Published online Jan 27, 2018. doi: 10.4254/wjh.v10.i1.134
Peer-review started: October 1, 2017
First decision: November 27, 2017
Revised: December 1, 2017
Accepted: December 13, 2017
Article in press: December 13, 2017
Published online: January 27, 2018
To examine the effect of center size on survival differences between simultaneous liver kidney transplantation (SLKT) and liver transplantation alone (LTA) in SLKT-listed patients.
The United Network of Organ Sharing database was queried for patients ≥ 18 years of age listed for SLKT between February 2002 and December 2015. Post-transplant survival was evaluated using stratified Cox regression with interaction between transplant type (LTA vs SLKT) and center volume.
During the study period, 393 of 4580 patients (9%) listed for SLKT underwent a LTA. Overall mortality was higher among LTA recipients (180/393, 46%) than SLKT recipients (1107/4187, 26%). The Cox model predicted a significant survival disadvantage for patients receiving LTA vs SLKT [hazard ratio, hazard ratio (HR) = 2.85; 95%CI: 2.21, 3.66; P < 0.001] in centers performing 30 SLKT over the study period. This disadvantage was modestly attenuated as center SLKT volume increased, with a 3% reduction (HR = 0.97; 95%CI: 0.95, 0.99; P = 0.010) for every 10 SLKs performed.
In conclusion, LTA is associated with increased mortality among patients listed for SLKT. This difference is modestly attenuated at more experienced centers and may explain inconsistencies between smaller-center and larger registry-wide studies comparing SLKT and LTA outcomes.
Core tip: Simultaneous liver kidney transplantation (SLKT) has doubled from 2002-2013. We studied the effect of transplant center volume on survival outcomes. There was a significant survival disadvantage for liver transplant alone (LTA) vs SLKT in centers performing 30 SLKT over the study period, although this disadvantage was slightly diminished with increasing center SLKT volume. Therefore, centers with higher transplant volume have a lesser mortality difference in LTA compared to SLKT than those centers with smaller volume.