Transanal endoscopic microsurgery: a prospective evaluation of functional results

Local excision is a commonly used technique for many benign and selected malignant rectal lesions. Compared with radical resection, it is associated with decreased morbidity and mortality and improved functional results. Transanal endoscopic microsurgery is gaining popularity because of its ability to access the upper rectum and its precise excision techniques. However, the functional consequences have not been extensively studied.

All patients subject to transanal endoscopic microsurgery prospectively completed preoperative and postoperative (6 weeks) surveys including Fecal Incontinence Severity Index, Fecal Incontinence Quality of Life, number of bowel movements per 24 hours, and ability to defer defecation. All data were collected by an independent research coordinator. Demographics, operative details, and complications were also collected prospectively.

Forty-one patients successfully underwent transanal endoscopic microsurgery. Fourteen patients had malignant lesions and 27 had benign lesions. Two patients required abdominoperineal resection based on postoperative diagnosis. Thirty-nine patients have completed follow-up and were available for review. Mean length of surgery was 64 minutes and length of stay was 0.9 day. Average distance from the anal verge to the proximal tumor margin was 11.4 cm and mean tumor size was 8.75 cm. Twenty-three patients had full-thickness excision with primary closure, ten had full-thickness excision without closure, five had partial-thickness excision, one had an excision of a mass in the anovaginal septum, and one had resection of an anastomotic stricture. Each patient served as his own control. Preoperative and postoperative number of bowel movements per 24 hours were 2.0 and 2.0, respectively. Preoperative vs. postoperative urgency (ability to defer defecation less than ten minutes) was unchanged. Mean preoperative and postoperative Fecal Incontinence Severity Index scores were 2.4 (range, 0-43) and 2.4 (range, 0-17), respectively (higher scores indicate worse function). In addition, the four parameters measured by the Fecal Incontinence Quality of Life survey were unchanged when preoperative and postoperative data were compared.

Transanal endoscopic microsurgery allows precise excision of tumors throughout the rectum. However, it involves inserting a 40-mm-diameter operating proctoscope and significant operating times. Despite this, as measured by ability to defer defecation, number of bowel movements per 24 hours, Fecal Incontinence Severity Index, and Fecal Incontinence Quality of Life survey, transanal endoscopic microsurgery has no detrimental affect on fecal continence.