Renovascular Hypertension In Children Research Articles

FIBROMUSCULAR DYSPLASIA IN CHILDREN – A SINGLE-CENTER EXPERIENCE

Objective: Fibromuscular dysplasia (FMD) is a stenotic disease of the arteries - most often renal, carotid, and cerebral. The disease can occur at any age and is the most common cause of renovascular hypertension in children. The study aimed to present the clinical course of FMD in patients of our Department. Design and method: In 2016-2023, the Department took care of 8 patients with FMD (4 boys, 4 girls). In all patients, we analyzed: age, sex, clinical symptoms, biochemical parameters, renin and aldosterone concentrations, imaging studies (ultrasonography, computed tomography), pharmacological and invasive treatment, and outcome. Results: Age at diagnosis ranged from 10/12 to 15 9/12 years. All patients were referred due to arterial hypertension (7/8 of 2nd degree). Patients presented various symptoms: hypertensive crisis with heart failure (patient 10/12 months), headache (2 patients), vomiting (1 patient), hyperactivity (1 patient), polydipsia and polyuria (1 patient). All patients had normal renal function, 5/8 hypokalemia, 1/8 hyponatremia, and 5/8 metabolic alkalosis; all had hyperreninemia with hyperaldosteronism. Imaging examinations showed critical stenosis of the renal artery trunk in 3 patients, slight stenosis in 1 patient, and stenosis of accessory arteries or branches of main arteries in the remaining patients. Stenosis in other vessels was found in 2 patients (left middle cerebral artery in one patient and abdominal aorta, celiac trunk, superior mesenteric artery, and inferior mesenteric artery in another one). Invasive treatment was performed in 6/8 patients - in 2 patients nephrectomy was necessary; in 2 – embolization of the vessel; in 2 – angioplasty, one patient is waiting for the procedure. Before the procedure, the patients required 3 (max. 5) antihypertensive drugs. After the procedure, antihypertensive treatment was discontinued in 3 patients, and the number and dose of drugs were reduced in the remaining patients. Conclusions: 1. Renal artery stenosis should be excluded in all pediatric hypertensive patients, regardless of age and symptoms. 2.Patients with FMD require an individually selected therapeutic plan. 3.Vessel embolization is an effective method of treating stenoses of the peripheral branches of the renal arteries in the course of FMD in children.

Pediatric Renovascular Hypertension: A Pediatric Interventional Radiologist's Perspective.

Renovascular hypertension (RVH) contributes close to one-fourth of the secondary etiologies of hypertension in children and a delay in diagnosis can result in adverse clinical outcomes. RVH in children is clinically silent with elevations in blood pressure measurements sometimes as its sole manifestation. Only a high index of suspicion by the clinician can prompt its detection. Despite the availability of other imaging modalities like ultrasound, computed tomography, and magnetic resonance imaging, digital subtraction angiography is still considered the gold standard to make a diagnosis of RVH. Angioplasty is considered the treatment of choice in appropriately selected patients. In this article, we shall focus on the various imaging findings, and management of RVH in children, which requires a multidisciplinary approach with a special focus on the role of interventional radiology.

Hypertension crisis as the first symptom of renovascular hypertension in children

BackgroundRenovascular hypertension (RVH) is one of the main causes of hypertensive crisis (HTN-C). It is characterized by acute onset and severe disease, and early diagnosis and treatment are difficult. The objective was to describe the characteristics of RVH and factors associated with RVH leading to HTN-C in children. At present, there are few clinical studies on RVH in children with large cases in China.MethodsThis study retrospectively analyzed the clinical data of inpatient children with RVH. Patients were divided into non-hypertensive crisis (non-HTN-C) group, and HTN-C group according to the first symptoms and blood pressure. Further, HTN-C were classified as hypertensive urgency (HTN-U) or hypertensive emergency (HTN-E).ResultsFifty-four pediatric cases (41 boys and 13 girls) were included. 83.3% of the RVH cases were ≥ 6 years old. Three cases were classified into the non-HTN-C group. Of the 51 HTN-C cases, 18 cases were grouped as HTN-U and 33 as HTN-E. The HTN-U group were mainly asymptomatic (50.0%, 9/18) while the HTN-E group mainly presented with neurological symptoms (72.7%, 24/33). The number of unknown etiology children was 32 (59.2%). The top three known etiologies were Takayasu’s arteritis (50.0%, 11/22), congenital renal dysplasia (27.3%, 6/22) and fibromuscular dysplasia (13.6%, 3/22). As for the target organ damage of RVH, patients had a higher prevalence of left ventricular hypertrophy (71.4%, 35/49) and retinopathy (77.8%, 21/27).ConclusionsMost RVH patients with HTN-C as the first symptoms, especially for males over 6 years old, should be assessed for RVH even if they were asymptomatic. Most asymptomatic patients with RVH already had target organ damage, and symptomatic patients even developed life-threatening complications. As preventive measures, routine monitoring of BP during children’s physical examinations is advised.

Percutaneous cutting balloon angioplasty for the treatment of renovascular hypertension in children and adolescents.

Percutaneous transluminal renal angioplasty (PTRA), the recommended treatment in children with renovascular hypertension (RVH), often has unsatisfactory outcomes. Cutting balloons may improve the results of angioplasty in different vascular beds with complex and resistant lesions. We retrospectively analysed the effects of percutaneous cutting balloon angioplasty (PCBA) on blood pressure, cardiac mass and renal artery acceleration time in children/adolescents referred to our centre for RVH. Thirteen patients (aged 9-19 years) with renal artery stenosis (RAS) and severe hypertension were identified. RASs were focal fibromuscular (FMD) or FMD-like dysplasia (in six cases bilateral, in five associated with mid aortic syndrome). Ten patients had uncontrolled hypertension, in nine cases associated with left ventricular hypertrophy (LVH). Acceleration time was abnormal in all stenotic arteries. Eighteen PCBA were performed, in three arteries associated with stent implantation. PCBA was technically successful in all individuals without major complications. In one patient, an intra-stent restenosis occurred, successfully redilated with conventional angioplasty without recurrence at 4 years distance. One year after PCBA, mean SBP and DBPs were markedly reduced from 146 ± 25 to 121 ± 10 mmHg and from 87 ± 11 to 65 ± 12 mmHg, respectively ( P < 0.001 for both). At that time, hypertension was cured in seven children and controlled in five individuals. This favourable outcome was confirmed with ambulatory blood pressure measurement in four patients. At the latest follow-up, left ventricular mass and acceleration time were normal in all patients. PCBA proved to be a well tolerated and effective procedure that can be considered as an alternative to PTRA to treat hypertensive children/adolescents with recurrent or resistant RAS.

Pediatric Renovascular Hypertension: Not Just a “String of Beads”

It is with great enthusiasm ( 1 Zhao L Zhao X Hu X Yang H Wu L Midterm outcome of angioplasty for pediatric renovascular hypertension. J Vasc Interv Radiol. 2022; 33: 399-407 Google Scholar ) that I read the recent publication on the midterm outcome of angioplasty for the treatment of pediatric renovascular hypertension in children. This publication expands on the pre-existing pediatric renal angioplasty literature with the addition of diethylenetriaminepentaacetic acid (DTPA) renal function outcome measurements. Midterm Outcomes of Angioplasty for Pediatric Renovascular HypertensionJournal of Vascular and Interventional RadiologyVol. 33Issue 4PreviewTo evaluate the midterm outcomes of percutaneous transluminal renal angioplasty (PTRA) for pediatric renovascular hypertension (RVH). Full-Text PDF

Molecular genetic evaluation of pediatric renovascular hypertension due to renal artery stenosis and abdominal aortic coarctation in neurofibromatosis type 1.

The etiology of renal artery stenosis (RAS) and abdominal aortic coarctation (AAC) causing the midaortic syndrome (MAS), often resulting in renovascular hypertension (RVH), remains ill-defined. Neurofibromatosis type 1 (NF-1) is frequently observed in children with RVH. Consecutive pediatric patients (N = 102) presenting with RVH secondary to RAS with and without concurrent AAC were prospectively enrolled in a clinical data base, and blood, saliva and operative tissue, when available, were collected. Among the 102 children, 13 were having a concurrent clinical diagnosis of NF-1 (12.5%). Whole exome sequencing was performed for germline variant detection, and RNA-Seq analysis of NF1, MAPK pathway genes and MCP1 levels were undertaken in five NF-1 stenotic renal arteries, as well as control renal and mesenteric arteries from children with no known vasculopathy or NF-1. In 11 unrelated children with sequencing data, 11 NF1 genetic variants were identified, of which 10 had not been reported in gnomAD. Histologic analysis of NF-1 RAS specimens consistently revealed intimal thickening, disruption of the internal elastic lamina and medial thinning. Analysis of transcript expression in arterial lesions documented an approximately 5-fold reduction in NF1 expression, confirming heterozygosity, MAPK pathway activation and increased MCP1 expression. In summary, NF-1-related RVH in children is rare but often severe and progressive and, as such, important to recognize. It is associated with histologic and molecular features consistent with an aggressive adverse vascular remodeling process. Further research is necessary to define the mechanisms underlying these findings.

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.

Renovascular hypertension in pediatric patients: update on diagnosis and management

Renovascular hypertension (RVH) is defined as an elevated blood pressure caused by kidney hypoperfusion, generally as a result of anatomic stenosis of the renal artery with consequent activation of the Renin Angiotensin-Aldosterone System. The main causes include genetic and inflammatory disorders, extrinsic compression, and idiopathic alterations. RVH is often asymptomatic and should be suspected in any child with refractory hypertension, especially if other suggestive findings are present, including those with severe hypertension, abdominal bruit, and abrupt fall of glomerular filtration rate after administration of angiotensin-converting enzyme inhibitors or angiotensin-receptor blockers. There is a consensus that digital subtraction angiography is the gold standard method for the diagnosis of RVH. Nevertheless, the role of non-invasive imaging studies such as Doppler ultrasound, magnetic resonance angiography, or computed tomographic angiography remains controversial, especially due to limited pediatric evidence. The therapeutic approach should be individualized, and management options include non-surgical pharmacological therapy and revascularization with percutaneous transluminal renal angioplasty (PTRA) or surgery. The prognosis is related to the procedure performed, and PTRA has a higher restenosis rate compared to surgery, although a decreased risk of complications. This review summarizes the causes, physiopathology, diagnosis, treatment, and prognosis of RVH in pediatric patients. Further studies are required to define the best approach for RVH in children.

Surgical management of pediatric renovascular hypertension and midaortic syndrome at a single-center multidisciplinary program

ObjectiveTo evaluate the outcomes of various surgical approaches in the treatment of renovascular hypertension and midaortic syndrome (MAS) in children. MethodsWe performed a retrospective medical record review of patients who had undergone surgery for renovascular hypertension from 2010 to 2018 at our center under the care of a multidisciplinary team. The operative interventions included mesenteric artery growth improves circulation (MAGIC), tissue expander-stimulated lengthening of arteries (TESLA), aortic bypass using polytetrafluorethylene, renal artery reimplantation, and autotransplantation. The MAGIC procedure uses the meandering mesenteric artery as a free conduit for aortic bypass. The TESLA procedure is based on lengthening the normal distal aorta and iliac arteries by gradual filling of a retroaortic tissue expander for several weeks, followed by resection of the stenotic aorta and subsequent primary reconstruction. ResultsA total of 39 patients were identified, 10 with isolated renal artery stenosis, 26 with MAS, and 3 with systemic inflammatory vasculitis. The median age at presentation and surgery was 6.4 years (range, 0-16.3 years) and 9.3 years (range, 0-9.2 years), respectively. The MAS-associated syndromes included neurofibromatosis type 1 (15.4%) and Williams syndrome (5.1%), although most cases were idiopathic. At surgery, 33.3% had had stage 1 hypertension (HTN), 53.8% stage 2 HTN, and 12.8% normal blood pressure with a median of three antihypertensive medications. Follow-up of 37 patients at a median of 2.5 years demonstrated normal blood pressure in 86.1%, stage 1 HTN in 8.3%, and stage 2 HTN in 5.6%, with a median of one antihypertensive medication for the entire cohort. ConclusionsThe patterns of vascular involvement leading to renovascular hypertension in children are variable and complex, requiring thoughtful multidisciplinary planning and surgical decision-making. The MAGIC and TESLA procedures provide feasible approaches for aortic bypass and reconstruction using autologous tissues and will result in normalization of blood pressure in 85% of children 2.5 years after surgery.

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

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. 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. 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%). 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.

Genetics of renovascular hypertension in children.

In most cases of renovascular hypertension in children, the cause is unclear. The aim of this study was to investigate genetic variation as a factor in the development of renovascular hypertension in children. In a cohort of 37 unrelated children from a single tertiary referral center, exome sequencing was performed. We assessed variants in recognized and suspected disease genes and searched for novel ones with a gene-based variant-burden analysis. In the majority of patients, exome sequencing could not identify causative variants. We found a pathogenic variant in a recognized associated disease gene in five patients (three pathogenic variants in NF1, one in ELN and a deletion of chromosome 7q11.23, consistent with Williams syndrome). In two other patients, (likely) pathogenic variants were found in putative renovascular hypertension genes (SMAD6 and GLA), with clinical implications for both. Ten additional patients carried variants of uncertain significance (VUS) in known (n = 4) or putative (n = 6) renovascular hypertension disease genes. Rare variant burden analysis yielded no further candidate genes. Genetic contributors, such as germline mutations in NF1, ELN, 7q11.23del were present in only 5 out of 37 (14%) children with renovascular hypertension. Twelve other children (32%) had potentially causal variants identified, including a pathogenic variant in SMAD6; a vasculopathy gene hitherto unknown to link with renovascular hypertension. Most importantly, our data show that exome sequencing can rarely identify the cause of renovascular hypertension in nonsyndromic children. We suggest that nongenetic factors or somatic genetic variation will play a more important role.

Diagnosis and management of renovascular hypertension in children

Renovascular hypertension accounts for 5%-10% of hypertension in children, which is usually di-fficult to control by medicine and leads to severe clinical complications.However, it is potentially amenable to curative treatment.Clinical early recognition and proper treatment might not only effectively control hypertension, but also preserve renal blood supply and renal function, which is of great significance for the long-term prognosis in children.In this review, the author provide current knowledge of renovascular hypertension in children, including its cause, pathogenesis, diagnostic method, and medical, interventional, and surgical treatment. Key words: Renovascular hypertension; Renal artery stenosis; Percutaneous transluminal angiography; Revascularization; Child

Surgical management of renovascular hypertension in children and young adults: a 13-year experience.

In this study, we aimed to evaluate the early and mid-term outcomes of surgery for renovascular hypertension (RVH) at our institution, within the last 13 years. We retrospectively reviewed 19 patients who underwent surgery for RVH, between 2005 and 2017. The age at operation, clinical characteristics, cause of arterial stenosis, diagnostic workup, surgical management and outcomes during the follow-up were analysed. The continuous variables were expressed as mean ± standard deviation. Twelve female and 7 male patients underwent surgery for RVH. Their mean age was 17.07 ± 11.9 years (range 4-42 years). Nine patients had renal arterial stenosis, and 10 patients had midaortic syndrome (MAS). Aortorenal bypass with the saphenous vein was performed in 6 patients with renal arterial stenosis and 1 patient with MAS. An isolated thoracic aorta-abdominal aortic bypass was performed in 1 patient with MAS, and thoracic aorta-abdominal aortic bypass combined with unilateral aortarenal bypass was performed in 9 patients with MAS. The other surgical procedures performed were 2 autotransplantations and 2 unilateral nephrectomies. Among the patients with MAS, 4 underwent reoperation. The mean follow-up duration was 45.58 ± 32.7 months. Hypertension was cured in 3 patients and improved in 14 patients. The postoperative follow-up creatinine levels were similar to preoperative creatinine levels. All bypasses were patent on mid-term follow-up. One patient who underwent aortorenal bypass died 14 months postoperatively. Surgical management is a suitable option for patients with RVH, who were unresponsive to medical and/or endovascular management. Surgical methods are safe and effective in children and young adults with RVH.

Diagnostic Role of Renal Doppler Ultrasound and Plasma Renin Activity as Screening Tools for Renovascular Hypertension in Children.

The diagnostic role of an ultrasound (US) and plasma renin activity (PRA) combination is unknown, despite the usefulness of Doppler US as a screening tool for renovascular hypertension (RVHT). The purpose of this study was to evaluate the diagnostic usefulness of US for RVHT in children stratified according to PRA. We identified 336 children who underwent renal Doppler US examinations for hypertension and divided them into a high-renin group (n = 177) and a normal-renin group (n = 159) based on PRA and stratified them by age. The Doppler US findings were retrospectively reviewed, and computed tomographic angiography (CTA) for the same children was used as the reference standard. In the high-renin group, 36 patients had positive Doppler US findings that were confirmed by CTA in 32 cases. The sensitivity and specificity values for Doppler US in the high-renin group were 84.2% and 93.6%, respectively. In the normal-renin group, 10 patients had positive Doppler US findings; these positive findings were confirmed by CTA in 9 cases. The sensitivity and specificity values for US in the normal-renin group were 100.0% and 100.0%. There were anatomic variations (n = 3) and segmental artery stenosis (n = 2) among the cases with false-negative US findings, which were confirmed by CTA. If patients have high PRA, a Doppler US examination should be performed with caution to avoid false-negative detection. If patients have normal PRA, renal Doppler US might be adequate for diagnosis of RVHT to avoid unnecessary CTA.

Renovascular hypertension: results in adulthood of renal autotransplantation performed in children.

This study describes the long-term results of renal autotransplantation for renovascular hypertension performed in children who are now 21 years of age or older. Sixteen children (4 boys, 12 girls) with a mean age of 11.2 years at the time of the procedure underwent ex-vivo surgery at the university hospital of Saint-Etienne between 1992 and 2008. Acetylsalicylic acid was used for antiplatelet therapy in the postoperative period, without routine anticoagulation. The mean follow-up period was 15years. The clinical course of these patients was retrospectively reviewed in adulthood and the results analyzed. The children were treated with a mean of 2.37 drugs per patient, and the mean preoperative blood pressure of the entire patient population was 151/89mmHg. Mean preoperative creatinine clearance was 80ml/min/1.73 m2. There was no postoperative death. One patient experienced a thrombosis immediately after the surgery, leading to a redo surgery. In this patient diuresis was restarted, but without efficient concentration and filtration, ultimately leading the patient to have a renal transplant after 1year. At the end of the follow-up period, eight of the 16 patients (50%) were cured and the others were improved. At the last follow-up the mean blood pressure was 127/70mmHg, and the mean number of drugs per patient was 0.68. The mean creatinine clearance at last follow-up was 104.3ml/min/1.73 m2. Three patients had secondary procedures, with two undergoing percutaneous angioplasty (at postoperative months 9 and 12, respectively) and one having an hepatorenal bypass at postoperative year 4. Primary patency was 12/16 (75%); primary assisted patency was 15/16 (94%); secondary patency was 16/16 (100%). This study shows that renal autotransplantation has good and stable long-term results and is an effective conservative strategy for treating renovascular hypertension in children, thus avoiding nephrectomy.

Sonographic evaluation of renovascular hypertension in the pediatric population: State-of-the-art.

Hypertension in children affects 2-5% of the pediatric population. Identifying secondary causes of hypertension is crucial, as some of these entities may be treatable. Renovascular hypertension accounts for 5-10% of the secondary causes of hypertension in children and is mainly related to fibromuscular dysplasia and neurofibromatosis type 1. Ultrasonographic evaluation of the kidneys, including Doppler interrogation, is the recommended primary screening tool. A comprehensive study of the upper abdomen and retroperitoneum allows for identification of additional underlying etiologies. The purpose of this review is to emphasize the different causes of renovascular hypertension in children one can diagnose during the initial ultrasonographic evaluation. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:282-292, 2017.

Impact of revascularization on hypertension in children with Takayasu's arteritis-induced renal artery stenosis: a 21-year review.

Surgery for reno-vascular hypertension (RVH) is complex, and the techniques utilized vary with anatomical presentations of the disease. The long-term outcome of revascularization on RVH in children with Takayasu's arteritis (TA)-induced renal artery stenosis (RAS) at our centre was reviewed. This study was a 21-year retrospective review of pre- and post-intervention RVH in children with angiographically confirmed RAS. The outcome of hypertension was defined as follows: (1) cured (normotensive off anti-hypertensives), (2) improved (normotensive on same or reduced number of medications), or (3) failure (no cure or improvement in number of medications). The medical histories of 59 children (median age 9.98 years) were reviewed, of whom 20 (44 %) had revascularization procedures. All were hypertensive, with a mean systolic and diastolic blood pressure of 161.5 ± 36 and 106.5 ± 31 mmHg, respectively. RAS was present in 45 (76.3 %) children. Twenty-four revascularization procedures were performed in 20 children (44 %), of whom five had contralateral nephrectomies. Outcome was available for 17 patients at the 3- and 6-months follow-up, with cure, improvement and failure rates at 3 months of 2/17 (11.8 %), 7/17 (41.2 %) and 8/19 (47 %), respectively, and similar rates at 6 months. Associations between outcome and age (p = 0.51), sex (p = 0.32), number of pre-surgery anti-hypertensives (p = 0.18) and stenosis sites (p = 0.22) were not statistically significant. Revascularization was beneficial to the management of blood pressure control in about half of our RVH patients.

Diagnostic and medical strategy for renovascular hypertension: report from a monocentric pediatric cohort.

Renovascular hypertension accounts for 5-10 % of hypertension cases in children; there is currently no consensus on treatment. Here, we report on our clinical experience with this disease and outline the different pathways in which to investigate it. We report retrospectively on ten children diagnosed with renovascular hypertension at the University Hospital of Nantes from 2001 to 2012. The main findings were obtained by fortuitous screening of children aged 2 months to 14 years old with neurofibromatosis (n = 2) and fibromuscular dysplasia (n = 8). The hypertension was always severe yet asymptomatic. Lesions were complicated in nine out of ten cases and included bilateral, multiple, mid-aortic syndrome and aneurysm. Doppler ultrasound associated with computed tomography allowed for a precise diagnosis in seven out of ten cases. Where ambiguities persisted, they were highlighted by arteriography, the gold standard investigation. Medical treatment was insufficient, leading to invasive procedures in nine out of ten children: 2 nephrectomies, 2 autotransplantations, and 21 repetitive percutaneous transluminal angioplasties. After invasive procedures, blood pressure control improved in four cases and was resolved in three. Arteriography remains to be the gold standard technique for renovascular hypertension in children and can be combined with angioplasty when medical treatment is rendered obsolete. The role of computed tomography is controversial. Despite the heterogeneity of the children studied, we present a general medical and therapeutic management pathway for the treatment of this disease.

Mid-Aortic Syndrome Demonstrated by Three-Dimensional Computed Tomography: Case Report

A 14-year-old male patient was admitted to our clinic for evaluation of systemic arterial hypertension. His right and left arm arterial blood pressures were extremely high and measured 200/120 and 180/120 mmHg, respectively. His bilateral femoral pulses were weak, and lower limb blood pressures could not be measured. By conventional echocardiography, increased left ventricular wall thickness, narrowed lumen size, and disturbed antegrade flow at the lower thoracic part of aorta were shown (Fig. 1, Movie clip 1). Three-dimensional computed tomography (CT) clearly demonstrated a long-segment severe coarctation involving the distal half of thoracic aorta (Fig. 2). The affected segment was 3 cm in length, and the intra-aortic lumen size decreased gradually to \95 % of the expected lumen size. Intrarenal part of the abdominal aorta was also narrowed, and there were no stenosis in the other branches of the aorta. Multiple aortico-aortic collaterals were also detected by CT evaluation. Cranial magnetic resonance imaging and ophthalmologic examinations were normal, and serum inflammatory markers were within the normal ranges. Thus, the patient was diagnosed with an idiopathic form of mid-aortic syndrome (MAS). Due to long-segment involvement of aorta, percutaneous transluminal angioplasty of the aorta could not be performed. We therefore planned aorta‐aortic bypass graft surgery for this patient. MAS is a rare congenital abnormality characterized by segmental narrowing of the abdominal or distal descending thoracic aorta [2‐5]. It is frequently seen with stenosis of the renal and mesenteric arteries. It can be acquired or congenital. Acquired forms are usually associated with neurofibromatosis, fibromuscular dysplasia, retroperitoneal fibrosis, Williams syndrome, mucopolysaccharidosis, and giant-cell arteritis [2, 4]. Three-dimensional CT can provide more detailed information regarding cardiovascular structures than conventional echocardiographic techniques. MAS can cause severe renovascular hypertension in children and adolescents. It is generally difficult to manage the hypertension which requires treatment with several

Educational Exhibit Abstract No. 422 - Diagnosis and treatment of renovascular hypertension in children

Learning Objectives To describe and illustrate with examples the techniques and unique management challenges in diagnosing and treating renovascular hypertension in children. Background Renovascular hypertension (RVH) is an uncommon yet important and potentially curable cause of secondary hypertension in children, accounting for approximately 10% of cases. The management of RVH in the pediatric population presents specific challenges related to both the size and expected growth of the involved vessels as well as the often bilateral, subsegmental, and intrarenal distribution of disease. A variety of laboratory and imaging criteria are useful in establishing a diagnosis of RVH, however catheter angiography augmented by direct renal vein renin measurement remains the test of choice. Likewise, percutaneous transluminal renal artery angioplasty remains a highly effective front line treatment option with the goal of reducing or eliminating the need for medical therapy and avoiding complex surgical revascularization. Clinical Findings/Procedure Details The clinical pathway for the diagnosis of RVH will be discussed including the relevant pre-procedural non-invasive imaging and laboratory tests aimed at excluding more common causes of secondary hypertension. The angiographic features of RVH will be illustrated in multiple cases, with an emphasis on findings unique to pediatric patients. The diagnostic relevance and proper technique for direct renal vein renin sampling will be described. Angiographic technique and equipment particularly useful for imaging and successful treatment of the pediatric population will be reviewed. Additional cases will illustrate the uncommon occurrence of angioplasty failure requiring stent placement as well as unexpected causes of hypertension encountered during angiography. Conclusion and/or Teaching Points Interventional radiologists play a pivotal role in the diagnosis and treatment renovascular hypertension in children. Knowledge of the unique features of this disease and technical challenges in the pediatric population is critical in providing potentially curative endovascular therapy.