MRI, or angiogram is necessary Acute HAT with allograft failure is a surgical emergency and requires immediate listing for retransplantation While awaiting transplant, biliary stenting or percutaneous draining may be indicated to manage the biliary complications associated with HAT Late HAT may be asymptomatic or present with progressive biliary stenosis and as such, total bilirubin, alkaline phosphatase, and GGT levels may be elevated With late HAT, arterial collaterals may develop and if there is adequate hepatic blood flow whether through these collaterals or via compensation by the portal vein, then treatment may not be required Imaging with ultrasound followed by CT or angiogram may help to map the hepatic vasculature and collaterals Treatment options of HAT remain fairly limited as anticoagulation and thrombolysis are not typically effective Surgical reconstruction is typically contraindicated as disruption of the collateral supply can precipitate hepatic ischemia with resultant parenchymal necrosis Most cases of HAT ultimately require retransplantation