Renovascular hypertension in children. Report of seven cases treated surgically including two cases of renal autotransplantation

Renal Autotransplantation for Uncontrolled Hypertension in Nonatherosclerotic Renal Artery Stenosis-2 Case Reports and a Brief Review of the Literature

Fibromuscular dysplasia is the most common cause of renovascular hypertension in young adults under 40 years old. It is potentially amenable to renal artery angioplasty, which frequently normalizes blood pressure. However, limited options exist if angioplasty is not technically possible, or restenosis occurs. Here, we describe 2 patients who presented with hypertension secondary to renal artery stenosis. In the first case, a young adult with hypertension secondary to renal artery stenosis (fibromuscular dysplasia), developed restenosis 11 weeks after an initially successful renal artery angioplasty. In the second case, a patient with neurofibromatosis type 1 was diagnosed with hypertension secondary to renal artery stenosis. Angioplasty was not possible due to multiple branch occlusions. Both individuals went on to have successful renal autotransplantations, which ultimately cured their hypertension. In this article, we review the background, indications, and blood pressure outcomes in relation to renal autotransplantation in nonatherosclerotic renal artery stenosis.

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.

Pediatric renal artery dysplasia: a morphologic study

Renal arteries from 12 pediatric patients who had stenosis due to renal artery dysplasia (9 surgical resections and 3 autopsy cases) were examined by light microscopy. The patients ranged in age from 15 months to 14 years; the male/female ratio was one. Bilateral renal artery disease was clinically diagnosed in 8 of the 12 patients; 6 of the 8 also had aortic anomalies. All of the lesions were designated as forms of dysplasia, a departure from previous reports in which dysplasia was subclassified as fibroplasia and hyperplasia. The most common lesion was medial fibrous dysplasia (6), followed by perimedial elastic dysplasia (4); intimal fibrous dysplasia (1) and medial muscular dysplasia (1) were the least common. Medial fibrous dysplasia was present as often with bilateral as with unilateral renal artery stenosis, while perimedial elastic dysplasia was seen exclusively in patients with bilateral renal artery disease. Three patients who came to autopsy had extrarenal vascular involvement by a similar dysplastic lesion. The three patients who had neurofibromatosis showed no distinctive histologic type of renal artery dysplasia.

Renal autotransplantation in children: a successful treatment for renovascular hypertension

Renovascular hypertension in children is not a common disease. With improved surgical technique the incidence of nephrectomy has decreased and renovascular reconstruction is currently the preferred method to manage this entity. Between 1977 and 1988, 21 patients with renovascular hypertension were treated at our hospital: 7 patients 6 to 16 years old underwent renal autotransplantation. Of the children 4 had unilateral and 3 had bilateral disease requiring bilateral autotransplantation. Autotransplantation was performed by anastomosis of each renal artery end-to-side to the common iliac artery. The renal veins were anastomosed end-to-side to the common iliac veins. The ureters were left intact in all but 1 patient who required a bench operation. Of the 4 patients who had a unilateral procedure 3 are cured and 1 is improved with a normal blood pressure on a small dose of antihypertensive medication. The 3 patients with bilateral autotransplants are cured. These results, with normalization of the blood pressure in 86% of the patients and improvement in blood pressure in 14% with a patency rate of 87%, are similar to other reported reconstructive modalities in children.

Imaging techniques in the evaluation of pediatric hypertension

Moderate or severe hypertension occurs in a small percentage of hypertensive children, but it is within this group that the surgically correctable causes of hypertension are found. Since cure rates up to 90% have been reported, it is important to diagnose a secondary cause of hypertension. Excretory urography is recommended to screen for renovascular hypertension and renal parenchymal disease. Renal scintigraphy can be substituted for the urogram, but the anatomical resolution is poorer. If renovascular hypertension is suggested by abnormal results of screening examination, arteriography should be part of the evaluation. Ultrasonography is reserved primarily for evaluating neonatal hypertension which most frequently is related to thrombosis. If this diagnosis is documented, renal function should be assessed with radionuclide techniques. If a hormonally active tumor is suspected, evaluation of the adrenals and retroperitoneum is accomplished best by CT.

Three patients with arteritis

Three boys were treated for arteritis of the aorta and great vessels and bilateral renal artery stenosis. One presented at age 6 months with failure to thrive, excessive sweating, and vomiting: hypertension and cardiac failure were subsequently diagnosed. The two older boys (7 and 14 years) presented with symptomless hypertension. The clinical and angiographic findings in the three patients suggest that the illness may have been Takayasu's arteritis, which should be included in the differential diagnosis of hypertension in infancy and childhood. Renal autotransplantation was performed in all three patients with good results. Early renal autotransplantation may reduce the morbidity associated with this disease.

Surgically correctable hypertension of renal origin in childhood

Since 1960, 22 children were treated for surgically correctable hypertension or renal origin. The series included two children with tumors, two with hydronephrosis from ureteropelvic junction obstruction, nine in whom one kidney was atrophic, and nine with renal artery narrowing from fibromuscular dysplasia (with bilateral involvement in two). Hypertension was cured in the cases with tumors and ureteropelvic junction obstruction. It was also cured in four of the nine patients with an atrophic kidney and in five of the nine with a narrow renal artery. In those not cured hypertension was more easily controlled by medication. One patient died from brain hypoxia during surgery. About 10 percent of the children investigated for hypertension at the Massachusetts General Hospital proved to have a surgically correctable cause of renal origin.

Technical considerations in the surgical management of renovascular hypertension in children

Fifteen children with severe renovascular hypertension have been treated at the Mott Children's Hospital in the University of Michigan Medical Center between July 1974 and December 1980. The average age was 10.4 yr. Stenoses were of both intimal and medial fibrodysplastic types. Four patients had significant bilateral disease. Three patients had coexistent renal artery aneurysmal disease, and three others had midabdominal aortic coarctations. The most important diagnostic studies included assays of plasma renin activity and selective renal arteriography. Primary operations (11 unilateral, 4 bilateral) included 14 aortorenal by passes (13 vein grafts, 1 hypogastric artery graft), 1 vein patch angioplasty, 1 primary anastomosis, 1 aortic reimplantation, 1 partial nephrectomy (segmentectomy), and 1 arterial dilation. Four secondary operations were performed. Critical factors in pediatric reconstructive renovascular surgery include: (1) exposure through a generous transverse anterior abdominal incision, (2) systemic anticoagulation with sodium heparin, (3) end-to-end graft-to-renal artery anastomoses, (4) generous spatulation of vessels and grafts at anastomoses, (5) use of microvascular clamps, (6) use of silicon lubricants on dilators, and (7) extreme gentleness in handling all tissues. Eleven children experienced complete remission of hypertension. Four children were improved. Excellent results were attributable to carefully planned and executed reconstructive procedures.

Renal artery stenosis in children

Because high blood pressure in children is rare and most of these patients are asymptomatic, many are overlooked until they present with a hypertensive crisis or irreparable damage. Most children with renal artery stenosis are asymptomatic and the hypertension is detected only by blood pressure recording during physical examination. Angiography is the most helpful diagnostic study. It is generally agreed that renal artery lesions in children should be considered for surgical correction. An illustrated case is described.

Surgical treatment of renovascular hypertension in children: the roile of renal autotransplantation

We describe 2 children with renovascular hypertension treated successfully by autotransplantation, as well as an additional child in whom ex vivo microsurgical repair was attempted. The literature is reviewed and all patients within the pediatric age group with renovascular hypertension who were treated surgically are reported. The different types of vascular reconstructive techniques and, particularly, the previous use of autotransplantation are discussed.

Renovascular hypertension from segmental renal artery stenosis: importance of segmental renal vein renin sampling

We report a case of severe hypertension in a girl with no evidence of parenchymal renal disease. Arteriography revealed segmental stenosis and a saccular aneurysm affecting a branch of the left renal artery. Segmental renal vein renin sampling demonstrated a markedly increased rate of renin secretion from the ischemic portion of the left kidney. Partial nephrectomy resulted in normalization of the blood pressure. The resected kidney showed striking hyperplasia of the juxtaglomerular apparatus and medial fibromuscular dysplasia as the etiology of the arterial stenosis. This case emphasizes the value of segmental renin vein sampling in the evaluation of pediatric hypertension and illustrates the high cure rate obtained by surgical correction.

Surgical treatment of renovascular hypertension in the pediatric patient

Of 27 children who underwent surgical treatment for renovascular hypertension 16 (59 per cent) were cured, 5 (19 per cent) were improved and 6 (22 per cent) were failures. Improved results were obtained in patients with unilateral renal artery stenosis. Several reconstructive vascular procedures were used, and their relative efficacy and indications are discussed. Renovascular hypertension in children is a curable disease and revascularization with preservation of renal parenchyma should be the aim of surgical therapy in most cases.

Renal arteriography in the evaluation of unexplained hypertension in children and adolescents

Arteriography demonstrated renal artery stenosis in 24% of 101 selected patients whose hypertension was first diagnosed before the age of 20 years. Arteriographic findings were normal in 58%. The prevalence of RAS was greater in the younger than in the older age groups. An abdominal bruit and urographic abnormalities were frequently observed in association with RAS. Adequate follow-up information was available for 16 patients who underwent vascular repair or nephrectomy for RAS. In 14 of the 16, the hypertension was eliminated (81%) or definitely reduced (6%).