Anal function after endoluminal locoregional resection by transanal endoscopic microsurgery and radiotherapy for rectal cancer.

Abstract

In patients with rectal cancer, surgery and chemoradiotherapy may affect anal sphincter function. Few studies have evaluated anorectal function after neoadjuvant chemoradiotherapy (n-CRT) and/or transanal endoscopic microsurgery (TEM). The aim of this study was to evaluate the effects of n-CRT and TEM on anorectal function. Thirty-seven patients with rectal cancer underwent anorectal manometry and Wexner scoring for faecal incontinence at baseline, after n-CRT (cT2-T3N0 cancer) and at 4 and 12 months after surgery. Water-perfused manometry measured anal tone at rest and during squeezing, rectal sensitivity and compliance. Twenty-seven and 10 patients, respectively, underwent TEM without (Group A) or with n-CRT (Group B). In Group A, anal resting pressure decreased from 68 ± 23 to 54 ± 26 mmHg at 4 months (P = 0.04) and improved 12 months after surgery (60 ± 30 mmHg). The Wexner score showed a significant increase in gas incontinence (59%), soiling (44%) and urgency (37%) rates at 4 months, followed by clinical improvement at 1 year (41%, 26% and 18%, respectively). In group B, anal resting pressure decreased from 65 ± 23 to 50 ± 18 mmHg at 4 months but remained stable at 12 months (44 ± 11 mmHg, P = 0.02 vs preoperative values - no significant difference compared with evaluation at 4 months). Gas incontinence, soiling and urgency were observed in 50%, 50%, 25% and in 38%, 12% and 12% of cases, respectively, 4 and 12 months after treatment. TEM does not significantly affect anal function. Instead, n-CRT does affect anal function but without causing major anal incontinence.