Anorectal sphincter function and rectal barostat study in patients following transanal endoscopic microsurgery

Abstract

Background and aims: This study evaluated the effect of transanal endoscopic microsurgery (TEM) on anorectal sphincter functions and determined the risk factors for anorectal dysfunctions (including incontinence). Patients and methods: A study group of 33 patients with small, mobile rectal tumors (adenoma and carcinoma) located up to 12 cm from the anal verge underwent anorectal motility studies (using pull-through anorectal manometry and rectal barostat) and endoanal ultrasound prior to surgery and 3 weeks and 6 months after TEM; controls were 20 healthy volunteers. Results: Resting and squeeze anal pressures were reduced 3 weeks after TEM. Resting anal pressure remained reduced 6 months after surgery; the changes were related to low preoperative levels and to the internal anal sphincter defects rather than to the procedure duration or the type of surgery. High-pressure zone length and vector volume were decreased 3 weeks after TEM and restored 6 months later. Rectoanal inhibitory reflex, reflex sphincter contraction, rectoanal pressure gradients, threshold and maximal tolerable volume of rectal sensitivity, and compliance were significantly changed 3 weeks after TEM; only rectal wall compliance remained low at 6 months. The rectoanal inhibitory reflex, reflex sphincter contraction, rectal sensitivity, and compliance were related to the extent and type of excision (partial or full thickness). Anal ultrasound revealed internal anal sphincter defects in 29% of patients studied 3 weeks after TEM. Only 76% of patients were fully continent. Disturbed anorectal function (including partial fecal incontinence) was observed in up to 50% of patients at 3 weeks. Partial and moderate anorectal dysfunction was found in 21% patients 6 months after surgery. The main risk factors of anorectal dysfunctions following TEM included: postoperative internal anal sphincter defects, low preoperative resting anal pressure, disturbed rectoanal coordination, extent (>50% of wall circumference) and the depth (full thickness) of tumor excision. Conclusion: TEM has a relevant but temporary effect on anorectal motility. As a result of TEM procedures 21% of the patients had disturbed anorectal functions, mostly due to the extent or depth of tumor excision (influencing rectal compliance and rectoanal coordination), and to the sphincter defects lowering resting anal pressure. Preoperative anorectal motility studies and anal ultrasound allow the identification of patients with the risk of postoperative anorectal dysfunctions.

Transanal endoscopic surgery: patient selection and perspectives

“…Specifically, there are several studies that have looked at functional outcomes after TEM, given that it entails a large, rigid rectoscope inserted through the anus for a prolonged period of time. In a small prospective study, Herman et al 56 assessed the risk factors for anorectal dysfunction after TES and found that ~50% of their patients had disturbances in anorectal function at 3 weeks, with partial-to-moderate dysfunction in 21% at 6 months after TES. The most common risk factors were preoperative disturbances in anorectal function, pre-or postoperative abnormalities on endoanal ultrasound, and the extent of excision of the lesion (lesions that were >50% of the circumference and full-thickness excisions).…”

“…Nevertheless, functional issues were temporary and appeared worse in patients with the aforementioned risk factors. 56 . Jin et al 57 assessed 37 patients who underwent TEM for rectal tumors, including adenomas and carcinomas.…”

Transanal total mesorectal excision: a pure NOTES approach for selected patients

“…The studies report contradictory results. Some demonstrated a temporary effect on anorectal function [36,37], but others reported preserved function after TEM [38][39][40]. In order to evaluate the functional outcomes, we used two scales (FIQoLS and Wexner score).…”

Transanal Endoscopic Microsurgery - State of the Art

“…Regarding the effect of a prolonged anal dilatation with the 40 mm diameter TEM operative rectoscope, manometric studies indicate a decrease in anal sphincter tone ranging from 25% to 37% of pre-operative sphincter pressure, with recovery to clinical continence within 6-16 weeks (Herman et al, 2001). We observed postoperative transitory grade II incontinence in 65 of the 100 patients, with full recovery in 98% of the cases after 12 weeks.…”