Comparison of triplicated (S) and quadruplicated (W) pelvic ileal reservoirs. Studies on manovolumetry, fecal bacteriology, fecal volatile fatty acids, mucosal morphology, and functional results.

Capacity and compliance, efficiency of evacuation, fecal bacteriology, fecal volatile fatty acids, mucosal morphology, and functional outcome were studied in 20 patients with triplicated (S) and 20 patients with quadruplicated (W) reservoirs after ileal pouch-anal anastomosis. Compared with patients with S reservoirs, patients with W reservoirs were found to have greater efficiency of evacuation of radiolabeled synthetic stool [97% (91%-98%) vs. 74% (62%-89%); P less than 0.05], and their reservoirs were more capacious [350 mL (320-400 mL) vs. 228 mL (175-290 mL); P less than 0.01] and compliant [16.0 mL/cm H2O (13.8-19.0 mL/cm H2O) vs. 12.3 mL/cm H2O (7.4-14.6 mL/cm H2O); P less than 0.01]. Effluent from S reservoirs contained significantly greater numbers of bacteroides (P less than 0.05) and concentrations of acetic and propionic acids (P less than 0.05) than effluent from W reservoirs. The degree of mucosal inflammation and villous atrophy in each design of reservoir was not significantly different. The ratio of anaerobes to aerobes in pouch effluent was significantly correlated with the degree of mucosal inflammation (rs = 0.433; P = 0.035). Fecal volatile fatty acids were significantly correlated with the percentage of stool retained after defecation and degree of mucosal inflammation. The frequency of bowel action was significantly less in patients with W reservoirs than in patients with S reservoirs [3.5/day (3-4/day) vs. 6.0/day (4-7/day); P less than 0.01]. The results indicate marked differences between these two ileal reservoir designs.