ETAMIS: Endoscopic visualization for transanal minimally invasive surgery

Background: Transanal endoscopic microsurgical (TEM) resection is associated with improved outcomes compared to transanal excision of rectal lesions. However, TEM equipment requires additional operative setup time, and tumor location dictates patient positioning. In 2010, Drs. Attallah, Albert, and Larach developed an alternative technique, transanal minimally invasive surgery (TAMIS). Herein, we describe our novel experience using endoscopic visualization to perform TAMIS (eTAMIS) to remove a large rectal polyp. Methods: This is a technical note describing a new surgical technique, eTAMIS. The technique is performed with the Gelpoint Path TAMIS platform (Applied Medical, Rancho Santa Margarita, CA) and a standard single-channel endoscope for visualization. Patient demographics, operative data, and pathologic data were recorded. Results: eTAMIS was initially performed in a 50-year-old woman with an endoscopically defiant rectal mass discovered on routine screening colonoscopy. The lesion was a tubulovillous adenoma, 10 cm from the anal verge, anterior, and occupied 15-20 % of the circumference. The rectal mass was removed by eTAMIS. The operative time was 101 minutes, and the patient was discharged within 24 h without event. Final pathology revealed a focus of well-differentiated rectal adenocarcinoma with focal invasion into the muscularis mucosa (Haggit level 0, pTis) arising in the head of a pedunculated tubulovillous adenoma. At 1-year follow-up endoscopy, the patient had no evidence of recurrent mass or polyp. Conclusions: This is the first technical report describing endoscopic visualization for TAMIS. Endoscopic visualization facilitates intraluminal articulation and lens cleaning while minimizing extraluminal instrument collisions. eTAMIS is a practical and logical evolution of the visual approach to natural orifice transluminal endoscopic surgery and laparoendoscopic surgery.