Evaluation of histologic changes in the livers of patients with early and late hepatic artery thrombosis.

Hepatic artery thrombosis (HAT) following orthotopic liver transplantation (OLT) can cause hepatic parenchymal necrosis and ischemic cholangiopathy. This study investigates additional histologic features that may suggest HAT in post-OLT liver specimens. For 94 liver specimens (explanted allografts and biopsies) from patients with a clinical or pathologic diagnosis of HAT, we recorded length of time between OLT and procedure, categorizing cases into early HAT (;≤30 days since OLT) and late HAT (>30 days since OLT). Common histologic findings in HAT included lobular necrosis (60 cases, 64%), portal inflammation (68 cases, 72%), ductular reaction (73 cases, 78%), lobular cholestasis (70 cases, 74%), and bile-tinged macrophages (40 cases, 43%). Ductular cholestasis was seen in 30 cases (32%); 10 of those patients were clinically septic. Bile in veins was seen in 16 (17%) cases and arteritis in 6 (6%) cases. Findings more common in resection than biopsy specimens included lobular necrosis (P < .0001), hemorrhage (P = .0044), ductular cholestasis (P = .0003), and bile-tinged macrophages (P < .0001). Lobular necrosis was more common in early HAT (P = .0002), and ductular reaction (P = .006) and bile in veins (P = .03) were more common in late HAT. Histologic changes in HAT vary based on specimen type and whether HAT is early or late. In late HAT, biliary injury might occur after a prolonged period of ischemia, with subsequent bile duct necrosis, bile in veins, and remodeling (eg, ductular reaction). Bile in veins is an unusual finding that may occur in HAT, although it can be seen in bile infarcts from other causes.