Association between hospital liver transplantation volume and mortality after liver re-transplantation

Abstract

Background: The relationship between institutional liver transplantation (LT) case volume and clinical outcomes after liver re-transplantation is yet to be determined. Methods: Patients who underwent liver re-transplantation between 2007 and 2016 were selected from the Korean National Healthcare Insurance Service database. Liver transplant centers were categorized to either high-volume centers (≥64 LTs/year) or low-volume centers (< 64 LTs/year) according to the annual LT case volume. In-hospital and long-term mortality after liver re-transplantation were compared. Results: A total of 258 liver re-transplantations were performed during the study period: 175 liver retransplantations were performed in 3 high-volume centers and 83 were performed in 21 lowvolume centers. In-hospital mortality after liver re-transplantation in high and low-volume centers were 25% and 36% (P = 0.069), respectively. Adjusted in-hospital mortality was not different between low and high-volume centers. Adjusted 1-year mortality was significantly higher in low-volume centers (OR 2.14, 95% CI 1.05-4.37, P = 0.037) compared to high-volume centers. Long-term survival for up to 9 years was also superior in high-volume centers (P = 0.005). Other risk factors of in-hospital mortality and 1-year mortality included female sex and higher Elixhauser comorbidity index. Conclusion: Centers with higher case volume (≥64 LTs/year) showed lower in-hospital and overall mortality after liver re-transplantation compared to low-volume centers.