Risk factors and treatment of rectal stenosis after transanal endoscopic microsurgery.

[AIM] Rectal stenosis is a relatively rare complication after transanal endoscopic microsurgery (TEM). This study aims to identify the predictive parameters for stenosis and the application of TEM in the treatment.

[METHOD] The clinical data of patients who underwent TEM for rectal adenoma and early cancer from 2008 to 2019 were retrospectively reviewed. We compared the clinicopathological characteristics of patients with stenosis and those without stenosis and analysed the risk factors for stenosis. Treatment outcomes of stenosis with TEM were evaluated.

[RESULTS] A total of 230 patients were enrolled in this study. Overall, the postoperative complication rate was 11.7% (27/230), including eight (3.5%) patients with stenosis. Patients with stenosis exhibited a higher rate of tumour showing a laterally spreading morphology (P = 0.048), a wider circumferential extent of mucosal defect (P < 0.001), a shorter distance of the tumour from the anal verge (P = 0.001) and a wider longitudinal extent of mucosal defect (P = 0.027). A circumferential extent of mucosal defect >3/4 (OR 94.945, 95% CI 3.611-2496.41, P = 0.006) was identified as the only independent risk factor for stenosis. The four patients with both stenosis and clinical symptoms were treated by incising the stenosis ring using the TEM platform; the stenosis was cured, and symptoms disappeared after one to four courses of treatment.

[CONCLUSIONS] Circumferential extent of mucosal defect ≥3/4 was an independent risk factor for stenosis in treating rectal adenoma and early cancer with TEM. Incision of the stenosis ring using the TEM platform is an effective strategy for treating stenosis.