Objective: The aim of this study was to compare the outcomes of simultaneous and delayed implantation of kidney grafts in combined liver-kidney transplantation (CLKT).
Background data: Delayed function of the renal graft (DGF), which can result from hypotension and pressor use related to the liver transplantation (LT), may cause worse outcomes in CLKT.
Methods: A total of 130 CLKTs were performed at Indiana University between 2002 and 2015 and studied in an observational cohort study. All kidneys underwent continuous hypothermic pulsatile machine perfusion until transplant: 69 with simultaneous kidney transplantation (KT) (at time of LT, group 1) and 61 with delayed KT (performed at a later time as a second operation, group 2). All patients received continuous veno-venous hemodialysis during the LT. Propensity score match analysis in a 1:1 case-match was performed.
Results: Mean kidney cold ischemia time was 10 ± 3 and 50 ± 15 hours, for groups 1 and 2 (P < 0.0001), respectively. The rate of DGF was 7.3% in group 1, but no DGF was seen in group 2 (P = 0.0600). Kidney function was significantly better in group 2, if the implantation of kidneys was delayed >48 hours (P < 0.01). Patient survival was greater in group 2 at 1 year (91%), and 5 year (87%) post-transplantation (P = 0.0019). On multivariate analysis, DGF [hazard ratio (HR), 165.7; 95% confidence interval (CI), 9.4-2926], extended criteria donor kidneys (HR, 15.9; 95% CI 1.8-145.2), and recipient hepatitis C (HR, 5.5; 95% CI 1.7-17.8) were significant independent risk factors for patient survival.
Conclusions: Delayed KT in CLKT (especially if delayed >48 h) is associated with improved kidney function with no DGF post-KT, and improved patient and graft survival.