Transanal total mesorectal excision (taTME) for rectal cancer: a training pathway

Background: With increasing interest in natural orifice surgery, there has been a dramatic evolution of transanal and endoluminal surgical techniques. These techniques began with transanal endoluminal surgical removal of rectal masses and have progressed to transanal radical proctectomy for rectal cancer. The first transanal total mesorectal excision (taTME) was performed in 2009 by Sylla, Rattner, Delgado, and Lacy. The improved visibility and working space associated with the taTME technique is intriguing. This video manuscript outlines the training pathway followed by pioneers in the taTME technique, the process of implementation into clinical practice, and initial case report. Methods: A double board-certified colorectal surgeon with expertise in rectal cancer, minimally invasive total mesorectal excision, transanal endoscopic surgery (TES), and intersphincteric dissection, underwent taTME training in male cadaver models. Institutional review board (IRB) approval for a phase I clinical trial was achieved. The entire operative team including surgeons, nurses, and operative staff underwent taTME cadaver training the day prior to the first clinical case. The case was proctored by an expert in taTME. Results: A 66-year-old male with uT3N1M0 rectal cancer located in the posterior distal rectum, underwent taTME with laparoscopic abdominal assistance, hand sewn coloanal anastomosis, and diverting loop ileostomy. The majority of the TME was performed transanally with laparoscopic assistance for exposure, splenic flexure mobilization, and high ligation of the vascular pedicles. Operative time was 359 min. There were no intraoperative complications. Pathology revealed a ypT2N1 moderately differentiated invasive adenocarcinoma, grade I TME, 1 cm circumferential radial margin, and 2/13 positive lymph nodes. Conclusion: Implementation of taTME into practice can be achieved by surgeons with expertise in minimally invasive TME, TES, pre-clinical taTME training in cadavers, case observation, proctoring, and ongoing mentorship. IRB peer review process and participation in a clinical registry are additional measures that should be employed.