Nodular Regenerative Hyperplasia Is Not a Rare Condition After Liver Transplantation: Incidence, Predictive Factors, and Impact on Survival

Background. The objectives of this study were to evaluate incidence and to identify the risk factors of occurrence and the predictive factors of symptomatic forms of nodular regenerative hyperplasia (NRH) after liver transplantation (LT). Methods. To identify risk factors of NRH following LT, we included 1648 patients transplanted from 2004 to 2018 and compared the patients developing NRH after LT to those who did not. To identify predictive factors of symptomatic NRH, we selected 115 biopsies displaying NRH and compared symptomatic to asymptomatic forms. Symptomatic NRH was defined as the presence of ascites, esophageal varices, hepatic encephalopathy, portal thrombosis, retransplantation, or death related to NRH. Results. The incidence of NRH following LT was 5.1%. In multivariate analysis, the independent factor of developing NRH after LT was the donor's age (odds ratio [OR] = 1.02; confidence interval, 1.01-1.03; P = 0.02). Symptomatic forms occurred in 29 (25.2%) patients: 19 (16.5%) patients presented with ascites, 13 (11.3%) with esophageal varices, 4 (3.5%) with hepatic encephalopathy, and 8 (7%) with portal thrombosis. The median period before the onset of symptoms was 8.4 (1.5-11.3) y after LT. The spleen size at diagnosis/before LT ratio (OR = 12.5; 114.17-1.37; P = 0.0252) and thrombectomy during transplantation (OR = 11.17; 1.48-84.11; P = 0.0192) were associated with symptomatic NRH in multivariate analysis. Conclusions. NRH following LT is frequent (5.1%) and leads to symptomatic portal hypertension in 25.2% of patients. Using older grafts increases the risk of developing NRH after LT. Clinicians should screen for signs of portal hypertension, particularly in measuring spleen size.