Graft arteriosclerosis and glomerulosclerosis correlate with flow and resistance to machine perfusion in kidney transplantation.

INTRODUCTION

Machine perfusion to preserve kidneys for transplantation has grown over the past decade with demonstrated diagnostic and therapeutic benefits. Flow and resistance patterns are used to predict delayed graft function (DGF) and posttransplant graft survival. Preimplantation biopsies obtained serve a similar role in evaluating kidneys especially if they meet expanded criteria. The reliability of available data is greater if there is a correlation among various forms of assessment. In this study we attempted to study serial pump parameters that might correlate with abnormal findings in preimplantation biopsies and subsequently in outcomes after transplantation.

METHODS

Two hundred sixty-eight kidneys were assessed for changes in pump pressures in mm Hg, flow in mL/min, resistance in mm Hg/mL/min, and temperature in °C at 15-minute intervals. Allografts were separated into two groups on the basis of pathology; group 1 showed abnormal (AH) and group 2 normal histology (NH). AH was defined by the presence of glomerulosclerosis in ≥10% of sampled glomeruli or arteriosclerosis affecting at least 10% of the arterial lumens of sampled intrarenal arteries. We assessed discordance between frozen and permanent sections. Measured clinical outcomes included DGF, 1-year graft survival, 1-year serum creatinine and estimated glomerular filtration rate (eGFR). Statistical analysis was performed using a paired Student t test and chi-square analysis.

RESULTS

Compared to NH kidneys, those with AH showed uniformly significant lower flow rates and higher resistances during the entire perfusion. Graft pathology did not predict DGF (70% versus 60%, P = .45). However, 1-year graft survival (96.2% versus 80%, P = .07) and eGFR (58 versus 48 mL/min, P = .19) were lower among kidneys with AH, though these matrics did not reach significance.

CONCLUSION

Preimplantation biopsy findings correlated with flow and resistance to perfusion. If a discrepancy is evident upon evaluation of a donor kidney, a repeat biopsy is prudent prior to discarding or using the organ.