Results of total mesorectal excision and transanal endoscopic microsurgery for rectal adenocarcinoma with submucosal invasion

Abstract

To analyze early and long-term outcomes after total mesorectal excision (TME) and transanal endoscopic microsurgery (TEM) in patients with T1 rectal cancer. A retrospective non-randomized comparative study included 2 groups of patients: group 1 - total mesorectal excision, group 2 - transanal endoscopic microsurgery. In the second group, total mesorectal excision was proposed for patients with tumor invasion depth pT1sm3 and/or lymphovascular invasion and/or low differentiation. If total mesorectal excision was performed as a salvage surgery, the patient was excluded from further analysis. There were 156 patients with rectal adenocarcinoma pT1 between October 2011 and August 2019 (102 cases - TEM, 54 cases - TME). We excluded 10 patients from the TEM group due to salvage surgery. Duration of TEM was 40.0 (34; 50) min, TME - 139 (120; 180) min (p=0.00001). Postoperative hospital-stay was also significantly less in the TEM group (7 (6; 9) vs. 10 (7; 11) days, p=0.00001). Six (6.5%) patients in the TEM group and 1 (1.8%) patient in the TME group developed a local recurrence in pelvic cavity (p=0.1). There were no distant metastases. Disease-free 3-year survival was 92% after TEM and 96% after TME (p=0.058). Transanal endoscopic microsurgery is a relatively safe alternative to total mesorectal excision for early rectal cancer.