Lawrence Lee, MD, PhD1, Deborah Keller, MD2, George Nassif, DO1, Teresa deBeche-Adams, MD1, John Monson, MD1, Matthew R Albert, MD1, Sam Atallah, MD1. 1Florida Hospital, 2Houston Methodist Hospital
Introduction: Transanal minimally invasive surgery (TAMIS) is an advanced endoscopic platform for local excision of rectal neoplasms. This new technique is a valuable minimally invasive tool, but may be technically demanding. To safely implement TAMIS and any new technology into clinical practice, the learning curve should be defined. The objective was to determine the number of TAMIS procedures for the local excision of rectal neoplasm required to reach proficiency.
Methods and Procedures: All TAMIS cases performed from 07/2009 to 12/2015 at a high-volume tertiary referral center for rectal neoplasia were identified from a prospective departmental database. A cumulative summation (CUSUM) analysis was performed to determine the number of cases required to reach proficiency. Proficiency was defined by positive margin status (R1 resection), with acceptable and unacceptable R1 rates based on previously published meta-analysis outcomes for transanal endoscopic microsurgery (TEM) and traditional transanal excision (TAE). Comparative analysis of patient, tumor, and operative characteristics before and after TAMIS proficiency was performed.
Results: A total of 201 TAMIS procedures were evaluated. The indication for TAMIS was benign adenoma (45%), high-grade dysplasia/carcinoma-in-situ (18%), invasive adenocarcinoma (32%), and neuroendocrine tumor (5%). The overall R1 resection rate was 7%. The benchmarked R1 rates for TEM and TAE were 11% and 27%, respectively. CUSUM analysis reported TAMIS reached an acceptable R1 rate after 24 cases (Fig 1A). Moving average plots showed that the mean operative times sharply decreased after the 24th case (Fig 1B). The mean lesion distance from anal verge (pre 8.6cm(SD2.8) vs. post 7.0cm(SD3.3), p=0.024) and operative time (pre 88min(SD50) vs. post 67min(SD35), p=0.010) significantly decreased after performing the 24th case. All other patient, tumor, and operative characteristics before and after the 24th case were comparable.
Conclusions: The learning curve for TAMIS excision of rectal neoplasms is defined at 24 cases. In a large series, 24 cases was the minimum required to consistently reach an acceptable R1 resection rate and shorter operative times. After 24 cases, TAMIS can be safely integrated into clinical practice.
Presented at the SAGES 2017 Annual Meeting in Houston, TX.
Abstract ID: 77555
Program Number: S134
Presentation Session: Colorectal 2
Presentation Type: Podium