Efficacy of Endoscopic Mucosal Resection after Circumferential Mucosal Incision of Small Rectal Carcinoid Tumors

Abstract

Background: Endoscopic mucosal resection is widely used for treating rectal carcinoid tumors. However, histopathology has revealed that submucosal invasion leads to incomplete resection. Endoscopic submucosal dissection, which enables en bloc resection regardless of tumor size, has recently been reported to be useful in treating rectal carcinoid tumors; however, it is not widely used as standard treatment because of technical demands. We use endoscopic mucosal resection after circumferential mucosal incision, which is performed after mucosal resection around the lesion to treat rectal carcinoid tumors. To our knowledge, this is the first report of endoscopic mucosal resection after circumferential mucosal incision for colorectal carcinoid tumors. Objective: To evaluate the efficacy of this method. Design: Single-center retrospective clinical trial. Setting: Shiga University of Medical Science. Patients: We retrospectively studied 6 patients with rectal carcinoid tumors ≤ 10 mm treated by endoscopic mucosal resection after circumferential mucosal incision, between August 2010 and December 2012 at Shiga University of Medical Science. Interventions: Endoscopic mucosal resection after circumferential mucosal incision. Main outcome measures: En bloc resection rate, procedure time, complications. Results: The mean tumor size was 6.8 ± 1.8 mm (range 4-9 mm). The mean procedure time was 19.7 ± 5.1 min (range, 12-26 min). The en bloc and complete resection rates were 100% (6/6) and 50% (3/6), respectively. All tumor depths were contained in the submucosa, and clear resection margins were pathologically confirmed in all 6 patients. Three patients with lymphovascular involvement required additional radical surgical therapy. There were no complications or distant/local recurrence during the follow-up period (median, 4 months; range 4-26 months). Limitations: This study was limited by its retrospective nature. Conclusions: Endoscopic mucosal resection after circumferential mucosal incision was effective for treating ≤ 10-mm-diameter rectal carcinoid tumors.