Feasibility of injected indocyanine green for ureteral identification during robotic left-sided colorectal resections

Abstract

Background: Ureteral identification is essential to performing safe colorectal surgery. Injected immunofluorescence may aid with ureteral identification, but feasibility without ureteral catheterization is not well described.

Methods: Case series of robotic colorectal resections where indocyanine green (ICG) injection with or without ureteral catheter placement was performed. Imaging protocol, time to ureteral identification, and factors impacting visualization are reported.

Results: From 2019 to 2020, 83 patients underwent ureteral ICG injection, 20 with catheterization and 63 with injection only. Main indications were diverticulitis (52%) and cancer (36%). Median time to instill ICG was faster with injection alone than with catheter placement (4min vs 13.5min, p < 0.001). Median time [IQR] to right ureter (0.3 [0.01-1.2] min after robot docking) and left ureter (5.5 [3.1-8.8] min after beginning dissection) visualization was not different between injection alone and catheterization.

Conclusion: ICG injection alone is faster than with indwelling catheter placement and equally reliable at intraoperative ureteral identification.

Keywords: Indocyanine green; Intraoperative fluorescence; Robotic colorectal surgery; Ureteral identification.