’s disease colectomy and ileorectal anastomosis. As a consequence of restorative surgery, clinical recurrence is seen within 10 years in 50–80% of these patients. 3 Figure 1 makes the point quite dramatically: the upper curve represents recurrence rates after colectomy and ileorectal anastomosis, whereas the lower shows how infrequent it can be when a permanent stoma is used instead of an anastomosis. Yet despite this high rate of recurrence, restorative surgery in these circumstances is generally accepted by the surgical and medical community. Does such a policy result in undue loss of small intestine? One study of 82 patients who underwent colectomy and ileorectal anastomosis found that 46 (56%) subsequently underwent revisional surgery with an average cumulative loss of small intestine of 44 cm in the fixed state. Although these losses at first glance might seem to be quite high, short bowel syndrome is an uncommon problem in patients with Crohn’s disease and there is as yet no sign of waning enthusiasm for either right hemicolectomy or colectomy and ileorectal anastomosis because of this anxiety. Ileal pouch-anal anastomosis has, for some time, been considered to be quite inappropriate in patients with Crohn’s disease. To some extent this has arisen owing to poor results when compared with pouches in ulcerative colitis and familial adenomatous polyposis, but to some extent it has also arisen because of a tendency to compare apples with oranges. Kock pouches were originally constructed for both Crohn’s disease and ulcerative colitis. Nils Kock selected patients with disease limited to the colon, in many of whom the preoperative diagnosis had in fact been ulcerative colitis but who later turned out to have Crohn’s disease. Of the 280 patients treated with Koch pouches, 49 had Crohn’s disease. One patient died postoperatively and 27% developed complications as inpatients. In eight (16%) the pouch had to be removed some time later, in four because of recurrent disease. Of the remaining 40 patients, another 17 developed recurrent disease, six in the ileal segment proximal to the reservoir, five in the reservoir alone and six at both sites. Fourteen of these patients had surgical removal of their recurrent Crohn’s disease. Overall, 37 of these 40 patients had continent ileostomies and only three needed to wear an ileostomy appliance. For restorative operations in patients with Crohn’s disease these results were really very good. But Kock, comparing apples with oranges, was worried because the in-hospital complication rate was double that for patients with colitis and excision of the pouch had been necessary in 16% compared with only 2% in ulcerative colitis. He concluded that, “this procedure should be performed in patients with Crohn’s disease only exceptionally”.