Estudo experimental do rim suíno submetido a diferentes tempos de isquemia quente com e sem o uso de manitol

Abstract

Our objective is to study the effects of different renal warm ischemia times, with and without the use of Mannitol as kidney protector applied during renal surgical procedures like a partial nephrectomy involving warm ischemia. The temporary occlusion of the renal artery and vein, necessary both to suppress bleeding and to allow a free operating field of blood. Stereological analyzes were performed to assess possible decrease in the number of glomeruli and renal function in porcine model. For this, were used 40 pigs(Sus domesticus), divided into 5 groups: Sham- without ischemia, groups 10, 20 and 30 minutes of renal warm ischemia, and Mannitol group (warm ischemia 30 minutes) via laparoscopic. Dosed creatinine of the various groups. The kidneys identified according to the groups. The weight and volume (Scherle method) were measured, also cortico-medullary ratio. Cortical fragments were removed randomly, processed for histological technique. Were estimated volumetric density of clusters (Vv [Glom]), the weighted average volume of the glomeruli (VWGV), obtaining the total number of glomeruli from each kidney. In the Sham group, G10 and G20 there was no statistically significant difference. There was no difference in the Vv [Glom] and VWGV between groups. The warm ischemia for 20 minutes or less, did not cause loss of nephrons statistically significant. The creatinine rates analyzed in all groups showed no statistically significant changes. The weight and volume of the kidneys subjected to 30 minutes of ischemia were decreased by 6.2% and 6.3%, respectively, compared to contralateral kidneys. Were reduced by 24.5% or 290,000 glomeruli submitted to warm ischemia for 30 minutes. There is a statistically significant negative correlation between the warm ischemia time and the number of glomeruli. p <0.05; r2 = 0.9147. There are an estimated loss of nephrons 8000 for each minute of warm ischemia. In the same study, it was observed that in the group where used mannitol (with warm ischemia 30 minutes), this promoted a protection to the renal parenchyma statistically significant compared with the group 30 minutes arteriovenous warm ischemia without the use of mannitol, where there was a statistically significant reduction in the number of nephrons. Based on these results we conclude that: the analysis of serum creatinine levels are not reliable tests to evaluate renal function, time 30 minutes of renal warm ischemia causes significant kidney damage and should be avoided, 8000 nephrons are lost to each minute under ischemia and the use of mannitol in fact protected the renal parenchyma.