Preoperative chemoradiotherapy affects postoperative outcomes and functional results in patients treated with transanal endoscopic microsurgery for rectal neoplasms

Background: The aim of this study was to quantify the incidence of short-term postoperative complications and functional disorders at 1 year from transanal endoscopic microsurgery (TEM) for rectal neoplasms, to compare patients treated with TEM alone and with TEM after preoperative chemoradiotherapy (CRT) and to analyse factors influencing postoperative morbidity and functional outcomes. Methods: A retrospective study was conducted on all patients treated with TEM for rectal neoplasms at our institution in January 2000–December 2017. Data from a prospectively maintained database were retrospectively analysed. Patients were divided into two groups: adenoma or early rectal cancer (no CRT group) and locally advanced extraperitoneal rectal cancer with major or complete clinical response after preoperative CRT (CRT group). Short-term postoperative mortality and morbidity and the functional results at 1 year were recorded. The two groups were compared, and a statistical analysis of factors influencing postoperative morbidity and functional outcomes was performed. Functional outcome was also evaluated with the low anterior resection syndrome (LARS) score (0–20 no LARS, 21–29 minor LARS and 30–42 major LARS). Results: One hundred and thirteen patients (71 males, 42 females, median age 64 years [range 41–80 years]) were included in the study (46 in the CRT group). The overall postoperative complication rate was 23.0%, lower in the noCRT group (p < 0.001), but only 2.7% were grade ≥ 3. The most frequent complication was suture dehiscence (17.6%), which occurred less frequently in the noCRT group (p < 0.001). At 1 year from TEM, the most frequent symptoms was urgency (11.9%, without significant differences between the CRT group and the noCRT group); the noCRT group experienced a lower rate of soiling than the CRT group (0% vs. 7.7%; p: 0.027). The incidence of LARS was evaluated in 47 patients from May 2012 on and was 21.3% occurring less frequently in the noCRT group (10% vs. 41.2%; p: 0.012). Only 6.4% of the patients evaluated experienced major LARS. In multivariate analysis, preoperative CRT significantly worsened postoperative morbidity and functional outcomes. Conclusions: TEM is a safe procedure associated with only low risk of severe postoperative complications and major LARS. Preoperative CRT seems to increase the rate of postoperative morbidity after TEM and led to worse functional outcomes at 1 year after surgery.