A unique case of renal artery fibromuscular dysplasia

Fibromuscular dysplasia (FMD) is a noninflammatory, nonatherosclerotic disorder resulting in arterial stenosis. Here, a unique case of renal artery FMD (RA FMD) is presented. With the use of angiograpic and intravascular ultrasound (IVUS) imaging modalities, a patient was diagnosed with two distinct types of FMD. Until now, the prevalence of FMD has been underestimated due to limitations in diagnostic modalities. Clinically, the correct identification of RA FMD is essential because these patients have been shown to respond to revascularization therapy with significant improvement in blood pressure whereas renal artery lesions secondary to other etiologies such as atherosclerosis have yet to show the same consistent response. Further, the presence of two subtypes of FMD in a single patient may suggest the possibility of genetic factors that predispose certain vessels to certain subtypes of FMD.