A case report of a large rectal tumor close to anal verge successfully resected by one piece by the submucosal dessection EMR using a flex-knife

Abstract

The patient was 49-year-old male without any symptom. Because of positive fecal occult blood reaction, total colonoscopy was performed. In that examination, there was a granular LST which measured 4 cm in daimeter close to the anal verge. Although there was gross nodular lesion, 2.8 cm in diameter, in the tumor, EUS examination might suggest, including that region, the whole tumor was intramucosal lesion. So we decided to perform the submucosal dissection EMR for that lesion using a flex-knife, because resection by one piece was preferable to evaluate whether sm invation existed or not strictly and the complete resection of the distal parts of the tumor, near the anal verge was considered to be impossible using the conventional piece-meal EMR.
To make procedure safer and easier, we used some special equipment like a flex-knife, an endoscopy with water jet system and sodium hyaluronate as an injection solution at the submucosal layer. The course of EMR was done without any complication. The tumor was resected by single-step and able to have accurate evaluation. Pathological examination showed tubular adenoma with moderate to severe atypia. Both lateral and vertical margin was negative for adenoma and there was no conponent of carcinoma despite that size.
In conclusion, Single-step EMR makes it possible to gain accurate histologic evaluation and seems to be desirable whenever possible.