Excellent outcomes in combined liver-kidney transplantation: Impact of kidney donor profile index and delayed kidney transplantation

Abstract
The positive impact of delayed kidney transplantation (KT) on patient survival for combined liver-kidney transplantation (CLKT) has already been demonstrated by our group. The purpose of this study is to identify whether the quality of the kidneys (based on kidney donor profile index [KDPI]) or the delayed approach KT contributes to improved patient survival. In total, 130 CLKTs were performed between 2002 and 2015, 69 with simultaneous KT (group S) and 61 with delayed KT (group D) (performed as a second operation with a mean cold ischemia time [CIT] of 50 +/- 15 hours). All patients were categorized according to the KDPI score: 1%-33%, 34%-66%, and 67%-99%. Recipient and donor characteristics were comparable within groups S and D. Transplant outcomes were comparable within groups S and D, including liver and kidney CIT, warm ischemia time, and delayed graft function. Lower KDPI kidneys (<34%) were associated with increased patient survival in both groups. The combination of delayed KT and KDPI 1%-33% resulted in 100% patient survival at 3 years. These results support that delayed KT in CLKT improves patient survival. The combination of delayed KT and low KDPI offers excellent patient survival up to 3 years. Improved outcomes in the delayed KT group including high KDPI kidneys supports expansion of the donor pool with the use of more extended criteria donor and donation after circulatory death kidneys. Liver Transplantation 24 222-232 2018 AASLD.