Zeljka Jutric, MD1, Maria A Cassera, BS1, Pippa H Newell, MD, FACS2, Ronald F Wolf, MD, FACS2, Paul D Hansen, MD, FACS2, Chet W Hammill, MD, FACS2. 1Providence Portland Medical Center, 2The Oregon Clinic
Our objective was to evaluate the use of indocyanine green and fluorescence imaging to identify the liver segmental anatomy, portal anatomy, and bile leaks during liver resections.
Description of the technology and methods of use:
Indocyanine green (ICG) has two properties that potentially make it useful in hepatobiliary surgery. First when injected intravascularly indocyanine green is metabolized by the liver and excreted in the bile and second when illuminated with near infrared light it fluoresces. Utilizing these properties we conducted a clinical study evaluating the use of ICG and the PINPOINT Endoscopic Fluorescence Imaging System in hepatobiliary surgery.
A total of 13 cases were accrued. The technique was not found to be useful for identifying portal anatomy or bile leaks. This was primarily due to the fluorescence of the liver in the background overwhelming the fluorescence of foreground structures. Several different methods were tried for segmentation of the liver, including injection of ICG into the portal vein of the segment planned for resection (4 cases), injection into the hepatic artery of the segment planned for resection (2 cases), injection into the liver parenchyma of the segment planned for resection (1 case), and ligation of the portal vein and hepatic artery of the segment planned for resection with intravenous injection of the ICG (6 cases). Injections into the vessels or parenchyma of the liver segments identified for resection lead to visualization of the segmental anatomy; however, the rest of the liver incorporated excess ICG, resulting in fluorescence of the whole liver within seconds. Ligation of the inflow of the segments planned for resection and intravenous injection resulted in clear visualization of the line of transection that persisted throughout the case. In two cases the fluorescence revealed vascular anatomy that had not been previously appreciated.
Conclusions and future directions:
The technology is useful in cases where the vascular inflow is ligated prior to significant parenchymal transection, primarily formal right and left hepatectomies. The biggest advantage is in the accurate identification of the vascular anatomy. In addition, the ability to visualize the demarcation between the liver segments throughout the case ensures that the transection does not involve perfused liver and that a significant amount of unperfused liver is not left behind.