Use of Indocyanine Green for Intraoperative Perfusion Assessment in Women with Ureteral Endometriosis: A Preliminary Study

Abstract

Study objective: To evaluate the feasibility, safety, and potential usefulness of near-infrared imaging (NIR) with indocyanine green (ICG) to assess ureteral perfusion after conservative surgery (ureterolysis or nodule removal) for ureteral endometriosis. Any changes to the surgical plan regarding intraoperative ureteral stent placement after NIR-ICG evaluation and early postoperative outcomes were recorded.

Design: Prospective case series study.

Setting: Tertiary level referral center for endometriosis and minimally invasive gynecology.

Patients: Consecutive symptomatic women scheduled for laparoscopic conservative ureteral surgery for ureteral endometriosis.

Interventions: After ureterolysis or nodule removal, residual perfusion of the ureters with regular caliber and peristalsis was evaluated through NIR-ICG imaging. Ureteral perfusion grade was defined as absent, irregular, or regular. Time required for NIR-ICG assessment, interoperator agreement regarding ureteral perfusion grade, any changes to the surgical plan after NIR-ICG evaluation, perioperative complications, and clinical-radiologic outcomes at early follow-up were recorded.

Measurements and main results: A total of 31 ureters were examined with NIR-ICG imaging after conservative ureteral procedures. ICG assessment required 5.4 + 2.3 minutes. No complications related to fluorescence imaging were observed. Local ischemia supporting ureteral stent placement was suspected in 5 ureters (16.1%) at white light. Of these, 2 (40.0%) presented regular fluorescence; thus, ureteral stent placement was avoided. In the remaining 3 (60.0%), NIR-ICG confirmed irregular or absent fluorescence, requiring ureteral stent placement. Interoperator agreement regarding NIR-ICG evaluation was high. At a 3-month follow-up, all procedures were clinically and radiologically successful.

Conclusion: NIR-ICG imaging after conservative surgery for ureteral endometriosis seems to be a feasible, safe, and useful tool to assess ureteral perfusion and guide surgical decision, together with other visual cues at white light. However, this approach needs to be validated by further larger and controlled studies.

Trial registration: ClinicalTrials.gov NCT03950206.

Keywords: Indocyanine green imaging; Near-infrared; Ureter; Ureteral surgery.