Identification and Resection of Endometriosis Using Indocyanine Green [26D]

INTRODUCTION: Endometriosis is a common cause of nonspecific pelvic symptoms, typically diagnosed through laparoscopic biopsies. An innovative technique utilizing indocyanine green (ICG), a dye that fluoresces in areas of increased vascularity such as endometriotic lesions, is used to diagnose normal-appearing, “clear” lesions of endometriosis. These lesions would have otherwise been missed by conventional laparoscopy. METHODS: A retrospective chart review and analysis included all patients on whom ICG was used from July 2014 to August 2016. Preoperative symptoms and postoperative localization of lesions were analyzed using the Fisher Exact test. Preoperative symptoms included abnormal uterine bleeding, pelvic pain, fibroids, and dyspareunia. Postoperative localization included lesions in the ovary, cul-de-sacs, vesicouterine peritoneum, pelvic peritoneum, uterosacral ligaments, and uterine serosa. RESULTS: Of 30 patients undergoing laparoscopic excision of endometriosis using ICG, twenty-one with positive fluorescence had endometriosis confirmed on pathology; eight with no ICG fluorescence had negative pathology results; and one patient had fluorescence with no identifiable endometriosis. This statistically indicates a positive predictive value of 95% with a sensitivity of 100%. The preoperative symptoms analyzed were not statistically significant for endometriosis, but clear lesions present in pelvic and vesicouterine peritoneum were statistically significant for endometriosis (p=0.001 and 0.01, respectively). CONCLUSION: Use of ICG fluorescence led to pathology-proven diagnosis in 29 of 30 patients. ICG is an inexpensive, non-toxic dye whose application could help change how endometriosis is diagnosed with minimal risk to patients. Future studies would benefit from larger patient recruitment by adding power to the analysis.