A 57-year-old woman presented to the emergency department (ED) with left arm and leg weakness that resolved after 2 hours. She had a similar episode 1 week previously. She was otherwise healthy and active, although her blood pressure was 160/94 mm Hg, without a previous history of hypertension. She underwent a computed tomogram (CT) of the head that was negative for bleeding or stroke. She then had a carotid duplex ultrasound examination, which showed a focal area of increased velocity in the distal internal carotid artery (ICA) distally without any significant plaque formation at the bifurcation or the proximal ICA. It was felt that she needed a carotid angiogram to better delineate the disease process.
The contrast angiogram revealed fibromuscular dysplasia (FMD) in the mid and distal cervical ICA (Figure 25-1). Further investigation also showed FMD in both common iliac arteries (Figure 25-2) and both renal arteries (Figures 25-3 and 25-4). She denied any claudication symptoms. Renal artery intervention was discussed for her hypertension.
Carotid angiogram demonstrating mid and distal internal carotid artery (ICA) fibromuscular dysplastic changes (blue arrow).
Abdominal aortogram showing bilateral iliac artery fibromuscular dysplasia (FMD) (blue arrows).
Abdominal aortogram showing bilateral renal artery FMD (blue arrow).
Selective right renal angiogram detailing right renal artery FMD changes.
She agreed and a balloon angioplasty of the right renal artery was successfully carried out. Her carotid disease was managed with antiplatelet therapy and she has had no recurrence of her symptoms.
Women are most commonly affected; although it is thought to be a rare disease, it may occur in up to 4% of women.1
In a large carotid duplex imaging study, the overall incidence of FMD was 0.14%.2
ETIOLOGY AND PATHOPHYSIOLOGY
FMD is a noninflammatory, nonatherosclerotic process that most commonly affects the carotid and renal arteries, although it can occur elsewhere in medium-sized vessels.1
FMD usually occurs in the mid and distal ICA, sometimes extending into the intracranial region.3 Aneurysms may be a component of the disease process as well.
There are several pathologic types, with medial fibrodysplasia being the most common.3 The pathophysiology is mostly unknown.
When the carotids are affected, ipsilateral cerebral ischemia, spontaneous dissection, or pseudoaneurysm or true aneurysms may occur, but many times FMD is discovered incidentally on diagnostic studies for workup of other diseases.
Renal artery FMD ...