Submucosal resection via a transanal approach for treatment of epithelial rectal tumors – a multicenter study

Objective To report complications and long‐term outcomes after submucosal resections of benign and malignant epithelial rectal masses. Study design Retrospective multicentric study. Sample population Medical records of 93 dogs at 7 referral hospitals. Methods Records were reviewed for surgical time, diagnosis, margins, complications, and recurrences. Survival of dogs was evaluated based on tumor types, categorized as benign, carcinoma in situ, and carcinoma. The Kaplan‐Meier survival curve and Cox proportional hazards analysis were used to determine the association of a range of variables with recurrence and survival time. Results Duration of follow up was 708 days (range, 25‐4383). Twenty‐seven dogs (29%) developed complications. Recurrence was identified in 20/93 (21%), with 12/20 recurrent masses treated with repeat submucosal resection. Median survival was not reached in any group. The 1‐,2‐, 5‐year survival rates for carcinomas were 95%, 89%, and 73% respectively. However, overall survival was longer for benign tumors than carcinomas (P = .001). Recurrence was more likely when complications (P = .032) or incomplete margins (P = .023) were present. Recurrence was associated with an increased risk of death (P = .046). Conclusion Submucosal resection of both benign and malignant rectal masses was associated with a low rate of severe complications and prolonged survival in the 93 dogs described here. Clinical significance Submucosal resection is a suitable technique for resection of selected rectal masses.