Novel Technique of Pelvic Autonomic Nerve-Sparing with Near-Infrared Fluorescence Technology and ICG during Deep Endometriosis Surgery

Abstract

<h3>Study Objective</h3> To describe the anatomical and technical highlights of a novel nerve-sparing surgery for deep endometriosis (DE) using near-infrared (NIR) fluorescence technology and indocyanine green (ICG). <h3>Design</h3> Stepwise demonstration of a technique. <h3>Setting</h3> An urban general hospital. ICG is a fluorescent dye that allows accurate, intraoperative, real-time assessment of tissue vascularization, once excited with light of a specific wavelength in the near-infrared spectrum. NIR fluorescence technology and ICG have been confirmed as feasible, safe, and useful tools to guide surgery in several settings, including colorectal and urologic surgeries. However, no reports have discussed pelvic autonomic nerve-sparing surgery using this tool in the gynecological field. <h3>Patients or Participants</h3> Stage IV endometriosis patients with parametrial involvement. <h3>Interventions</h3> An intravenous injection of 0.25mg/kg body weight of ICG for intraoperative NIR fluorescence imaging. Pelvic autonomic nerves were highlighted by ICG because these nerves are surrounded by many capillaries. <h3>Measurements and Main Results</h3> Evaluation of blood perfusion of DE nodules and achieving better visualization of anatomical relationship to the pelvic autonomic nerves. We could easily identify ischemic nodules which included DE and fibrosis under NIR fluorescence imaging, beyond the limits of macroscopic disease. Endometriosis or fibrosis was confirmed pathologically from all resected tissues, and resection margins of these tissues were negative for disease. These results suggest that this technique might be feasible for objectively identifying the border between DE lesions and healthy tissue. Furthermore, the hypogastric nerve and inferior hypogastric plexus were strongly highlighted by ICG and objectively preserved with assessment of perfusion. The patients developed no perioperative complications, including postoperative bladder or rectal dysfunction after surgery. <h3>Conclusion</h3> Application of ICG with NIR fluorescence appears potentially useful, not only to remove DE, but also to improve nerve-sparing. To our knowledge, this is the first reported use of ICG during pelvic autonomic nerve-sparing surgery for gynecologic disease.