Reduction in anastomotic leakage by fluorescent laparoscopic resection for ultra-low rectal cancer: a propensity-matched analysis with BMI stratification.

Anastomotic leakage (AL) is a serious complication in colorectal surgery, particularly after laparoscopic intersphincteric resection (LsISR) for ultra-low rectal cancer. This study evaluates the effectiveness of ICG fluorescence laparoscopic (FL) resection in reducing AL and improving recovery, especially in high-BMI patients. A retrospective cohort study was conducted on patients undergoing LsISR for ultra-low rectal adenocarcinoma from January 2012 to July 2023, comparing FL (n = 133) and non-FL groups (n = 266). The primary endpoint was the incidence of anastomotic leakage, including symptomatic AL. Secondary endpoints included intraoperative blood loss, lymph node yield, and short-term recovery parameters such as bowel function recovery, soft diet initiation, and hospital stay.Propensity score matching (PSM) was used to reduce baseline differences. In the PSM cohort, the FL group had a significantly lower AL rate (3.0%) compared to the non-FL group (9.4%) (P = 0.035). Severe symptomatic anastomotic leaks (SSAL) were also reduced in the FL group (0.8% vs. 5.6%, P = 0.045). Subgroup analysis showed that FL significantly reduced AL in normal BMI patients (2.4% vs. 8.5%, P = 0.041). In high-BMI patients, FL reduced AL (3.9% vs. 10.8%, P = 0.063), but the difference was not statistically significant. FL also reduced blood loss, improved lymph node yield, and accelerated recovery, including earlier return of bowel function, quicker soft diet initiation, and shorter hospital stays. ICG FL reduces AL and enhances recovery, particularly in normal BMI patients, with a potential benefit for high-BMI patients. Further studies are needed to confirm its effect in this group.