Fibromuscular dysplasia in an accessory renal artery causing renovascular hypertension: a case report.

BACKGROUND: Renovascular hypertension is defined as hypertension caused by renal artery stenosis. The two main etiologies are atherosclerosis and fibromuscular dysplasia. Fibromuscular dysplasia in an accessory renal artery as a cause of renovascular hypertension is uncommon.

CASE PRESENTATION: In this report, we present a relatively uncommon case of renovascular hypertension in a 35-year-old female with a history of intractable hypertension as a result of fibromuscular dysplasia involving an accessory renal artery. Selective renal angiography was performed and revealed a single renal artery on the right and two renal arteries supplying the left kidney, upper and lower poles. Selective renal angiography showed the typical fibromuscular dysplasia lesion characterized by its classic "string of beads" appearance, consisting of alternating areas of narrowing and dilatation, located in the middle portion of the lower left renal artery (accessory artery) associated with moderate stenosis. Percutaneous balloon dilatation of the stenotic lesion was successfully performed. Following angioplasty, her blood pressure normalized over a period of several months using a single antihypertensive medication (rather than 3 medications).

CONCLUSION: Fibromuscular dysplasia in an accessory renal artery can, even though rarely, be responsible for renovascular hypertension. Selective renal angiography is the 'gold standard' test and should be performed when renovascular intervention is contemplated.