[Hystologic and hemodynamic aspects of warm ischemic graft in relation to the preservation method].

OBJECTIVE The non-heart-beating donor has been proposed as a solution to donor shortage for renal transplantation. Because the nature of such donors, the kidneys so derived have been damaged by primary warm ischemia (WI), and so potentially they may never function. Minimizing graft injury is especially important in case of transplantation form marginal donors because of a high rate of delayed graft function or primary nonfunction. The aim of this experimental study is to assess the structural and hemodynamic consequences of hypothermic perfusion (HP) versus cold storage (CS), in renal allograft after a period of WI. MATERIAL AND METHODS We used 20 mini-pigs. WI was achieved by vascular pedicle occlusion during 45 min. We divided organs in 4 groups: A (n=5), kidneys with WI and then transplanted; group B (n=5), grafts with WI and implanted after HP with Belzer solution in our computerized perfusion system. Group C-control, (n=5) transplanted without WI and D (n=5) with WI and 60 min of CS in UW-Viaspan solution. All the procedure was recorded by a computerized data system. Renal vascular resistance (RVR) and renal vascular flow (RVF) were automatically calculated by means of mathematical formulas after renal transplantation. Subsequently histological study was completed in all cases. RESULTS We observed two patterns after transplantation: (1). Initial increase of RVR with posterior decrease and increase of vascular flow: in organs with WI and HP prior to transplantation (group B) // organs transplanted without WI (group C-control). Electronic and conventional microscopy showed integrity of endothelial and tubule structure. (2). Initial decrease with posterior increase of RVR. Organs with WI (group A) // organs with WI and CS (group D). Structural study showed endothelial and tubule disruption. CONCLUSION In our experimental model machine perfusion preserves endothelial and tubule structure of kidneys with WI. After transplantation the hemodynamic pattern of grafts with WI and HP is similar to the control group (without WI and direct transplantation).