The influence of pulsatile preservation on renal transplantation in the 1990s.

BACKGROUND: Unlike simple cold storage (CS), pulsatile machine preservation (MP) of kidneys for transplantation permits pharmacologic manipulation of the perfusate and aids in the pretransplant assessment of the kidney graft. These characteristics of MP may have importance in the era of increasing use of extended criteria donor kidneys. The overall aim of this article is to critically assess practices at our preservation unit with respect to graft function. Specific aims are to (1) compare the influence of MP versus CS on graft function, (2) determine which pretransplant variables have significance in pretransplant assessment, and (3) determine whether pharmacologic manipulation during MP is advantageous. METHODS: There were 650 consecutive kidneys preserved in our laboratory between January 1, 1993 and March 1, 999, by either MP or CS. All MP kidneys were preserved by continuous hypothermic pulsatile perfusion using Belzer-MPS or Belzer II solution. Perfusion parameters and electrolytes were measured serially during pulsatile perfusion. All CS kidneys were stored in University of Wisconsin solution. All kidneys obtained from donors exhibiting extended criteria features underwent pretransplant frozen section biopsies. Transmission electron microscopy (EM) was performed on a subset of kidneys undergoing pharmacologic manipulation. Four agents were assessed prospectively for their ability to influence MP characteristics when added to perfusate: PGE1, trifluoperazine, verapamil, and papaverine. RESULTS: MP was associated with improved immediate, 1-, and 2-year graft function and reduced length of initial hospital stay when compared with CS grafts. Changes in the machine perfusion variables flow and resistance, and the [Ca++] in perfusate, were significantly associated with delayed graft function (DGF) after the transplant. Biopsy information was not predictive of DGF. The addition of PGE1 to perfusate improved MP characteristics, reduced the release of [Ca++] into perfusate, and ameliorated mitochondrial ischemic injury in transmission EM images. Early graft function was improved in the presence of PGE1+MP, compared with function in the presence of other pharmacologic agents or CS alone. CONCLUSIONS: MP is associated with improved early and long term renal function. Moreover, PGE1 augments MP in improving graft function. The combination of MP+PGE1 may be important in optimizing the ability to use extended donor criteria kidneys and, thereby, improve the overall efficiency of cadaveric renal transplantation.

Pushing the envelope in renal preservation; improved results with novel perfusate modifications for pulsatile machine perfusion of cadaver kidneys.

INTRODUCTION: Novel preservation techniques may diminish ischemia/reperfusion (I/R) injury. Our preservation laboratory has modified Belzer MPS for machine perfusion (MP) with prostaglandin E1 (PGE 1), nitroglycerin (NTG), and polyethylene glycol-superoxide dismutase (PEG-SOD) to attenuate I/R injury. We reviewed our recent experience using this novel formulation (NF) compared with standard perfusates. RESULTS: Between January 1998 and March 2000, 1060 consecutive kidneys were preserved in our laboratory. One hundred forty-eight kidneys (14%) were discarded. Fifty-eight percent of kidneys during this time period underwent MP (n = 532). En bloc kidney pairs were randomly assigned to pulsatile MP using Waters RM3 or MOX-100 perfusion systems using 1 of 3 perfusates; NF (NF; n = 119), Belzer MPS (MPS; n = 201), or Belzer II albumin gluconate (ALB; n = 212) Significant improvements in delayed graft function (DGF) rate were seen with NF versus other perfusates (8% vs 14% vs 19%, respectively; P =.03). At 6 months, graft survival was significantly improved with NF compared with MPS and ALB (96% vs 90% vs 87%, respectively; P =.03). NF also produced a significantly higher percentage of recipients with a serum creatinine level < or = 1.5 mg/dL. CONCLUSIONS: Novel modifications of standard MP perfusate improved outcomes after renal transplantation. Preservation-based interventions targeted to ameliorate I/R injury can improve outcomes and may allow expansion of the donor pool.