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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Renovascular hypertension is more common in hypertensive children than in hypertensive adults, and renal artery stenosis is second only to coarctation of the thoracic aorta as a cause of surgically correctable hypertension. Three infants presented with uncontrollable hypertension secondary to renal artery thrombosis due to umbilical artery catheterization for respiratory distress in the neonatal period. They all responded to nephrectomy. A fourth infant had stenosis of a polar vessel secondary to umbilical artery catheterization and was cured by partial nephrectomy. Two infants with renal artery stenosis secondary to fibromuscular dysplasia benefited from revascularization and, at last follow-up, were normotensive and off all blood pressure medication. Ultrasonography, isotope scanning, angiography and selective renal vein renin assays should be used to identify patients with surgically correctable lesions. The use of fine suture material and microvascular surgical techniques, including ex vivo revascularization and autotransplantation, can salvage renal parenchyma and relieve hypertension. Infants with less than 10 percent renal function on the involved side should have a nephrectomy. The infant with an umbilical arterial catheterization line needs blood pressure monitoring and aggressive evaluation and treatment of persistent hypertension.
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PMID:Early diagnosis and management of renovascular hypertension. 355 43

Renovascular hypertension superimposed on essential hypertension, a condition encountered in the elderly, was studied. An experimental animal model consisting of a two-kidney one-clip Goldblatt preparation in the spontaneous hypertensive (SHR) rat, that would simulate this condition, was designed. A 0.25 mm silver clip was placed on the left renal artery of SHR male rats. The same procedure performed on WKY rats served as control. All experiments were performed on low, normal, and rich sodium diet. Systolic blood pressure (BP) was measured by tail-cuff method. Plasma renin concentration (PRC) was determined before and after clipping of the renal artery. Results were as follows: Mean systolic BP increased significantly in clipped rats fed with normal and rich sodium diets. SHR showed an increase from 144 +/- 3 (mean + s.e.m.) to 168 +/- 3 mmHg, and WKY rats showed an increase from 120 +/- 2 to 139 +/- 5 mmHg. There was a two- to threefold rise in PRC. A low-salt diet given prior to clipping prevented the appearance of renovascular hypertension despite a significant rise in PRC. We concluded that renal artery narrowing plays a significant role in the rise of BP in the basically essential type of hypertension.
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PMID:Renovascular hypertension in spontaneous hypertensive rats: an experimental model of renal artery stenosis superimposed on essential hypertension. 366 6

A case with extra-adrenal pheochromocytoma, which was found by chance in the course of renovascular hypertension, is reported. The tumor was on the stenotic portion of the right renal artery. The results of examinations for pheochromocytoma were not conclusive, that is, inconsistent elevation of plasma catecholamines and urinary catecholamine excretion, equivocal results of pharmacological tests for pheochromocytoma, and negative results in [131I]metaiodobenzylguanidine scintigraphy. The stenosis of the right renal artery disappeared, the blood pressure was normalized by surgical resection of the tumor, and the extra-adrenal pheochromocytoma was finally diagnosed by pathohistological findings. Renovascular hypertension appeared to be the primary cause of this hypertension, judging from the significant decrease in blood pressure induced by an angiotensin II analog and a renal vein renin ratio of 7.3. Even in the case of obvious renovascular hypertension, the possibility of this unusual coexistence with pheochromocytoma should be considered.
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PMID:Extra-adrenal pheochromocytoma manifesting renovascular hypertension. 366 90

Among the many potential causes of secondary hypertension are renal parenchymal disease, occlusive renal arterial disease, adrenocortical abnormalities, and pheochromocytoma. Renovascular hypertension can result from either renal parenchymal or occlusive renal arterial disease. Laboratory testing can help in identification and differentiation. Parenchymal diseases usually modify the urine substantially without producing urographic abnormalities, while occlusive arterial lesions produce urographic abnormalities but the urine remains normal. The diagnosis of renal occlusive arterial disease is best defined by arteriography. The only definite criterion for the existence of hypertension of renal origin is cure by either nephrectomy or renal revascularization. Adrenocortical causes of hypertension include enzymatic deficiencies, Cushing's syndrome, and primary aldosteronism. In enzymatic deficiencies, the physical findings provide the most important clues to the type of enzyme deficiency involved. In Cushing's syndrome, accurate determination of the cause of the hypercortisolism is important in terms of choice and success of treatment. The diagnosis of primary aldosteronism rests primarily on the demonstration of nonsuppressible aldosterone excretion rate during salt loading; the presence of inappropriate kaliuresis and/or suppressed plasma renin activity provides corroborative evidence of primary aldosteronism, but the absence of either or both does not preclude the diagnosis. Pheochromocytoma, although rare, is a serious and potentially fatal cause of hypertension. Definitive diagnosis depends on laboratory test results, and the tumor is usually localized by computed tomography.
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PMID:Secondary hypertension. A streamlined approach to diagnosis. 372 9

Renovascular hypertension is more common in hypertensive children and adolescents than in hypertensive adults. This article discusses the diagnostic evaluation, operative therapy, and outcome of patients with renovascular hypertension.
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PMID:Surgical management of childhood renovascular hypertension. 407 64

The etiology of several specific types of hypertension are described in order of increasing difficulty of diagnosis: glycyrrhizine poisoning, oral contraceptives, coarctation of the aorta, pheochromocytoma, Conn syndrone, Cushing syndrome, parenchymal nephropathy, unilateral renal atrophy, and renovascular hypertension. Glycerryyzine and oral contraceptive etiologies can be diagnosed by questioning the patient and improved by eliminating their intake. Coarctation of the aorta is easily identified by clinical signs, but surgical repair is probably mor e risky than drug treatment. A pheochromocytoma is signaled clinically and by catecholamine excretion. Conn syndrome has characteristic clinical signs, particularly hypokalemia during intake of diuretics. Cushing syndrome is recognized by corticosteroid excretion as well as peculiear obesity, acne, erythrosis, and diabetes. Bilateral nephropathy is common (25% of hypertensions) and rather difficult to dia gnose and treat. Unilateral renal atrophy can be demonstated by renal arteriography and cystography, but predicting the outcome of nephrectomy is problematic. Renovascular hypertension due to occlusion of the renal artery requires the most sophisticated tests and care for an effective treatment. A table and an outline of diagnostic tests to differentiate these disorders are included.
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PMID:[Etiologic survey of arterial hypertension. Its justifications and practical modalities]. 549 42

To evaluate the clinical validity of 99m Tc DTPA renal investigation, we have studied 60 patients with different renal diseases: 1) Renovascular hypertension (22 patients); 2) Chronic pyelonephritis (11 patients); 3) Renal hypoplasia (12 patients); 4) Bilateral parenchymatous nephropathy with hypertension (15 patients). We observed a good correlation between the creatinine clearance and the total DTPA clearance (N = 51: r = 0.68; p less than 0.001); and also a good correlation between the respective renal surface extrapolated from renal X-Rays, and the respective renal function of each kidney (expressed in percentage) measured from DTPA data. This correlation is higher in group 1 and lower in group 2. From individual kidney function percentage and glomerular filtration rate measurement or estimation, we could calculate the GFR of each kidney, which serves as a guideline for surgical decisions.
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PMID:[Comparative evaluation of the function of each kidney using Tc 99m DTPA]. 637 85

Renovascular hypertension in a 15-years-old girl, originating in a lower pole aberrant renal artery stenosis by fibromuscular hyperplasia. Microsurgical management by polar artery reimplantation in the renal artery. Unknown evolutivity and diffusion of arterial dysplasias explain the more and more distal repairs reported in literature concerned with renovascular hypertension in infancy and childhood. Nephrectomy and segmental resection are now only done when revascularization is not possible.
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PMID:[Renovascular hypertension in a child, originating in a lower pole aberrant renal vessel dysplastic stenosis (author's transl)]. 746 59

The finding from a normal-appearing angiotensin converting enzyme (ACE)-inhibitor renal scan is generally reassuring to the physician screening for renovascular hypertension. In fact, the false-negative rate for captopril scintigraphy is very low. Possible reasons for false-negative scans have not been well documented. A fifty-two-year-old man was evaluated and found to have renovascular hypertension on two occasions, at initial presentation and again eight months later (restenosis had occurred). Renovascular hypertension was present on both occasions as judged by decline of blood pressure following angioplasty of right renal artery stenosis (approximately 80% and approximately 70% stenosis on the two occasions, respectively). However, ACE-inhibitor renal scanning with 99mTc MAG-3 gave disparate results on the two occasions. The first study using oral captopril (25 mg) indicated a low probability of renal artery stenosis, whereas the second study done with the patient regularly taking lisinopril (10 mg daily) was markedly positive. Possible reasons for the initial negative study include poor absorption of oral captopril or inadequate inhibition of the renin-angiotensin system by the 25 mg dose.
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PMID:Normal-appearing captopril MAG-3 renal scintigraphy in hemodynamically significant renal artery stenosis. A case report. 748 14

Renovascular hypertension (RVH) remains a leading cause of potentially curable hypertension. Although RVH affects less than 1% of the unselected hypertensive population, between 10% and 35% of appropriately screened patients referred to specialised centres for problematic hypertension may prove to have renovascular disease. Advances in percutaneous transluminal renal angioplasty (PTRA) have renewed interest in developing better noninvasive screening tests for identifying patients with potentially correctable hypertension or renal impairment due to renovascular disease caused by either fibromuscular dysplasia (FMD) or arteriosclerosis. Duplex ultrasound with the two-dimensional Echo-Colour-Doppler technique for measurements of blood flow velocities in the renal interlobar arteries as expressed in the Pulsatility Index (PI) has been evaluated. Experimentally induced changes in renovascular resistance (RVR) in normotensives and in primary hypertensives were registered noninvasively by means of PI-measurements. A significant correlation between the absolute values of PI and RVR was found in hypertensives (r = 0.50, p < 0.002), but not in normotensives. In both groups, the changes of RVR due to angiotensin II infusion and ACE-inhibition were significantly correlated to the changes in PI (normotensives: r = 0.69, p < 0.001, primary hypertensives: r = 0.64, p < 0.001). Normally, the blood flow velocities as expressed by the PI in the renal vasculature of the two kidneys are equal. In hypertensive patients, PI was lower in kidneys with significant renal artery stenosis (RAS) than in kidneys without RAS (p < 0.001). Doppler signals were absent in all kidneys with renal artery occlusion. A bilateral low PI combined with normal side difference in PI may in hypertensive patients indicate bilateral RAS. RVH was correctly diagnosed in 84% of the patients and the presence of RAS in 94%. Provocative testing of an activated renin-angiotensin system by means of an angiotensin converting enzyme inhibitor (ACEI) constitutes the foundation for screening for RVH using gamma camera renography with 99mTc-DTPA as a glomerular filtration marker. In 20 consecutive patients with successfully treated RVH, one-third of the patients were not correctly diagnosed using ACEI-enhanced 99mTc-DTPA gamma camera renography, which indicates that some patients with RVH have compensatory mechanisms to maintain GFR after ACE inhibition. The relationship between the renin-angiotensin system and erythropoietin (EPO) production was studied in 20 patients with RAS and hypertension.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Renovascular hypertension. New diagnostic and therapeutic procedures. 766 14


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