Background:  Indocyanine green (ICG) near-infrared fluoroscopy has been widely implemented in laparoscopic donor hepatectomy for precise demarcation of the liver midplane. The aim of this study is to show the effectiveness of ICG fluoroscopy in comparison to the traditional demarcation method used in laparoscopic donor hepatectomy and also to confirm that a single injection of ICG is adequate for completion of both midplane dissection and bile duct division.
Method: Retrospective analysis was done with images acquired from recordings of 46 laparoscopic living donor hepatectomies performed between June 2016 and May 2017. Intraoperatively, vascular inflow of the targeted hemiliver was temporarily clamped so that the ischemic line dividing the right and left lobes would become visible. ICG was then injected intravenously (0.025mg/kg) and the near-infrared camera was switched on for visualization in the black-and-white mode and fluorescent mode. Images were captured in the natural, black-and-white, and fluorescent views, and the color values of the clamped vs non-clamped regions were quantitated. Additionally, the time from ICG injection to bile duct illumination and that from bile duct illumination to fluoroscopy termination were measured.
Results: The color differences between the clamped vs non-clamped regions in the natural, black-and-white, and fluorescent views were 39.7±36.2, 89.6±46.9, and 19.1±36.8 (P< 0.001), respectively, demonstrating that ICG visualized in the black-and-white view is most effective for demarcation of the liver midplane. Furthermore, the time from ICG injection to bile duct illumination and that from bile duct illumination to fluoroscopy termination were 85.6±25.8mins and 8.7±4.8mins, respectively, indicating that a single injection of ICG is adequate for midplane dissection followed by bile duct division.
Conclusion: ICG injection visualized with black-and-white imaging is most effective for demarcating the exact liver midplane during laparoscopic donor hepatectomy. Also, a single injection of ICG is sufficient for midplane dissection as well as bile duct division.