"EP Method" of Intra-Ureteral Indocyanine Green Injection by Gynecologists: Strategy to Prevent Inadvertent Ureteral Injury in Complex Laparoscopic/Robotic Gynecologic Surgeries.

Abstract

Objectives: This study evaluated the safety and feasibility of a simplified intra-ureteral indocyanine green (ICG) injection technique performed by gynecologists during complex laparoscopic surgeries.

Materials and methods: A retrospective analysis of 110 cases performed from March 2023 to March 2024 was conducted. A set of hysteroscope (Karl Storz), a set of epidural catheter, a vial of ICG (25 mg), and a Near-Infrared (NIR) three-dimensional (3D) RUBINA camera system were used. A hysteroscope was used to inspect the bladder and identify the ureteral openings. Epidural catheter was inserted into the operating channel of the hysteroscope and advanced into the ureteral orifice up to 150-200 mm from the ureteral opening. Approximately 2.5 ml of ICG was injected into each ureter from the outer end of the epidural catheter. The planned 3D laparoscopic procedures were then followed. The ICG highlighted the ureters, and their course was observed and visualized in real-time under NIR light as desired.

Results: Among the 110 cases, 62 involved severe endometriosis, 40 had large uterine masses, 8 involved malignancy, and 48 had prior pelvic surgeries. ICG injection was successfully performed in 107 cases (97%) with a mean time of 2.2 min. Three near-miss ureteral injuries were prevented with real-time visualization. Mean operative time was 210.8 min, the mean estimated blood loss was 198 ml, and the mean hospital stay was 2.8 days. No adverse events were reported.

Conclusion: The simplified "EP Method" for intra-ureteral ICG injection is safe, feasible, cost-effective, and time-saving. It prevents ureteral injuries and can be performed independently by gynecologists without urologist assistance.