Renovascular hypertension in children

Pediatric Hypertension: A Condition That Matters

Systemic hypertension has been considered mainly as an adult health issue for a long time, but it is now being increasingly acknowledged as a significant problem also among pediatric patients. The frequency of pediatric hypertension has grown mostly because of increases in childhood obesity and sedentary lifestyles, but secondary forms of hypertension play a role as well. Considering that unaddressed hypertension during childhood can result in enduring cardiovascular complications, timely identification and intervention are essential. Strategies for addressing this disease encompass not only lifestyle adjustments, but also the use of medications when needed. Lifestyle modifications entail encouraging a nutritious diet, consistent physical activity, and the maintenance of a healthy weight. Moreover, educating both children and their caregivers about monitoring blood pressure at home can aid in long-term management. Thus, the aim of this review is to discuss the etiologies, classification, and principles of the treatment of hypertension in pediatric patients.

Cardiovascular outcomes improve in children with renovascular hypertension following endovascular and surgical interventions

BACKGROUND

Renovascular hypertension (RenoVH) is a cause of hypertension in children. A common cause of RenoVH is renal artery stenosis which acts by reducing blood supply to renal parenchyma and activating the renin-angiotensin-aldosterone axis, often leading to cardiac remodelling. This longitudinal observational study aims to describe occurrence of cardiovascular changes secondary to RenoVH and also any improvement in cardiac remodelling after successful endovascular and/or surgical intervention.

METHODS

All patients with RenoVH referred to our centre, who received ≥ 1 endovascular intervention (some had also undergone surgical interventions) were included. Data were collected by retrospective database review over a 22-year period. We assessed oscillometric blood pressure and eight echocardiographic parameters pre- and post-intervention.

RESULTS

One hundred fifty-two patients met inclusion criteria and had on average two endovascular interventions; of these children, six presented in heart failure. Blood pressure (BP) control was achieved by 54.4% of patients post-intervention. Average z-scores improved in interventricular septal thickness in diastole (IVSD), posterior Wall thickness in diastole (PWD) and fractional shortening (FS); left ventricular mass index (LVMI) and relative wall thickness (RWT) also improved. PWD saw the greatest reduction in mean difference in children with abnormal (z-score reduction 0.25, p < 0.001) and severely abnormal (z-score reduction 0.23, p < 0.001) z-scores between pre- and post-intervention echocardiograms. Almost half (45.9%) had reduction in prescribed antihypertensive medications, and 21.3% could discontinue all antihypertensive therapy.

CONCLUSIONS

Our study reports improvement in cardiac outcomes after endovascular + / - surgical interventions. This is evidenced by BP control, and echocardiogram changes in which almost half achieved normalisation in systolic BP readings and reduction in the number of children with abnormal echocardiographic parameters. A higher resolution version of the Graphical abstract is available as Supplementary information.

SUPPLEMENTARY INFORMATION

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.

A Nine-year-old Boy with Renovascular Hypertension: Knowing Where to Look

Renal artery entrapment (RAE) by hypertrophic diaphragmatic crura is an extremely rare cause of renovascular hypertension (RVH). Here, we report the case of a 9-year-old boy diagnosed with RVH caused by right RAE by a hypertrophic diaphragmatic crus and successfully managed with close medical monitoring. Diagnosis of this entity is easily overlooked if the optimal views are not obtained during imaging, which depends on a high index of suspicion. We would like to remind clinicians to keep this rare condition in mind when evaluating children with RVH.

Prevalence and clinical characteristics of renovascular hypertension associated with fibromuscular dysplasia in China

OBJECTIVES

The aim of this study was to investigate the clinical characteristics of renal artery fibromuscular dysplasia (FMD) in patients in China and identify the cure rate of hypertension after angioplasty.

METHODS

Consecutive hypertensive patients with renal artery stenosis caused by FMD who underwent catheter-based angiography, and were followed at two Chinese referral centres, were retrospectively analysed. All patients underwent a detailed investigation, including demographic characteristics, clinical characteristics, biochemical sampling, Doppler ultrasonography of carotid arteries, magnetic resonance angiography (MRA) of the intracranial artery, and CTA or MRA of the abdominal artery and catheter-based renal angiography. Patients were routinely followed up at 1 month, 6 months and every year after the procedure.

RESULTS

Among 245 study participants, with a mean diagnosed age of 26.9 ± 9.9 years, 137 (55.9%) were women, and 38 (15.5%) were children. All patients were diagnosed with hypertension at a mean age of 23.4 ± 8.4 years. There were 73.5% focal and 15.2% multivessel cases. Aneurysms, arterial dissections and total occlusions were found in 21.6, 4.1 and 12.2% of patients, respectively. Patients with multifocal FMD were older (26.0 vs. 23.7 years, P  = 0.021) and more often female (70.8 vs. 50.6%, P  = 0.004). Among children with renal FMD, 55.2% were men, and 86.8% were focal. After a median follow-up of 7.0 years, multifocal FMD had a higher cure rate of hypertension than focal FMD after revascularization (71.7 vs. 55.8%, P  = 0.032).

CONCLUSION

In a cohort of mostly young Chinese patients, the prevalence of hypertension associated with renal FMD is similar in both sexes. Focal FMDs were more frequent than the multifocal ones and, after angioplasty, were associated with a worse blood pressure outcome.

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.

Role of drug-eluting stent on Takayasu arteritis with renal artery stenosis

Takayasu arteritis (TA) is defined as granulomatous inflammation of large arteries involving the aorta and its primary branches. Takayasu arteritis with renal artery stenosis (TARAS) is a common cause of pediatric renovascular hypertension. The main purposes of TARAS management are to improve high blood pressure and recover renal function. When general medication fails to improve symptoms, renal revascularization may be attempted.  Implantation of a drug-eluting stent (DES) has been used as an alternative strategy for pediatric renal revascularization. Here, we report on a 10-year-old, female, Javanese patient with bilateral TARAS who underwent DES implantation. Her clinical presentation was hypertensive crisis and worsened renal function. Bilateral renal artery DES implantation was performed successfully without complications. The child’s blood pressure was controlled using two anti-hypertensive medications after DES implantation and her renal function recovered. Dual anti-platelet therapy was given to minimize the risk of stent thrombosis.

Hypertension crisis as the first symptom of renovascular hypertension in children

BACKGROUND

Renovascular 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.

METHODS

This 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).

RESULTS

Fifty-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).

CONCLUSIONS

Most 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.

Oral agents for acute severe hypertension in children with minimal or no symptoms

Acute hypertension is common among children admitted to hospital, and large or rapid increases in blood pressure place children at risk of complications such as posterior reversible encephalopathy syndrome. Guidelines in the United States and Europe now include definitions guiding the identification of acute severe hypertension (otherwise known as hypertensive crisis) and its management. This review discusses these recommendations and the appropriate use of oral antihypertensive agents for children with minimal or no symptoms. We focus on the role of oral calcium channel blockers, including isradipine (a second-generation dihydropyridine), given recent changes to regulatory approvals in Australia. The differing pharmacokinetic and pharmacodynamic properties of agents are compared, with the aim of facilitating directed drug selection and dosing.

Neonatal hypertension: concerns within and beyond the neonatal intensive care unit

Neonatal hypertension occurs in 1%-2% of neonates in the neonatal intensive care unit (NICU) although may be underdiagnosed. Blood pressure values in premature neonates change rapidly in the first days and weeks of life which may make it more difficult to recognize abnormal blood pressure values. In addition, the proper blood pressure measurement technique must be used to ensure the accuracy of the measured values as most blood pressure devices are not manufactured specifically for this population. In premature neonates, the cause of the hypertension is most commonly related to prematurity-associated complications or management while in term neonates is more likely to be due to an underlying condition. Both oral and intravenous antihypertensive medications can be used in neonates to treat high blood pressure although none are approved for use in this population by regulatory agencies. The natural history of most neonatal hypertension is that it resolves over the first year or two of life. Of concern are the various neonatal risk factors for later cardiovascular and kidney disease that are present in most NICU graduates. Prematurity increases the risk of adulthood hypertension while intrauterine growth restriction may even lead to hypertension during childhood. From neonates through to adulthood NICU graduates, this review will cover each of these topics in more detail and highlight the aspects of blood pressure management that are established while also highlighting where knowledge gaps exist.

Vein Graft Aneurysm after Aorto-Renal Bypass for Childhood Renovascular Hypertension Due to Fibromuscular Dysplasia

Renovascular hypertension (RVHT) is a major cause of surgically correctable secondary hypertension. Refractory hypertension despite multiple antihypertensive drugs requires angioplasty, surgical revascularization, or even nephrectomy. Herein, we report a pediatric patient who had been treated with angioplasty, nephrectomy, and aortorenal bypass surgery for RVHT due to fibromuscular dysplasia and re-do endoaneurysmal graft replacement for a vein graft aneurysm. This case highlights the various treatment modalities for RVHT and the recurrent nature of the disease with a rare presentation of a vein graft aneurysm after aortorenal bypass.

Systemic Hypertension in Infants with Bronchopulmonary Dysplasia

PURPOSE OF REVIEW

Neonatal hypertension is increasingly recognized as improvements in neonatal intensive care have led to increased survival of premature infants. Among infants with bronchopulmonary dysplasia (BPD), the rates of hypertension are much higher than the general neonatal population. However, the etiology and pathophysiology of this increased risk of hypertension in neonates with lung disease remain unclear.

RECENT FINDINGS

Among infants with bronchopulmonary dysplasia, the rates of hypertension are much higher than the general neonatal population. New studies suggest outcomes in neonates with BPD with hypertension are usually good, with resolution of hypertension in most infants with lung disease. Several potential mechanisms of hypertension in this patient population have been recently proposed. This review focuses on the recent epidemiologic data on prevalence of hypertension in neonates with bronchopulmonary dysplasia, reviews the typical clinical course, and discusses available strategies for management of infants with bronchopulmonary dysplasia that develop hypertension.

Neonatal Hypertension

Neonatal hypertension is uncommon but is becoming increasingly recognized. Normative blood pressure data are limited, as is research regarding the risks, treatment, and long-term outcomes. Therefore, there are no clinical practice guidelines and management is based on clinical judgment and expert opinion. Recognition of neonatal hypertension requires proper blood pressure measurement technique. When hypertension is present there should be a thorough clinical, laboratory, and imaging evaluation to promptly diagnose causes needing medical or surgical management. This review provides a practical overview for the practicing clinician regarding the identification, evaluation, and management of neonatal hypertension.

HISTOLOGIC AND MORPHOLOGIC CHARACTER OF PEDIATRIC ABDOMINAL AORTIC DEVELOPMENTAL COARCTATION AND HYPOPLASIA

OBJECTIVES

Abdominal aortic coarctation and hypoplasia are uncommon diseases, recognized most often in pediatric-aged individuals. Comprehensive studies regarding the pathologic spectrum of these aortopathies are nonexistent. This investigation was undertaken to better define the histologic and morphologic character of abdominal aortic narrowings affecting children and assess its potential relevance to contemporary clinical practice.

METHODS

Aortic specimens obtained during open operations in children being treated for symptomatic, noninflammatory abdominal aortic narrowings at the University of Michigan were subjected to histologic study following hematoxylin-eosin, Movat, Verhoeff Van Gieson, and Masson's trichrome preparations. Microscopic findings were correlated with the anatomic aortic images. In addition, a detailed review was completed of all prior reports in the English literature that included images depicting the histologic character of noninflammatory abdominal aortic narrowings in children.

RESULTS

Among a series of 67 pediatric-aged individuals undergoing open surgical interventions for abdominal aortic narrowings, eight children ranging in age from 9 months to 18 years, had adequate aortic tissue available for study. The loci of the specimens paralleled the anatomic sites of segmental coarctations observed in the entire series, with involvement of the suprarenal abdominal aorta (3), intrarenal aorta (2), and infrarenal aorta (1). Diffusely hypoplastic abdominal aortas (2) included one case of a de facto aortic duplication, represented by a channel that paralleled the narrow native aorta and gave origin to celiac artery branches, as well as the superior mesenteric and renal arteries. Concentric or eccentric intimal fibroplasia was observed in every aorta, often with internal elastic fragmentation and duplication (4). Media abnormalities included elastic tissue disorganization (3), and focal medial fibrosis (1). Organizing luminal thrombus occurred in two infants. Coexistent ostial stenoses of the celiac, superior mesenteric, or renal arteries were observed in all but the only child who having an infrarenal aortic coarctation. Neurofibromatosis-1 affected one child whose histologic findings were indistinguishable from those of the other children. Review of prior published histologic images of abdominal aortic coarctation and hypoplasia affecting children from other centers revealed a total of 14 separate reports, each limited to single case photomicrographs of which 11 exhibited intimal fibroplasia.

CONCLUSIONS

Intimal fibroplasia is a common accompaniment of developmental abdominal aortic coarctation and hypoplasia. It is posited that intimal fibroplasia, that is likely progressive in instances of abnormal shear stresses in these diminutive vessels, may contribute to less salutary outcomes following endovascular and certain open reconstructions of pediatric abdominal aortic narrowings.

Fifteen-minute consultation: Neonatal hypertension

Neonatal hypertension is a rare but well recognised condition, especially in newborns needing invasive monitoring in the intensive care unit. Recognition of newborns with hypertension remains challenging because of natural variability in blood pressure with postconceptional age and the lack of reference data for different gestational ages. Investigation of neonates with hypertension can be challenging in light of the myriad differing aetiologies. This may be simplified by a systematic approach to investigation. There remains a relative paucity of data to guide the use of pharmacological therapies for hypertension in neonates. Clinicians rely on empirical management protocols based on experience and expert opinion. Much of the information on dosing regimens and protocols has simply been derived from the use of antihypertensive agents in older children and in adults, despite fundamental pathophysiological differences.

Presentation, treatment, and outcome of renovascular hypertension below 2 years of age

Renovascular hypertension in most cases requires endovascular treatment and/or surgery. This is technically much more difficult in small children and there is very limited published knowledge in this age group. We here present treatment and outcome of young children with renovascular hypertension at our institution. Children below 2 years of age, with renovascular hypertension between January 1998 and March 2020 were retrospectively reviewed. Demographics and treatment modalities were noted. Primary outcome was blood pressure within a week after the procedures and at last available visit. Sixty-six angiographies were performed in 34 patients. Median age at time of first angiography was 1.03 (interquartile range (IQR) 0.4-1.4) years and systolic blood pressure at presentation 130 (IQR 130-150) mm Hg. Thirty-eight percent (13/34) of children were incidentally diagnosed and 18% (6/34) presented with heart failure. Twenty-six (76%) children had main renal artery stenosis and 17 (50%) mid-aortic syndrome. Seventeen (50%) children showed intrarenal, six (18%) mesenteric, and three (9%) cerebrovascular involvement. Twenty patients underwent 45 percutaneous transluminal angioplasty procedures and seven children surgeries. In 44% of the 16 patients who underwent only percutaneous transluminal angioplasty blood pressure was normalized, 38% had improvement on same or decreased treatment and 19% showed no improvement. Complications were seen in 7.5% (5/66) of angiographies. In four of the seven (57%) children who underwent surgery blood pressure was normalized, two had improved (29%) and one unchanged (14%) blood pressure.

CONCLUSION

In small children with renovascular hypertension below the age of 2 years, percutaneous transluminal angioplasty caused significant improvement in blood pressure with low complication profile. Surgery can be recommended where percutaneous transluminal angioplasty and medical treatments failed.

WHAT IS KNOWN

• Renovascular hypertension is diagnosed in all age groups from a few weeks of life until adulthood. • Both angioplasty and surgery are significantly more difficult to perform in small children and the published information on short and long-term outcome in these children is very scarce.

WHAT IS NEW

• Children below the age of two years can safely and successfully undergo selective renal angiography and also safely be treated with angioplasty. • We here present a large group of babies and infants where angioplasty and in some cases surgery effectively and safely improved their blood pressure.

Mid-term outcome of angioplasty for pediatric renovascular hypertension

PURPOSE

To evaluate the mid-term outcome 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 our hospital from 2012 to 2019 were analyzed retrospectively. Post-procedural blood pressure, glomerular filtration rate (GFR) of the affected kidney, restenosis and complications were closely followed up.

RESULTS

The procedure of PTRA was performed in total of 30 children (20 males and 10 females), with a mean age of 7.32±0.74 years (40 days ∼13.92 years) and a mean weight of 24.99±2.26 kg (3.4 ∼ 53kg). The median follow-up period was 26.5 months (1 month ∼7.5 years). Technical success was achieved in 26 of 30 patients (86.7%). Three patients (10.0%) developed restenosis. Only 1 patient underwent stent implantation, and the stent fractured 8 months later, requiring further intervention. No other complication was found. In terms of clinical benefit of blood pressure control after the initial PTRA procedure, 15 patients (50%) were cured and 7 (23.3%) improved. There was no significant difference in etiology, lesion location and length between patients with clinical benefit and failure (p=0.06, 0.202 and 0.06). The GFR of the affected kidney was significantly improved from 19.85±11.24 (ml/min) to 38.09±11.88 (ml/min) at 6 months follow-up after PTRA (p<0.001).

CONCLUSION

The overall results of PTRA for pediatric RVH caused by different etiologies are promising. Not only does it provide clinical benefit of blood pressure control in 73.3% of patients, it also significantly improves the function of the affected kidney.

Validation of computed tomography angiography as a complementary test in the assessment of renal artery stenosis: a comparison with digital subtraction angiography

BACKGROUND

Renal artery stenosis is an important cause of hypertension in children, accounting for 5-10% of cases. When suspected, noninvasive imaging options include ultrasound (US), computed tomography (CT) angiography and magnetic resonance (MR) angiography. However, digital subtraction angiography (DSA) remains the gold standard.

OBJECTIVE

To investigate the accuracy and inter-reader reliability of CT angiography in children with suspected renal artery stenosis.

MATERIALS AND METHODS

This is a retrospective study of patients suspected of having renal artery stenosis evaluated by both CT angiography and DSA between 2008 and 2019 at a tertiary pediatric hospital. Only children who underwent CT angiography within 6 months before DSA were included. CT angiography studies were individually reviewed by two pediatric radiologists, blinded to clinical data, other studies and each other's evaluation, to determine the presence of stenosis at the main renal artery and 2nd- and 3rd-order branches. The sensitivity, specificity and accuracy were calculated using DSA as the reference. The effective radiation dose for CT angiography and DSA was also calculated. Kappa statistics were used to assess inter-reader agreement.

RESULTS

Seventy-four renal units were evaluated (18 girls, 19 boys). The patients' median age was 8 years (range: 1-21 years). Overall, CT angiography was effective in detecting renal artery stenosis with a sensitivity of 85.7%, specificity of 91.5% and accuracy of 88.9%. There was moderate inter-reader agreement at the main renal artery level (k=0.73) and almost perfect inter-reader agreement at the 2nd/3rd order (k=0.98). However, the sensitivity at the 2nd- and 3rd-order level was lower (14.3%). CT angiography provided excellent negative predictive value for evaluating renal artery stenosis at the main renal artery level (90.1%) and at the 2nd- or 3rd-order branches (82.7%). The median effective dose of CT angiography studies was 2.2 mSv (range: 0.6-6.3) while the effective dose of DSA was 13.7 mSv.

CONCLUSION

CT angiography has high sensitivity and specificity at the main renal artery level with a lower radiation dose than previously assumed. Therefore, it can be used as a diagnostic tool in patients with low to medium risk of renal artery stenosis, and as a screening and treatment planning tool in patients at high risk.

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.

Unilateral Renal Artery Stenosis Associated with Severe Hypertension: Atypical Presentation of Tuberculosis

Background

Renal artery stenosis is a common cause of hypertension in children; however, infectious causes of renal artery stenosis are rare. Diagnosis of TB in children is challenging, causing delay in diagnosis.

Case Presentation

We report a case of a 4-year-old girl who was presented with loss of consciousness and seizure of one day duration. The patient had severe acute malnutrition, symptom complex of TB and contact with adults having smear positive tuberculosis. Subsequently, her blood pressure was 200/140 mmhg. The patient was diagnosed with disseminated TB with left renal artery stenosis, severe hypertension, cardiomegaly, upper gastrointestinal bleeding, stroke and severe malnutrition. Diagnosis was confirmed with head CT scan, MRI and ultrasound of the kidneys. The patient was on antituberculosis drugs, prednisolone, nifedipine, furosemide, antiepileptic drugs and nutritional therapy. After treatment with antituberculosis drugs and other supportive care all the symptoms subsided, while the hypertension was not controlled, necessitating surgical intervention for the left renal stenosis.

Conclusion

Atypical presentations of TB have to be considered especially when there is a strong contact history. Tuberculosis preventive therapy may have prevented all the complications, had it been given the moment the index cases were diagnosed.

Blunt renal trauma-induced hypertension in pediatric patients: a single-center experience

PURPOSE

Children have a greater chance of sustaining a renal injury than adults and higher odds of having a high-grade renal injury. Hypertension is a rare complication of blunt renal trauma, with risk being higher in cases of major renal trauma. We reviewed the cases of pediatric blunt renal trauma-induced hypertension in our tertiary referral center in an attempt to better understand this rare condition.

STUDY DESIGN

A retrospective evaluation of children under the age of 18 who were admitted to our department during the last 20 years and were diagnosed with blunt renal trauma.

RESULTS

Twenty-three children presented with blunt renal trauma, one of whom was treated with emergency nephrectomy. Four children (18%) developed post-traumatic hypertension. All four cases were associated with a reduction in blood flow to the kidney, either through injury to the renal artery (in three cases) or through extrinsic compression of the kidney by a large perirenal hematoma (Page kidney; in one case). The Page kidney case developed hypertension during the initial hospitalization, and it resolved spontaneously after five months through the gradual resorption of the perirenal hematoma. Among the three cases of renal artery injury, hypertension during the initial hospitalization was only observed in one case, with hypertension in the other two cases manifesting after two months and four years, respectively. All three cases of renal artery injury resulted in a complete loss of function of the injured kidney, and two cases were treated with nephrectomy. Following nephrectomy, the blood pressure level returned to normal within a few days.

DISCUSSION

Development of hypertension following a blunt renal trauma can be heterogenous, with the time of manifestation stretching between days after the accident and years thereafter. Children have a higher risk of renal trauma and, according to published data out of the National Trauma Data Bank, a 20-times higher risk of renal artery injury in comparison to the adult population. Large multicenter studies are required to answer the question of whether children are therefore more prone to blunt renal trauma-induced hypertension than adults.

CONCLUSIONS

Our study highlights the importance of blood pressure monitoring in children following blunt renal trauma, as post-traumatic hypertension can develop even years after the accident. In cases of a poorly functioning kidney, nephrectomy may be regarded as a curative therapy.

Beyond Atherosclerosis and Fibromuscular Dysplasia: Rare Causes of Renovascular Hypertension

Renovascular hypertension is one of the most common forms of secondary hypertension. Over 95% of cases of renovascular hypertension are due either to atherosclerosis of the main renal artery trunks or to fibromuscular dysplasia. These two causes of renal artery stenosis have been extensively discussed in recent reviews and consensus. The aim of the current article is to provide comprehensive and up-to-date information on the remaining causes. While these causes are rare or extremely rare, etiologic and differential diagnosis matters both for prognosis and management. Therefore, the clinician cannot ignore them. For didactic reasons, we have grouped these different entities into stenotic lesions (neurofibromatosis type 1 and other rare syndromes, dissection, arteritis, and segmental arterial mediolysis) often associated with aortic coarctation and other arterial abnormalities, and nonstenotic lesions, where hypertension is secondary to compression of adjacent arteries and changes in arterial pulsatility (aneurysm) or to the formation of a shunt, leading to kidney ischemia (arteriovenous fistula). Finally, thrombotic disorders of the renal artery may also be responsible for renovascular hypertension. Although thrombotic/embolic lesions do not represent primary vessel wall disease, they are characterized by frequent macrovascular involvement. In this review, we illustrate the most characteristic aspects of these different entities responsible for renovascular hypertension and discuss their prevalence, pathophysiology, clinical presentation, management, and prognosis.

Clinical characteristics and long-term outcomes of endovascular treatment of renal artery fibromuscular dysplasia with branch lesions

BACKGROUND

Renal artery fibromuscular dysplasia (FMD) can cause arterial stenosis, dissection, and aneurysm of renal arteries. This study aimed to analyze the clinical characteristics and evaluate the long-term outcomes of renal branch artery FMD in children and adults.

METHODS

Sixty-one patients with renal artery FMD underwent endovascular treatment, including 23 children and 38 adults. They were divided into two groups, the main artery FMD group (n = 40, with severe stenosis located in the main renal artery) and the branch artery FMD group (n = 21, with only the branch lesions in unilateral or bilateral branch artery). The clinical characteristics and long-term outcomes of these pediatric and adult patients were evaluated.

RESULTS

The incidence of branch FMD was higher in children than in adults (P = 0.005). Thirteen children showed one or more branch artery involvements. Hypertension and headache were the most common symptoms. The branch aneurysm with coexisting stenosis was more common in patients with branch artery FMD. During the follow-up, blood pressure was normal in 8 patients and lowered in 11 patients in the branch FMD group. The patient's glomerular filtration was increased in 61 patients (P < 0.001). Four-year freedom from reintervention in 21 branch artery FMD patients was lower than that in 40 main artery FMD patients (P < 0.05).

CONCLUSIONS

A higher incidence of renal branch artery FMD was observed in children than in adults. Endovascular treatment with balloon angioplasty can be used for treating renal branch artery FMD.

Timing of procedural interventions in childhood renovascular hypertension

BACKGROUND

Renovascular hypertension (RVHTN) is a rare, often complex condition due to multiple etiologies including congenital stenoses, vasculitides, and fibromuscular dysplasia. Among children with RVHTN who require multiple and escalating medications to control blood pressure, the optimal timing of a procedural intervention involves a balance of numerous factors.

CASE-DIAGNOSIS/TREATMENT

In this presentation of a 1-month-old girl with RVHTN, the treating medical team had to consider multiple factors in the initial management and timing of interventions to treat her underlying cause of RVHTN, including concerns for kidney health, degree of hypertension, age and size of the patient, and potential methods of procedural intervention. Initially, she was treated conservatively until concern for poor renal growth arose and a durable surgical intervention was thought feasible and safe.

CONCLUSION

The evidence regarding the timing of non-medical interventions in pediatric RVHTN is limited. Considerations should include patient age, size, disease severity, comorbid conditions, and degree of medical management required to maintain safe blood pressures that allow for growth and reverse cardiac damage. The optimal interventions have not been evaluated by controlled trials and should be decided on a case-by-case basis with consideration of center expertise and family preferences.

Beyond Atherosclerosis and Fibromuscular Dysplasia: Rare Causes of Renovascular Hypertension

Renovascular hypertension is one of the most common forms of secondary hypertension. Over 95% of cases of renovascular hypertension are due either to atherosclerosis of the main renal artery trunks or to fibromuscular dysplasia. These two causes of renal artery stenosis have been extensively discussed in recent reviews and consensus. The aim of the current article is to provide comprehensive and up-to-date information on the remaining causes. While these causes are rare or extremely rare, etiologic and differential diagnosis matters both for prognosis and management. Therefore, the clinician cannot ignore them. For didactic reasons, we have grouped these different entities into stenotic lesions (neurofibromatosis type 1 and other rare syndromes, dissection, arteritis, and segmental arterial mediolysis) often associated with aortic coarctation and other arterial abnormalities, and nonstenotic lesions, where hypertension is secondary to compression of adjacent arteries and changes in arterial pulsatility (aneurysm) or to the formation of a shunt, leading to kidney ischemia (arteriovenous fistula). Finally, thrombotic disorders of the renal artery may also be responsible for renovascular hypertension. Although thrombotic/embolic lesions do not represent primary vessel wall disease, they are characterized by frequent macrovascular involvement. In this review, we illustrate the most characteristic aspects of these different entities responsible for renovascular hypertension and discuss their prevalence, pathophysiology, clinical presentation, management, and prognosis.

Beyond Atherosclerosis and Fibromuscular Dysplasia: Rare Causes of Renovascular Hypertension

Renovascular hypertension is one of the most common forms of secondary hypertension. Over 95% of cases of renovascular hypertension are due either to atherosclerosis of the main renal artery trunks or to fibromuscular dysplasia. These two causes of renal artery stenosis have been extensively discussed in recent reviews and consensus. The aim of the current article is to provide comprehensive and up-to-date information on the remaining causes. While these causes are rare or extremely rare, etiologic and differential diagnosis matters both for prognosis and management. Therefore, the clinician cannot ignore them. For didactic reasons, we have grouped these different entities into stenotic lesions (neurofibromatosis type 1 and other rare syndromes, dissection, arteritis, and segmental arterial mediolysis) often associated with aortic coarctation and other arterial abnormalities, and nonstenotic lesions, where hypertension is secondary to compression of adjacent arteries and changes in arterial pulsatility (aneurysm) or to the formation of a shunt, leading to kidney ischemia (arteriovenous fistula). Finally, thrombotic disorders of the renal artery may also be responsible for renovascular hypertension. Although thrombotic/embolic lesions do not represent primary vessel wall disease, they are characterized by frequent macrovascular involvement. In this review, we illustrate the most characteristic aspects of these different entities responsible for renovascular hypertension and discuss their prevalence, pathophysiology, clinical presentation, management, and prognosis.

Beyond Atherosclerosis and Fibromuscular Dysplasia: Rare Causes of Renovascular Hypertension

Renovascular hypertension is one of the most common forms of secondary hypertension. Over 95% of cases of renovascular hypertension are due either to atherosclerosis of the main renal artery trunks or to fibromuscular dysplasia. These two causes of renal artery stenosis have been extensively discussed in recent reviews and consensus. The aim of the current article is to provide comprehensive and up-to-date information on the remaining causes. While these causes are rare or extremely rare, etiologic and differential diagnosis matters both for prognosis and management. Therefore, the clinician cannot ignore them. For didactic reasons, we have grouped these different entities into stenotic lesions (neurofibromatosis type 1 and other rare syndromes, dissection, arteritis, and segmental arterial mediolysis) often associated with aortic coarctation and other arterial abnormalities, and nonstenotic lesions, where hypertension is secondary to compression of adjacent arteries and changes in arterial pulsatility (aneurysm) or to the formation of a shunt, leading to kidney ischemia (arteriovenous fistula). Finally, thrombotic disorders of the renal artery may also be responsible for renovascular hypertension. Although thrombotic/embolic lesions do not represent primary vessel wall disease, they are characterized by frequent macrovascular involvement. In this review, we illustrate the most characteristic aspects of these different entities responsible for renovascular hypertension and discuss their prevalence, pathophysiology, clinical presentation, management, and prognosis.

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

BACKGROUND

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.

OBJECTIVE

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.

MATERIALS AND METHODS

All patients 0-18 years 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.

RESULTS

Twenty-three patients (17 boys, 6 girls) with a mean age of 6 years 3 months (range: 3 months to 14 years 7 months) 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.

CONCLUSION

Renal CT angiography has a high sensitivity and specificity for pediatric RAS diagnosis in patients referred for DSA.

Renovascular hypertension in children

Paediatric hypertension, defined as systolic blood pressure > 95th percentile for age, sex and height is often incidentally diagnosed. Renovascular hypertension (RVH) is responsible for 5-25% of hypertension in children. Renal artery stenosis and middle aortic syndrome can both can be associated with various conditions such as fibromuscular dysplasia, Williams syndrome & Neurofibromatosis type 1. This paper discusses the approaches to diagnosis and interventional management and outcomes of renovascular hypertension in children. Angiography is considered the gold standard in establishing the diagnosis of renovascular disease in children. Angioplasty is beneficial in the majority of patients and generally repeated angioplasty is considered more appropriate than stenting. Surgical options should first be considered before placing a stent unless there is an emergent requirement. Given the established safety and success of endovascular intervention, at most institutions it remains the preferred treatment option.

Secondary Hypertension in Children and Adolescents: Novel Insights

Hypertension is a significant risk factor for cardiovascular morbidity and mortality, not only in adults, but in youths also, as it is associated with long-term negative health effects. The predominant type of hypertension in children is the secondary hypertension, with the chronic kidney disease being the most common cause, however, nowadays, there is a rising incidence of primary hypertension due to the rising incidence of obesity in children. Although office blood pressure has guided patient management for many years, ambulatory blood pressure monitoring provides useful information, facilitates the diagnosis and management of hypertension in children and adolescents, by monitoring treatment and evaluation for secondary causes or specific phenotypes of hypertension. In the field of secondary hypertension, there are numerous studies, which have reported a strong association between different determinants of 24-hour blood pressure profile and the underlying cause. In addition, in children with secondary hypertension, ambulatory blood pressure monitoring parameters offer the unique advantage to identify pediatric low- and high-risk children for target organ damage. Novel insights in the pathogenesis of hypertension, including the role of perinatal factors or new cardiovascular biomarkers, such as fibroblast growth factor 23, need to be further evaluated in the near future.

Genetics of renovascular hypertension in children

OBJECTIVE

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

The hypertensive neonate

Hypertension in neonates is increasingly recognized because of improvements in neonatal intensive care that have led to improved survival of premature infants. Although normative data on neonatal blood pressure remain limited, several factors appear to be important in determining blood pressure levels in neonates, especially gestational age, birth weight and maternal factors. Incidence is around 1% in most studies and identification depends on careful blood pressure measurement. Common causes of neonatal hypertension include umbilical catheter associated thrombosis, renal parenchymal disease, and chronic lung disease, and can usually be identified with careful diagnostic evaluation. Given limited data on long-term outcomes and use of antihypertensive medications in these infants, clinical expertise may need to be relied upon to decide the best approach to treatment. This review will discuss these concepts and identify evidence gaps that should be addressed.

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.

Abdominal Applications of Pediatric Body MR Angiography: Tailored Optimization for Successful Outcome

OBJECTIVE. The purpose of this article is to summarize current common techniques and indications for pediatric abdominopelvic MR angiography and strategies for optimizing them to achieve successful outcomes. We also discuss newer MR angiography techniques, including whole-body imaging and blood pool contrast agents, as well as various approaches to reducing the need for anesthesia in pediatric MRI. CONCLUSION. Pediatric body vascular imaging presents a unique set of challenges that require a tailored approach. Emerging pediatric abdominopelvic MR angiography techniques hold promise for continued improvement in pediatric body MR angiography.

Surgical management of pediatric renin-mediated hypertension secondary to renal artery occlusive disease and abdominal aortic coarctation

BACKGROUND

Renovascular hypertension (RVH) associated with renal artery and abdominal aortic narrowings is the third most common cause of pediatric hypertension. Untreated children may experience major cardiopulmonary complications, stroke, renal failure, and death. The impetus of this study was to describe the increasingly complex surgical practice for such patients with an emphasis on anatomic phenotype and contemporary outcomes after surgical management as a means of identifying those factors responsible for persistent or recurrent hypertension necessitating reoperation.

METHODS

A retrospective analysis was performed of consecutive pediatric patients with RVH undergoing open surgical procedures at the University of Michigan from 1991 to 2017. Anatomic phenotype and patient risk factors were analyzed to predict outcomes of blood pressure control and the need for secondary operations using ordered and binomial logistic multinomial regression models, respectively.

RESULTS

There were 169 children (76 girls, 93 boys) who underwent primary index operations at a median age of 8.3 years; 31 children (18%) had neurofibromatosis type 1, 76 (45%) had abdominal aortic coarctations, and 28 (17%) had a single functioning kidney. Before treatment at the University of Michigan, 51 children experienced failed previous open operations (15) or endovascular interventions (36) for RVH at other institutions. Primary surgical interventions (342) included main renal artery (136) and segmental renal artery (10) aortic reimplantation, renal artery bypass (55), segmental renal artery embolization (10), renal artery patch angioplasty (8), resection with reanastomosis (4), and partial or total nephrectomy (25). Non-renal artery procedures included patch aortoplasty (32), aortoaortic bypass (32), and splanchnic arterial revascularization (30). Nine patients required reoperation in the early postoperative period. During a mean follow-up of 49 months, secondary interventions were required in 35 children (21%), including both open surgical (37) and endovascular (14) interventions. Remedial intervention to preserve primary renal artery patency or a nephrectomy if such was impossible was required in 22 children (13%). The remaining secondary procedures were performed to treat previously untreated disease that became clinically evident during follow-up. Age at operation and abdominal aortic coarctation were independent predictors for reoperation. The overall experience revealed hypertension to be cured in 74 children (44%), improved in 78 (46%), and unchanged in 17 (10%). Children undergoing remedial operations were less likely (33%) to be cured of hypertension. There was no perioperative death or renal insufficiency requiring dialysis after either primary or secondary interventions.

CONCLUSIONS

Contemporary surgical treatment of pediatric RVH provides a sustainable overall benefit to 90% of children. Interventions in the very young (<3 years) and concurrent abdominal aortic coarctation increase the likelihood of reoperation. Patients undergoing remedial surgery after earlier operative failures are less likely to be cured of hypertension. Judicious postoperative surveillance is imperative in children surgically treated for RVH.

Efficacy of Antihypertensive Therapy in a Child with Unilateral Focal Fibromuscular Dysplasia of the Renal Artery: A Case Study and Review of Literature

Background: Fibromuscular dysplasia (FMD) is one of the important etiologies of renovascular hypertension in children. It is usually resistant to multiple antihypertensive agents and can cause extreme elevation in blood pressures, which can lead to end organ damage if not promptly diagnosed and treated. Treatment options include medical management with antihypertensive agents, balloon or stent angioplasties, surgical revascularization, and nephrectomy. The aim of the study was to review the efficacy of antihypertensive therapy only in the management of FMD in a very young child. Methods: This is a retrospective chart study with review of literature. Results: Here, we report a 22-month-old toddler who presented with severe resistant hypertension and cardiomyopathy who was found to have focal FMD of the right renal artery. She also presented with proteinuria, hyponatremia that was probably secondary to pressure natriuresis, hypokalemia, hyperaldosteronism, and elevated plasma renin activity. The stabilization of blood pressures was done medically with the usage of antihypertensive medications only, without the need for angioplasty or surgical revascularization. Conclusions: We demonstrate that surgical intervention may not always be necessary in the treatment of all cases of FMD, especially in a small child where such intervention may be technically challenging and lead to potential complications. Hence, medical management alone may be sufficient, at least for the short-term, in small children with controlled hypertension and normal renal function, with surgical intervention reserved for FMD with medication-refractory hypertension and/or compromised renal function.

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.

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

OBJECTIVES

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Hemorrhagic stroke and renovascular hypertension with Grange syndrome arising from a novel pathogenic variant in YY1AP1

Pediatric hypertension can cause hypertensive emergencies, including hemorrhagic stroke, contributing to rare but serious childhood morbidity and mortality. Renovascular hypertension (RVH) is one of the major causes of secondary hypertension in children. Grange syndrome (MIM#602531) is a rare disease characterized by multiple stenosis or occlusion of the renal, abdominal, coronary, and cerebral arteries, which can cause phenotypes of RVH and fibromuscular dysplasia (MIM#135580). We report the case of a 7-year-old girl with Grange syndrome who showed RVH and multiple seizure episodes. At 1 year of age, she experienced seizures and sequential hemiparesis caused by a left thalamic hemorrhage without cerebral vascular anomalies. Chronic hypertension was observed, and abdominal computed tomography angiography showed characteristic bilateral renal artery stenosis. Whole-exome sequencing revealed a novel homozygous pathogenic variant in the YY1AP1 gene (NM_001198903.1: c.1169del: p.Lys390Argfs*12). Biallelic YY1AP1 mutations are known to cause Grange syndrome. Unlike previously reported patients, our patient presented with intracerebral hemorrhagic stroke without anomalous brain artery or bone fragility. The phenotype in our patient may help better understand this ultra-rare syndrome. Grange syndrome should be considered in patients presenting with childhood-onset hypertension and/or hemorrhagic stroke for early clinical intervention.

Neonatal hypertension: cases, causes, and clinical approach

Neonatal hypertension is increasingly recognized as dramatic improvements in neonatal intensive care, advancements in our understanding of neonatal physiology, and implementation of new therapies have led to improved survival of premature infants. A variety of factors appear to be important in determining blood pressure in neonates, including gestational age, birth weight, and postmenstrual age. Normative data on neonatal blood pressure values remain limited. The cause of hypertension in an affected neonate is often identified with careful diagnostic evaluation, with the most common causes being umbilical catheter-associated thrombosis, renal parenchymal disease, and chronic lung disease. Clinical expertise may need to be relied upon to decide the best approach to treatment in such patients, as data on the use of antihypertensive medications in this age group are extremely limited. Available data suggest that long-term outcomes are usually good, with resolution of hypertension in most infants. In this review, we will take a case-based approach to illustrate these concepts and to point out important evidence gaps that need to be addressed so that management of neonatal hypertension may be improved.

Treatment of Renal Artery Stenosis in a Solitary Kidney Using Cutting Balloon Angioplasty in a Paediatric Patient

Aims:

Renovascular hypertension is a rare cause of paediatric hypertension. It is however, a potentially treatable cause particularly when caused by renal artery stenosis (RAS).

Materials and Methods:

We present the case of an 11-month-old girl presenting with cardiac dysfunction. She was found to be hypertensive with a systolic blood pressure >180mmHg. DMSA demonstrated a small right kidney and a divided renal function of 6% on the right and 94% on the left. Spectral analysis demonstrated abnormal waveforms suggestive of RAS of the left kidney.

Results:

Angioplasty with a cutting balloon was successful. Blood pressure measurements, renal function and left ventricular function improved.

Conclusion:

RAS can be successfully treated with cutting balloon angioplasty after failure of convention balloon angioplasty to relieve the narrowing. In our case, there was an immediate successful angiographic result that on mid-term follow-up demonstrated significant improvement in clinical and biochemical outcomes and cessation of all anti-hypertensive medication.

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.