Transanal endoscopic microsurgery excision - Is anorectal function compromised?

PURPOSE: Transanal endoscopic microsurgery is a new technique that has not yet found its place in routine practice. The procedure results in dilation of the anal sphincter with a large-diameter operating sigmoidoscope, sometimes for a prolonged period. The purpose of the present study was to assess the effect of transanal endoscopic microsurgery on anorectal function. METHODS: Eighteen consecutive patients undergoing transanal endoscopic microsurgery excision of rectal tumors, of whom 13 were available for evaluation,,ere included. Continence was scored by a numeric scale before surgery and at three and six weeks after surgery. Anorectal physiology studies were performed preoperatively and six weeks postoperatively with manometry, pudendal nerve motor terminal latency, anal mucosal electrosensitivity, rectal balloon volume studies, and endoanal ultrasound. RESULTS: There was a significant reduction in mean anal resting pressure (104 +/- 32 cm H2O before surgery, 73 +/- 30 cm H2O after surgery; P = 0.0009). There was no significant change in squeeze or cough pressure, pudendal nerve terminal motor latency, anal mucosal electrosensitivity, or rectal balloon study volumes. Fall in resting pressure was significantly correlated with length of operating time (r(2) = 0.39, P = 0.047). There was no significant change in mean continence score after surgery. CONCLUSION: Transanal endoscopic microsurgery results in a reduction in internal sphincter tone. This did not affect continence in a short-term study.