Renovascular hypertension.

Hypertension occurs in 1% to 5% of children; the younger the child, the more likely a surgically correctable cause. In children up to 5 years of age, the incidence of potentially correctable hypertension is 78%. Hypertension has congenital as well as acquired etiologies including a wide variety of endocrine, neurological, metabolic, renal infectious, and vascular disorders. Renovascular causes are the most common ones. When renovascular hypertension is suspected, studies should include serum urea and electrolyte determinations, sedimentation rate, and 24-hour urine collection for urea electrolytes, creatinine, vanillylmandelic acid, catecholamines, 17-OH, and 17-keto steroids. The most accurate imaging study is aortography with bilateral renal arteriography and bilateral renal vein renin determinations when indicated. Transluminal balloon angioplasty usually is successful for stenosis of a branch vessel of the renal artery but not for stenoses at the origin of the renal artery adjacent to the aorta, which is the most common presentation. For the latter proximal forms, aortorenal bypass is the best approach unless direct reimplantation into the aorta is possible. Although partial nephrectomy for selected distal branch vessel stenoses may be curative, total nephrectomy should be avoided unless no other option exists. The ideal graft material for reconstruction of the renal artery is not known. Whereas many prefer to use a segment of autogenous hypogastric artery for aortorenal interposition grafting, saphenous vein also is useful provided it is supported with a Dacron net wrap to prevent aneurysm formation. When renal revascularization is successful, more than 90% of patients will be cured or have significant improvement in their hypertension with minimal early mortality.