Near infrared cholangiography (NIRC) with indocyanine green (ICG) is performed to improve laparoscopic cholecystectomy safety in human patients. This technique has not been reported in clinical veterinary patients, nor has it been used to determine the patency of the biliary tract in either human or veterinary patients. This study aims to assess the accuracy of direct NIRC in determining common bile duct (CBD) and major duodenal papilla (MDP) patency. We hypothesize that an injection of ICG into the gallbladder will be visible through the duodenal wall demonstrating biliary system patency. Client-owned dogs (N=30) presenting for gallbladder mucocele or extrahepatic biliary obstruction will be included.

Specific Aim 1: To develop a less invasive method to assess common bile duct (CBD) and major duodenal papilla (MDP) patency in animals with gallbladder mucocele or extrahepatic biliary obstruction. This technique would avoid performing a duodenotomy and CBD flushing procedure, avoiding their associated complications (dehiscence, pancreatitis, cholangiohepatitis) and hopefully expand the number of laparoscopic cholecystectomies performed at Cornell University Hospital for Animals (CUHA). Injection of 2mls of ICG (2.5 mg/ml) into the gallbladder fundus will be performed and intraoperative fluorescence images within the biliary tract and duodenum recorded. Patients will undergo duodenotomy and CBD catheterization to verify patency findings. Fluorescence intensity for duodenal images will be calculated and compared to surgical findings. Patients will receive routine postoperative care including monitoring for any signs of allergic reactions or worsening liver function. Intraoperative and postoperative complications, and mortalities in this population will be reported.

Potential Impact for Animal Health: Continuing concerns regarding laparoscopic cholecystectomy center around the inability to accurately detect the biliary system’s patency before removing the gallbladder. Because of this, many clinicians prefer to perform open cholecystectomies instead as flushing or interrogating the biliary system can be executed definitively. Multiple recent reports document the risks associated with flushing the common bile duct, which are not minor, and include dehiscence of duodenotomy, pancreatitis, and cholangiohepatitis. This novel NIRC procedure could eliminate the need for duodenotomy and biliary duct flushing regardless of the surgical approach, leading to decreased morbidity and improved outcomes. With the availability of this procedure, laparoscopic cholecystectomies can be performed more often with higher degree of safety and decreased discomfort for patients.