Possible role of the autonomic nervous system in sphincter impairment after restorative proctocolectomy

Peroperative manometry was performed in 12 patients operated on with endoanal proctectomy and a hand-sewn pouch-anal anastomosis and in 12 in whom proctectomy was performed entirely from above, with the ileal pouch stapled to the top of the anal canal. Results from both groups showed that division of the superior rectal artery reduced the median (95 per cent confidence interval (c.i.)) resting anal pressure from 77.5 (69.9-83.3) mmHg to 64.5 (55.2-70.0) mmHg (P < 0.01). Complete rectal mobilization to the pelvic floor decreased resting pressure by an additional 22 per cent, to a median of 50.0 (95 per cent c.i. 40.1-53.5) mmHg (P < 0.01). After completion of anastomosis, irrespective of the operative technique used, a further decline in median pressure to 35.0 (95 per cent c.i. 26.0-47.7) mmHg could be demonstrated (P < 0.05). This study indicates that anal sphincter pressure is reduced to a similar extent after hand-sewn and stapled anastomoses. Injury to the autonomic nervous supply to the anal sphincter mechanism might be the major cause for this reduction.