Long-term outcomes of open versus closed rectal defect after transanal endoscopic microscopic surgery

Aim Management of the rectal defect after transanal endoscopic microsurgery (TEM) is a matter of debate. Data are lacking on long term outcomes and continence of patients with open or closed rectal defect. We sought to analyse these in a retrospective cohort study. Methods Patients undergoing TEM via the Specialist Early Rectal Cancer (SERC) MDT between 2012 and 2019 were included from a prospectively maintained database. These were divided into two groups - open and closed, based on management of rectal defect. Patient demographics and outcomes, including pre- and postoperative oncological staging, morbidity, mortality, length of stay and faecal incontinence severity score (FISI) scores were assessed. Results A total of 170 matched patients were included (70-open, 100-closed rectal defects). Short-term complications (bleeding, infection, urinary retention and infection, length of stay and pain) were 18.8% with no significant difference between the two groups (22% vs. 16%). Most of the defects were well healed upon endoscopic follow-up; more unhealed/sinus formation was noticed in the open group (p = 0.01); more strictures were encountered in the closed group (p = 0.04). Comparing the open and closed defect groups, there was no difference in the functional outcome of patients in those who developed sinus (p = 0.87) or stricture (p = 0.79) but a significant difference in post-TEMS FISI scores in those with healed scar, with those in closed rectal defect group with worsening function (p = 0.02). Conclusion There are pros and cons associated with both rectal defect management approaches. Long-term complications should be expected and actively followed up. Patients should be thoroughly counselled about these and possible deterioration in continence post-TEM.