During a routine physical examination, a 42-year-old female is found to have an elevated blood pressure of 150/100 mmHg. Workup reveals a small left kidney and a normal-sized right kidney. Laboratory examination reveals elevated serum renin levels. Fuher workup reveals that renal vein renin levels are increased on the left but decreased on the right. This patient's hypeension is most likely the result of
A rare cause of hypeension is renal aery stenosis, which may occur secondary to either an atheromatous plaque at the orifice of the renal aery or fibromuscular dysplasia of the renal aery. The former is more common in elderly men, while the latter is more common in young women. The decrease in blood flow to the kidney with the renal aery obstruction (Goldblatt's kidney) causes hyperplasia of the juxtaglomerular apparatus and increased renin production. This produces increased secretion of angiotensin and aldosterone, which leads to retention of sodium and water and produces hypeension. Increased levels of aldosterone also produce a hyperkalemic alkalosis. The kidney with stenosis of the renal aery becomes small and shrunken due to the effects of chronic ischemia, but the stenosis protects this kidney from the effects of the increased blood pressure. The other kidney, however, is not protected and may develop microscopic changes of benign nephrosclerosis (hyaline aeriolosclerosis). Reference: Robbins & Cotran Pathologic Basis of Disease, 9edition
Atherosclerotic narrowing of the left renal aery
Atherosclerotic narrowing of the right renal aery
Fibromuscular hyperplasia of the left renal aery
Fibromuscular hyperplasia of the right renal aery
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