A Rare Case of Focal Renal Fibromuscular Dysplasia Treated With Angioplasty: A Case Report.

BACKGROUND: Fibromuscular dysplasia is an idiopathic, segmental, nonatherosclerotic, noninflammatory vascular disease that can lead to arterial stenosis, tortuosity, occlusion, aneurysms, and dissection. Fibromuscular dysplasia is a rare cause of hypertension that can easily be missed. To date, there has been no definitive treatment for fibromuscular dysplasia. CASE REPORT: In this report, we present an uncommon case of renovascular hypertension in a 21-year-old non-white female with a 3-year history of hypertension secondary to fibromuscular dysplasia involving bilateral renal arteries. Computed tomography angiography during the arterial phase revealed distal focal narrowing of the right main renal artery, distal focal narrowing of the left main renal artery, and proximal focal narrowing of the left accessory lower renal artery. Percutaneous balloon dilatation of the stenotic lesion was performed successfully up to 1 year After the procedure, the arterial blood pressure was within the normal range (110/70 to 125/75 mmHg) without medication. After 1 year of follow-up, CTA revealed re-stenosis in left main renal artery without clinical symptoms and normal blood pressure. Repeated procedure was done successfully. CONCLUSIONS: This case report highlights the difficulty in the diagnosis and treatment of focal fibromuscular dysplasia in young non-white female patients. Computerized tomographic angiography is a useful tool for identifying the cause and showing the benefit of percutaneous transluminal renal angioplasty treatment for this rare entity, as an early percutaneous angioplasty intervention may have a clinical cure for hypertension.

Posterior Reversible Encephalopathy Syndrome in a Child With Renovascular Hypertension.

A 6-year-old child presented with headache for 1 month and seizures followed by altered consciousness for 1 day. He had new-onset daily occipital headache for 1 month of mild to moderate severity and pulsating character. What is your diagnosis?

Defining Hemodynamic Significance of Renal Artery Stenosis: Insights From a Porcine Model of Graded Renal Artery Stenosis.

RATIONALE AND OBJECTIVES: To investigate the renal pressure-flow relationship and its relation to renin release, because the renal perfusion pressure below which renal flow starts to decline and renin secretion is upregulated is unclear. MATERIALS AND METHODS: A porcine model of graded unilateral renal artery stenosis was created. The severity of the stenosis was expressed as the ratio between distal renal pressure (Pd) and aortic pressure (Pa). Pd and renal flow velocity were continuously measured using a combined pressure-flow wire (Combowire®). Hemodynamic measurements and blood sampling for renin, angiotensin and aldosterone were performed in baseline conditions and during progressive balloon inflation in the renal artery leading to Pd decrease per 5% increment. Resistive index (RI) was computed as (1 - (End Diastolic V/Peak Systolic V))*100. RESULTS: For a 5% decrease in renal perfusion pressure (95% of aortic pressure or 5% decrease compared to Pa), peak systolic velocity started to decrease. A significant decrease in average peak flow velocity was observed when distal renal perfusion pressure decreased by 25% and was associated with activation of ipsilateral renin secretion. The RI decreased already for minimal changes in Pd/Pa ratio. CONCLUSION: In an animal model of unilateral graded renal artery stenosis, a 25% decrease in perfusion pressure results in a significant decrease in distal renal flow, causing upregulation of renin secretion.

Long-term outcomes of angioplasty for pediatric renovascular hypertension: A single-center experience.

OBJECTIVES: We used single-center data to evaluate the long-term outcome of percutaneous transluminal angioplasty (PTA) for pediatric renovascular hypertension (RVH) and to analyze the factors that influence effectiveness. METHODS: We retrospectively evaluated 33 pediatric RVH patients (18 boys; mean age: 9.1 ± 4 years, range: 2-16) who underwent PTA from January 2007 to December 2019. 15 patients had Takayasu arteritis (TA) and 18 were non-TA. The median follow-up from the initial PTA was 69 months (range: 12-157; IQR: 25.5-89). RESULTS: The technical success rate of 52 PTA procedures was 90.4% in 33 children. Renal artery stents were implanted in two patients, external guidewires were used in two patients, and a drug-coated balloon was used in only one patient. The overall effective rate of PTA was 63.6%, including cured 39.4% and improved 24.2%, at the end of follow-up. Overall clinical outcomes were not statistically different between the TA and non-TA groups (p = 0.316), nor were cure rates (p = 0.072). 15 patients received reintervention due to restenosis after the first successful PTA; the interval was 2-56 months (median: 12 months). Four patients received reintervention due to a failed PTA. A total of four patients received open surgery. Binary logistics regression analysis showed that stenosis length and residual stenosis rate were strongly correlated with effective PTA (p = 0.045, p = 0.044). CONCLUSIONS: As a primary treatment for pediatric RVH, PTA can achieve satisfactory results, which are influenced by lesion length and residual stenosis rate.

Renal Artery Stenosis due to Entrapment.

BACKGROUND: Common etiologies of renovascular occlusive disease include atherosclerosis disease, developmental fibrotic conditions such as fibromuscular dysplasia, and vasculitis. Extrinsic compression of the renal artery is a rarely reported phenomenon but can lead to similar clinical manifestations. METHODS: We report recent experience with 2 patients who presented with extrinsic renal artery compression due to entrapment. Diagnosis was made with a constellation of findings on computed tomography angiography, dynamic duplex sonography, and catheter angiography. Both patients had hypertension and 1 had downstream subsegmental renal infarcts. The patients, both with right-sided renal artery entrapment, were treated with open surgical decompression. Exposure was achieved via extended Kocher maneuver followed by mobilization of the right kidney and, in 1 patient, detachment of the right lobe of liver to allow circumferential exposure of the proximal right renal artery to the aorta. All entrapping tissue was circumferentially released. RESULTS: Both operations were uncomplicated. Intraoperative sonography was used to confirm luminal patency of the released segments. Follow-up of renal artery duplex in both patients demonstrated resolution of dynamic compression. Renal artery peak systolic velocity and accelerations indices were all within normal limits. In both patients, improvement in blood pressure control was noted and discontinuation of anticoagulation was possible in the patient who had recurrent episodes of renal infarct. CONCLUSIONS: Extrinsic compression of renal artery by diaphragmatic crura is rare but should be considered in younger patients or otherwise any patients with no vascular risk factors when renovascular hypertension workup yields no demonstrable intrinsic disease. A high index of suspicion should be raised when an anomalously high origin of the renal artery or proximity to the diaphragmatic crura is seen on cross-sectional imaging. Work-up should include dynamic imaging to assess compression of renal arteries during expiration. Open surgical or laparoscopic decompression of the involved renal arteries can be curative.

The clinical and radiological cerebrovascular abnormalities associated with renovascular hypertension in children: a systematic review.

Renovascular disease is an important secondary cause of hypertension in childhood. In this cohort, many may have undiagnosed cerebrovascular disease, and some children present acutely with cerebrovascular complications. However, these associations are yet to be defined in the literature.A systematic review of clinical and radiological abnormalities associated with renovascular hypertension in the global pediatric (< 18 years) population. The MEDLINE, Embase, and Google Scholar databases were searched, from database inception to 26 January 2021. Primary articles were unrestricted by study design and geographical location but were limited to those published in English.A total of 303 individuals (median age: 7.6 years [range 10 days-17.9 years]; M:F, 174:129) from 34 studies were included, across 13 countries. Twenty-seven individual cases were published for children with coexisting renovascular hypertension and cerebrovascular disease. Most children had bilateral renal artery stenosis, secondary to fibromuscular dysplasia and had coexisting occlusive cerebrovascular disease. The majority presented with neurological symptoms, and cerebral complication ranged from asymptomatic cerebrovascular stenosis to acute stroke and posterior reversible encephalopathy syndrome. The location or underlying etiology of the renovascular disease did not predict the location or extent of the cerebrovascular disease. The evidence from the cohort studies was limited, as none specifically established a cohort of children with coexisting disease. Furthermore, the conclusions drawn were subjected to considerable bias from the treating clinicians.A prospective cohort of children with renovascular hypertension and cerebrovascular complications should be established so the long-term prognosis and impact of treatment may be better understood.

Endovascular interventions in main renal artery pathologies: an overview and update.

Renal arteries are involved in a wide spectrum of pathologies including atherosclerosis, fibromuscular dysplasia, Takayasu arteritis, aneurysms, and aortic type B dissections extending into main renal arteries. They manifest as renovascular hypertension, renal ischemia, and cardiovascular dysfunction. The location of the renal arteries in relation to the abdominal aortic aneurysm is a critical determinant of interventional options and long-term prognosis. This article provides a comprehensive review of the role of interventional radiologists in transcatheter interventions in various pathologies involving the main renal arteries with analysis of epidemiology, pathophysiology, newer interventional techniques, and management options.

Midterm Outcomes of Angioplasty for Pediatric Renovascular Hypertension.

PURPOSE: To evaluate the midterm outcomes of percutaneous transluminal renal angioplasty (PTRA) for pediatric renovascular hypertension (RVH). MATERIALS AND METHODS: The clinical data of patients who underwent PTRA for RVH in the authors' hospital from 2012 to 2019 were retrospectively analyzed. Postprocedural blood pressure, glomerular filtration rate (GFR) of the affected kidney, restenosis, and complications were closely monitored. RESULTS: PTRA was performed in a total of 30 children (20 boys and 10 girls), with a mean age of 7.3 years ± 0.7 (range, 40 days to 13.9 years) and a mean weight of 25.0 kg ± 2.3 (range, 3.4-53 kg). The median follow-up period was 26.5 months (range, 1 month to 7.5 years). Technical success was achieved in 26 (86.7%) of the 30 patients. Restenosis developed in 3 patients (10.0%). Only 1 patient underwent stent implantation, and the stent fractured 8 months later, requiring further intervention. There were no other complications. In terms of clinical benefit of blood pressure control after the initial PTRA procedure, 15 patients (50%) were cured and 7 patients (23.3%) showed improvement. There was no significant difference in the etiology, lesion location, and lesion length between patients with clinical benefit and failure (P = .06, P = .202, and P = .06, respectively). GFR of the affected kidney was significantly improved from 19.9 mL/min ± 11.2 to 38.1 mL/min ± 11.9 at the 6-month follow-up after PTRA (P < .001). CONCLUSIONS: The overall results of PTRA for pediatric RVH caused by different etiologies are promising. PTRA not only provided a clinical benefit of blood pressure control in 73.3% of the patients but also significantly improved the function of the affected kidney.

Ischemic Nephropaty: The Role of the Renal Artery Stenosis Revascularization on Renal Stem Cells.

We report the case of a 65-year-old man with acute GFR decline to 37 mL/min and uncontrolled high blood pressure. He was suspected for renovascular hypertension and underwent a renal color Doppler ultrasound scan that detected a bilateral atherosclerotic renal artery stenosis. A digital selective angiography by percutaneous transluminal angioplasty and stenting (PTRAs) was successfully performed. Blood pressure rapidly normalized, GFR increased within a few days, and proteinuria disappeared thereafter. These clinical goals were accompanied by a significant increase of circulating renal stem cells (RSC) and a slight increase of resistive index (RI) in both kidneys. This single observation suggests the need for extensive studies aimed at evaluating the predictive power of RI and RSC in detecting post-ischemic renal repair mechanisms.

Renal Artery Reconstruction for Refractory Hypertension Caused by Congenital Renal Artery Deficiency.

Renovascular hypertension is a common cause of secondary hypertension. According to the epidemiological survey, the prevalence of renovascular hypertension accounts for 1-5% of the population with hypertension. Most of the cases are associated with atherosclerosis and Fibromuscular Dysplasia (FMD). Owing to the lack of standard treatment, they will eventually develop into chronic kidney disease, which significantly affects the patient's quality of life. Hypertension is considered a prerequisite for renal artery surgery; renal function research is used to guide the treatment of unilateral lesions because endovascular intervention can only slightly improve hypertension and renal function. We advocate open surgery for patients with congenital dysplasia of renal vascular hypertension, in which the most common surgical operations are aortorenal artery bypass, renal artery endarterectomy, and renal artery replantation. This paper reports a rare case of renovascular hypertension. The patient was a 13-year-old female, and the operation was risky and complicated. He was diagnosed with a congenital absence of the right renal artery. The right renal function was recovered, and the blood pressure was well controlled after the Aorta-Right Renal Artery Bypass.

Hypertension Caused by Renal Arteriovenous Fistula with Multiple Renal Artery Aneurysms.

Renal arteriovenous fistula with renal artery aneurysms and dilated renal veins presents as an infrequent lesion. Endovascular therapy has recently been considered the first-line treatment for these conditions. We report a case of a patient with idiopathic renal arteriovenous fistula concomitant with multiple renal artery aneurysms that was successfully treated by the placement of a covered stent.

Complex Vascular Revascularization in a Young Woman with Type 1 Neurofibromatosis.

We present an uncommon case of a 16-year-old woman with type 1 neurofibromatosis and renovascular hypertension due to bilateral renal stenosis associated with asymptomatic digestive artery stenosis. Our patient was treated by several autologous bypasses to the superior mesenteric artery and the left and right renal arteries. She had no postoperative complications and good clinical and imaging outcomes at 10 years. Furthermore, there are few data on the vascular impairment of this rare disease, thus justifying its presentation.

A simple, refined approach to diagnosing renovascular hypertension in children: A 10-year study.

BACKGROUND: Despite advances in non-invasive vascular imaging, detection of renal artery stenosis via catheter angiography is the criterion standard for the diagnosis of renovascular hypertension (RVH). However, because of lack of evidence, the utility of various blood tests and imaging modalities remains unclear. METHODS: We retrospectively analyzed the utility of blood tests (plasma renin activity [PRA], aldosterone, and renal vein renin [RVR] values) and imaging studies (computed tomography angiography [CTA], kidney ultrasonography [US]) by comparing them with catheter angiography. Ten pediatric patients with RVH at two institutions from January 2008 to December 2017 were recruited. The sensitivities for diagnosing RVH via imaging and blood tests (kidney [US], PRA, and aldosterone) were derived by examining patient records. Furthermore, the sensitivity and specificity of CT angiography were calculated by considering both the affected and non-affected renal arteries of the patients. RESULTS: A high sensitivity for diagnosing RVH via kidney US (89%) and PRA (80%) was observed. The sensitivity and specificity of CTA were 100%, each. RVR sampling did not aid in the diagnosis of RVH; only two of six patients with unilateral RVH showed significant laterality of RVR boundary ratios. Renal scintigraphy facilitated detection of a non-functional kidney (split renal function <5%). CONCLUSIONS: RVH in children could be diagnosed utilizing non-invasive blood and imaging tests, without catheter angiography. We recommend kidney length measurement along with measurement of PRA level, as a simple and highly useful screening test, followed by CTA as a diagnostic test.

Cocaine-Induced Renal Artery Dissection as a Cause of Secondary Hypertension: A Rare Presentation.

BACKGROUND Cocaine abuse is a globally recognized problem with great socioeconomic and health impacts on society. We report a case of dissection of vertebral arteries and right renal artery after cocaine abuse that clinically presented as atypical headache and hypertension. CASE REPORT A 36-year-old male sought emergency care due to cervical pain after cocaine abuse. The pain was located to the right cervical side with irradiation to the homolateral temporal region. He had no previous comorbidities, except for cocaine abuse on a weekly basis. Angiotomography showed alterations compatible with recent arterial dissection of the right vertebral artery, confirmed on angioresonance. The patient received double anti-aggregation and antihypertensive drugs and was discharged. He was readmitted 5 days later due to hypertensive crisis and mild abdominal pain. Abdominal ultrasound with a Doppler of renal arteries showed signs right renal artery stenosis. Magnetic resonance angiography confirmed dissection of the same vessel. The patient underwent arteriography with stent implantation in the right renal artery. During outpatient follow-up, he progressed with gradual reduction of antihypertensive drugs. CONCLUSIONS There is only 1 case report correlating renal artery dissection with cocaine use and none with concomitant presentation of dissection in the vertebral and renal arterial beds. The scarcity of reports is a consequence of many problems. Therefore, young patients presenting with new-onset hypertension or abdominal pain and cocaine abuse history should raise suspicion for renal artery dissection.

Endovascular Management of Neurofibromatosis Type I-Associated Vasculopathy: A Case Series and Brief Review of the Literature.

PURPOSE: Neurofibromatosis type 1 (NF1) is an autosomal-dominant disorder found in approximately 1 of every 3000 individuals. Neurofibromatosis type 1 can have vascular manifestations including aneurysms, stenoses, and arteriovenous malformations. The purpose of this article is to describe the clinical manifestations of NF1 vasculopathy, discuss therapeutic options, and highlight endovascular therapies from our institutional experience. MATERIALS AND METHODS: The radiology information system was searched for cases of NF1. Cases with vasculopathy managed with endovascular therapies were included. Demographics, clinical histories, procedural details, and outcomes were recorded. A review of the literature for the management strategies of NF1 vasculopathy was performed. RESULTS: Two pediatric patients with NF1 were identified, both of whom presented with hypertension found to be secondary to renal artery stenosis. One of the patients also had infrarenal aortic narrowing. Both patients were successfully treated with balloon angioplasty, resulting in improved blood pressures. The review of the literature identified case series of pharmacologic, surgical, and endovascular therapies, although, endovascular therapies appear to be preferred due to lower morbidity and mortality. CONCLUSIONS: NF1 vasculopathy is a rare condition that most often presents with hypertension due to renal artery stenosis. In these situations, endovascular management is the preferred approach.

Ask-Upmark Kidney, Imaging Features.

Renovascular hypertension is known to occur due to varied causes. Absence of Renal artery stenosis or changes in renal vascular flow make it tough to establish a diagnosis of renovascular hypertension in the absence of invasive investigations. Segmental renal hypoplasia is not only a rare cause for renin mediated hypertension but also requires expertise and high index of suspicion while evaluating children with hypertension. We describe the classical imaging findings of a child with secondary hypertension which was due to hypoplasia of a renal segment.

Secondary Hypertension and Complications: Diagnosis and Role of Imaging.

Hypertension is a common problem; if left untreated, it can result in significant complications, including those involving the cardiovascular system and end organs. Approximately 10% of patients with hypertension are classified as having secondary hypertension, defined as hypertension attributable to a specific and potentially remediable cause. The evaluation for secondary hypertension typically begins with acquiring the patient history and performing a physical examination and screening laboratory tests. Directed imaging may be performed, on the basis of laboratory test results, to assess for potential causes of secondary hypertension. The causes can be broadly classified as endocrine (eg, hyperaldosteronism, pheochromocytoma, hyperparathyroidism) and nonendocrine (eg, aortic coarctation, renal vascular hypertension). In addition, patients with hypertension can develop significant complications that also are diagnosed with imaging, including conditions involving the cardiovascular system (eg, aortic aneurysm, acute aortic syndrome) and central nervous system (eg, stroke, subarachnoid hemorrhage, and posterior reversible encephalopathy syndrome). The imaging workup and imaging appearances of some of the causes of secondary hypertension are reviewed, treatment options are discussed, and the imaging appearances of hypertension-related complications are described. It is important for radiologists to accurately diagnose the secondary causes of hypertension, as many of them are treatable, and treatment may result in improved symptoms or resolution of hypertension. ©RSNA, 2019.

A novel method for comparison of arterial remodeling in hypertension: Quantification of arterial trees and recognition of remodeling patterns on histological sections.

Remodeling of spatially heterogeneous arterial trees is routinely quantified on tissue sections by averaging linear dimensions, with lack of comparison between different organs and models. The impact of experimental models or hypertension treatment modalities on organ-specific vascular remodeling remains undefined. A wide variety of arterial remodeling types has been demonstrated for hypertensive models, which include differences across organs. The purpose of this study was to reassess methods for measurement of arterial remodeling and to establish a morphometric algorithm for standard and comparable quantification of vascular remodeling in hypertension in different vascular beds. We performed a novel and comprehensive morphometric analysis of terminal arteries in the brain, heart, lung, liver, kidney, spleen, stomach, intestine, skin, skeletal muscle, and adrenal glands of control and Goldblatt hypertensive rats on routinely processed tissue sections. Mean dimensions were highly variable but grouping them into sequential 5 µm intervals permitted creation of reliable linear regression equations and complex profiles. Averaged arterial dimensions demonstrated seven remodeling patterns that were distinct from conventional inward-outward and hypertrophic-eutrophic definitions. Numerical modeling predicted at least nineteen variants of arterial spatial conformations. Recognition of remodeling variants was not possible using averaged dimensions, their ratios, or the remodeling and growth indices. To distinguish remodeling patterns, a three-dimensional modeling was established and tested. The proposed algorithm permits quantitative analysis of arterial remodeling in different organs and may be applicable for comparative studies between animal hypertensive models and human hypertension. Arterial wall tapering is the most important factor to consider in arterial morphometry, while perfusion fixation with vessel relaxation is not necessary. Terminal arteries in organs undergo the same remodeling pattern in Goldblatt rats, except for organs with hemodynamics affected by the arterial clip. The existing remodeling nomenclature should be replaced by a numerical classification applicable to any type of arterial remodeling.

The cardiovascular phenotype of childhood hypertension: a cardiac magnetic resonance study.

BACKGROUND: The cardiovascular phenotype is poorly characterized in treated pediatric hypertension. Cardiovascular magnetic resonance imaging (MRI) can be used to better characterize both cardiac and vascular phenotype in children with hypertension. OBJECTIVE: To use MRI to determine the cardiac and vascular phenotypes of different forms of treated hypertension and compare the results with those of healthy children. MATERIALS AND METHODS: Sixty children (15 with chronic renal disease with hypertension, 15 with renovascular hypertension, 15 with essential hypertension and 15 healthy subjects) underwent MRI with noninvasive blood pressure measurements. Cardiovascular parameters measured include systemic vascular resistance, total arterial compliance, left ventricular mass and volumetric data, ejection fraction and myocardial velocity. Between-group comparisons were used to investigate differences in the hypertension types. RESULTS: Renal hypertension was associated with elevated vascular resistance (P≤0.007) and normal arterial compliance. Conversely, children with essential hypertension had normal resistance but increased compliance (P=0.001). Renovascular hypertension was associated with both increased resistance and compliance (P≤0.03). There was no difference in ventricular volumes, mass or cardiac output between groups. Children with renal hypertension also had lower systolic and diastolic myocardial velocities. CONCLUSION: Cardiovascular MRI may identify distinct vascular and cardiac phenotypes in different forms of treated childhood hypertension. Future studies are needed to investigate how this may inform further optimisation of blood pressure treatment in different types of hypertension.