The effectiveness and cost-effectiveness of methods of storing donated kidneys from deceased donors: a systematic review and economic model

Abstract

To review the evidence for the effectiveness and cost-effectiveness of storing kidneys from deceased donors prior to transplantation, using cold static storage solutions or pulsatile hypothermic machine perfusion. Electronic databases were searched in January 2008 and updated in May 2008 for systematic reviews and/or meta-analyses, randomised controlled trials (RCTs), other study designs and ongoing research. Sources included: Cochrane Library, MEDLINE, EMBASE, CINAHL, ISI Web of Knowledge, DARE, NRR, ReFeR, Current Controlled Trials, and (NHS) HTA. Bibliographies of articles were searched for further relevant studies, and the Food and Drugs Administration (FDA) and European Regulatory Agency Medical Device Safety Service websites were searched. Only English language papers were sought. The perfusion machines identified were the LifePort Kidney Transporter (Organ Recovery Systems) and the RM3 Renal Preservation System (Waters Medical Systems). The cold storage solutions reviewed were: University of Wisconsin, ViaSpan; Marshall's hypertonic citrate, Soltran; and Genzyme, Celsior. Each intervention was compared with the others as data permitted. The population was recipients of kidneys from deceased donors. The main outcomes were measures of graft survival, patient survival, delayed graft function (DGF), primary non-function (PNF), discard rates of non-viable kidneys, health-related quality of life and cost-effectiveness. Where data permitted the results of studies were pooled using meta-analysis. A Markov (state transition) model was developed to simulate the main post-transplantation outcomes of kidney graft recipients. Eleven studies were included: three full journal published RCTs, two ongoing RCTs [European Machine Preservation Trial (MPT) and UK Pulsatile Perfusion in Asystolic donor Renal Transplantation (PPART) study], one cohort study, three full journal published retrospective record reviews and two retrospective record reviews published as posters or abstracts only. For LifePort versus ViaSpan, no significant differences were found for DGF, PNF, acute rejection, duration of DGF, creatinine clearance or toxicity, patient survival or graft survival at 6 months, but graft survival was better at 12 months post transplant with machine perfusion (LifePort = 98%, ViaSpan = 94%, p < 0.03). For LifePort versus RM3, all outcomes favoured RM3, although the results may be unreliable. For ViaSpan versus Soltran, there were no significant differences in graft survival for cold ischaemic times up to 36 hours. For ViaSpan versus Celsior, no significant differences were found on any outcome measure. In terms of cost-effectiveness, data from the MPT suggested that machine preservation was cheaper and generated more quality-adjusted life-years (QALYs), while the PPART study data suggested that cold storage was preferable on both counts. The less reliable deterministic outputs of the cohort study suggested that LifePort would be cheaper and would generate more QALYs than Soltran. Sensitivity analyses found that changes to the differential kidney storage costs between comparators have a very low impact on overall net benefit estimates; where differences in effectiveness exist, dialysis costs are important in determining overall net benefit; DGF levels become important only when differences in graft survival are apparent between patients experiencing immediate graft function (IGF) versus DGF; relative impact of differential changes to graft survival for patients experiencing IGF as opposed to DGF depends on the relative proportion of patients experiencing each of these two outcomes. The conclusions drawn for the comparison of machine perfusion with cold storage depend on which trial data are used in the model. Owing to the lack of good research evidence that either ViaSpan or Soltran is better than the other, the cheaper, Soltran, may be preferable. In the absence of a cost-utility analysis, the results of our meta-analysis of the RCTs comparing ViaSpan with Celsior indicate that these cold storage solutions are equivalent. Further RCTs of comparators of interest to allow for appropriate analysis of subgroups and to determine whether either of the two machines under consideration produces better outcomes may be useful. In addition, research is required to: establish the strength and reliability of the presumed causal association between DGF and graft, and patient survival; investigate the utility impacts of renal replacement therapy; determine what the additional cost, survival and QALY impacts are of decreased or increased non-viable kidneys when discarded pre transplantation; and identify a reliable measure for predicting kidney viability from machine perfusion.