Renovascular Hypertension
Saturday, May 15th, 2010Increase in acute or chronic systemic values of the PA produced partial or complete occlusion of one or both renal arteries or their branches often correctable by surgery or percutaneous transluminal angioplasty.
Stenosis or occlusion of one or both main renal arteries or accessory renal artery or its branches may cause hypertension by stimulating the release of the enzyme renin by the juxtaglomerular cells of the kidney in question. The cross-sectional area of the lumen must be reduced by 70% before the stenosis is hemodynamically significant.
The most common cause of renal artery stenosis in patients> 50 years of age (usually men) is atherosclerosis, in younger patients (usually women), is one form of fibrous dysplasia. Rare causes of renal artery stenosis or obstruction are emboli, trauma, inadvertent ligation during surgery and extrinsic compression of the renal pedicle by a tumor.
Although renovascular disease represents the most frequent cause of curable hypertension (probably with the exception of female hormonal contraceptive therapy and excessive ingestion of ethanol), it explains <2% of all cases of hypertension.
Symptoms, signs and diagnosis
Renovascular hypertension should be suspected when diastolic hypertension appears in patients <30 or> 55 years of age or when a previously stable hypertension worsen suddenly. The rapid evolution towards malignant hypertension within 6 months suggests arterial impairment. A systolic-diastolic epigastric vascular murmur, usually sent to one or both upper abdomen and sometimes the spine, is a goal almost pathognomonic finding, but unfortunately is absent in about 50% of patients with forms of fibrous dysplasia and is detected rarely in patients with atherosclerotic renovascular basis. (more…)