Transanal endoscopic microsurgery in the treatment of rectal carcinoid tumor

This study aimed to assess the efficacy of transanal endoscopic microsurgery (TEM) in the treatment of rectal carcinoid tumor.

Between May 1994 and April 2006, 27 patients with rectal carcinoid tumor underwent TEM, and their clinical data were reviewed retrospectively.

The TEM procedure was performed as a primary excision (n = 14) or as completion surgery after incomplete resection by endoscopic polypectomy (n = 13). The average size of a primary tumor was 9.1 mm (range, 5-13 mm), and the average distance of the tumor from the anal verge was 8.5 cm. The mean duration of the operation was 51.6 min. Minor morbidities, transient soilage, and mild dehiscence occurred in two cases (7.4%). Histopathologically, all tumors were localized within the submucosal layer showing typical histology without lymphatic or vessel infiltration, and both deep and lateral surgical margins were completely free of tumors. Among 13 cases of completion surgery after endoscopic polypectomy, 4 (30.8%) were histologically shown to have a residual tumor in the specimens obtained by TEM. No additional radical surgery was performed. The mean follow-up period was 70.6 months, and no recurrence was noted.

The results indicate that TEM is a safe, minimally invasive procedure for the local excision of rectal carcinoid tumors, particularly those in the proximal rectum. Furthermore, for patients with microscopic positive margins after endoscopic polypectomy, TEM can be an effective surgical option for complete removal of residual tumors.