Hepatic Artery Thrombosis After Orthotopic Liver Transplant: A 20-Year Monocentric Series

Background/Objectives: Hepatic artery thrombosis (HAT) is a serious vascular complication in patients undergoing orthotopic liver transplantation (OLT). It is associated with a high risk of graft loss, re-transplantation (re-OLT), and mortality. This study aimed to evaluate the incidence and management of HAT, analyzing potential risk factors. The secondary objectives included quantifying 90-day postoperative morbidity and mortality rates. Methods: In this retrospective, observational, single-center study, data from liver transplant donors and recipients who underwent OLT between 2004 and 2024 were analyzed. HAT was classified as early (e-HAT, <= 30 days) or late (l-HAT, >30 days). Univariate statistical analysis was performed to identify the risk factors associated with HAT occurrence. Multivariate analysis was not performed due to the small number of HAT events, which would increase the risk of model overfitting. Results: In the 20 year study period, a total of 532 OLTs were performed, including 37 re-OLTs. The rates of major morbidity, reoperation, and mortality within 90 days were 44.5%, 22.3%, and 7.1%, respectively. HAT occurred in 2.4% of cases (e-HAT: 1.6%; l-HAT: 0.7%). Among e-HAT cases, 66.6% were asymptomatic and identified through routine postoperative Doppler ultrasound. All e-HAT cases were surgically treated, with a re-OLT rate of 33.3%. Three l-HAT cases required re-OLT. Overall, the HAT-related mortality and re-OLT rates were 7.6% and 46.1%, respectively. At a follow-up of 86 months, the rate of graft loss was 9.2%, and the rate of post-OLT survival was 77%. Patients who developed HAT had a higher donor-to-recipient body weight ratio and longer warm ischemia times (WITs). Additionally, patients undergoing re-OLT had a higher risk of developing HAT. Conclusions: Although the incidence of HAT is low, its clinical consequences are severe. Early Doppler ultrasound surveillance is crucial for detecting e-HAT and preventing graft loss. A high donor-to-recipient body weight ratio, a prolonged warm ischemia time, and re-OLT seem to be associated with a high risk of HAT.