Comparison of clinical and compliance characteristics between S and W ileal reservoirs

Ileal reservoir reconstruction has become the preferred technique for restoration of bowel continuity in most patients after colectomy for ulcerative colitis or familial adenomatous polyposis. We analyzed and compared compliance characteristics of triple-limb S and quadruple-limb W reservoir designs and correlated changes in capacity with overall function. Fifty patients underwent colectomy and reservoir construction for ulcerative colitis or familial adenomatous polyposis; 12 received S reservoirs and 38 received W reservoirs. Reservoir compliance was assessed by means of a specially designed condom catheter that continuously recorded intrareservoir pressure and changes in perfused volume. During reservoir infusion, volumes and pressures at initial fullness, normal sensation of evacuation, and maximum tolerated volume were noted. Studies were performed at 2 and 12 months after ileostomy takedown. An increase in normal evacuation volume from 218 +/- 9 mL to 310 +/- 12 mL between 2 and 12 months (p less than or equal to 0.05) was observed in patients with W reservoirs. Similar changes were recorded in S reservoir reconstructions (201 +/- 14 mL to 291 +/- 22 mL, p less than or equal to 0.05). No significant differences were observed in the mean pressure at normal evacuation volume between the S and W groups at 2 and 12 months. The 24-hour stool frequency decreased an average of 3 per day for both reservoir designs between the 2- and 12-month study period (p less than or equal to 0.05). This frequency was most directly predicted by normal evacuation volume (r = 0.90 for W and 0.88 for S). The decrease in stool frequency correlated with increased reservoir compliance, as shown by larger tolerated volumes at similar pressures. Restorative proctocolectomies with S or modified W reservoirs are both acceptable alternatives and demonstrate similar compliance characteristics and functional results.