Consequences of Cold-Ischemia Time on Primary Nonfunction and Patient and Graft Survival in Liver Transplantation: A Meta-Analysis

INTRODUCTION The ability to preserve organs prior to transplant is essential to the organ allocation process. OBJECTIVE The purpose of this study is to describe the functional relationship between cold-ischemia time (CIT) and primary nonfunction (PNF), patient and graft survival in liver transplant. METHODS To identify relevant articles Medline, EMBASE and the Cochrane database, including the non-English literature identified in these databases, was searched from 1966 to April 2008. Two independent reviewers screened and extracted the data. CIT was analyzed both as a continuous variable and stratified by clinically relevant intervals. Nondichotomous variables were weighted by sample size. Percent variables were weighted by the inverse of the binomial variance. RESULTS Twenty-six studies met criteria. Functionally, PNF% = -6.678281+0.9134701*CIT Mean+0.1250879*(CIT Mean-9.89535)2-0.0067663*(CIT Mean-9.89535)3, r2 = .625, , p<.0001. Mean patient survival: 93% (1 month), 88% (3 months), 83% (6 months) and 83% (12 months). Mean graft survival: 85.9% (1 month), 80.5% (3 months), 78.1% (6 months) and 76.8% (12 months). Maximum patient and graft survival occurred with CITs between 7.5-12.5 hrs at each survival interval. PNF was also significantly correlated with ICU time, % first time grafts and % immunologic mismatches. CONCLUSION The results of this work imply that CIT may be the most important pre-transplant information needed in the decision to accept an organ.