Renovascular Hypertension

1

What is renovascular hypertension?

Renovascular hypertension (RVH) is the elevated blood pressures resulting from significant obstruction to renal artery blood flow and decreased renal perfusion pressure.

2

What is the prevalence of RVH?

RVH accounts for 1% to 2% of all hypertension (HTN) in the general population and up to 6.8% of those older than 65 years old with greater than 60% renal artery stenosis (RAS) on imaging. The prevalence is 11% to 18% in those with known coronary artery disease, using a greater than 50% stenosis cutoff. The prevalence is up to 24% in some selected populations with resistant HTN.

3

What are the common and uncommon causes of RVH?

Common causes include atherosclerosis (90%) and fibromuscular dysplasia (FMD) (10%). Atherosclerotic plaques are typically found at the ostium of the renal artery and are associated with typical risk factors including age, dyslipidemia, smoking, diabetes mellitus, and atherosclerosis in other vascular beds. FMD more commonly involves the mid to distal two-thirds of the renal artery and is associated with distinct risk factors including female sex, age younger than 50 years old, and family history of FMD or arterial dissection/aneurysm.

Uncommon causes include iatrogenic dissection, aortic stent graft occlusion, renal artery stent branch vessel occlusion, trauma, Takayasu arteritis, aortic dissection, and arterial embolus. Microvascular disease caused by small and medium vessel vasculitis (e.g., polyarteritis nodosa, scleroderma renal crisis) can also produce renin-dependent HTN.

4

What is FMD?

FMD is an idiopathic, segmental, nonatherosclerotic and noninflammatory disease of the musculature of the arterial walls, leading to stenosis of small and medium-sized arteries. FMD lesions are characterized by their angiographic appearance as either focal or multifocal. The most common type of FMD (90% of lesions) is the multifocal type in which there are alternating areas of stenosis and aneurysmal dilatation, usually in the mid to distal portion of the artery, resulting in a “string-of-beads” appearance ( Fig. 12.1 A). Focal FMD may occur in any portion of the artery and appears as a single concentric lesion or a smooth tapered lesion (see Fig. 12.1 B). Both types of FMD are important causes of RVH.