Transanal minimally invasive surgery (TAMIS) for local excision of benign neoplasms and early-stage rectal cancer: efficacy and outcomes in the first 50 patients.

Background: Since its inception in 2009, transanal minimally invasive surgery has been used increasingly in the United States and internationally as an alternative to local excision and transanal endoscopic microsurgery for local excision of neoplasms in the distal and mid rectum. Despite its increasing acceptance, the clinical benefits of transanal minimally invasive surgery have not yet been validated.

Objective: The aim of this study is to assess the adequacy of transanal minimally invasive surgery for the local excision of benign and malignant lesions of the rectum.

Design: This is a retrospective analysis of consecutive patients who underwent transanal minimally invasive surgery for local excision of neoplasms at a single institution.

Settings: The study was conducted by a single group of colorectal surgeons at a tertiary referral center.

Patients: Eligible patients with early-stage rectal cancer and benign neoplasms were offered transanal minimally invasive surgery as a means for local excision. Data from these patients were collected prospectively in a registry.

Main Outcome Measures: The primary outcome measures included the feasibility of transanal minimally invasive surgery for local excision, resection quality, and short-term clinical results.

Results: : Fifty patients underwent transanal minimally invasive surgery between July 2009 and December 2011. Twenty-five benign neoplasms, 23 malignant lesions, and 2 neuroendocrine tumors were excised. All lesions were excised using transanal minimally invasive surgery without conversion to an alternate transanal platform. The average length of stay was 0.6 days (range, 0-6), and 68% of patients were discharged on the day of surgery. The average distance from the anal verge was 8.1 cm (range, 3-14 cm). All lesions were excised completely with only 2 fragmented specimens (4%). All specimens were removed with grossly negative margins, although 3 (6%) were found to have microscopically positive margins on final pathology. There were 2 recurrences (4%) at 6- and 18-month follow-up. Early complications occurred in 3 patients (6%). No long-term complications were observed at a median follow-up of 20 months.

Limitations: The study was limited by its retrospective nature and midterm follow-up.

Conclusions: Transanal minimally invasive surgery is an advanced transanal platform that provides a safe and effective method for resecting benign neoplasms, as well as carefully selected, early-stage malignancies of the mid and distal rectum.