Study of anorectal function after transanal endoscopic surgery

Aim: To evaluate the impact of Transanal Endoscopic Microsurgery (TEM) on anorectal function, using clinical and manometric assessments. To identify subgroups likely to develop incontinence after TEM, by stratifying the sample. Method: Descriptive, prospective study. Between December 2004 and May 2011, 222 patients were operated on at our hospital, of whom 21 were excluded from the study. Patients underwent anal manometry and answered a clinical incontinence questionnaire (the Wexner scale) prior to surgery, one month post-surgery, and then at four months post-surgery. Results: There were no statistically significant differences between preoperative Wexner questionnaire scores and values at one month and four months post-surgery. Preoperative baseline pressure (BP) values were 64mmHg±26.18, falling to 44.26mmHg±20.11at one month and to 48.86mmHg±21.14at four months. Voluntary Contraction Pressure (VCP) reached preoperative values of 200.49mmHg±88.85, falling to 169.5mmHg±84.95 and to 173.6±79at four months. The differences in BP and VCP were statistically significant. The sample was stratified in order to identify subsets susceptible to incontinence after surgery, but no at-risk subgroups were found. Multivariate analysis did not detect any predictors of incontinence. Conclusion: The sustained, controlled anal dilatation produced with TEM caused statistically significant decreases in VCP and BP one month and four months after surgery. However, the Wexner questionnaire scores did not show any association with clinical incontinence. No predictors of postoperative incontinence were observed. We conclude that TEM is a safe technique and does not affect continence.