Key factors influencing bowel function after ileal W-pouch and anastomosis: A spectral analysis of W-pouch motor activity

Restorative proctocolectomy with ileal pouch anal anastomosis (IPAA) has be come the standard surgical procedure for ulcerative colitis (UC). The purpo se of this study was to determine which factors are important to achieve go od anal continence after IPAA in terms of the motor activity and pressure-v olume relationship. A total of 17 patients with UC who underwent IPAA were evaluated. The internal ileal pouch pressure was transanally measured with and without volume-loading of the pouch which induces the urge to evacuate. The maximum tolerable volume (MTV), first urge volume (FUV), and ileal pou ch compliance were calculated and the internal ileal pouch pressure records were subjected to spectral analysis for intensive evaluation of the intral uminal pressure waves. The FUV, correlation of the compliance of the FUV wi th MTV, and the remaining volume up to the MTV (RVMTV) were analyzed. Compl iance of the FUV was significantly correlated with the RVMTV (r = 0.736, P < 0.01). The frequency of the phasic waves in the pouch decreased with leng th of follow up, reflecting improved function (r = -0.588, P < 0.05). The f indings of this intensive analysis of manometric measurement indicate that the key factors in postoperative pouch function are RVMTV and the frequency of phasic waves in the W-pouch.