Renovascular hypertension in children with neurofibromatosis type 1

Abstract

Arterial hypertension in pediatric patients with neurofibromatosis type 1 (NF 1) is usually due to renal artery stenosis (RAS) mainly involving the proximal part of the vessel. The treatment modalities are highly individualized. In severe and/or bilateral RAS, antihypertensive drugs are either ineffective or have the potential risk for acute renal failure, while percutaneous transluminal angioplasty (PTA) has limited success due to the ostial localization of RAS and the tough fibrotic tissue involved that is refractory to dilatation Renal autotransplantation has potential advantages when medical control and PTA/or bypass techniques failed. Here we report 5 year-old girl with NF 1 and hyponatremic hypertensive syndrome due to severe bilateral disease, occluded proximal part of the right artery and ostial stenosis (80%) of the left one. Only left kidney was identified on 99 m Tc DTPA, but the right one was visualized on the renal ultrasonography and in the late phase of arterial renography due to well developed collateral circulation. Multiple antihypertensive drugs (nifedipine, labetolol and minoxidil) in maximal doses and PTA failed to normalize BP while short term therapy with ACEI with NF1 and hyponatremic hypertensive syndrome due to severe bilateral renovascular disease; occluded proximal part of the right renal artery and ostial stenosis (80%) of the left one. Only left kidney was identified on 99 m Tc DTPA, but the right one was visualized on the renal ultrasonography and in the late phase of arterial renography due to well developed collateral circulation. Multiple antiphypertensive drugs (nifedipine, labetolol and minoxidil) in maximal doses and PTA failed to normalize BP while. short term therapy with ACEI, captopril induced transient acute renal failure. Autotransplantation of right kidney saved its function and improved BP control. Our current case Autotransplantation of right kidney saved its function and improved BP control. Our current case is illustrative for a difficult management of renovascular hypertension in children with NF1. This is the first and up to now the only case of autotransplantation performed in Yugoslavia.

Unilateral renal ischemia causing the hyponatremic hypertensive syndrome in children—more common than we think?

“…Vomiting is common and could contribute considerably to the electrolyte disturbances whilst exacerbating volume depletion. In children and neonates, presenting features are polydipsia, polyuria or enuresis, weight loss and volume depletion, drowsiness, and, as in adults, various neurological and behavioral signs and symptoms [7][8][9][10][11][12][13][14][15][16][17][18][19][20].…”

“…It seems, however, that the HH syndrome secondary to unilateral renal ischemia in children has been documented as case reports involving only one or two patients [7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Indeed, most reported discussions of renovascular disease in the pediatric age group make little or no mention of the HH syndrome [38].…”

Renal autotransplantation for the treatment of renovascular hypertension in the pediatric population

“…Children with the first 2 pathologies constitute a selected group of patients due to particular characteristics of their renal arteries or due to ostial localization of RVD and the presence of tough fibrotic tissue refractory to dilation [3,4,20]. Although several techniques have been described to treat RVD in these cases, many authors prefer to perform an RA [17].…”

“…In children with neurofibromatosis type 1 [2], PTRA may have limited success due to ostial localization of RVD and the presence of tough fibrotic tissue refractory to dilation [3,4] Open surgery is the primary treatment for tubular aortic narrowing (middle aortic syndrome) associated with RVH and visceral arterial stenosis. Endovascular therapy such as PTRA may provide a sound minimally invasive treatment in these cases only when they are caused by discrete aortic stenoses that do not encompass the mesenteric and renal arteries [5].…”

Hyponatremic hypertensive syndrome and posterior reversible encephalopathy secondary to unilateral renal artery stenosis - a case report

“…In most adult patients with HHS, the underlying renal pathology has been atherosclerosis. However, in children, HHS has been described with renal ischemia due to bromuscular dysplasia, Wilm's tumor, neuro bromatosis type 1, and renal damage secondary to bladder dysfunction [16,17,[35][36][37].…”