SIMULTANEOUS LIVER KIDNEY TRANSPLANTATION IN LIVER TRANSPLANT CANDIDATES WITH RENAL DYSFUNCTION: IMPORTANCE OF CREATININE LEVELS, DIALYSIS, AND ORGAN QUALITY IN SURVIVAL.

backgroundThe survival benefit from simultaneous liver-kidney transplantation (SLK) over liver transplant alone (LTA) in recipients with moderate renal dysfunction is not well understood. Moreover, the impact of deceased donor organ quality in SLK transplant survival has not been well described in the literature.

methodsThe Scientific Registry of Transplant Recipients was studied for adult recipients receiving LTA (N=2,700) or SLK (N=1,361) transplantation with moderate renal insufficiency between 2003 and 2013. The study cohort was stratified into four groups based on serum creatinine (Scr< 2 mg/dL versus Scr≥ 2 mg/dL) and dialysis status at listing and at transplant. The patients with end-stage renal disease and requiring acute dialysis more than three months before transplantation were excluded. A propensity score (PS)-matching was performed in each stratified groups to factor out imbalances between the SLK and LTA regarding covariates distribution and to reduce measured confounding. Donor quality was assessed with liver-donor risk index (L-DRI). The primary outcome of interest was post-transplant mortality.

resultsOn multivariable PS-matched Cox proportional hazard models, SLK led to decrease in post-transplant mortality compared to LTA across all four groups, but only reached statistical significance (HR 0.77; 95% CI, 0.62-0.96) in the recipients not exposed to dialysis and Scr≥ 2 mg/dL at transplant (mortality incidence rate per patient-year 5.7% in SLK vs. 7.6% in LTA, p=0.005). The decrease in mortality was observed among SLK recipients with better quality donors (L-DRI<1.5).

conclusionsExposure to pre-transplantation dialysis and donor quality affected overall survival among SLK recipients.