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Philip A. Kalra - One of the best experts on this subject based on the ideXlab platform.

  • Atherosclerotic Renovascular Disease
    Oxford Textbook of Medicine, 2020
    Co-Authors: Philip A. Kalra, Diana Vassallo
    Abstract:

    Atherosclerotic Renovascular Disease (ARVD) refers to atheromatous narrowing of one or both renal arteries and frequently coexists with atherosclerotic Disease in other vascular beds. Patients with this condition are at high risk of adverse cardiovascular events, with mortality around 8% per year. Many patients with ARVD have chronic kidney Disease, but only a minority progress to endstage kidney Disease, suggesting that pre-existing hypertensive and/or ischaemic renal parenchymal injury is the usual cause of renal dysfunction. Many patients with ARVD are asymptomatic, but there can be important complications such as uncontrolled hypertension, rapid decline in kidney function, and recurrent acute heart failure (flash pulmonary oedema). Management—patients with ARVD should receive medical vascular protective therapy just like other patients with atheromatous Disease. This involves antiplatelet agents such as aspirin, statins, antihypertensive agents (angiotensin-converting enzyme inhibitors or angiotensin receptor blockers are the drugs of choice), optimization of glycaemic control in diabetic patients, and advice/help to stop smoking. On the basis of randomized controlled trial data, they should not be offered revascularization by angioplasty/stenting for the purpose of improving blood pressure control or stabilizing/improving renal function. However, there is evidence that a subgroup of patients with specific complications of ARVD (as previously mentioned) may benefit from revascularization.

  • Atherosclerotic Renovascular Disease: Epidemiology and Clinical Manifestations
    Renal Vascular Disease, 2014
    Co-Authors: James Ritchie, Philip A. Kalra
    Abstract:

    Atherosclerotic Renovascular Disease (ARVD) is a frequently occurring condition, most commonly observed in patients with other macrovascular Diseases. The presence of ARVD is associated with a significantly increased risk for cardiovascular morbidity and mortality. Although factors associated with systemic atheroma are implicated in the development of ARVD, the subsequent evolution of hypertension and renal impairment is more complex, with both whole organ and local factors playing important roles.

  • The heart in atherosclerotic Renovascular Disease.
    Frontiers in bioscience (Elite edition), 2012
    Co-Authors: Darren Green, Philip A. Kalra
    Abstract:

    Atherosclerotic Renovascular Disease (ARVD) is associated with a high rate of cardiovascular Disease and mortality. ARVD is an independent risk factor for adverse outcome in coronary artery Disease and there is a correlation between the presence of ARVD and severity of cardiovascular Disease. ARVD is the most common cause of secondary hypertension and can be found in up to half of elderly patients with chronic heart failure. Abnormal cardiac structure and / or function will be present in 95 % of ARVD patients, with left ventricular hypertrophy (LVH) and diastolic dysfunction the predominant abnormalities. These are likely to be due in part to over-activity of the renin-angiotensin pathway. Up to now, randomised trials have shown no benefit of renal artery revascularisation over medical therapy in terms of cardiovascular events but small case series clearly demonstrate situations where cardiac structure and function respond to revascularisation. Future strategies must focus on accurately identifying sub-groups of ARVD patients for whom revascularisation should be first line therapy.

  • Current views on the management of atherosclerotic Renovascular Disease.
    Annals of medicine, 2012
    Co-Authors: James Ritchie, Darren Green, Philip A. Kalra
    Abstract:

    Atherosclerotic Renovascular Disease (ARVD) is a common condition in both elderly patients and those with other vascular Disease. No published randomized controlled trial has demonstrated an overall benefit of revascularization on any clinical or biochemical end-point, and optimal medical therapy in this condition is not clearly defined. In this review we consider the epidemiology of ARVD and discuss the evidence for current medical treatment. We also address the literature on revascularization, consider settings in which an interventional approach may still be considered, and touch upon on-going areas of research.

  • Contemporary management of atherosclerotic Renovascular Disease: Before and after ASTRAL
    Nephrology (Carlton Vic.), 2011
    Co-Authors: James Ritchie, Constantina Chrysochou, Philip A. Kalra
    Abstract:

    Atheromatous Renovascular Disease is an increasingly common diagnosis in our ageing population. Although there is a wide spread of experience in its treatment, the evidence base is heterogeneous and inconclusive. The Angioplasty and Stenting for Renal Artery Lesions trial has provided some, but not all, answers regarding the place of renal revascularization therapy and has also raised more questions and generated further debate. We present a brief review of the significance of atheromatous Renovascular Disease, discussion of historical treatments, a short analysis of Angioplasty and Stenting for Renal Artery Lesions, and an exploration of where future research lies.

Alejandro R. Chade - One of the best experts on this subject based on the ideXlab platform.

  • systemic biopolymer delivered vascular endothelial growth factor promotes therapeutic angiogenesis in experimental Renovascular Disease
    Kidney International, 2017
    Co-Authors: Alejandro R. Chade, Maxx L Williams, Erika Guise, Luke J Vincent, Taylor W Harvey, Marija Kuna, Fakhri Mahdi, Gene L Bidwell
    Abstract:

    We recently developed a therapeutic biopolymer composed of an elastin-like polypeptide (ELP) fused to vascular endothelial growth factor (VEGF) and showed long-term renoprotective effects in experimental Renovascular Disease after a single intra-renal administration. Here, we sought to determine the specificity, safety, efficacy, and mechanisms of renoprotection of ELP-VEGF after systemic therapy in Renovascular Disease. We tested whether kidney selectivity of the ELP carrier would reduce off-target binding of VEGF in other organs. In vivo bio-distribution after systemic administration of ELP-VEGF in swine was determined in kidneys, liver, spleen, and heart. Stenotic-kidney renal blood flow and glomerular filtration rate were quantified in vivo using multi-detector computed tomography (CT) after six weeks of Renovascular Disease, then treated with a single intravenous dose of ELP-VEGF or placebo and observed for four weeks. CT studies were then repeated and the pigs euthanized. Ex vivo studies quantified renal microvascular density (micro-CT) and fibrosis. Kidneys, liver, spleen, and heart were excised to quantify the expression of angiogenic mediators and markers of progenitor cells. ELP-VEGF accumulated predominantly in the kidney and stimulated renal blood flow, glomerular filtration rate, improved cortical microvascular density, and renal fibrosis, and was accompanied by enhanced renal expression of VEGF, downstream mediators of VEGF signaling, and markers of progenitor cells compared to placebo. Expression of angiogenic factors in liver, spleen, and heart were not different compared to placebo-control. Thus, ELP efficiently directs VEGF to the kidney after systemic administration and induces long-term renoprotection without off-target effects, supporting the feasibility and safety of renal therapeutic angiogenesis via systemic administration of a novel kidney-specific bioengineered compound.

  • Disparate effects of single endothelin-A and -B receptor blocker therapy on the progression of renal injury in advanced Renovascular Disease.
    Kidney international, 2013
    Co-Authors: Alejandro R. Chade, Nicholas J. Stewart, Patrick R. Peavy
    Abstract:

    We hypothesized that chronic specific endothelin-A (ET-A) receptor blockade therapy would reverse renal dysfunction and injury in advanced experimental Renovascular Disease. To test this, unilateral Renovascular Disease was induced in 19 pigs, and after 6 weeks, single-kidney hemodynamics and function was quantified in vivo using computed tomography. All pigs with Renovascular Disease were divided such that seven were untreated, seven were treated with ET-A blockers, and five were treated with ET-B blockers. Four weeks later, all pigs were restudied in vivo, and then killed and ex vivo studies performed on the stenotic kidney to quantify microvascular density, remodeling, renal oxidative stress, inflammation, and fibrosis. Renal blood flow, glomerular filtration rate, and redox status were significantly improved in the stenotic kidney after ET-A but not ET-B blockade. Furthermore, only ET-A blockade therapy reversed renal microvascular rarefaction and diminished remodeling, which was accompanied by a marked decreased in renal inflammatory and fibrogenic activity. Thus, ET-A but not ET-B blockade ameliorated renal injury in pigs with advanced Renovascular Disease by stimulating microvascular proliferation and decreasing the progression of microvascular remodeling, renal inflammation, and fibrosis in the stenotic kidney. These effects were functionally consequential as ET-A blockade improved single kidney microvascular endothelial function, renal blood flow, and glomerular filtration rate, and decreased albuminuria.

  • Angiogenic cytokines in Renovascular Disease: do they have potential for therapeutic use?
    Journal of the American Society of Hypertension : JASH, 2013
    Co-Authors: Alejandro R. Chade, Nicholas J. Stewart
    Abstract:

    Experimental and clinical studies suggest that the damage of the renal microvascular function and architecture may participate in the early steps of renal injury in chronic renal Disease, irrespective of the cause. This supporting evidence has provided the impetus to targeting the renal microvasculature as an attempt to interfere with the progressive nature of the Disease process. Chronic Renovascular Disease is often associated with renal microvascular dysfunction, damage, loss, and defective renal angiogenesis associated with progressive renal dysfunction and damage. It is possible that damage of the renal microvasculature in Renovascular Disease constitutes an initiating event for renal injury and contributes towards progressive and later on irreversible renal injury. Recent studies have suggested that protection of the renal microcirculation can slow or halt the progression of renal injury in this Disease. This brief review will focus on the therapeutic potential and feasibility of using angiogenic cytokines to protect the kidney microvasculature in chronic Renovascular Disease. There is limited but provocative evidence showing that stimulation of vascular proliferation and repair using vascular endothelial growth factor or hepatocyte growth factor can slow the progression of renal damage, stabilize renal function, and protect the renal parenchyma. Such interventions may potentially constitute a sole strategy to preserve renal function and/or a co-adjuvant tool to improve the success of current therapeutic approaches in Renovascular Disease.

  • Role of renal microcirculation in experimental Renovascular Disease
    Nephrology dialysis transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association, 2009
    Co-Authors: Radu Iliescu, Solana R. Fernandez, Silvia Kelsen, Christine Maric, Alejandro R. Chade
    Abstract:

    Background. Renal artery stenosis (RAS) causes renal injury partly via microvascular (MV) endothelial dysfunction and damage. Vascular endothelial growth factor (VEGF) is crucial for preservation of microvasculature and promotes vascular proliferation and endothelial repair. We have previously shown that MV rarefaction is associated with decreased VEGF in the kidney exposed to chronic RAS, accompanied by deteriorated renal function and fibrosis. We hypothesized that preserving the renal microcirculation in the stenotic kidney will halt the progression of renal damage. Methods. Unilateral RAS was induced in 16 pigs. In eight, VEGF (0.05 micrograms/kg) was infused intra-renally at the onset of RAS. After 6 weeks, single-kidney haemodynamics and function were assessed using in vivo multi-detector computed tomography (CT). Renal microvessels, angiogenic pathways and morphology were investigated ex vivo using micro-CT, real-time PCR and histology. Results. Blood pressure and degree of RAS was similar in RAS and RAS + VEGF pigs. Single-kidney renal blood flow (RBF) and glomerular filtration rate (GFR) were reduced in RAS compared to Normal (221.1 ± 46.5 and 29.9 ± 3.8 vs. 522.5 ± 60.9 and 49.3 ± 3.4 mL/min, respectively, P < 0.05), accompanied by decreased cortical MV density and increased renal fibrosis. Pre-emptive administration of VEGF preserved MV architecture, attenuated fibrosis and normalized RBF and GFR (510.8 ± 50.9 and 39.9.1 ± 4.1 mL/min, P = not significant vs. Normal). Conclusions. This study underscores the importance of the renal microcirculation in Renovascular Disease. Intra-renal administration of VEGF preserved renal MV architecture and function of the stenotic kidney, which in turn preserved renal haemodynamics and function and decreased renal fibrosis. These observations suggest that preventing renal MV loss may be a potential target for therapeutic approaches for patients with chronic Renovascular Disease.

  • endothelial progenitor cells restore renal function in chronic experimental Renovascular Disease
    Circulation, 2009
    Co-Authors: Alejandro R. Chade, James D. Krier, Amir Lerman, Claudio Napoli, Xiang Yang Zhu, Ronit Lavi, Sorin V Pislaru, Robert D Simari, Lilach O. Lerman
    Abstract:

    Background—Endothelial progenitor cells (EPCs) promote neovascularization and endothelial repair. Renal artery stenosis (RAS) may impair renal function by inducing intrarenal microvascular injury and remodeling. We investigated whether replenishment with EPCs would protect the renal microcirculation in chronic experimental Renovascular Disease. Methods and Results—Single-kidney hemodynamics and function were assessed with the use of multidetector computed tomography in vivo in pigs with RAS, pigs with RAS 4 weeks after intrarenal infusion of autologous EPCs, and controls. Renal microvascular remodeling and angiogenic pathways were investigated ex vivo with the use of micro–computed tomography, histology, and Western blotting. EPCs increased renal expression of angiogenic factors, stimulated proliferation and maturation of new vessels, and attenuated renal microvascular remodeling and fibrosis in RAS. Furthermore, EPCs normalized the blunted renal microvascular and filtration function. Conclusions—The present study shows that a single intrarenal infusion of autologous EPCs preserved microvascular architecture and function and decreased microvascular remodeling in experimental chronic RAS. It is likely that restoration of the angiogenic cascade by autologous EPCs involved not only generation of new vessels but also acceleration of their maturation and stabilization. This contributed to preserving the blood supply, hemodynamics, and function of the RAS kidney, supporting EPCs as a promising therapeutic intervention for preserving the kidney in Renovascular Disease. (Circulation. 2009;119:547-557.)

Kimberley J. Hansen - One of the best experts on this subject based on the ideXlab platform.

  • Randomized clinical trials regarding management of atherosclerotic Renovascular Disease.
    Seminars in vascular surgery, 2010
    Co-Authors: Shawn H. Fleming, Kimberley J. Hansen
    Abstract:

    Prospective randomized clinical trials that support operative correction of atherosclerotic Renovascular Disease or catheter-based intervention compared with optimal medical management are lacking. Despite various limitations in study design, each of the five randomized trials reported to date had demonstrated no apparent benefit for renal artery intervention compared with medical management. Three ongoing randomized trials promise to provide additional data and the results of these latter studies will likely dictate future reimbursement through the Centers for Medicare and Medicaid Services.

  • Renovascular Disease and the risk of adverse coronary events in the elderly: a prospective, population-based study.
    Archives of internal medicine, 2005
    Co-Authors: Matthew S. Edwards, Richard H. Dean, Timothy E. Craven, Gregory L. Burke, Kimberley J. Hansen
    Abstract:

    Background Renovascular Disease is a cause of secondary hypertension and renal insufficiency and is suspected to contribute to morbidity and mortality of coronary heart Disease. This investigation prospectively examined associations between Renovascular Disease and adverse coronary events among a population-based sample of elderly Americans. Methods The Cardiovascular Health Study is a prospective, multicenter cohort study of cardiovascular Disease risk factors, morbidity, and mortality among Americans older than 65 years. Renal duplex sonography was performed on 870 individuals between January 1995 and February 1997. Renovascular Disease was defined as any focal peak systolic velocity of 1.8 m/s or greater (renal artery stenosis) or the absence of a Doppler-shifted signal from an imaged artery (renal artery occlusion). Adverse coronary events were defined as hospitalized angina, fatal or nonfatal myocardial infarction, and coronary revascularization. Results During a mean follow-up of 14 months, 68 participants experienced incident or recurrent adverse coronary events. The presence of Renovascular Disease demonstrated a significant relationship with adverse coronary events (hazard ratio, 1.96; 95% confidence interval, 1.00-3.83; P  = .05) that remained after controlling for the effects of coexisting atherosclerotic risk factors and prevalent cardiovascular Disease. The relationship between Renovascular Disease and adverse coronary events was not dependent on the effects of increased blood pressure. Conclusions The presence of Renovascular Disease was associated with an increase in the risk of adverse coronary events in this sample. The increment in risk was not dependent on the effects of associated atherosclerotic risk factors, other prevalent cardiovascular Disease, or increased blood pressure.

  • Renovascular Disease in children and adolescents
    Journal of vascular surgery, 2005
    Co-Authors: K. Todd Piercy, Richard H. Dean, Timothy E. Craven, Jonathan C. Hundley, Jeanette M. Stafford, Shashi K. Nagaraj, Kimberley J. Hansen
    Abstract:

    Purpose This retrospective review describes the surgical management of Renovascular Disease in 25 consecutive children and adolescents with severe hypertension. Methods Patients ≤21 years of age (mean age, 11.6 ± 5.4 years; 12 females, 13 males) underwent repair of 34 renal arteries (RAs), and their management forms the basis of this report. Early and late blood pressure responses were adjusted for gender, age, and height. RA repair was evaluated by angiography, renal duplex sonography (RDS) scanning, or both. Primary patency and survival were estimated by product-limit methods. Results Thirty-four RAs among 32 kidneys were repaired. Bilateral renal RA Disease to a solitary kidney was present in nine patients. RA lesions included dysplasia (44%), RA hypoplasia (20%), midaortic syndrome (12%), RA aneurysm (12%), dissection (8%), and arteritis (4%). All patients had severe hypertension (>95 th percentile systolic or diastolic pressure adjusted for gender, age, and height). RA repair comprised 25 bypasses (73%) consisting of 28% saphenous vein, 60% hypogastric artery, and 12% polytetrafluoroethylene; 2 patch angioplasties (6%), and 7 reimplantations (21%). Branch RA exposure was required in 28 kidneys (88%), and branch reconstruction was required in 61%. Warm in situ repair was used in 53%, in situ cold perfusion in 24%, and ex vivo cold perfusion in 23%. Of six bilateral RA repairs, one was staged and two patients are awaiting a staged repair. Combined aortic reconstruction was required in three patients. No unplanned nephrectomy was performed. There were no perioperative deaths. Hypertension was cured in 36%, improved in 56%, and failed in 8% at mean follow-up of 46.4 ± 7.8 months. The mean calculated glomerular filtration rate increased from 82.0 mL/min/1.73 m 2 preoperatively to 98.2 mL/min/1.73 m 2 postoperatively. The postoperative patency of 30 RA reconstructions was evaluated by angiography, RDS scanning, or both. At mean follow-up of 32.8 months (median, 21.2 months), primary RA patency was 91%. No failures were observed after 2 months follow-up. Estimated survival was 100% at 60 months, with one death 9 years after surgery. Conclusions Renovascular hypertension in children and adolescents was caused by a heterogeneous group of lesions. All patients had RA repair, with arterial autografts in most of the RA bypasses. Cold perfusion preservation was used in half of the complex branch RA repairs. These strategies provided 91% primary patency at mean follow-up of 32.8 months, with beneficial blood pressure response in 92%. Surgical repair of clinically significant Renovascular Disease in children and adolescents is supported by these results.

  • surgical management of atherosclerotic Renovascular Disease
    Journal of Vascular Surgery, 2002
    Co-Authors: Gregory S Cherr, Kimberley J. Hansen, Matthew S. Edwards, Timothy E. Craven, John Ligush, Pavel J Levy, Barry I Freedman, Richard H. Dean
    Abstract:

    Abstract Objective: This review describes the clinical outcome of surgical intervention for atherosclerotic Renovascular Disease in 500 consecutive patients with hypertension. Methods: From January 1987 to December 1999, 626 patients underwent operative renal artery (RA) repair at our center. A subgroup of 500 patients (254 women and 246 men; mean age, 65 ± 9 years) with hypertension (mean blood pressure, 200 ± 35/104 ± 21 mm Hg) and atherosclerotic RA Disease forms the basis of this report. Hypertension response was determined from preoperative and postoperative blood pressure measurements and medication requirements. Change in renal function was determined with estimated glomerular filtration rates (EGFRs) calculated from serum creatinine levels. Proportional hazards regression models were used for the examination of associations between selected preoperative parameters, blood pressure and renal function response, and eventual dialysis-dependence or death. Results: Two hundred three patients underwent unilateral RA procedures, 297 underwent bilateral RA procedures, and 205 patients underwent combined renal and aortic reconstruction. After surgery, there were 23 deaths (4.6%) in the hospital or within 30 days of surgery. Significant and independent predictors of perioperative death included advanced age ( P P =.013; HR, 3.05; 95% CI, 1.26 to 7.34). Among the patients who survived surgery, hypertension was considered cured in 12%, improved in 73%, and unchanged in 15%. For the entire group, renal function increased significantly after operation (preoperative versus postoperative mean EGFR, 41.1 ± 23.9 versus 48.2 ± 25.5 mL/min/m 2 ; P P P =.007; HR, 2.14; 95% CI, 1.15 to 3.97), prior stroke ( P =.042; HR, 1.50; 95% CI, 1.02 to 2.22), and severe aortic occlusive Disease ( P =.003; HR, 1.69; 95% CI, 1.19 to 2.31) showed significant and independent associations with death or dialysis during the follow-up examination period. After operation, blood pressure cured ( P =.014; HR, 0.52; 95% CI, 0.30 to 0.88) and improved renal function ( P =.011; HR, 0.40; 95% CI, 0.19 to 0.81) showed significant and independent associations with improved dialysis-free survival rate. All categories of function response and time to death or dialysis showed significant interactions with preoperative EGFR. Conclusion: The surgical correction of atherosclerotic Renovascular Disease resulted in blood pressure benefit and retrieval of renal function in selected patients with hypertension. The patients with cured hypertension or improved EGFR after operation showed increased dialysis-free survival as compared with other patients who underwent surgery. (J Vasc Surg 2002;35:236-45.)

  • Renovascular Disease in Blacks: Prevalence and Result of Operative Management
    The American journal of the medical sciences, 1998
    Co-Authors: Domenic A. Sica, Kimberley J. Hansen, Jonathan Deitch, Richard H. Dean
    Abstract:

    ABSTRACT Hypertension in blacks differs in a quantitative sense from hypertension in whites; it occurs in blacks with greater frequency and severity and at a younger age when compared with whites. In addition, elevated blood pressure at any level is associated with increased cardiovascular morbidity and mortality in black patients. Several mechanisms have been suggested to account for this form of hypertension, implying that hypertension in black patients is intrinsically different from that in whites. Although these mechanisms remain unproven, it has generally been accepted that correctable Renovascular Disease and Renovascular hypertension (RVH) occur infrequently in blacks; the authors, however, will review preliminary populationbased data which suggest that the presence of renal artery Disease is not determined by raceor ethnicity. In addition, the prevalence of Renovascular Disease in a large group of consecutive hypertensive subjects will be presented.Finally, the blood pressure and renal function response after surgical renal artery repair in blacks will be compared with whites treated at the authors' institution. Taken collectively, these data and clinical experience support the search for and treatment of renal artery Disease in properly selected hypertensive blacks. KEY INDEXING TERMS: Hypertension; Renovascular Disease; Renovascular hypertension.[Am J Med Sci 1998;315(5):337-342.]

Richard H. Dean - One of the best experts on this subject based on the ideXlab platform.

  • Renovascular Disease and the risk of adverse coronary events in the elderly: a prospective, population-based study.
    Archives of internal medicine, 2005
    Co-Authors: Matthew S. Edwards, Richard H. Dean, Timothy E. Craven, Gregory L. Burke, Kimberley J. Hansen
    Abstract:

    Background Renovascular Disease is a cause of secondary hypertension and renal insufficiency and is suspected to contribute to morbidity and mortality of coronary heart Disease. This investigation prospectively examined associations between Renovascular Disease and adverse coronary events among a population-based sample of elderly Americans. Methods The Cardiovascular Health Study is a prospective, multicenter cohort study of cardiovascular Disease risk factors, morbidity, and mortality among Americans older than 65 years. Renal duplex sonography was performed on 870 individuals between January 1995 and February 1997. Renovascular Disease was defined as any focal peak systolic velocity of 1.8 m/s or greater (renal artery stenosis) or the absence of a Doppler-shifted signal from an imaged artery (renal artery occlusion). Adverse coronary events were defined as hospitalized angina, fatal or nonfatal myocardial infarction, and coronary revascularization. Results During a mean follow-up of 14 months, 68 participants experienced incident or recurrent adverse coronary events. The presence of Renovascular Disease demonstrated a significant relationship with adverse coronary events (hazard ratio, 1.96; 95% confidence interval, 1.00-3.83; P  = .05) that remained after controlling for the effects of coexisting atherosclerotic risk factors and prevalent cardiovascular Disease. The relationship between Renovascular Disease and adverse coronary events was not dependent on the effects of increased blood pressure. Conclusions The presence of Renovascular Disease was associated with an increase in the risk of adverse coronary events in this sample. The increment in risk was not dependent on the effects of associated atherosclerotic risk factors, other prevalent cardiovascular Disease, or increased blood pressure.

  • Renovascular Disease in children and adolescents
    Journal of vascular surgery, 2005
    Co-Authors: K. Todd Piercy, Richard H. Dean, Timothy E. Craven, Jonathan C. Hundley, Jeanette M. Stafford, Shashi K. Nagaraj, Kimberley J. Hansen
    Abstract:

    Purpose This retrospective review describes the surgical management of Renovascular Disease in 25 consecutive children and adolescents with severe hypertension. Methods Patients ≤21 years of age (mean age, 11.6 ± 5.4 years; 12 females, 13 males) underwent repair of 34 renal arteries (RAs), and their management forms the basis of this report. Early and late blood pressure responses were adjusted for gender, age, and height. RA repair was evaluated by angiography, renal duplex sonography (RDS) scanning, or both. Primary patency and survival were estimated by product-limit methods. Results Thirty-four RAs among 32 kidneys were repaired. Bilateral renal RA Disease to a solitary kidney was present in nine patients. RA lesions included dysplasia (44%), RA hypoplasia (20%), midaortic syndrome (12%), RA aneurysm (12%), dissection (8%), and arteritis (4%). All patients had severe hypertension (>95 th percentile systolic or diastolic pressure adjusted for gender, age, and height). RA repair comprised 25 bypasses (73%) consisting of 28% saphenous vein, 60% hypogastric artery, and 12% polytetrafluoroethylene; 2 patch angioplasties (6%), and 7 reimplantations (21%). Branch RA exposure was required in 28 kidneys (88%), and branch reconstruction was required in 61%. Warm in situ repair was used in 53%, in situ cold perfusion in 24%, and ex vivo cold perfusion in 23%. Of six bilateral RA repairs, one was staged and two patients are awaiting a staged repair. Combined aortic reconstruction was required in three patients. No unplanned nephrectomy was performed. There were no perioperative deaths. Hypertension was cured in 36%, improved in 56%, and failed in 8% at mean follow-up of 46.4 ± 7.8 months. The mean calculated glomerular filtration rate increased from 82.0 mL/min/1.73 m 2 preoperatively to 98.2 mL/min/1.73 m 2 postoperatively. The postoperative patency of 30 RA reconstructions was evaluated by angiography, RDS scanning, or both. At mean follow-up of 32.8 months (median, 21.2 months), primary RA patency was 91%. No failures were observed after 2 months follow-up. Estimated survival was 100% at 60 months, with one death 9 years after surgery. Conclusions Renovascular hypertension in children and adolescents was caused by a heterogeneous group of lesions. All patients had RA repair, with arterial autografts in most of the RA bypasses. Cold perfusion preservation was used in half of the complex branch RA repairs. These strategies provided 91% primary patency at mean follow-up of 32.8 months, with beneficial blood pressure response in 92%. Surgical repair of clinically significant Renovascular Disease in children and adolescents is supported by these results.

  • surgical management of atherosclerotic Renovascular Disease
    Journal of Vascular Surgery, 2002
    Co-Authors: Gregory S Cherr, Kimberley J. Hansen, Matthew S. Edwards, Timothy E. Craven, John Ligush, Pavel J Levy, Barry I Freedman, Richard H. Dean
    Abstract:

    Abstract Objective: This review describes the clinical outcome of surgical intervention for atherosclerotic Renovascular Disease in 500 consecutive patients with hypertension. Methods: From January 1987 to December 1999, 626 patients underwent operative renal artery (RA) repair at our center. A subgroup of 500 patients (254 women and 246 men; mean age, 65 ± 9 years) with hypertension (mean blood pressure, 200 ± 35/104 ± 21 mm Hg) and atherosclerotic RA Disease forms the basis of this report. Hypertension response was determined from preoperative and postoperative blood pressure measurements and medication requirements. Change in renal function was determined with estimated glomerular filtration rates (EGFRs) calculated from serum creatinine levels. Proportional hazards regression models were used for the examination of associations between selected preoperative parameters, blood pressure and renal function response, and eventual dialysis-dependence or death. Results: Two hundred three patients underwent unilateral RA procedures, 297 underwent bilateral RA procedures, and 205 patients underwent combined renal and aortic reconstruction. After surgery, there were 23 deaths (4.6%) in the hospital or within 30 days of surgery. Significant and independent predictors of perioperative death included advanced age ( P P =.013; HR, 3.05; 95% CI, 1.26 to 7.34). Among the patients who survived surgery, hypertension was considered cured in 12%, improved in 73%, and unchanged in 15%. For the entire group, renal function increased significantly after operation (preoperative versus postoperative mean EGFR, 41.1 ± 23.9 versus 48.2 ± 25.5 mL/min/m 2 ; P P P =.007; HR, 2.14; 95% CI, 1.15 to 3.97), prior stroke ( P =.042; HR, 1.50; 95% CI, 1.02 to 2.22), and severe aortic occlusive Disease ( P =.003; HR, 1.69; 95% CI, 1.19 to 2.31) showed significant and independent associations with death or dialysis during the follow-up examination period. After operation, blood pressure cured ( P =.014; HR, 0.52; 95% CI, 0.30 to 0.88) and improved renal function ( P =.011; HR, 0.40; 95% CI, 0.19 to 0.81) showed significant and independent associations with improved dialysis-free survival rate. All categories of function response and time to death or dialysis showed significant interactions with preoperative EGFR. Conclusion: The surgical correction of atherosclerotic Renovascular Disease resulted in blood pressure benefit and retrieval of renal function in selected patients with hypertension. The patients with cured hypertension or improved EGFR after operation showed increased dialysis-free survival as compared with other patients who underwent surgery. (J Vasc Surg 2002;35:236-45.)

  • Renovascular Disease in Blacks: Prevalence and Result of Operative Management
    The American journal of the medical sciences, 1998
    Co-Authors: Domenic A. Sica, Kimberley J. Hansen, Jonathan Deitch, Richard H. Dean
    Abstract:

    ABSTRACT Hypertension in blacks differs in a quantitative sense from hypertension in whites; it occurs in blacks with greater frequency and severity and at a younger age when compared with whites. In addition, elevated blood pressure at any level is associated with increased cardiovascular morbidity and mortality in black patients. Several mechanisms have been suggested to account for this form of hypertension, implying that hypertension in black patients is intrinsically different from that in whites. Although these mechanisms remain unproven, it has generally been accepted that correctable Renovascular Disease and Renovascular hypertension (RVH) occur infrequently in blacks; the authors, however, will review preliminary populationbased data which suggest that the presence of renal artery Disease is not determined by raceor ethnicity. In addition, the prevalence of Renovascular Disease in a large group of consecutive hypertensive subjects will be presented.Finally, the blood pressure and renal function response after surgical renal artery repair in blacks will be compared with whites treated at the authors' institution. Taken collectively, these data and clinical experience support the search for and treatment of renal artery Disease in properly selected hypertensive blacks. KEY INDEXING TERMS: Hypertension; Renovascular Disease; Renovascular hypertension.[Am J Med Sci 1998;315(5):337-342.]

  • Duplex scanning in Renovascular Disease
    Geriatric Nephrology and Urology, 1996
    Co-Authors: Kimberley J. Hansen, Scott W. Reavis, Richard H. Dean
    Abstract:

    This review describes our experience with renal duplex sonography (RDS) in the elderly as a screening study for Renovascular Disease and as an intraoperative completion study to define technical error after operative renal artery repair. Methods of patient preparation, technical aspects of renal duplex interrogation and the comparison of RDS results with angiography in the elderly are presented in detail. In the hands of an experienced sonologist, RDS examination performed according to these methods and techniques correlates highly with angiography. We believe renal duplex sonography is the preferred screening test for main renal artery stenosis and occlusion in the elderly population.

Lilach O. Lerman - One of the best experts on this subject based on the ideXlab platform.

  • ROS in Atherosclerotic Renovascular Disease
    Studies on Atherosclerosis, 2016
    Co-Authors: Xiang Yang Zhu, Lilach O. Lerman
    Abstract:

    The hallmark of atherosclerotic Renovascular Disease (ARVD) is activation of the renin-angiotensin-aldosterone system, in which Ang II induces NAD(P)H oxidase-derived reactive oxygen species (ROS). Renovascular hypertension may also induce oscillatory shear stress, which is linked to increased ROS production with consequent oxidative damage. Induction of these signaling cascades leads to expression of pro-inflammatory mediators, cell apoptosis, and modification of extracellular matrix, eventuating in endothelial dysfunction, glomerulosclerosis, microvascular rarefaction, and tissue fibrosis. ROS-mediated kidney injury, primarily in the stenotic and also in the contralateral kidney, impair renal function. Intervention with antioxidants has the potential to improve renal function in experimental setting but failed to translate into clinical outcome. Angiotensin converting enzyme inhibitor/angiotensin receptor blockers have showed potential of attenuation of oxidative stress while improving clinical outcome. Stem cells combined with percutaneous transluminal renal angioplasty has promising results in experimental ARVD and translational studies are urgently needed in this area.

  • Obesity and Renovascular Disease
    American journal of physiology. Renal physiology, 2015
    Co-Authors: Xin Zhang, Lilach O. Lerman
    Abstract:

    Obesity remains a prominent public health concern. Obesity not only contributes greatly to cardiovascular events but has also been identified to initiate and affect the progression of preexisting chronic kidney Disease. The prevalence of renal artery stenosis is growing world-wide, especially in the elderly population and in individuals with atherosclerotic risk factors such as obesity. Prolonged Renovascular Disease causes inflammation and microvascular remodeling within the post-stenotic kidney, which promote tissue scarring and may account for irreversible renal damage. Obesity has been shown to aggravate kidney damage via several pathways, including exacerbation of microvascular regression and renal cell injury mediated by adipocytes and insulin resistance, thereby worsening the structural and functional outcomes of the kidney in Renovascular Disease. Dietary modification and inhibition of the renin-angiotensin-aldosterone system have been shown to alleviate obesity-induced tissue injury and remodeling. Possibly, angiogenic factors may boost microvascular repair in the ischemic kidney in the obesity milieu. Novel therapeutic interventions targeting deleterious pathways that are activated by obesity and responsible for kidney damage need to be explored in future studies.

  • Paradigm Shifts in Atherosclerotic Renovascular Disease: Where Are We Now?
    Journal of the American Society of Nephrology : JASN, 2015
    Co-Authors: Stephen C. Textor, Lilach O. Lerman
    Abstract:

    Results of recent clinical trials and experimental studies indicate that whereas atherosclerotic Renovascular Disease can accelerate both systemic hypertension and tissue injury in the poststenotic kidney, restoring vessel patency alone is insufficient to recover kidney function for most subjects. Kidney injury in atherosclerotic Renovascular Disease reflects complex interactions among vascular rarefication, oxidative stress injury, and recruitment of inflammatory cellular elements that ultimately produce fibrosis. Classic paradigms for simply restoring blood flow are shifting to implementation of therapy targeting mitochondria and cell-based functions to allow regeneration of vascular, glomerular, and tubular structures sufficient to recover, or at least stabilize, renal function. These developments offer exciting possibilities of repair and regeneration of kidney tissue that may limit progressive CKD in atherosclerotic Renovascular Disease and may apply to other conditions in which inflammatory injury is a major common pathway.

  • Approach to the Patient with Chronic Kidney Disease and Renovascular Disease
    Chronic Renal Disease, 2015
    Co-Authors: Stephen C. Textor, Lilach O. Lerman
    Abstract:

    Renovascular Disease results most commonly from atherosclerotic vascular occlusion. Although clinically significant loss of GFR is characteristic of its more severe forms, Renovascular Disease is often complicated by widespread cardiovascular manifestations and pre-existing microvascular injury, making management of these patients challenging. The kidney tolerates moderate reductions of blood flow and oxygenation, but severe arterial occlusion eventually leads to loss of kidney function. Recent studies demonstrate pro-inflammatory changes in the renal vasculature preceding kidney injury, which are followed by rarefaction of the renal microvasculature. Tissue inflammation and fibrosis ensue and eventually reach a point of irreversible structural injury that precludes recovery of glomerular filtration. Medical treatment of hypertension, comorbidities, anemia and electrolyte disorders is the cornerstone of management for these patients. Renal revascularization is beneficial for selected patients with progressive decline in kidney function, refractory hypertension and/or recurrent circulatory congestion or pulmonary edema. Experimental studies indicate that novel adjunctive measures, including cell-based therapies, may attenuate injury or facilitate renal repair mechanisms for more effective recovery of kidney function.

  • human Renovascular Disease estimating fractional tissue hypoxia to analyze blood oxygen level dependent mr
    Radiology, 2013
    Co-Authors: Ahmed Saad, Lilach O. Lerman, Sandra M. Herrmann, John A Crane, James F Glockner, Hannah Friedman, Behzad Ebrahimi, Stephen C. Textor
    Abstract:

    Fractional kidney hypoxia correlated inversely with renal blood flow, cortical or medullary perfusion, and glomerular filtration rate in human subjects with essential hypertension and atherosclerotic Renovascular Disease; whether these estimates will allow the clinician to quantify the severity of vascular occlusive kidney Disease and predict renal functional response (eg, beyond revascularization of atherosclerotic renal artery stenosis) merits further investigation.