EFFECT OF ANORECTAL EVERSION DURING RESTORATIVE PROCTOCOLECTOMY ON ANAL-SPHINCTER FUNCTION

Twenty-six patients underwent restorative proctocolectomy with end-to-end ileal pouch-anal anastomosis, without resection of the anal mucosa, by the eversion technique. Before surgery patients underwent tests of anorectal function. These were repeated a median of 8 (range 3-21) months after operation. The median (range) maximum resting anal pressure was 93 (36-149) cmH2O before and 71 (40-131) cmH2O after operation (P = 0.002). The median (range) maximum squeeze pressure before operation was 136 (73-280) cmH2O; it was 149 (69-290) cmH2O afterwards (P not significant). The median (range) length of the anal sphincter was 3.5 (2.5-4.5) cm before and 3.5 (2.0-4.5) cm after operation (P not significant). Thresholds for sensation in the upper, middle and lower thirds of the anal canal before and after operation were, respectively, 8-7 versus 8.7, 6-8 versus 7.4 and 4.2 versus 6.2 mA (P not significant). All 26 patients were continent, although one experienced minor leakage. Function of the anal sphincter is not significantly impaired by eversion of the rectum and anus during restorative proctocolectomy.