Purpose: Up to one in five patients undergoing surgery for ulcerative colitis will have ambiguous histology, with features of both ulcerative colitis and Crohn's disease, and are categorized as having indeterminate colitis. We hypothesized that functional outcomes in indeterminate colitis patients undergoing ileal pouch-anal anastomosis are comparable with those of ulcerative colitis patients undergoing ileal pouch-anal anastomosis.
Methods: Physician-conducted interviews of 120 consecutive ileal pouch-anal anastomosis patients with a preoperative diagnosis of ulcerative colitis were reviewed, with a mean follow-up of 54 months. All colectomy specimens were reviewed by a single pathologist. Any changes in histologic diagnosis from ulcerative colitis to indeterminate colitis or Crohn's disease, frequency of postoperative complications, pouch function, and long-term postoperative medication usage were recorded.
Results: Although postoperative fistulas were more common in indeterminate colitis than ulcerative colitis (26 vs. 10 percent; P = 0.02, chi-squared), no indeterminate colitis patient required a permanent ileostomy as compared with six ulcerative colitis patients. Long-term functional results were similar. Overall, two-thirds of patients developed pouchitis. Ulcerative colitis and Crohn's disease patients were more likely to have had >3 episodes of pouchitis (58 and 72 percent) compared with indeterminate colitis patients (29 percent; P = 0.006, chi-squared). A greater number of Crohn's disease patients required maintenance oral antibiotic therapy (64 percent) to achieve satisfactory functional results compared with both indeterminate colitis and ulcerative colitis patients (20 and 28 percent; P = 0.014, chi-squared).
Conclusions: Although ileal pouch-anal anastomosis patients with indeterminate colitis have more postoperative fistulas, long-term function is equal to that of ulcerative colitis patients and better than Crohn's disease patients. Ileal pouch-anal anastomosis should be offered to patients with indeterminate colitis and those with severe colitis in whom clear differentiation between indeterminate colitis and ulcerative colitis cannot be made.