Comparing advanced platforms for local excision of rectal lesions

Transanal surgery facilitates organ preservation in select patients with benign and early malignant rectal lesions to avoid the functional consequences of radical surgery. The transanal endoscopic microsurgery (TEM) platform created a standard for local excision with lower margin positivity and recurrence rates than traditional transanal excision. The single-port robot (SP r) presents a promising alternative transanal platform. The goal of this study was to compare perioperative and pathologic outcomes of TEM and SP r for excision of rectal lesions.

A review of consecutive patients who underwent local excision of rectal lesions at a tertiary referral center from 1/2001 to 5/2022 was performed. Cases were stratified into TEM or SP rTAMIS in a 1:1 propensity score-matched cohort, adjusting for all baseline characteristics. Clinical, tumor-specific, and perioperative outcomes were compared using χ², and Mann-Whitney U-tests. The main outcomes were oncologic quality measures, complications, and operative time.

Matching resulted 50 patients in each cohort. Groups had similar age, gender, body mass index, comorbidity, diagnosis, lesion characteristics, and neoadjuvant chemoradiation rates. There were no intraoperative complications in either cohort. Three SP rTAMIS cases were converted intraoperatively; there were no conversions in TEM. SP rTAMIS had significantly shorter operative times than TEM (mean 104 vs. 245, p = 0.027). The rates of positive distal margins (2% TEM, 0% SP rTAMIS) and piecemeal resection (4% TEM, 0% SP rTAMIS) were similar. SP rTAMIS had significantly lower postoperative morbidity rates than TEM (9% vs. 20%, p = 0.031). There was no mortality in either cohort.

SP robotics provided high-quality outcomes similar to TEM for local excision of rectal lesions. SP robotics had faster operative time with comparable clinical and oncologic outcomes to TEM. These early data are promising for expanding use of SP robotic platforms.