Fibromuscular dysplasia is abnormal thickening of the walls of arteries that is not related to atherosclerosis or inflammation but that causes artery narrowing or blockage.
Fibromuscular dysplasia usually occurs in women aged 40 to 60. The cause is unknown. However, there may be a genetic component, and smoking may be a risk factor. Fibromuscular dysplasia is more common among people with certain connective tissue disorders (for example, Ehlers-Danlos syndrome, cystic medial necrosis, hereditary nephritis, or neurofibromatosis).
Fibromuscular dysplasia may affect the arteries that supply the kidneys (renal arteries), brain (carotid and intracranial arteries), stomach and intestine (intra-abdominal arteries such as the celiac and mesenteric arteries), or the arteries that branch off the lower part of the aorta to supply the legs (external iliac arteries). People may have fibromuscular dysplasia in more than one artery.
Fibromuscular dysplasia usually causes no symptoms regardless of location. Symptoms, when they occur, vary by location:
Leg arteries: Painful, aching, cramping, or tired feeling in the muscles of the leg (claudication), unusual sounds heard through a stethoscope that are caused by blood rushing through the narrowed artery (bruits), and decreased pulses in the femoral vein
Renal arteries: High blood pressure
Carotid arteries: Transient ischemic attack or stroke symptoms (such as trouble speaking, muscle weakness, paralysis on one side of the body, vision problems)
Intracranial arteries: Symptoms of an aneurysm (such as headaches, pain above and behind the eye, numbness, weakness, paralysis on one side of the body, vision problems)
Intra-abdominal arteries: Vomiting or abdominal pain (rare)
Ultrasonography may suggest the diagnosis, but angiography is done to confirm the diagnosis.
Treatment varies by location. It may involve angioplasty, bypass surgery, or aneurysm repair. Smoking cessation is important. Because atherosclerosis also blocks arteries, people with fibromuscular dysplasia and risk factors for atherosclerosis (such as high blood pressure, high levels of cholesterol in the blood, and diabetes) may also need treatment of those disorders.