Y. Kawaguchi1,2, Y. Nomura1, M. Nagai1, N. Tanaka1 1Asahi General Hospital,Department Of Surgery,,Asahi, CHIBA, Japan 2the University of Tokyo,Hepato-Biliary-Pancreatic Surgery Division,Bunkyo, TOKYO, Japan
Introduction: A fluorescence imaging technique using indocyanine green (ICG) as a fluorophore has been increasingly used for hepatobiliary surgery, and visualizes liver cancer and the bile duct as fluorescence. However, the usefulness of the technique for laparoscopic liver resection and complex biliary surgery remains unclear. We aimed to evaluate the identification of liver cancer in laparoscopic approach and the visualization of the bile duct during complex biliary surgery in open approach using ICG-fluorescence imaging.
Methods: (1) Visualization of liver cancer was evaluated in 6 patients (13 lesions) who underwent laparoscopic liver resection. As a fluorophore of the technique, ICG was injected intravenously at a dose of 0.5 mg/kg as a routine liver function test within 2 weeks before surgery. (2) Visualization of the bile duct was evaluated in 7 patients who underwent complex biliary surgery. ICG was administered by intrabiliary (IB) injection (0.025 mg/mL) or by intravenous (IV) injection (2.5 mg). The values of fluorescence intensity (FI) of the bile duct and the liver were calculated using a luminance analyzing software.
Results:(1) Of the 13 lesions, there were hepatocellular carcinoma (n=3) and colorectal liver metastasis (n=10). Fluorescence imaging visualized 8 (61.5%) lesions, which were invisible on the surface but were located less than 10 mm from the liver surface (Figure 1A). In contrast, the other 5 were located more than 10 mm from the liver surface and were not visualized as fluorescence. (2) Fluorescence imaging technique with the IB injection method was used for 6 patients with severe inflammation (n=3), abnormal biliary anatomy (n=2), and perforation of the bile duct (n=1). In contrast, the IV injection method was used for 1 patient with abnormal biliary anatomy. When using the IB injection method, the liver did not provide fluorescence as it showed fluorescence using the IV injection method. The fluorescence of the bile duct was clearly visualized on the low FI of the surrounding structures using the IB injection method (Figure1B) compared to fluorescence imaging using the IV injection method (Figure 1C). The median (range) FI ratio of the bile duct to the liver was 19.1 (5.0-67.7) using the IB injection method while it was 1.4 using the IV injection method.
Conclusion:ICG-fluorescence imaging is useful to visualize liver cancers which were not visible from the liver surface during laparoscopic liver resection. The IB injection method provided clear contrast between the bile duct and the surrounding structures compared with the IV injection method. The IB injection method is useful for recognizing the biliary anatomy, especially when biliary drainage tubes were inserted as an intervention of severe biliary tract infection.
