correct answer
c intraoperative cholangiogram
Indocyanine green (ICG) is a water-soluble fluorescent dye that is rapidly taken up by the liver and excreted into the bile ducts within minutes of application. Fluorescence of the liver and bile ducts may continue up to six hours after injection. It has a near-infrared (NIR) emission wavelength of 820 nm which makes it easily detected. Since bile is excreted via the stool, detection of ICG in the stool confirms bile flow. In healthy control babies, ICG was detected in the stool by 15 hours post injection. A recent study evaluated the utility of ICG in the diagnosis of biliary atresia. Babies were injected iv with 0.1mg/kg of ICG. Soiled diapers were collected, and the stool examined for presence of ICG. In 6/7 babies with confirmed biliary atresia, ICG was not detected in the stool.
ICG was invented in 1957 and has since been used in a myriad of surgical applications including assessing bowel viability, defining biliary anatomy for laparoscopic cholecystectomy, detecting bile leak after liver resection or transplant, and localizing hepatic tumors.
In the baby presented in this scenario, although a lack of ICG in the stool may strongly suggest the diagnosis of biliary atresia, the best choice of the interventions listed would be an intraoperative cholangiogram (IOC). IOC is still considered the gold standard for definitive diagnosis which would provide a definitive diagnosis of biliary atresia. Proceeding directly to Kasia in this scenario would be premature. Gallbladder US and MRCP may prove to be useful adjuncts but would also not provide a definitive diagnosis of biliary atresia.
