Glomerular loss after arteriovenous and arterial clamping for renal warm ischemia in a swine model (original) (raw)
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Acta cirurgica brasileira, 2017
To investigate the glomerular number after different warm ischemia times. Thirty two pigs were assigned into four groups. Three groups (G10, G20, and G30) were treated with 10, 20, and 30 minutes of left renal warm ischemia. The sham group underwent the same surgery without renal ischemia. The animals were euthanized after 3 weeks, and the kidneys were collected. Right kidneys were used as controls. The kidney weight, volume, cortical-medullar ratio, glomerular volumetric density, volume-weighted mean glomerular volume, and the total number of glomeruli per kidney were obtained. Serum creatinine levels were assessed pre and postoperatively. Serum creatinine levels did not differ among the groups. All parameters were similar for the sham, G10, and G20 groups upon comparison of the right and left organs. The G30 group pigs' left kidneys had lower weight, volume, and cortical-medullar ratio and 24.6% less glomeruli compared to the right kidney. A negative correlation was found betw...
Journal of Endourology, 2012
Purpose: To evaluate glomerular injury in the rat model during renal warm ischemia (WI), comparing artery and vein (AV) clamping with artery only (AO) clamping. Materials and Methods: Twenty-four adult male rats underwent 60 minutes of renal WI in the left kidney. The animals were divided into three groups: AV clamping, AO clamping, and Sham surgery. After 30 days, the animals were euthanized, and both kidneys were processed for paraffin embedding and stained with hematoxylin and eosin. Glomerular volume density (Vv[glom]), mean glomerular volume (MGV), and number of glomeruli per mm 3 (Nv[glom]) were evaluated in the renal cortex. Results: The Vv[glom] was reduced in the left kidney (ischemic) when compared with the right kidney in both AV and AO groups by 11.1% and 35.4%, respectively; however, the difference was significant only in the AV group. The Nv[glom] was reduced in the left kidney when compared with the right kidney in both AV and AO groups by 11.6% and 31.4%, respectively; nevertheless, the difference was significant only in the AV group. The MGV of left and right kidneys was the same in both Sham and AO groups and was diminished by 6.7% in the AV group-not significant. Conclusion: AV clamping causes a significant decrease in the number of glomeruli in the rat model, while AO clamping reduces the glomerular number, but not significantly. To minimize renal injury, AO clamping may be preferred over AV clamping when WI is necessary in patients with previously compromised renal function. Abbreviations Used AO ¼ artery only AV ¼ artery and vein MGV ¼ mean glomerular volume Nv[glom] ¼ number of glomeruli per mm3 LPN ¼ laparoscopic partial nephrectomy Vv[glom] ¼ glomerular volume density WI ¼ warm ischemia RENAL ARTERY CLAMPING REDUCES GLOMERULI IN RATS 1339 View publication stats View publication stats
Comparison of Clamping Modalities in a Rabbit Model of Normothermic Renal Ischemia
Journal of Endourology, 2011
Purpose: The objective of this study was to investigate the patterns of renal function recovery with different renal vessel clamping modalities during a prolonged warm ischemia (WI) condition in an experimental two-kidney rabbit model. Materials and Methods: Twenty-eight rabbits were randomly clustered into four groups and underwent laparotomy with different types of renal pedicle clamping. Group 1 (n = 4) was sham-operated. Group 2 (n = 8) underwent 80 minutes of WI with artery only clamping. Group 3 (n = 8) underwent arteriovenous clamping for 80 minutes, and group 4 (n = 8) received an arteriovenous clamping for 80 minutes with 10-second declamping periods every 20 minutes. Serum levels of creatinine (SCr) were recorded preoperatively and on postoperative days (PODs) 1, 3, and 7. Renal function was evaluated by 99m technetium-mercaptoacetyltriglycine scintigraphy. Afterward, the animals were euthanized, and the kidneys were harvested and evaluated microscopically. Results: Renal function completely recuperated on POD 7 in the groups that underwent artery only and ateriovenous intermittent clamping, and both of these methods were superior to ateriovenous clamping (P < 0.001). SCr showed a similar variation in all the clamping groups and did not demonstrate statistical differences among the groups. Histopathologic changes were similar among the ischemic groups. Conclusion: The less deleterious clamping modalities in this experimental model were the artery only and intermittent en bloc clamping methods.
Physiological reports, 2014
Several techniques to induce renal ischemia have been proposed: clamp, PVA particles, and catheter-balloon. We report the development of a controlled, single-insult model of unilateral renal ischemia/reperfusion (I/R) without contralateral nephrectomy, using a suitable model, the pig. This is a ballooncatheter-based model using a percutaneous, interventional radiology procedure. One angioplasty balloon-catheter was placed into the right renal artery and inflated for 120 min and reperfusion over 24 h. Serial serums were sampled from the inferior vena cava and urine was directly sampled from the bladder throughout the experiment, and both kidneys were excised after 24 h of reperfusion. Analyses of renal structure and function were performed by hematoxylin-eosin/periodic Acid-Schiff, serum creatinine (SCr), blood urea nitrogen (BUN), fractional excretion of ions, and glucose, SDS-PAGE analysis of urinary proteins, and serum neutrophil gelatinase-associated lipocalin (NGAL). Total nitrated protein was quantified to characterize oxidative stress. Acute tubular necrosis (ATN) was identified in every animal, but only two animals showed levels of SCr above 150% of baseline values. As expected, I/R increased SCr and BUN. Fractional sodium, potassium, chloride, and bicarbonate excretion were modulated during ischemia. Serum-nitrated proteins and NGAL had two profiles: decreased with ischemia and increased after reperfusion. This decline was associated with increased protein excretion during ischemia and early reperfusion. Altogether, these data show that the renal I/R model can be performed by percutaneous approach in the swine model. This is a suitable translational model to study new early renal ischemic biomarkers and pathophysiological mechanisms in renal ischemia.
Cold Renal Ischemia: Comparison of Efficacy Between Two Techniques of Cooling, in a Swine Model
Journal of Endourology, 2010
Objectives: In a swine model of renal ischemia, we compared the effectiveness of the transureteral retrograde cold saline perfusion technique to the traditional method of renal cooling with ice slush, in achieving adequate parenchymal temperatures for functional preservation of the organ. Physiological and histological effects were also assessed. Methods: Twenty-four domestic male pigs were sampled into four groups to be submitted to a 60-minute ischemia of the left kidney without cooling, with either one of the two cooling techniques (cold saline retrograde perfusion or ice slush), or sham surgery. All of them had also a concomitant right nephrectomy. Renal cortical and medullary temperatures were recorded throughout the experiment. Urinary output was measured, and serum renal function tests were carried on, pre-and postoperatively. After 5 days, the animals were euthanized and their kidneys were submitted to histological analysis. Results: Mean renal temperature fell in both groups submitted to kidney cooling. With ice slush, a faster drop was observed and a lower minimum temperature was achieved (5.08C in the cortex and 6.38C in the medulla, vs. 25.48C and 24.98C with retrograde cooling). In the other groups, temperature was unchanged. Urinary output and serum creatinine worsened after the experiment, but without significant differences among groups. The histological analysis showed no differences among the four groups, for the studied ischemia time. Conclusions: Ice slush and retrograde perfusion of cold saline are both effective for cooling the kidney during ischemia. Ice slush is faster in doing so, and it allows much lower temperatures to be achieved in the renal parenchyma. With ischemia time of 60 minutes, no significant differences on the occurrence of functional and histological alterations were detected, even for the group without a cooling procedure.
Laparoscopic warm renal ischemia in the solitary porcine kidney model
Urology, 2004
To determine the effect of a laparoscopic approach on warm renal ischemia in the pig with a solitary kidney. Although the maximal safe duration for warm ischemia during open partial nephrectomy is commonly accepted to be 30 minutes, the maximal safe ischemic time during laparoscopic partial nephrectomy has not been previously determined. Methods. Sixteen farm pigs underwent unilateral laparoscopic right nephrectomy. Two weeks later, the pigs underwent complete laparoscopic mobilization of the remaining left kidney and were randomized to complete hilar clamp times of 0, 30, 60, or 90 minutes. Serum creatinine was evaluated before right nephrectomy and at days 0, 2, 4, 7, 14, and 30 after renal ischemia during laparoscopy. All renal specimens were evaluated by an experienced nephropathologist in a blinded fashion. Results. The serum creatinine remained stable at all points in the control and 30-minute ischemia groups. The serum creatinine level rose initially on days 2 and 4 in the 60-minute and 90-minute ischemia groups but returned to baseline by day 7. At harvest, no statistically significant difference was found among the groups in serum creatinine or histologic features. Conclusions. Renal ischemic times up to 90 minutes during laparoscopy were well tolerated by the solitary porcine kidney. Possible explanations for this finding include the protective effect of a solitary kidney and the potential protective effect of relative ischemic preconditioning provided by the pneumoperitoneum. UROLOGY 64: 592-597, 2004.
International braz j urol
Purpose: This study aimed to study morphological and renal structural changes in relation to different ischemic times and types of renal vascular pedicle clamping. Methods: Sixteen pigs were divided into two groups (n = 8): Group AV -unilateral clamping of the renal artery and vein and Group A -unilateral clamping of the renal artery only, both with the contralateral kidney used as control. Serial biopsies were performed at 0, 10, 20, 30, 40, 50, 60, 70, 80, and 90 minutes after clamping. Results: there is a correlation between the occurrence of renal damage as a function of time (p <0.001), with a higher frequency of Group A lesions for cellular alterations (vascular congestion and edema, interstitial infl ammatory infi ltrate, interstitial hemorrhage and cell degeneration), with the exception of in the formation of pigmented cylinders that were evidenced only in the AV Group. Conclusion: the number of lesions derived from ischemia is associated with the duration of the insult, there is a signifi cant difference between the types of clamping, and the AV Group presented a lower frequency of injuries than Group A. The safety time found for Group A was 10 minutes and for Group AV 20 minutes.
Ultrastructural Pathology, 2011
Ischemia-reperfusion injury can be detrimental to the solitary kidney, especially when it is accompanied by ablation. To the authors' knowledge, the effects of partial nephrectomy with prolonged application of ischemia have never been described at the ultrastructural level. Therefore, the authors used an animal model and focused on putative structural effects in the glomerular basement membrane and the podocytes. They demonstrate the advantageous role of cold ischemia, even in up to 120 min. In contrast, more than 60 min of warm ischemia leads to catastrophic lesions in all the cellular structures, as is reflected by mortality due to acute renal failure.