Saralasin test as a diagnostic and prognostic aid in renovascular hypertensive patients subjected to renal operation.

A positive saralasin test in patients with angiographic evidence of renovascular disease and other positive functional tests gives further assurance that these patients will achieve normal or substantially reduced blood pressure postoperatively. In our experience with proved renovascular hypertension there was a 19 per cent incidence of falsely negative saralasin tests. Therefore, saralasin should not be used as the sole screening test in hypertensive patients suspected of having surgically correctable lesions. There is a direct correlation between elevated renin activity and a positive saralasin test. In some patients saralasin may be more sensitive than any other currently used test to detect overactivity of the renin-angiotensin system. This would determine those patients with technical errors in renin sampling and assays. Of the 16 patients (all normotensive) who had 6-month followup tests 5 had elevated peripheral renin activity, probably owing to furosemide stimulation. Of these 5 patients 2 had a positive postoperative saralasin test, raising the question of potential falsely positive responses in cases of essential hypertension and coincidental non-functional renal artery stenosis. Patients with high renin essential hypertension may respond to saralasin, even in the absence of renal artery lesions. A saralasin test should be done in a hospital where all specific conditions can be met and potential complications handled promptly.

Saralasin test as a diagnostic and prognostic aid in renovascular hypertensive patients subjected to renal operation.

A positive saralasin test in patients with angiographic evidence of renovascular disease and other positive functional tests gives further assurance that these patients will achieve normal or substantially reduced blood pressure postoperatively. In our experience with proved renovascular hypertension there was a 19% incidence of falsely negative saralasin tests. Therefore, saralasin should not be used as the sole screening test in hypertensive patients suspected of having surgically correctable lesions. There is a direct correlation between elevated renin activity and a positive saralasin test. In some patients saralasin may be more sensitive than any other currently used test to detect overactivity of the renin-angiotensin system. This would determine those patients with technical errors in renin sampling and assays. Of the 16 patients (all normotensive) who had 6-month followup tests 5 had elevated peripheral renin activity, probably owing to furosemide stimulation. Of these 5 patients 2 had a positive postoperative saralasin test, raising the question of potential falsely positive responses in cases of essential hypertension and coincidental non-functional renal artery stenosis. Patients with high renin essential hypertension may respond to saralasin, even in the absence of renal artery lesions. A saralasin test should be done in a hospital where all specific conditions can be met and potential complications handled promptly.

Pediatric hypertension as a delayed sequela of reflux-induced chronic pyelonephritis.

Chronic pyelonephritis secondary to vesicoureteral reflux has been shown to cause occasionally systemic hypertension. The hypertension may occur in the presence or absence of bacterial urinary infection, is renin-mediated and may develop years after ureteral reimplantation. Surgical excision of a scarred atrophic renin-producing segment may result in amelioration of the hypertension or at least provide better medical control with less toxic antihypertensive agents. Surgical removal of renal tissue is not recommended in patients with depressed renal function unless the hypertension is malignant and uncontrolled.

Malignant hypertension in children secondary to chronic pyelonephritis: laboratory and radiologic indications for partial or total nephrectomy.

Severe renin-mediated hypertension was noted in 2 children as a result of selective renal damage from vesicoureteral reflux during the early years of life. In each case the reflux had been corrected successfully long before hypertension developed. In 1 case the late damage involved only 1 kidney and nephrectomy resulted in immediate relief of the hypertension. In the second case, even though both kidneys showed segmental scarring from calicectasis and chronic pyelonephritis, removal of the atrophied lower pole of 1 kidney made hypertension amenable to medical treatment and reduced excessive renin output to a fraction of the original high levels. The mechanism of renin-mediated hypertension in kidneys with segmental scars of chronic pyelonephritis is believed to be ischemia of the relatively normal renal cortex in proximity to areas of interstitial fibrosis, within which are tortuous interlobular and smaller arterioles with severe intimal thickening. Hypertrophy of normal renal segment occurs in young patients with segmental chronic pyelonephritis. To accommodate this enlargement the original calix develops an extension or elongation readily distinguishable from other dilated calices.

Renal artery aneurysms.

The various types of renal artery aneurysms are described, the most common one being the congenital saccular aneurysm. Usually asymptomatic it may be associated with hypertension and generally undergoes atherosclerotic degeneration. An arteriovenous fistula may form and rupture into the renal pelvis or retroperitoneal space in some rare instances. Small, well calcified saccular aneurysms should be left alone and followed; larger, incompletely calcified or non-calcified aneurysms should be removed. Fusiform aneurysmal dilatation of the renal artery occurs distal to a focal fibromuscular dysplastic stenosis. This type is almost invariably found in hypertensive young people. Thrombosis of a branch may occur distal to the aneurysm. These aneurysms should be treated surgically, usually by excision of the stenotic area and its aneurysm, and anastomosis of branches back to the main renal artery. Dissecting aneurysms of the renal artery are the most damaging to the kidney. Complications are thrombosis of the branches, infarction of the kidney and a virulent form of hypertension. An operation should be done to correct the dissection and to remove part or all of the kidney when infarction is severe. Intrarenal arterial aneurysms are prone to hemorrhage and should be removed by local excision or partial nephrectomy.