Unilateral renal artery stenosis. Color-coded Doppler sonography and captopril scintigraphy in a 13-year-old patient]

Modern noninvasive techniques, such as doppler sonography or color-encoded doppler sonography, have only rarely been used for diagnosis of renovascular hypertension in children. In the following case report, we describe the successful diagnosis of renovascular hypertension in a 13-year-old girl by using color-encoded doppler sonography and Captopril renal scintigraphy. The patient was admitted with hypertension of 180/130 mmHg. Laboratory findings showed elevated plasma renin and aldosterone concentrations. No abnormalities were found by abdominal sonography, isotope renography, intravenous pyelography, or in venous digital subtraction angiography. However, subsequent color-encoded doppler sonography clearly showed evidence of an artery stenosis of the right kidney. Furthermore, isotope renography one hour after oral administration of captopril revealed an almost complete loss of glomerular filtration rate of the right kidney. Based on these findings, arterial digital subtraction angiography, including transluminal angioplasty, was performed. During this treatment procedure, the right renal artery stenosis could be confirmed and was subsequently dilated without complication. In the following twelve months the patient remained normotensive and required no further antihypertensive drug treatment.     

Pediatric hypertension: an approach to imaging

Since 1981, we have made diagnoses of secondary hypertension using state of art imaging equipment in 18 pediatric patients. The most valuable tests were ultrasound in identifying renal parenchymal disease, computed body tomography for adrenal tumors and intra-arterial renal angiography for renovascular disorders. Based on our experience, we have formulated an algorithm for the evaluation of the hypertensive pediatric patient. The initial step is careful clinical and laboratory screening to identify those patients that are likely to have essential hypertension and who should not undergo imaging tests. In the cases where there is a possible secondary etiology, renal ultrasound is usually performed first to identify parenchymal disease. If catecholamines are elevated, then abdominal computed tomography is the initial test. If no etiology is identified from these noninvasive studies, then direct intraarterial renal angiography is performed. The authors do not feel that excretory urography, radionuclide renography, intravenous digital subtraction angiography or selective renal vein sampling for renin are useful or practical screening tests for renovascular hypertension.     

Evaluation of percutaneous transluminal renal angioplasty in childhood hypertension

Percutaneous transluminal renal angioplasty (PTRA) has been infrequently used in the treatment of children with hypertension due to renal artery stenosis. We report our results in five patients aged 4 to 22 years with hypertension diagnosed at ages 1 1/2 to 10 years. Four of the five patients had been on antihypertensive medication prior to angioplasty. Four had fibromuscular disease and one had probable Takajasu's arteritis; two had solitary kidneys. Following angioplasty, a prompt decrease in blood pressure was observed in all patients. Further, four of five patients after PTRA were normotensive without antihypertensive medications, and in all PRA declined. PTRA can be a safe and effective alternative to surgical treatment in the management of renovascular hypertension in childhood. We suggest that PTRA should be the first procedure attempted to correct renovascular hypertension in children.     

Renovascular disease in childhood.

Fifty-four children referred for investigation of hypertension had renovascular disease. In eight patients it was associated with neurofibromatosis, in three with idiopathic hypercalcemia of infancy, and in five cases it followed an arteritic illness. Fibromuscular dysplasia was the underlying abnormality in the majority of cases (46%). Twenty-six patients (48%) were first seen with accelerated hypertension; 38 children (70%) had bilateral renal arterial disease, and in 41 (76%), disease of the small intrarenal vessels was found. Renal vein renin ratios indicated unilateral disease in 31 cases; the results correlated with arteriography findings in 32 (62%) of 51 patients. Eleven children also had the middle aortic syndrome, and 9 of 16 patients, investigated by cerebral arteriography because of cranial bruits or focal neurologic signs, had cerebral vascular abnormalities. Twenty patients were treated surgically--10 by reconstructive procedures, 11 by nephrectomy or heminephrectomy, and 6 by transluminal angioplasty. Of these, 9 (45%) are normotensive with no treatment, 10 have a decreased requirement for antihypertensive drugs, and 1 had no improvement. Thirty-four patients were treated medically because of the extent of their disease; two patients have died of hypertensive complications. We conclude that renal vascular disease in children is often widespread, may be associated with intracerebral vascular disease, frequently affects both kidneys, including both intrarenal and extrarenal vessels, and is therefore not always amenable to surgical intervention and cure.     

Single-dose captopril scintigraphy in the neonate with renovascular hypertension: prediction of renal failure, a side effect of captopril therapy

Baseline and single-dose captopril scintigraphy with 1 mCi of 99mTc-diethylenetriamine-pentaacetic acid (or 99mTc-glucoheptonate) was performed in 5 neonates with renovascular hypertension. Unilateral renal artery thrombosis and/or renal infarction was associated with severe impairment or lack of function on both studies (3 patients). Renal ischemia due to aortic thrombus manifested itself as lack of function only following captopril (2 patients). This approach predicted renal failure as a side effect of captopril therapy in 2 patients, 1 with unilateral (contralateral kidney infarcted) and the other with bilateral renal ischemia from aortic thrombus. Single-dose captopril scintigraphy may be a useful tool to predict tolerance to captopril therapy.     

Renovascular hypertension in childhood: a changing perspective in management

Seventeen children with renovascular hypertension caused by intrinsic renal artery lesions received treatment during the past 10 years. At presentation nine were asymptomatic, four had headaches, and one had epistaxis; three infants had anorexia and failure to thrive. Routine intravenous pyelogram and radionuclide renal scan findings were abnormal in 29% and 31% of patients, respectively. Arteriography showed a branch artery stenosis in seven patients and a main artery lesion in 10. A renal vein renin ratio of greater than or equal to 1.5 between the affected and the contralateral kidney was obtained in 10 of 17 patients. Of 16 patients available for follow-up, 15 are normotensive after a mean follow-up of 3.7 years. Cure was achieved by partial nephrectomy and ligation of a stenosed vessel in two and nephrectomy in five (three having undergone an unsuccessful angioplasty procedure). Autotransplantation or angioplasty was curative in a further six. Transluminal balloon angioplasty was attempted in seven patients but was successful in only two with main renal artery stenoses. With preservation of renal parenchyma as the main goal, medical and surgical therapy can be individualized for each patient.     

Congenital abdominal aortic aneurysm and renal dysplasia

We report a 6-month-old boy with abdominal aortic aneurysm and dysplastic kidneys. To the best of our knowledge, this is the first report of abdominal aortic aneurysm associated with dysplastic kidneys. Serial US, MR angiography and scintigraphy were performed. No underlying cause of the aneurysm was identified. Spontaneous thrombosis occurred within 2.5 years of diagnosis, but there was persistent renovascular hypertension and progressive deterioration of renal function.     

Intrarenal aneurysm of the renal artery in children

Two children with hypertension had intrarenal aneurysms in the renal artery. In both children, renovascular hypertension was documented by renal vein renin assay showing elevated renin secretion from the involved kidney and suppression of renin secretion from the contralateral kidney. Transcatheter embolization of a segmental artery cured the hypertension in one case. A nephrectomy performed in the other case, because of multiple intrarenal aneurysms, was curative. Intrarenal renal artery aneurysms are an uncommon cause of renovascular hypertension in children. The aneurysms may be mycotic or congenital in origin, or secondary to diffuse vasculitis. Although spontaneous resolution of the aneurysms may occur when due to vasculitis, treatment of most aneurysms is usually necessary. Transcatheter embolization of solitary aneurysms is an attractive alternative to partial nephrectomy, since it allows maximal preservation of renal parenchyma with minimal morbidity.     

Hypoplasie de l'aorte abdominale, cause rare d'hypertension artérielle du grand enfantCoarctation of the abdominal aorta, a rare cause of hypertension in childhood

The majority of children with secondary hypertension have a renal abnormality or renovascular lesions. Coarctation of the aorta is also a classical cause, rarely located to the abdominal aorta. Case reports. - Two girls, 11 and 12 years-old, were suspected of having recent sustained hypertension. Pulsed-wave doppler ultrasonography and angiography showed abdominal aortic hypoplasia associated with renal artery stenosis, unilateral in one patient and bilateral in the other. Both patients became normotensive 10 and 18 months, respectively, after corrective vascular surgery. Conclusion. - Examination of the abdominal part of the aorta is mandatory in all patients with hypertension.     

Treatment of high-renin hypertension with propranolol in children after renal transplantation.

Ten children with hypertension poorly controlled with other drugs and high peripheral plasma renin activity after renal transplantation were treated with propranolol. The mean systolic pressure decreased from 139 to 127 mm Hg (p less than 0.05) and the mean diastolic pressure from 98 to 83 mm Hg (p less than 0.01). Eight children had an antihypertensive response; two did not respond. The maximum dose of propranolol in responders varied from 1.0 to 6.2 mg/kg/day and duration of treatment until response varied from four to 49 days. PRA, repeated in seven responders, decreased in all (p less than 0.01).There was no correlation between changes in PRA and blood pressure. Propranolol was well tolerated and was a valuable antihypertensive drug in these children.     

Arterial hypertension. Prevention in infants with congenital urinary tract malformations]

Eighty-nine newborns and infants with congenital urinary tract malformations were treated in the childrens' hospital of the Westf?lische Wilhelms-University from 1986 to 1989. Twenty patients of this group (22.5%) developed severe hypertension requiring treatment within the first year of life. Mean age of diagnosis of hypertension was 5 months (range 0.5-12 months). Median values for blood pressure at time of diagnosis were 138 mmHg (range 120-170) for systolic and 92 mmHg (range 80-110) for diastolic values. Six patients showed characteristic symptoms for hypertension such as restlessness, sweating and sleep disorders. Plasma levels of renin were obtained in 12 of 20 patients. Five patients had raised plasma renin levels. All patients with a severe hypertension were treated with one to several antihypertensive drugs. Risk factors for the development of severe renal hypertension in early infancy are cystic renal malformation, vesico-ureteral reflux, obstructive uropathy and to our experience also short term percutaneous nephrostomy in obstructive uropathy in particular in connection with pyelonephritis. Hypertension can still appear after the successful surgical correction of urinary obstruction. We describe the group of patients with severe hypertension in our study group; diagnostic principles and our therapeutic approach are explained. We conclude that early diagnosis of severe hypertension and consecutive treatment are important in infants with congenital urinary malformations.     

Hypertension in a cohort of African children with renal tumours

Hypertension is a frequent problem in children with renal tumour, yet there are few reports from centres in the third world. A retrospective study of blood pressure in a cohort of 46 patients with renal tumours seen over a 3-year period was carried out. Fifty percent of patients presenting with Wilms’ tumour were hypertensive. Serum concentrations of active renin correlated poorly with blood pressure. There was no correlation between serum concentrations of active renin and tumour mass or histology. Specific antihypertensive therapy was offered to 11 patients who had either neurological or cardiac complications of hypertension. All other patients with Wilms’ tumour had their blood pressure controlled by neoadjuvant chemotherapy. Patients with mesoblastic nephroma were managed by primary surgery. Patients with asymptomatic hypertension may be monitored as hypertension will resolve with neoadjuvant chemotherapy. Those with compelling symptomatology will require additional hypertensive medication.     

The role of CT angiography in the evaluation of pediatric renovascular hypertension

Historically, the evaluation of renovascular hypertension has been accomplished by US, renal scintigraphy and digital subtraction angiography. Based on its high accuracy reported in adults renal CT angiography (CTA) with pediatric-appropriate low radiation dose techniques has become an important tool in the workup of renovascular hypertension in children. Renal CTA has several advantages over more conventional imaging modalities, including rapid and non-invasive acquisition, high resolution and easy reproducibility. Additionally, in our experience high-quality renal CTA can be performed using low-dose radiation exposures and can be acquired without sedation in most instances. This article illustrates by examples the usefulness of renal CTA for diagnosis of childhood renovascular hypertension and provides an overview of renal CTA findings in the most common childhood renovascular diseases.     

Case report: neonatal hypertension

BACKGROUND: Neonatal arterial hypertension is rare with an incidence between 0.2 - 3 %. Clinical presentation varies widely and is in some cases dramatic. PATIENT: A 4-day old full-term neonate was admitted to the intensive care unit with severe congestive heart failure and metabolic acidosis. Mechanical ventilation was initiated and dobutamine administered because of poor systolic function. Continuous monitoring of blood pressure revealed severe arterial hypertension (30 to 40 mm Hg above the 95th percentile). Ultrasonography showed an echogenic left kidney with normal perfusion. Laboratory examinations revealed a raised peripheral renin activity, thrombocytopenia, slightly raised d-dimers, a microhematuria and mild proteinuria. After resolution of hypertension under therapy with an ACE-inhibitor, a MAG3 renal scan showed complete absence of renal function on the left side. Renal artery stenosis was excluded by venous transcardial angiography. Under therapy with Captopril, the patient was discharged and followed up for 8 months. He is developing normally with normal serum creatinine (0.4 mg/dl), but low renal function (17 %) of the left side as assessed by DMSA-scan and compensatory right kidney hypertrophy are observed. DISCUSSION: Diagnosis and treatment of neonatal hypertension are discussed with respect to the proposed case. After exclusion of other causes we conclude that a perinatal microangiopathic event may have lead to the renal lesions with malignant renovascular hypertension.     

Renal artery thrombosis — an unusual complication following removal of a neuroblastoma

A 2-month-old female infant with a retroperitoneal neuroblastoma on the left side was admitted to Niigata University Hospital. Her systolic blood pressure, as high as 220 mmHg, was attributed to renovascular hypertension because the plasma renin activity was increased up to 208 ng/ml per hour. Excision of the tumor, including the left kidney, and periaortic lymphnode dissection were performed. For safety during the lymphadenectomy, Nelaton catheters were placed around the inferior vena cava, aorta, superior mesenteric artery, and right renal artery. On the 2nd postoperative day anuria was noted, and aortography was performed revealing obstruction of the right renal artery, inferior mesenteric artery, and left common iliac artery. Thrombectomy via aortic incision was performed immediately to restore the blood flow. The patient developed chronic renal failure, however, and still requires hemodialysis or peritoneal dialysis. Pediatric surgeons should bear in mind that extensive periaortic lymphadenectomy may cause postoperative arterial thrombosis.     

Two cases of hyponatremic-hypertensive syndrome in childhood with renovascular hypertension

We report two children with renovascular hypertension and fibromuscular dysplasia. They initially presented with severe hyponatremia, hypokalemia, polyuria, and transient proteinuria. This combination of symptoms is known to occur in patients with renovascular and malignant hypertension, and is known as hyponatremic-hypertensive syndrome (HHS), although it is considered rare in children. Since in both of our patients, the renal arterial stenosis was very severely or almost totally occlusive, we could not perform percutaneous transluminal renal artery angioplasty, and therefore nephrectomy was the only option. A histological study showed partial or complete occlusion with intimal hyperplasia and medial fibroplasia of intrarenal arteries such as the interlobular arteries. Conclusion: Both patients showed rapidly progressive renovascular hypertension and loss of function of the affected kidney. In order to preserve renal function in such cases, early invasive intervention appears to be necessary.     

Renovascular hypertension

Renovascular hypertension results from a lesion that impairs blood flow to a part or all, of one or both kidneys. 3-10% of children referred for the evaluation of severe hypertension are subsequently found to have clinically significant renovascular lesions Renovascular hypertension is the second most common cause of correctable hypertension in children second only to coarctation of the aorta. Specific therapeutic options now available, justify the often-invasive investigations required to confirm the diagnosis of renovascular hypertension. A systematic evaluation of the child with hypertension will help the pediatrician select correctly, the child most likely to have renovascular hypertension, thus reducing the number of children exposed to the risks involved with diagnostic but invasive investigations like renal arteriography which remains the gold standard Other non-invasive newer modalities like doppler ultrasonography, computed duplex sonography, ACE inhibited radionuclide imaging, and MR/CT/spiral CT angiography may be used depending on the availability of the facilities. Definite therapeutic options for renal artery stenosis include angioplasty, stenting and surgical re-vascularization using a bypass graft.     

Epoetin alfa in anaemic children or adolescents on regular dialysis

Eighteen patients aged 5-18 years on regular dialysis had a packed cell volume (PCV) less than 0.27. On treatment with epoetin alfa (EA) PCV increased by 0.05 or more in all patients. Iron supplementation was necessary in 13 patients with a ferritinaemia less than 300 micrograms/l before study. During treatment, plasma potassium increased significantly and more vigorous antihypertensive measures were required in 8 patients, 5 of them being already on antihypertensive drugs before EA. Iliofemoral thrombosis occurred in 1 patient 10 days after renal transplant. The data indicate that EA ameliorates the anaemia of chronic renal disease. The main concerns arising during treatment with EA are hyperkalaemia, arterial hypertension and possibly thrombosis.     

Plasma renin activity in acute poststreptococcal glomerulonephritis and the haemolytic-uraemic syndrome

Plasma renin activity (PRA) was determined in 10 children with acute glomerulonephritis and in 10 with the haemolytic-uraemic syndrome (HUS). Low renin levels were found in the hypertensive children with acute nephritis, all of whom had evidence of fluid overload. The amount of this overload correlated directly with the degree of hypertension and inversely with PRA. All the hypertensive children with HUS had high levels of plasma renin, and the highest levels were found in those cases who were subsequently shown to have the more severe degree of renal arteriolar occlusion. The findings emphasize the importance of measures designed to reduce salt and water overloading in the management of hypertension in acute nephritis, while drugs which suppress plasma renin are more likely to control blood pressure in HUS. Estimation of PRA may provide a guide to the management of hypertension in acute renal insufficiency.     

Clinical spectrum of intrinsic renovascular hypertension in children

In the past two decades, 853 children and adolescents have been evaluated for elevated BP as inpatients and outpatients by the hypertension service at Children's Hospital Medical Center, Cincinnati. Most children with hypertension secondary to coarctation of the aorta and all children with glomerulonephritis are managed by other services and are not included in that total. In a retrospective study, 27 children (3%) were identified as having hypertension secondary to intrinsic renal arterial stenosis. The age at presentation ranged from 5 months to 20 years. The mean BP at that time was 171.6/114.2 mm Hg. Ten categories of causes were identified, including fibromuscular dysplasia, arteritis, Williams syndrome, neurofibromatosis, congenital malformations, blunt abdominal trauma, surgical vascular trauma-irradiation, thrombosis, congenital rubella syndrome, and unknown. Overall, symptoms were not common. However, findings of end-organ response, such as left ventricular hypertrophy and retinal vascular abnormalities were prevalent. This is not surprising given the mean BP level at presentation. Physical examination, laboratory tests, and radiologic evaluations (exclusive of renal angiography) were not useful in detecting or identifying the location and extent of the renovascular lesions. Fourteen patients were treated surgically, and 13 were managed medically. The outcome was variable for both treatment modalities. The management of renovascular hypertension in children must be individualized depending on the cause, location, and severity of the lesion, as well as the size of the child. Some forms of renovascular pathology, particularly the arteritides, may resolve spontaneously, and children with these entities should have their BP treated medically until the inflammatory process has subsided.(ABSTRACT TRUNCATED AT 250 WORDS)