Replacement of colonic mucosa by free and pedicled grafts of ileal mucosa in the dog.
Mucosal proctectomy and ileo-anal anastomosis is a relatively new operation in the treatment of patients with ulcerative colitis. The diseased rectal mucosa is removed and gastrointestinal continuity is restored by replacing it with full thickness ileum. The main disadvantage of the operation is frequency of bowel action and in an attempt to resolve this problem the feasibility of replacing colonic mucosa with grafts of ileal mucosa alone was explored. Both free and pedicled autografts of ileal mucosa were grafted into isolated loops of canine colon, denuded of mucosa and submucosa. All the free grafts failed to survive (eight dogs) and histological examinations confirmed graft rejection. All the pedicled grafts (seven dogs) were successful and retained the histological characteristics of normal ileum. Net movement and bidirectional transport of water and electrolytes were measured in six dogs with pedicled grafts and in four control dogs with intact full thickness ileal loops. Whereas the control loops absorbed water and electrolytes, the grafted loops secreted water, sodium, and potassium and absorbed significantly less chloride. The mucosa of the colon can thus be replaced successfully by grafts of ileal mucosa provided that an intact blood supply is preserved. The capacity and sensation of the neorectum after mucosal proctectomy may be improved if mucosal grafts were used instead of full thickness ileum. Before this procedure could be used in man, however, practical problems would have to be overcome and the secretion of water and electrolytes corrected.
D000818:Animals; D003106:Colon / Q000601:surgery*; D004285:Dogs; D007082:Ileum / Q000378:metabolism / Q000637:transplantation*; D007408:Intestinal Absorption; D007413:Intestinal Mucosa / Q000378:metabolism / Q000601:surgery / Q000637:transplantation*; D010477:Perfusion; D013524:Surgical Flaps; D014882:Water-Electrolyte Balance