Fluorescence-guided autonomic nerve preservation during total mesorectal excision: A prospective pilot study

Area of Science:

• Surgical Oncology
• Minimally Invasive Surgery
• Medical Imaging

Background:

• Total mesorectal excision (TME) improves rectal cancer outcomes but risks pelvic autonomic nerve injury, leading to urinary and sexual dysfunction.
• Identifying these nerves during surgery is difficult, especially after neoadjuvant chemoradiotherapy.
• This study investigates indocyanine green (ICG)-guided fluorescence imaging for selective nerve visualization.

Purpose of the Study:

• To evaluate the feasibility and safety of using ICG fluorescence imaging for intraoperative visualization of pelvic autonomic nerves during minimally invasive TME.
• To assess the impact of ICG-guided imaging on early post-operative urinary function.

Main Methods:

• A prospective pilot feasibility study involving 24 patients undergoing minimally invasive TME for rectal adenocarcinoma.
• Twelve patients received conventional nerve-preserving TME; twelve received intravenous ICG 12 hours preoperatively, visualized with near-infrared imaging.
• Post-operative outcomes included urinary catheter removal time, recatheterization rates, and urinary tract infection (UTI) incidence.

Main Results:

• Pelvic autonomic nerves were visualized as distinct non-fluorescent structures against a fluorescent background in the ICG group.
• Earlier urinary catheter removal was observed in the ICG group (post-op day 2 vs. day 3).
• Fewer patients required recatheterization (1 vs. 3) and no UTIs occurred in the ICG group, compared to the conventional group.

Conclusions:

• Pre-operative low-dose ICG administration is feasible and safe for real-time intraoperative visualization of pelvic autonomic nerves during minimally invasive TME.
• ICG-guided fluorescence imaging may improve early post-operative urinary outcomes.
• Larger prospective studies are warranted to confirm these findings.