Diagnosis of Biliary Complications
Early symptoms of biliary complications are often unspecific or missing. Biliary leaks typically occur early and are diagnosed by routine cholangiography or bilious secretion. Increased inflammatory parameters or fever might occur in the case of undrained bilious collections. Anastomotic or nonanastomotic stenoses are often affiliated with jaundice, increased cholestatic enzymes and fever. Also recurrent cholangitis is a common symptom and should entail additional diagnostic measures.
A cholangiography is easily performed if an external biliary drainage is present. Otherwise, the diagnostic workup is mostly started with noninvasive imaging studies, bearing in mind that these sometimes fail to detect relevant stenoses after LT. Especially ultrasound is less sensitive after LT, since severe dilatation of the intrahepatic bile ducts is absent in >60% of patients with anastomotic stenosis (AS). Even 1 week before ERC diagnosis of AS, 96% of patients revealed a normal ultrasound. However, in a newer series 92% of patients with biliary complications revealed ultrasound abnormalities. Hepatic artery thrombosis (HAT)—or stenosis is excluded by additional Doppler examination. Contrast-enhanced ultrasound has been used recently to investigate the perfusion of the hilar bile ducts, since detection of severely impaired perfusion may facilitate the early diagnosis of biliary complications.
Normal ultrasound findings should not preclude further diagnostic measures An ERC is able to detect the cause of biliary obstruction in 95% and the site of bile leaks in 90% of cases. However, a prospective study of MRCP and ERC revealed comparable sensitivities for detection of biliary obstruction. Other studies confirmed a ≥90% sensitivity and specificity and positive and negative predictive values of 90% for MRCP. A normal MRCP therefore might avoid further invasive measures. In the case of ongoing clinical suspicion, cholangiography remains the gold standard. The route of access to the biliary system is among others based on local experience. In our own practice ERC is the method of choice in patients with duct-to-duct anastomosis and PTC is used as a first-line method only in patients with bilioenteric anastomosis.
To exclude other causes of graft dysfunction (e.g. rejection, CMV-hepatitis) a liver biopsy might be useful. Additional investigations like hepatobiliary scintigraphy (HIDA-scan) have been described with controversial results and are rarely used in the routine workup nowadays.