Assessment of a novel biliary-specific near-infrared fluorescent dye (BL-760) for intraoperative detection of bile ducts and biliary leaks during hepatectomy in a preclinical swine model.

Abstract

Postoperative bile leakage is a common complication of hepatobiliary surgery and frequently requires procedural intervention. Bile-label 760 (BL-760), a novel near-infrared dye, has emerged as a promising tool for identifying biliary structures and leakage, owing to its rapid excretion and strong bile specificity. This study aimed to assess the intraoperative detection of biliary leakage using intravenously administered BL-760 compared with intravenous (IV) and intraductal (ID) indocyanine green (ICG). Laparotomy and segmental hepatectomy with vascular control were performed on two 25-30 kg pigs. ID ICG, IV ICG, and IV BL-760 were administered separately, followed by an examination of the liver parenchyma, cut liver edge, and extrahepatic bile ducts for areas of leakage. The duration of intra- and extrahepatic fluorescence detection was assessed, and the target-to-background (TBR) of the bile ducts to the liver parenchyma was quantitatively measured. In Animal 1, after intraoperative BL-760 injection, three areas of leaking bile were identified within 5 min on the cut liver edge with a TBR of 2.5-3.8 that was not apparent to the naked eye. In contrast, after IV ICG administration, the background parenchymal signal and bleeding obscured the areas of bile leakage. A second dose of BL-760 demonstrated the utility of repeated injections, confirming two of the three previously visualized areas of bile leakage and revealing one previously unseen leak. In Animal 2, neither ID ICG nor IV BL-760 injections showed obvious areas of bile leakage. However, fluorescence signals were observed within the superficial intrahepatic bile ducts after both injections. BL-760 enables the rapid intraoperative visualization of small biliary structures and leaks, with the benefits of fast excretion, repeatable intravenous administration, and high-fluorescence TBR in the liver parenchyma. Potential applications include the identification of bile flow in the portal plate, biliary leak or duct injury, and postoperative monitoring of drain output. A thorough assessment of the intraoperative biliary anatomy could limit the need for postoperative drain placement, a possible contributor to severe complications and postoperative bile leak.