Near-infrared intraoperative imaging of pelvic autonomic nerves: a pilot study

Background The pelvic autonomic nerves control and regulate anorectal and urogenital function. The dysfunction of pelvic autonomic nerves lead to disorders of anorectum, bladder and male sex organs. Thus the intraoperative identification of pelvic autonomic nerves could be crucial in complications prevention and diseases treatment. Our clinical trial aims at estimating the effectiveness and validity of intraoperative indocyanine green fluorescence imaging in pelvic autonomic nerves identification. Methods Intraoperative fluorescence imaging using indocyanine green was performed in ten patients and the feasibility was determined. From February 2019 to June 2019, the seven patients undergoing laparoscopic colorectal resection was administrated 4.5 mg/Kg indocyanine green 24 h before surgery. The near-infrared fluorescence imaging was conducted during surgery. A novel white light and near-infrared dual-channel laparoscopic equipment was applied. For each patient, signal-background ratio values for pelvic autonomic nerves were recorded and analyzed. Results We confirmed the dose and timing of indocyanine green administration was 4.5 mg/Kg and 24 h before surgery. Using the dual laparoscopic equipment, we could observe the splanchnic plexus, inferior mesenteric artery plexus, and sacral plexus successfully with a high signal background ratio value of 3.18 (standard deviation: 0.48). Conclusion This pilot trial shows feasibility of intraoperative indocyanine green fluorescence imaging in pelvic autonomic nerves observation. It demonstrates that nerves can be visualized using alternative imaging techniques but it is not ready yet for prime time. This technique might aid observation with white light alone. Registration number: ChiCTR1900025336.

Automated summary

The clinical trial demonstrated the feasibility of intraoperative indocyanine green fluorescence imaging in identifying pelvic autonomic nerves, but further development is needed before it can be widely implemented.