Study of kidney morphologic and structural changes related to different ischemia times and types of clamping of the renal vascular pedicle

Abstract

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 inflammatory infiltrate, 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 significant 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.

Lipopolysaccharide Pretreatment Prevents Medullary Vascular Congestion following Renal Ischemia by Limiting Early Reperfusion of the Medullary Circulation

“…Red blood cell (RBC) trapping, also known as vascular congestion, in the dense capillary plexus of the renal outer medulla (OM) is thought to contribute to ischemic AKI 1 – 5 A “hyperemic” or “dusky red” OM is a hallmark of ischemic acute tubular necrosis in human cadavers 6 – 9 and after renal ischemia-reperfusion injury (IRI) in animal models, including dog, 10 pig, 11 rat, 3 and mouse 12 . Vascular congestion represents an increased volume of tightly packed RBCs in the OM plexus or bundle zone (Figure 1).…”

Mass extravasation and tubular uptake of red blood cells results in toxic injury to the tubules during kidney ischemia from venous clamping

“…Vascular congestion, or red cell trapping, represents the formation of densely packed red blood cells (RBC) in the renal circulation 1,2 . Vascular congestion of the outer-medullary (OM) region of the kidney is a hallmark of ischemic acute kidney injury (AKI) with acute tubular necrosis (ATN), now acute tubular injury, in humans at autopsy [3][4][5][6][7][8] and is also present in animal models following ischemia reperfusion (IR) from arterial clamping, including in pigs, dogs, rats and mice [9][10][11][12] . Vascular congestion of the renal cortical circulation also occurs during periods of ischemia 13 however, this rapidly resolves following restoration of kidney perfusion 1, 14 .…”

Efeito da isquemia renal unilateral no rim contralateral avaliada pela expressão de Caspase 3

“…Diversos estudos experimentais [7][8][9] demonstraram a interferência da isquemia renal na diminuição da função de órgãos à distância, como fígado, coração, cérebro e pulmão, em um mecanismo reconhecido como organ crosstalk. Dois estudos, recentemente, observaram a interferência da isquemia renal unilateral sobre o rim contralateral, identificando o fenômeno de kidney-kidney crosstalk, demonstrado por análise histológica e por aumento dos índices de resistência e pulsatilidade na análise Dopplerfluxométrica 10,11 .…”

“…Two recent studies observed that unilateral renal ischemia affected the contralateral kidney, identifying the phenomenon of kidney-kidney crosstalk, demonstrated by histological analysis and by increases in resistance and pulsatility indexes calculated with Doppler flow measurement. 10 , 11 …”