Sphincter-saving surgery versus abdominoperineal resection in low rectal cancer: the role of indocyanine green fluorescence angiography in surgical decision-making.

Background: The choice between sphincter-saving surgery and abdominoperineal resection (APR) for low rectal cancer balances oncological radicality against functional preservation. Indocyanine green fluorescence angiography (ICG-FA) provides objective intraoperative assessment of bowel perfusion at the colonic stump, where ischemia is a leading cause of anastomotic failure. Materials and methods: In this prospective, single-center, descriptive cohort study (January 2021-December 2025) of more than 400 patients operated for colorectal cancer, 70 had low rectal cancer (≤6 cm from the anal verge) and 27 underwent sphincter-saving surgery - 7 intersphincteric resections, 4 immediate low colorectal or coloanal anastomoses, and 16 two-staged Turnbull-Cutait pull-through procedures. ICG-FA of the colonic stump was performed in 22 patients (81.5%), with proximal repositioning of the resection line whenever fluorescence was inadequate. Results: ICG-FA prompted modification of the resection line in 9 of 22 patients (40%), almost always proximally, but never altered the decision between sphincter preservation and APR. A radical (R0) resection was achieved in 19 of 21 patients with margin status recorded; two had an involved circumferential margin (R1), both in locally advanced node-positive tumors. Postoperative complications occurred in 15 of 27 patients (56%), mostly Clavien-Dindo grade I-II. There was no 30-day mortality; one late in-hospital death from an independent myocardial infarction occurred beyond 30 days. Conclusions: Sphincter-saving surgery for low rectal cancer is feasible but carries substantial morbidity. ICG-FA is a reproducible, low-risk adjunct that informs intraoperative decision-making; whether it reduces anastomotic complications requires confirmation in randomized studies.