Functional changes associated with short and long lateral ileal reservoirs in a canine model

Colectomy and endorectal ileal pull-through with ileal reservoir (PTR) have become a standard operative procedure for severe ulcerative colitis and familial polyposis coli. Satisfactory results have been reported with a number of different reservoir designs; however, the optimal reservoir size and configuration remain controversial. Two groups of five dogs each, undergoing colectomy and PTR with construction of either 5-cm-long or 18-cm-long lateral ileal reservoirs, were studied to compare defecatory patterns, intestinal transit, and reservoir emptying. Three months postoperatively, dogs with long ileal reservoirs demonstrated a higher stool frequency and made more unsuccessful attempts at defecation. Evacuation of viscous polyethylene glycol solution from the long reservoirs was prolonged during the first hour compared with short reservoirs. Two of the five long reservoirs showed mucosal ulcerations on postmortem examination, whereas none were present in any of the short pouches. Increases in stool water content and subsequent reduction of urine volumes as well as a prolongation in oroanal transit times occurred to a similar degree in both groups. It is concluded that short lateral isoperistaltic reservoirs empty more effectively than do long reservoirs.