Comparative Efficacy of Standard-Dose (15 mg) versus Reduced-Dose (5 mg) Indocyanine Green Fluorescence Angiography in Left-Sided Colon Cancer Surgery: A Randomized Clinical Trial

Abstract

Introduction. Colorectal anastomotic leakage remains a severe complication following colon resections, leading to increased mortality, reoperations, and diminished patient quality of life. Although intraoperative fluorescence angiography with indocyanine green (ICG) enhances intestinal wall perfusion assessment and has demonstrated reduced complication rates in prior studies, its widespread adoption is limited by high drug costs and the absence of standardized dosing regimens. This study represents the first global clinical investigation to compare the efficacy of standard (15 mg) versus reduced (5 mg) ICG doses in left-sided colon cancer surgery.

Materials and methods. This is a prospective, double-blind, randomized non-inferiority trial planned to enroll 60 patients (30 per group). Inclusion criteria: age 18–85 years, histologically confirmed left-sided colon cancer (cT1-4bN0-2bM0-1), scheduled resection with primary anastomosis. Primary endpoints include: 1. Intraoperative ICG fluorescence quality assessed via a 5-point Likert scale; 2. Frequency of surgical plan modifications (resection height) based on perfusion assessment; 3. Incidence of anastomotic leakage (including clinically insignificant), diagnosed by C-reactive protein levels (days 2 and 4) and contrast-enhanced CT findings (day 5 or as clinically indicated). The intervention involves bolus administration of ICG at 15 mg or 5 mg following bowel mobilization. The hypothesis posits that the reduced dose (5 mg) is non-inferior to the standard dose (15 mg) for perfusion visualization efficiency. As a pilot study, power calculations were not performed, with sample size justified by practical feasibility.

Conclusion. Confirmation of equivalence between the reduced ICG dose (5 mg) and the standard dose (15 mg) would reduce the procedural cost fivefold, enhancing accessibility for widespread clinical use. This approach could potentially decrease postoperative complication rates while optimizing healthcare resource utilization. Ultimately, this work may contribute to refining colorectal cancer surgical protocols by balancing clinical efficacy with economic efficiency.