Ureter identification utilizing indocyanine green (ICG) imaging in colorectal surgery: a systematic review of the literature

Aim: To describe the currently available evidence regarding the efficacy and safety of intraureteral indocyanine green (ICG) instillation for ureteral identification in colorectal surgery. Methods: Systematic search of PubMed and Scopus through May 2022 reported according to PRISMA 2020. Studies reporting treatment of patients < 18 years, with unavailable full-text, reviews, editorials, animal studies, and studies including non-colorectal operations were excluded.Results: Seven retrospective studies, published between 2020 and 2022, were identified, in which 142 patients (43% females) were evaluated, of which three were undertaken in the USA, two in Japan, and two in India. The most common indications for surgery were cancer in 58 patients (41%) and diverticular disease in 52 patients (36.6%). Most patients involved underwent robotic surgery (70%), while the remaining patients had laparoscopic surgery. The intraoperative ureteral injury was reported in one patient, while adverse effects (mainly transient hematuria) were reported in 10% of the study population (14 patients). The use of intrauretal ICG prolonged surgery by a median of 12.8 minutes.Conclusion: Intraoperative visualization of ureters using ICG in colorectal surgery is safe and effective, according to the results of this study. However, this technique still bears the potential disadvantages of ureteral catheterization. Research is focusing on future dyes combining the ICG properties with renal excretion to minimize the need for stents. Further comparative studies are needed to reach safe results