Renal Artery Stenosis In Children Research Articles

Case Report: Renal artery stenosis in children: ultrasound as a decisive diagnostic and therapy-accompanying technique!

Case Report: Renal artery stenosis in children: ultrasound as a decisive diagnostic and therapy-accompanying technique!

Diagnosing Renal Artery Stenosis in Children: Point-CTA Serves an Important Role in Diagnosis and Guiding Management.

This article does not include an abstract. Please see the accompanying Counterpoint by Anne Marie Cahill.

Diagnosing Renal Artery Stenosis in Children: Counterpoint-Angiography Is the Order of the Day.

This article does not include an abstract. Please see the accompanying Point by Siddharth P. Jadhav and Prakash M. Masand.

Diagnostic sensitivity and specificity of CT angiography for renal artery stenosis in children.

Children with suspected renal artery stenosis (RAS) are screened with renal Doppler ultrasonography or computed tomography (CT) angiography/magnetic resonance (MR) angiography depending on institutional preference. CT angiography produces images with superior resolution, allowing higher quality multiplanar two-dimensional reformats and three-dimensional reconstructions. However, there is a paucity of data in the literature regarding the utility and diagnostic performance of renal CT angiography in pediatric RAS. The objective of this study is to retrospectively review our experience with renal CT angiography in the diagnosis of pediatric RAS relative to digital subtraction angiography (DSA) as the reference standard. All patients 0-18years of age who underwent CT angiography for evaluation of RAS as a cause of hypertension between January 2012 and May 2019 were identified for the study. A total of 131 patients were identified, 23 of whom had DSA correlation. Twenty-three patients (17 boys, 6 girls) with a mean age of 6years 3months (range: 3months to 14years 7months) were included in this study. Of the 59 renal arteries studied by DSA, 22 were abnormal on CT angiography and 20 were abnormal on DSA. Of the 59 renal arteries, CT angiography was true positive in 18 and true negative in 35. The sensitivity and specificity of CT angiography for RAS diagnosis were 90.0% and 89.7%, respectively. CT angiography identified all cases of main RAS. Renal CT angiography has a high sensitivity and specificity for pediatric RAS diagnosis in patients referred for DSA.

Bilateral renal artery stenosis in children with vomiting and hypokalemia

Çocuklarda hipertansiyon nedenleri arasında sekonder nedenler ön plandadır. Bu nedenle hipertansiyonun erken tanınması ve tedavi altına alınması, çocukların ilerleyen yaşlarında yaşam kalitesinin artması ve kronik hastalıklardan korunması açısından öncelikli hedeftir. Hipertansiyonu olan çocuklar farklı klinik bulgular ile başvurabilir. Bu yazıda20 gündür olan kusması nedeniyle tetkik edilirken hipokalemi saptanan, fizik muayene esnasında ölçülen kan basıncı 205/115 mmHg olan ve yapılan tetkiklerinde bilateral renal arter darlığı tespit edilen 10 yaşındaki erkek olguyu sunmayı amaçladık. Bu sunumda çocukluk çağında kan basıncı ölçümünün rutin fizik muayenenin bir parçası olması gerektiğini ve hipertansif çocuk olguların farklı klinik bulgular ile gelebileceğini vurgulamak, ayrıca hipertansiyon tanı algoritmasını gözden geçirmek amaçlanmıştır.

Successful cutting balloon angioplasty in a child with resistant renal artery stenosis

BackgroundAlthough renovascular hypertension is a rare disease, it is associated with 5–10 % of cases of childhood hypertension. It is a potentially treatable cause of hypertension, and is often caused by renal artery stenosis (RAS). The most common cause of RAS in children is fibromuscular dysplasia (FMD). The options for treating RAS depend on the location, severity and abnormality underlying the condition.Case presentationA previously healthy 7-year-old Korean boy presented to our clinic with hypertension and headache. Renal ultrasonography and multi-detector computed tomography (MDCT) showed severe focal stenosis at the middle portion of the left renal artery (LRA) and multiple collateral vessels. Percutaneous balloon angioplasty was performed as an initial treatment, but yielded unsatisfactory results. The presence of intimal-type FMD was suspected based on his clinical features, angiographic appearance, and resistance to percutaneous transluminal renal angioplasty. Thereafter, his blood pressure was normalized using antihypertensive medication. Follow-up multi-detector computed tomography at 11 years of age showed persistent severe stenosis of the LRA. After unsuccessful attempts to perform balloon angioplasty, 3.5-mm cutting balloon angioplasty (CBA) was performed and yielded satisfactory results. He was discharged without any medication. At 1 year and 6 months after the intervention, he has been normotensive and had not required any antihypertensive medication.ConclusionThe author describes a case of resistant RAS that was detected on MDCT and successfully treated using percutaneous (CBA). Although cutting balloon angioplasty is useful in many clinical conditions, including the current case, clinicians should carefully consider the associated risk of arterial disruption and pseudoaneurysm formation.

Renal artery stenosis due to neurofibromatosis type 1: case report and literature review

BackgroundNeurofibromatosis type 1 (NF1) is a relatively common autosomal dominant disorder. The most common vascular abnormality in patients with NF1 is bilateral or unilateral renal artery stenosis.Case reportA 16-year-old boy presented with a headache of 4-year duration and was found to be moderately hypertensive. On physical examination, axillary freckling and multiple café-au-lait spots were revealed over the trunk, while numerous small nodules were palpable on the limbs. Biopsy of subcutaneous nodule showed neurofibroma. Lisch nodules were identified on slit-lamp examination and grade I hypertensive retinopathy was present on fundoscopy. Clinical laboratory investigations revealed that renal and liver function tests, blood cells count, urinalysis, serum electrolytes, serum levels of renin and aldosterone, and 24-hour urine levels of catecholamines were all within normal ranges. Abdominal ultrasound and CT were normal. Both kidneys were of normal size. CT angiography showed right renal artery stenosis (>90%) at the ostium. The final diagnosis of NF1 with right renal artery stenosis and secondary hypertension was then made. The patient was treated with Procardin (30 mg/d) and improved with a significant decline in blood pressure. The main outcomes were to control blood pressure without necessarily proceeding with PTRA. We also present a review of the literature.ConclusionsNF1 may present with hypertension due to renal artery stenosis in children. All young patients (<30 year) with hypertension should be clinically screened for secondary causes of hypertension, including NF1, so that renal revascularization can be offered before permanent end organ damage has occurred. First-line management using medication alone could be appropriate, keeping the interventional options for when the patient's condition deteriorates.

Renal artery stenosis in children: therapeutic percutaneous balloon and stent angioplasty

Renal artery stenosis (RAS) accounts for 10% of cases of systemic hypertension in children. Initial management involves anti-hypertensive therapy. Percutaneous interventions are documented for the treatment of RAS in the adult population. In children, case reports suggest benefit. This is a retrospective analysis of consecutive patients referred for catheterization for RAS between 2002 and 2010 at a single institution. Recorded variables included: age, weight, systemic blood pressure, minimal luminal diameter, interventional devices, antihypertensive medications, contrast volume, and complications. Twelve patients (median age 8.2, IQR 6-12.4years); median weight 42.8kg, IQR: 25-47.4kg) were referred for renal artery catheterization and underwent percutaneous intervention. Overall, minimal luminal diameter (MLD) increased by 1.2 ± 0.9mm for all patients (p < 0.05) and by 1.3 ± 0.9mm for post-renal transplant patients (p < 0.05). Only stent angioplasty patients demonstrated significant improved blood pressure (p < 0.05). One patient had stent thrombosis requiring re-intervention with repeat balloon angioplasty. This retrospective analysis suggests that percutaneous intervention might play a role in the management of RAS, with an improvement in MLD in children with RAS. Transcatheter intervention is technically feasible with low morbidity. A prospective, longitudinal study is warranted to compare standard medical therapy with percutaneous interventions.

Transplant renal artery stenosis in children: risk factors and outcome after endovascular treatment

Transplant renal artery stenosis (TRAS) is an increasingly recognised cause of post-transplant hypertension. We retrospectively analysed 216 paediatric renal recipients transplanted between 2001 and 2011 to assess TRAS prevalence and percutaneous transluminal angioplasty (PTA) efficacy. To assess risk factors, we compared children with TRAS with a propensity score-matched cohort of recipients without TRAS. Of the 216 paediatric patients who were transplanted in the study period, 44 were hypertensive (prevalence 20.3 %) and ten presented with TRAS (prevalence 4.6 %, median age at transplantation 14 years, range 6.78-17.36 years). Hypertensive patients without TRAS were prescribed one to two anti-hypertensive agents, whereas patients with TRAS required one to five medications. In the TRAS group, one recipient presented with vascular complications during surgery, and in three patients the graft had vascular abnormalities. TRAS was detected by Doppler ultrasonography (US) performed due to hypertension in nine of the patients with TRAS, but in the tenth case the TRAS was clinically silent and detected by routine Doppler-US screening. TRAS diagnosis was refined using angio-computed tomography or angio-magnetic resonance imaging. All patients underwent PTA without complications. Significant improvement after PTA was observed in the standard deviation scores for blood pressure [3.2 ± 1.4 (pre-PTA) vs. 1.04 ± 0.8 (post-PTA); p = 0.0006) and graft function [creatinine clearance: 69 ± 17.08 (pre-PTA) vs. 80.7 ± 21.5 ml/min/1.73 m(2) (post-PTA); p = 0.006] We observed no significant differences between the two cohorts for cold ischaemia time, recipient/donor weight ratio, delayed graft function, cytomegalovirus infections and acute rejection episodes. Our study reports a low but significant TRAS prevalence among the paediatric patients who were transplanted at our centre in the study period and confirms that PTA is an effective and safe therapeutic option in paediatric renal transplant recipients. Known risk factors do not appear to be related to the development of TRAS.

Neurofibromatosis Type 1 Complicated by Atypical Coarctation of the Thoracic Aorta

Neurofibromatosis type 1 (NF1) is a relatively common autosomal dominant genetic disorder with a prevalence of 1 in 3,000 (0.03%) at birth. Clinical features are café-au-lait macules, intertriginous freckling, dermal neurofibroma, iris hamartoma (Lisch nodules), and learning disability. NF1 vasculopathy is a serious but underrecognized complication involving the cerebrovascular and cardiovascular systems. The incidence of hypertension in patients with NF1 is around 1% and is associated mainly with renal artery stenosis in children. Only a few cases of thoracic aortic coarctation in association with hypertension and neurofibromatosis have been reported. Here we describe the case of a 4-year-old girl who presented with NF1 and hypertension due to atypical coarctation of the thoracic aorta. The diagnosis of coarctation of the thoracic aorta at the Th5-to-Th6 level was made following catheterization with a pressure gradient of 40 mmHg. The patient underwent surgery comprising resection of the coarctation of the thoracic aorta and graft interposition. On the basis of our findings, annual assessment of blood pressure is advised for patients with NF1.

Captopril-enhanced renal scintigraphy in the diagnosis of pediatric hypertension

Hypertension in childhood is no longer a rare condition mainly secondary to renal, or renovascular diseases, as a growing proportion of children are obese and hypertensive, with the phenotype of metabolic syndrome. Thus, we need to reconsider our practice in the examination of the hypertensive child and redefine the place of non-invasive methods for screening of renovascular hypertension, and specifically, to evaluate the value of captopril-enhanced renal scintigraphy at the two ends of the palette: the obese child with hypertension and the severely hypertensive prepubertal child. Renal artery stenosis in children is mainly due to fibromuscular dysplasia and stenoses associated with syndromes involving single or multiple smaller branch vessels. This explains the low specificity and sensitivity of the color-Doppler ultrasound method and captopril renal scintigraphy. Even the more sophisticated computed tomography (CT) and magnetic resonance imaging (MRI) angiographic techniques are, at present, not sensitive enough to exclude stenoses of the small branches definitely. Thus, children in whom there is a strong suggestion of renovascular hypertension should undergo angiography with a view to endovascular treatment, as non-invasive imaging has no significant benefit and might lead to a delay in treatment. In the cases when the probability of renovascular disease is moderate a basic assessment of renal function and structure is sufficient. In the neonate, catheter-associated thromboembolic disease is among the most common causes hypertension. It should be controlled medically until the patient is old enough to undergo angiography and angioplasty successfully. Thus, in this age group, there is a place for functional imaging with renal sonography and angiotensin-converting enzyme inhibitor (ACEI) renography to detect hemodynamically significant renovascular disease, with the limitations mentioned above. However, the rapid technical evolution of non-invasive methods requires periodic re-consideration of the actual standpoints.

Endovascular Therapy of Renovascular Hypertension in Children: Single Center Analysis

We present our results after percutaneous transluminal renal angioplasty (PTRA) and stent implantation in the treatment of eight children with renal artery stenosis (RAS) with consequential development of malignant renovascular hypertension (RVH) despite the administration of antihypertensive drugs. In the period between January 2000 and November 2007, endovascular interventional procedures in the renal arteries were performed in 8 children (six boys and two girls) to treat malignant RVH caused by RAS. The mean patient age+/-standard deviation was 10.8 years+/-3.7 years (median age 9 years; range 8-17 years). Interdisciplinary discussion and evaluation of the indications for endovascular treatment was carried out for all of the eight patients. Our indications for the PTRA procedure were severe RVH with arterial blood pressure (BP) values above the 99th percentile, which did not respond to the administration of antihypertensive drugs. Renal artery stenting was performed due to re-stenosis after PTRA. Diagnostic digital subtraction angiography demonstrated unilateral RAS of the main renal artery in seven children and bilateral stenosis of the renal arteries in one child. We performed 11 endovascular interventions on 9 main renal arteries in 8 children (10 PTRA and one stent placement). In 7 of 8 children, complete correction of RAS was achieved. Follow-up assessment over a mean period of 39 months (range 6-84 months) showed normotension with no antihypertensive treatment in 6 children. One child had a technically successful PTRA and improved BP with reduced requirement for antihypertensive treatment. Technical failure of the endovascular intervention occurred in a boy with severe FMD who underwent successful surgical autotransplantation of the kidney. Endovascular therapy of RAS in children with consequential development of malignant RVH despite antihypertensive drugs represents the treatment of choice. PTRA and/or stent implantation are technically and clinically feasible and safe in this group of children. Optimal treatment results in children can be expected in a clinical environment with successful interdisciplinary cooperation between the pediatrician, interventional radiologist and pediatric surgeon.

Anatomic distribution of renal artery stenosis in children: implications for imaging

Renal artery stenosis (RAS) causes significant hypertension in children. Frequently, pediatric RAS occurs with systemic disorders. In these cases, stenoses are often complex and/or include long segments. We believed that hypertensive children without comorbid conditions had a different lesion distribution and that the difference might have implications for imaging and treatment. To identify locations of RAS lesions in these hypertensive children without comorbid conditions. Patients who had renal angiography for hypertension from 1993 to 2005 were identified. Patients with systemic disorders, renovascular surgery, or normal angiograms were excluded. The angiograms of the remaining patients were reviewed for number, type, and location of stenoses. Eighty-seven patients underwent renal angiography for hypertension; 30 were excluded for comorbid conditions. Twenty-one of the remaining 57 patients had abnormal angiograms; 24 stenoses were identified in those patients. All were focal and distributed as follows: 6 (25%) main renal artery, 12 (50%) 2nd order branch, 3 (12.5%) 3rd order branch, and 3 (12.5%) accessory renal artery. Hypertensive children without comorbid conditions who have RAS usually have single, focal branch artery stenoses. This distribution supports angiography in these patients because of its superior sensitivity in detecting branch vessel disease and its therapeutic role in percutaneous transluminal renal angioplasty.

Renal Artery Aneurysm Secondary to Fibromuscular Dysplasia in a Young Patient

An 8-year-old male was found on routine physical examination to have a blood pressure of 220/110. Renal angiography demonstrated bilateral renal artery stenosis and an aneurysm of the distal left renal artery with branch involvement. At operation, the left renal artery stenosis and aneurysm was repaired by ex vivo arterial reconstruction and autotransplantation of the kidney. Pathologic evaluation of the resected aneurysm confirmed the diagnosis of fibromuscular dysplasia. Fibromuscular dysplasia is the most common cause of renal artery stenosis in children over 1 year of age and can in rare cases be associated with the development of renal artery aneurysms. In complex cases of renal artery stenosis with involvement of renal artery branches, ex vivo repair and orthotopic autotransplantation is an excellent approach for surgical management.

Percutaneous treatment of transplant renal artery stenosis in children

Percutaneous treatment of renal artery stenosis (RAS) is an accepted procedure and numerous reports have been published. However, experience with its use in RAS in the transplanted kidney in children is scarce. Since 1994 we have diagnosed RAS in seven children with the use of Doppler ultrasonography (US), confirming it with percutaneous angiography (PAG). In six of the seven patients percutaneous transluminal angioplasty (PTA) was performed. In one patient a metallic stent was placed due to the extension of the arterial lesion, and a second stent was placed in another child when a re-stenosis was diagnosed 1 month after the PTA. All patients presented with hypertension (de novo or 30% increase over previous values). After ruling out acute rejection, calcineurin inhibitor toxicity, and urinary obstruction, US was performed and, when an increase in arterial flux velocity was registered, PAG was also performed. Six children showed an increase in serum creatinine (Cr) and proteinuria. Blood pressure decreased after the procedure and Cr returned to previous levels in all children. One of the grafts was lost due to chronic transplant rejection 7 years later. The other children have a functioning kidney. Although this is a small group of patients, the consistently good results and the lack of reported experience prompted us to communicate our preliminary observation.

Percutaneous transluminal angioplasty of renal artery stenosis in children: J.V. Courtel, B. Soto, P.M. Niaudet, et al. Pediatr Radiol 28:59–63, (January), 1998

Percutaneous transluminal angioplasty of renal artery stenosis in children: J.V. Courtel, B. Soto, P.M. Niaudet, et al. Pediatr Radiol 28:59–63, (January), 1998

Percutaneous transluminal angioplasty of renal artery stenosis in children.

Twenty percutaneous transluminal renal angioplasties were performed on 16 children (mean age 8.7 years) with hypertension secondary to renal artery stenosis (RAS). The aetiologies were neurofibromatosis (n = 1), Williams syndrome (n = 2), Takayasu arteritis (n = 1) and fibromuscular dysplasia (n = 12). The stenosis was isolated proximal or distal in 13 cases and multiple in 3 cases. Angioplasty resulted in a complete cure without medical treatment in 9 cases. Angioplasty allowed a reduction of medical treatment in two single stenoses, but was ineffective in all cases of multiple stenoses. Our findings show that angioplasty of RAS in children is an effective treatment when the stenosis is isolated, with a 69 % success rate. It seems ineffective in case of multiple stenoses (three cases).

Evaluation and management of bilateral renal artery stenosis in children: A case series and review

This report describes the clinical course, diagnostic evaluation and management of six children with bilateral renal artery stenosis (RAS) and concurrent narrowing of the abdominal aorta. Except for one child with active arteritis, the others were asymptomatic. There were no clinical or laboratory features suggesting the etiology of hypertension in four of six patients, and diagnostic procedures, including Doppler duplex ultrasound and captopril scintigraphy, were unreliable in screening for such hypertension. Abdominal aortography and selective renal angiography confirmed the diagnosis of bilateral RAS and associated anatomical alterations of the aorta and its branches. The hypertension was severe and minimally responsive to antihypertensive agents. It was cured or improved after percutaneous transluminal angioplasty (PTA) of three vessels in two children with mid-vessel stenoses, while hypertension persisted after PTA of two mid-vessel stenoses in a third child and one vessel with ostium stenosis in a fourth child. Autotransplantation of seven kidneys in four children resulted in cure of significant improvement of the hypertension. Renal function was preserved in all children during a mean follow-up time of 41 months. Based on illustrative data from these six children, as well as information from a review of the literature, this report discusses the key diagnostic issues and stresses the potential advantages of renal autotransplantation in selected children with this disorder.

Renal transplant artery stenosis in children: Treatment with percutaneous transluminal angioplasty

Hypertension due to transplant renal artery stenosis was treated with percutaneous transluminal angioplasty (PTA) in 6 children. 8 angioplasties were performed and the follow-up period varied between 3 and 66 months (average 23 months). The stenoses were located at the site of anastomosis in 4 children and distal to the anastomosis in 2. PTA resulted in improvement of hypertension in all patients, although the need for antihypertensive medication remained. No grafts were lost. Our findings show that PTA of transplant renal artery stenosis in children is a good first choice of treatment.

Renal artery stenosis in children

In a large paediatric renal unit over the last 14 years, 19 children (10 male and 9 female, aged 1 week to 16 years, mean 7 years) with renal artery stenosis (RAS) were evaluated. Transplant RAS cases were not included. All 19 children were hypertensive. In 10 this was an incidental finding. Based on clinical findings and arteriography, the causes of RAS included a middle aortic syndrome (MAS) (n = 5), neurofibromatosis (n = 3), William's syndrome (n = 3), fibromuscular hyperplasia (FMH) (n = 4), idiopathic RAS (n = 2) and isolated branch artery stenosis (n = 2). Previous studies have suggested FMH is the commonest cause of RAS in the paediatric population. In our study the largest subgroup are MAS/William's syndrome children, in whom the angiographic appearances were indistinguishable. Where possible, management, both surgical and radiological, and eventual outcomes have been described.