Objective of the study: The primary goal of this study was the successful intraoperative near infrared fluorescence (NIRF) imaging of extra and intra hepatic bile ducts using the SPY and laparoscopic SPY2 scope systems (Novadaq Technologies Inc.) after parenteral administration of Indocyanine Green (ICG). Optimal NIRF imaging of biliary anatomy occurs when sufficient amount of Indocyanine Green (ICG) is excreted into the bile ducts to cause adequate fluorescence of the bile ducts, while at the same time sufficient ICG has cleared from the liver to minimize background fluorescence. Dosage, timing, and routes of administration of ICG and the safety of NIRF were secondary goals.
Methods and procedures: Thirty rats and six adult dogs under general anesthesia were used for intraoperative imaging of the biliary tree after parenteral administration of ICG. In rats, an open SPY system was used, and in dogs the SPY2 scope system was used for laparoscopic and open imaging of biliary structures. All animals were euthanized at the end of the surgery.
Results: In all animals studied, administration of either SQ or IV ICG resulted in specific and reproducible imaging of the intrahepatic biliary tree, common hepatic duct, common bile duct, and cystic duct as well as the pancreatic duct. The imaging quality allowed precise identification of all structures in both rat and dog models, from 5 minutes after IV injections and 15 minutes after SQ injection. Excretion of ICG could be followed down to the ampulla and into the duodenum. Intentional biliary tree injury resulted in easily recognizable bile duct leak while clamping of the bile duct resulted in fluorescence cut-off as a sign of obstruction. No adverse events were encountered
Conclusions: IV and SQ administration of ICG resulted in the effective and rapid near infrared fluorescence intraoperative imaging of intra and extra hepatic bile ducts in rat and dog models without the need for placement of a cholangiography catheter. This modality could prove superior to intraoperative cholangiography, and reduce or eliminate bile duct injuries during laparoscopic cholecystectomy.
Session: Podium Presentation
Program Number: S099