Abstract
BACKGROUND: Previous studies have suggested an association between preoperative portal vein thrombosis (PVT) and post-transplant PVT occurrence, but comprehensive evidence evaluating the impact of thrombosis severity grading remains limited. OBJECTIVE: To investigate the influence of preoperative PVT grading on cumulative PVT occurrence time and survival outcomes following liver transplantation. METHODS: This retrospective cohort study consecutively enrolled patients undergoing deceased donor liver transplantation between April 2020 and October 2023. All patients underwent dual-modality imaging assessment (Doppler ultrasound combined with contrast-enhanced CT/MRI) for PVT grading according to the Yerdel classification. A standardized anticoagulation protocol was implemented postoperatively. Statistical analyses included Kaplan-Meier curves for cumulative incidence, Fine-Gray competing risk models adjusting for death as a competing event, multivariable Cox regression analysis, and comprehensive sensitivity analyses. RESULTS: Among 126 enrolled patients, the preoperative PVT grading distribution showed significant differences in cumulative post-transplant PVT risk (Grade 0: 14.3%, Grade I: 52.4%, Grade II: 71.4%, Grade III: 85.7%, p<0.001). Fine-Gray competing risk analysis confirmed grading as an independent predictor after adjusting for death (subdistribution hazard ratio [sHR] for Grade III vs Grade 0: 6.24, 95% CI: 3.81-10.21, p<0.001). The combined predictive model incorporating PVT grading, donor factors, and ALBI score achieved superior discrimination (1-year AUC: 0.876; 2-year AUC: 0.843) compared to binary PVT assessment alone (1-year AUC: 0.739, p<0.001). Tertile-based risk stratification revealed significant differences in 3-year survival rates (high-risk: 76.2%, intermediate-risk: 88.1%, low-risk: 95.2%, p<0.001). CONCLUSION: Preoperative PVT grading represents a crucial predictor of cumulative PVT risk and survival differences after liver transplantation. Implementation of dual-modality imaging assessment and risk-stratified anticoagulation protocols may optimize post-transplant outcomes.