Question: A 34 year old male liver transplant recipient goes for cholagiography and has the findings seen below. Which of the following answer choices is not likely to be responsible for the findings?
A. total warm ischemic time
B. total cold ischemic time
C. tacrolimus overdose
D. hepatic artery thrombosis
Answer: The findings in the cholangiogram above are suggestive of diffuse biliary strictures. There are many risk factors for post-transplant biliary strictures, including warm and cold ischemic time. Warm ischemia takes place either 1. in the donor body as the organs are being harvested (as in the case of donation after cardiac death) or 2. as the organ is being moved from the cold preservation solution and into the recipient (before normal blood flow is restored). Cold ischemia represents the time ex vivo when the organ is bathed in preservation solution and transported to the recipient.
Hepatic artery thrombosis is another important risk factor. Recall that the hepatic artery is the exclusive supply of blood for the biliary tree, and therefore, a stenosis or thrombosis is likely to compromise the blood supply to the bile ducts and result in stricturing. Liver function tests may or may not be elevated in such cases.
Tacrolimus overdose does not cause biliary stricturing. Early after liver transplant, tacrolimus overdose is more likely to cause a neuropathy, like headaches, tremor or seizure; alternatively it can be nephrotoxic and lead to azotemia. In the long term, tacrolimus has many additional side effects as well, including dyslipidemia, hypertension, and may increase rates of cancers (particularly of the skin).