Renal Blood Supply Research Articles

Renovascular Arterial Hypertension Due to Triple Renal Arteries Stenoses: One Session Successful Stenting

The paper presents a case of a 65 year old white male with atherosclerosis, severe left triple renal arteries stenoses and secondary renovascular hypertension (RVH). The patient was treated in a single session by percutaneous balloon angioplasty and stenting of the three left renal arteries with important atherosclerotic lesions. The uneventful evolution permitted patient's discharge next day after the intervention, with antihypertensive and antiplatelet therapy. The authors discuss successively the morphogenetic phenomena involved in multiple renal arteries apparition, the historical contribution of a Renascence anatomist to the description of renal blood supply variants and recent trends in atherosclerotic RVH (interventional versus medical approach).

Dengue hemorrhagic fever and the kidney.

Dengue virus infection (DVI)/dengue hemorrhagic fever (DHF) is a common febrile illness with a variety of severities. The mortality rate is high in dengue shock syndrome (DSS), caused by circulatory failure due to plasma leakage resulting in multi-organ failure. However, acute kidney injury (AKI) is rarely reported. In areas of endemic DVI, the prevalence of AKI due to DVI has been reported to be as high as 6.0 % in children with AKI, and 0.9 % in children with DVI who were admitted to a hospital. The mechanism of AKI in DVI is not clear. It may result from (a) direct injury as in other infectious diseases, (b) an indirect mechanism such as via the immune system, since DHF is an immunological disease, or (c) hypotensive DSS, leading in turn to reduced renal blood supply and renal failure. The mortality rates of DF/DHF, DSS and DHF/DSS-related AKI are <1 %, 12-44 %, and >60 %, respectively. Kidney involvement is not actually that rare, but is under-recognized and often only reported when microscopic hematuria, proteinuria, electrolyte imbalance, or even AKI is found. The prevalence of proteinuria and hematuria has been reported as high as 70-80 % in DVI. A correct diagnosis depends on basic investigations of kidney function such as urinalysis, serum creatinine and electrolytes. Although DVI-related renal involvement is treated supportively, it is still important to make an early diagnosis to prevent AKI and its complications, and if AKI does occur, dialysis may be required. Fortunately, in patients who recover, kidney function usually completely recovers as well.

Multidetector Computed Tomography Features in Differentiating Exophytic Renal Angiomyolipoma from Retroperitoneal Liposarcoma: A Strobe-Compliant Observational Study.

This study aims to evaluate the multidetector computed tomography (CT) imaging features in differentiating exophytic renal angiomyolipoma (AML) from retroperitoneal liposarcoma.We retrospectively enrolled 42 patients with confirmed exophytic renal AML (31 patients) or retroperitoneal liposarcoma (11 patients) during 8 years period to assess: renal parenchymal defect at site of tumor contact, supply from branches of renal artery, tumoral vessel extending through the renal parenchyma, dilated intratumoral vessels, hemorrhage, non–fat-containing intratumoral nodules with postcontrast enhancement, calcification, renal sinus enlargement, anterior displacement of kidneys, and other associated AML.Renal parenchymal defect, renal arterial blood supply, tumoral vessel through the renal parenchyma, dilated intratumoral vessels, intratumoral/perirenal hemorrhage, renal sinus enlargement, and associated AML were seen only or mainly in exophytic renal AML (all P value < 0.05); however, non–fat-attenuating enhancing intratumoral nodules, intratumoral calcification, and anterior displacement of the kidney were more common in liposarcoma (all P value < 0.05).AMLs reveal renal parenchymal defect at the site of tumor contact, supply from renal artery, tumoral vessel extending through the renal parenchyma, dilated intratumoral vessels, intratumoral and/or perirenal hemorrhage, renal sinus enlargement, and associated AML. Non–fat-attenuating enhancing intratumoral nodules, intratumoral calcifications, and anterior displacement of kidney were more commonly seen in liposarcoma.

Retrograde Renal Ablation via the Renal Vein as a New Treatment Option for Renovascular Hypertension

Renovascular hypertension is a hormonal response to decreased renal blood supply. Treatments include medication, balloon angioplasty, arterial embolization, and nephrectomy. We attempted a new method, retrograde renal ablation via the renal vein. Our institutional review board approved this procedure. A 51-year-old man had uncontrolled hypertension for 3 years despite taking four antihypertensive drugs (calcium antagonist, angiotensin II receptor blocker, β-blocker, and α-blocker). The high serum renin level (4 20 ng/mL/h) and dynamic computed tomography (CT) findings (left renal arterial occlusion, renal atrophy, and parenchymal enhancement delay) suggested renovascular hypertension. Arterial embolization was attempted twice to eliminate the left renal function. Tortuous collateral arteries including lumbar and adrenal vessels supplied the kidney, so absolute ethanol and gelatin sponge embolization of these

Evaluation of Renal Blood Flow and Oxygenation in CKD Using Magnetic Resonance Imaging

Animal studies suggest that progression of chronic kidney disease (CKD) is related to renal hypoxia. With renal blood supply determining oxygen delivery and sodium absorption being the main contributor to oxygen consumption, we describe the relationship between renal oxygenation, renal artery blood flow, and sodium absorption in patients with CKD and healthy controls. Cross-sectional study. 62 stable patients with CKD stages 3 to 4 (mean age, 61±13 [SD] years) and 24 age- and sex-matched controls. CKD versus control status. Renal artery blood flow, tissue oxygenation (relative changes in deoxyhemoglobin concentration of the renal medulla [MR2*] and cortex [CR2*]), and sodium absorption. Renal artery blood flow was determined by phase-contrast magnetic resonance imaging (MRI); MR2* and CR2* were determined by blood oxygen level-dependent MRI. Ultrafiltered and reabsorbed sodium were determined from measured glomerular filtration rate (mGFR) and 24-hour urine collections. mGFR in patients was 37% that of controls (36±15 vs 97±23 mL/min/1.73 m(2); P < 0.001), and reabsorbed sodium was 37% that of controls (6.9 vs 19.1 mol/24 h; P < 0.001). Single-kidney patient renal artery blood flow was 72% that of controls (319 vs 443 mL/min; P < 0.001). Glomerular filtration fraction was 9% in patients and 18% in controls (P < 0.001). Patients and controls had similar CR2* (13.4 vs 13.3 s(-1)) and medullary MR2* (26.4 vs 26.5 s(-1)) values. Linear regression analysis demonstrated no associations between R2* and renal artery blood flow or sodium absorption. Increasing arterial blood oxygen tension by breathing 100% oxygen had very small effects on CR2*, but reduced MR2* in both groups. Only renal artery blood flow was determined and thus regional perfusion could not be related to CR2* or MR2*. In CKD, reductions of mGFR and reabsorbed sodium are more than double that of renal artery blood flow, whereas cortical and medullary oxygenation are within the range of healthy persons. Reduction in glomerular filtration fraction may prevent renal hypoxia in CKD.

Effects and Mechanism of Combination of Rhein and Danshensu in the Treatment of Chronic Kidney Disease.

Traditional Chinese medicine (TCM) plays a systemic role in disease treatment, targeting multiple etiological factors simultaneously. Based on clinical experience, rhubarb and Salvia miltiorrhiza are commonly prescribed together for the treatment of chronic kidney disease (CKD) and have been proven to be very effective. However, the rationale of the combination remains unclear. The major active ingredients of these two herbs are rhein (RH) and danshensu (DSS), respectively. The aim of this paper is to investigate the renoprotective effects of RH and DSS in vitro and in vivo, and the underlying mechanism. A total of 5/6 nephrectomy rats and HK-2 cells were subjected to chronic renal injury. The combination of RH and DSS conferred a protective effect, as shown by a significant improvement in the renal function, blood supply, and fibrotic degree. Proinflammatory cytokines and adhesion molecules were suppressed by RH and DSS through NK-κB signaling. The combination also inhibited apoptosis by up-regulating Bcl-2 and down-regulating Bax. Inhibiting the TGF-β/Smad3 pathway was at least in part involved in the antifibrotic mechanism of the combination treatment of RH and DSS. This study demonstrates for the first time the renoprotective effect and the mechanism of RH and DSS combination on chronic renal injury. It could provide experimental evidence to support the rationality of the combinatorial use of TCM in clinical practices.

Vibroacustic microvibrations enhance kidney blood supply, glomerular filtration and glutathione peroxidase activity in spontaneously hypertensive rats.

Limited numbers of studies include research of microvibration therapy in experimental models. We examined effects of chronic vibroacustic-microvibration treatment on haemodynamics and anti-oxidative defense in experimental hypertension. Study was performed on chronically treated hypertensive and normotensive Wistar rats. Mean arterial pressure (MAP), cardiac output (CO), renal blood flow (RBF), glomerular filtration and activity of anti-oxidative enzymes were determined after three weeks treatment. Vibroacustic treatment had no influence on MAP and CO, but RBF was increased in both groups of treated rats. Additionally, vibroacustic treatment enhanced diuresis and increased glomerular filtration in hypertensive rats. Glutathione peroxidase (GSH-Px) activity was elevated in both treated rat strains, but activity of superoxide dismutase was unchanged. We conclude that microvibration treatment doesn't ameliorate hypertension but improves renal blood supply (trough diminished renal vascular resistance), glomerular filtration, diuresis, and enhances glutathione dependent anti-oxidant defense with more important beneficials in hypertensive animals.

Laparoscopic Left Partial Adrenalectomy in a Child with Von Hippel–Lindau and Recurrent Pheochromocytoma

Introduction: Patients with Von Hippel–Lindau are at high risk of developing recurrent pheochromocytoma. In this 13-year-old patient status post right adrenalectomy with recurrence on the left, we hypothesized that a laparoscopic left partial adrenalectomy would be safe and effective at removing the tumor while preserving native adrenal function.1,2 This video includes a description of the patient's case and illustrates the key portions of his procedure, including complete removal of the tumor and preservation of the renal and adrenal blood supply. Methods: Although asymptomatic, surveillance abdominal ultrasound demonstrated enlarged paraaortic lymph nodes. Follow-up serum catecholamine was elevated, and abdominal computed tomography demonstrated a mass arising from the inferior aspect of the left adrenal gland. Preoperative alpha- and beta-blockade were undertaken. He presented electively on the day of surgery and underwent a laparoscopic left partial adrenalectomy. Key portions of the procedure include mobilization of the splenic flexure, circumferential dissection of the tumor with preservation of the renal vein, renal artery, and the adrenal vein, and separation of the tumor from normal residual adrenal gland.3 Results: Final pathology demonstrated complete resection and was consistent with a 2.6×2.3×1.9 cm pheochromocytoma with intact capsule. Postoperatively, the patient recovered well, with no complications and no requirement for cortisol replacement. He was discharged home on postoperative day 2. He will continue to be followed by his endocrinologist for annual screening. Conclusions: The technique for laparoscopic partial left adrenalectomy described here has utility in the pediatric population to preserve adrenal function during years of growth. Patients with Von Hippel–Lindau are at high risk of recurrence and need continued surveillance.4 This patient will continue to benefit from preserved native adrenal function for months to years before potential recurrence. The authors have nothing to disclose. There are no potential conflicts exist with any of the authors with this publication. Runtime of video: 4 mins 43 secs

Is there room for dual blockade of the renin–angiotensin–aldosterone system?

Is there room for dual blockade of the renin–angiotensin–aldosterone system?

Clinical anatomy of adrenal blood supply in different aged groups

Renal blood supply sources of adrenals in the norm are studied in the work as well as blood supply peculiarities of unilateral adrenal and kidney in renal artery stenosis are revealed. It is concluded that including the study of adrenal arteries into angiographic algorithm in case of renal artery stenosis is of necessity.

Renalase Deficiency in Heart Failure Model of Rats—A Potential Mechanism Underlying Circulating Norepinephrine Accumulation

BackgroundSympathetic overactivity and catecholamine accumulation are important characteristic findings in heart failure, which contribute to its pathophysiology. Here, we identify a potential mechanism underlying norepinephrine accumulation in a rat model of heart failure.Methodology/Principal FindingsInitially, we constructed a rat model of unilateral renal artery stenosis (n = 16) and found that the expression of renalase, a previously identified secreted amine oxidase, was markedly reduced in the ischemic compared to the non-ischemic kidney (protein: 0.295±0.085 versus 0.765±0.171, p<0.05). Subsequently, we utilized an isolated perfused rat kidney model to demonstrate that the clearance rate of norepinephrine decreased with reduction of perfusion flow. On the basis of these findings, we hypothesized the reduced renal blood supply which occurs in heart failure would result in impaired synthesis of renalase by the kidney and consequently reduced degradation of circulating norepinephrine. To verify this, we used a rat model of infarction-induced heart failure (n = 12 per group). In these rats, the flow velocity of renal artery, when measured at four weeks, is obviously lower in the operation group. Renal expression of renalase was reduced (protein: 0.476±0.043 for control, 0.248±0.029 for operation versus 0.636±0.151 for sham-operation) and this was associated with an increase in circulating norepinephrine (0.168±0.016 ng/mL for control, 0.203±0.019 ng/mL for operation versus 0.138±0.008 ng/mL for sham-operation).Conclusions/SignificanceRenalase expression is influenced by renal blood flow and impaired synthesis of renalase by the kidney may represent a potential mechanism underlying circulating norepinephrine accumulation in heart failure.

Renoprotective effect of small volumes of hypertonic saline solution in chronic heart failure patients with marked fluid retention: results of a case-control study

During intensive therapy of chronic heart failure (CHF) patients with marked fluid retention using high doses of i.v. furosemide the additional effect of agents which might exert osmotic attraction of interstitial fluids has been proposed. They are thought to impede the impairment of renal blood supply and glomerular filtration rate, which may be caused by a combined action of cardiac preload acute reduction, hypotension and neurohormonal activation.We therefore assessed in CHF patients with NYHA class III and BNP values from 900 to 1500 pg/ml, who were treated with i.v. furosemide, the predictors of iatrogenic short term creatinine impairment by means of a case-control observational study from two centers. Patients with CHF had been treated for 6-8 days with intravenous loop diuretics alone or with an additional i.v. administration of other agents (plasma expanders, albumin, mannitol, inotropic support etc.). A rise in serum creatinine ≥ 25% of the basal value was considered as renal impairment.A total of 15 cases and 38 controls were enrolled. At univariate analysis, serum creatinine basal value ≥ 2.2 mg/dl, absence of hypertonic saline solution (HSS) in the therapeutic protocol, hyposodic diet and refractory oligoanuria were associated with an increased risk of worsening renal function precipitated by i.v. diuretic therapy. At multivariate analysis as a predictor of loop diuretic-related renal function impairment, we found a serum creatinine ≥ 2.2 mg/dl at baseline (OR: 63.33, 95% CI: 3.68-1088.73, p=0.0043) and the absence of HSS in the therapeutic regimen (OR: 25.0461, 95% CI: 2.07-302.53, p=0.0113). Moreover, in multivariate analysis ascites had some predictive value of renal deterioration (OR: 13.28, 95% CI: 1.0055-175.41, p=0,0495).

E0181 Renalase deficiency in heart failure—a novel mechanism underlying circulating norepinephrine accumulation

BackgroundSympathetic overactivity and catecholamine accumulation are important characteristic findings in heart failure, which contribute to its pathophysiology. However, the mechanism underlying circulating catecholamine accumulation remains largely unclear.ObjectiveTo identify a novel...

Ligation of the Native Ureter as an Alternative to Nephrectomy in Paediatric Renal Transplantation

Purpose Native nephrectomy before or during transplantation has some indications in paediatric recipients, including intractable hypertension, polyuria, intractable massive proteinuria, recurrent renal infections and in very young patients. Another indication for nephrectomy is the need of native ureter for urinary tract reconstruction, although ureteroneocystostomy is the primary techniques. We describe our experience about intentional ligation of native ureter as an alternative to nephrectomy in paediatric renal transplant recipients. Material and Methods Between January and October 2009, 22 paediatric renal transplants were performed. In 8 (36 %) patients (age range, 8 to 18 years; mean age, 11,6 years), a native ipsilateral nephrectomy was planned for intractable hypertension (2 pts), polyuria (3 pts), intractable massive proteinuria (1 pt), recurrent renal infections (1 pt) and irreparable lesion of the graft ureter (1 pt). All 8 patients (planned for a native nephrectomy) underwent native ureteral ligation without native nephrectomy. Follow-up ranged 1 to 9 months (mean, 4,1 months) and consisted in periodic evaluation for flank pain, renal ultrasound and doppler, urinalysis and blood pressure. Results None patients with native ureteral ligation required secondary nephrectomy. Postoperative doppler scan at 72 hours showed a decrease of blood flow to the native kidney and at 1 week absence of renal blood supply. At 8-12 weeks the ultrasound showed a complete renal atrophy. None patients had pyelonephritis or pain during follow-up period. Hypertension was not noticed. Conclusions The intentional ligation of the native ureter without native nephrectomy in paediatric renal transplant recipients is safe, effective and it represents a mininvasive alternative to surgical nephrectomy. Native nephrectomy before or during transplantation has some indications in paediatric recipients, including intractable hypertension, polyuria, intractable massive proteinuria, recurrent renal infections and in very young patients. Another indication for nephrectomy is the need of native ureter for urinary tract reconstruction, although ureteroneocystostomy is the primary techniques. We describe our experience about intentional ligation of native ureter as an alternative to nephrectomy in paediatric renal transplant recipients. Between January and October 2009, 22 paediatric renal transplants were performed. In 8 (36 %) patients (age range, 8 to 18 years; mean age, 11,6 years), a native ipsilateral nephrectomy was planned for intractable hypertension (2 pts), polyuria (3 pts), intractable massive proteinuria (1 pt), recurrent renal infections (1 pt) and irreparable lesion of the graft ureter (1 pt). All 8 patients (planned for a native nephrectomy) underwent native ureteral ligation without native nephrectomy. Follow-up ranged 1 to 9 months (mean, 4,1 months) and consisted in periodic evaluation for flank pain, renal ultrasound and doppler, urinalysis and blood pressure. None patients with native ureteral ligation required secondary nephrectomy. Postoperative doppler scan at 72 hours showed a decrease of blood flow to the native kidney and at 1 week absence of renal blood supply. At 8-12 weeks the ultrasound showed a complete renal atrophy. None patients had pyelonephritis or pain during follow-up period. Hypertension was not noticed. The intentional ligation of the native ureter without native nephrectomy in paediatric renal transplant recipients is safe, effective and it represents a mininvasive alternative to surgical nephrectomy.

448 LIGATION OF THE NATIVE URETER AS AN ALTERNATIVE TO NEPHRECTOMY IN PEDIATRIC RENAL TRANSPLANTATION

Purpose Native nephrectomy before or during transplantation has some indications in paediatric recipients, including intractable hypertension, polyuria, intractable massive proteinuria, recurrent renal infections and in very young patients. Another indication for nephrectomy is the need of native ureter for urinary tract reconstruction, although ureteroneocystostomy is the primary techniques. We describe our experience about intentional ligation of native ureter as an alternative to nephrectomy in paediatric renal transplant recipients. Material and Methods Between January and October 2009, 22 paediatric renal transplants were performed. In 8 (36 %) patients (age range, 8 to 18 years; mean age, 11,6 years), a native ipsilateral nephrectomy was planned for intractable hypertension (2 pts), polyuria (3 pts), intractable massive proteinuria (1 pt), recurrent renal infections (1 pt) and irreparable lesion of the graft ureter (1 pt). All 8 patients (planned for a native nephrectomy) underwent native ureteral ligation without native nephrectomy. Follow-up ranged 1 to 9 months (mean, 4,1 months) and consisted in periodic evaluation for flank pain, renal ultrasound and doppler, urinalysis and blood pressure. Results None patients with native ureteral ligation required secondary nephrectomy. Postoperative doppler scan at 72 hours showed a decrease of blood flow to the native kidney and at 1 week absence of renal blood supply. At 8-12 weeks the ultrasound showed a complete renal atrophy. None patients had pyelonephritis or pain during follow-up period. Hypertension was not noticed. Conclusions The intentional ligation of the native ureter without native nephrectomy in paediatric renal transplant recipients is safe, effective and it represents a mininvasive alternative to surgical nephrectomy.

Timing and Selection for Renal Revascularization in an Era of Negative Trials: What to Do?

Management of atherosclerotic renal artery stenosis has become more complex with advances in both medical therapy and endovascular procedures. Results from recent trials fail to demonstrate major benefits of endovascular stenting in addition to optimal medical therapy. The general applicability of these results to many patients is limited by short-term follow-up and selection biases in recruitment. Many patients at highest risk were excluded from these studies and some were included with trivial lesions. Identification of patients with hemodynamically significant lesions remains a challenge and has led to more stringent criteria for Doppler ultrasound, measurement of translesional gradients and quantitative angiography. Although many patients can now be managed with medical therapy, it should be recognized that long-term reduction in antihypertensive drug requirements and recovery of kidney function are limited to those undergoing renal revascularization. As with any major vascular lesion, follow-up for disease stability and/or progression is essential. The ambiguity of present trial data may lead some to overlook selected subgroups that would benefit from restoring renal blood supply through revascularization. Further studies to more precisely identify kidneys that can recover function and/or are beyond meaningful recovery are essential. Considering the comorbid risks for the atherosclerotic population, it will remain imperative for clinicians to consider the hazards, costs and benefits carefully for each patient to determine the role and timing for both medical therapy and revascularization.

Vascular fluorescence casting and imaging cryomicrotomy for computerized three-dimensional renal arterial reconstruction

Authors from the Netherlands studied the use of a casting technique, cryomicrotome imaging and three-dimensional computer analysis to visualise and reconstruct the arterial anatomy in a porcine kidney model. They found that this could be done satisfactorily to a resolution of 50 microm. To assess the combined use of a casting technique, cryomicrotomy imaging, and three-dimensional (3D) computer analysis as a method for visualizing and reconstructing the arterial vascular tree in a porcine renal model. The arterial branches of two porcine kidneys were filled with a fluorescent cast, after which they were cut into slices of 50 microm in an imaging cryomicrotome. From each section, digital images of the cutting plane of the sample were taken and stored in the computer, after which stacks of images were rendered in 3D. A 3D computerized reconstruction of the arterial vascular tree was constructed and showed the complete arterial anatomy up to arterioles of 50 microm. With visualization by fluorescence imaging cryomicrotomy, the anatomical and 3D reconstruction of the renal arterial blood supply in a pig kidney is possible up to a resolution of 50 microm.

Quantitative analysis of embryonic kidney impairment by confocal microscopy and stereology: effect of 1,2-dibromoethane in the chick mesonephros

1. Chick embryos in ovo were treated with a teratogenic dose of 1,2-dibromoethane (DBE) on embryonic day (ED) 3. On ED 6 and 10, histological sections of whole embryos were prepared for confocal microscopy. In parallel, mesonephroi of 10-d-old embryos were dissected for in situ staining with acridine orange (AO), a fluorescence probe for lysosomes. 2. DBE impaired differentiation of renal vessels which manifested as a delay in rearrangement of primitive renal vascular architecture on ED 6 and a significant reduction of the mesonephric vascularisation on ED 10. This was accompanied by delayed functional maturation of embryonic kidney, as suggested by staining with AO. 3. Renal vessels appeared to be more susceptible to DBE than tubules. Unequal growth of these renal components might be a cause of DBE-induced spatial disorganisation of tubular apparatus. 4. Nephrotoxic effects of DBE during the embryonic period are associated primarily with damage to the renal blood supply. 5. Confocal microscopy, stereological methods and three-dimensional reconstruction of developing tissues are useful tools to investigate pathogenic processes during embryonic development.

Main arterial supply of a kidney from the opposite renal artery: an unusual case

Variations in renal anatomy and blood supply are not uncommon, but a supplementary renal artery arising from the opposite renal artery is rare. In such cases the kidneys are usually malrotated and anomalous in position and form. The case of a 65-year-old man with the left main renal artery arising from the opposite renal artery and without such anomalies of the kidneys is presented.

Highlights from the Literature

Highlights from the Literature