Subclavian arteries (there are two on each side of the neck) are branches of the aorta. Subclavian artery stenosis can be a cause of significant morbidity as it can lead to ischemia (due to insufficient blood supply in the tissues) affecting the upper extremities, brain and in some cases the heart.
What are the causes of stenosis?
Atherosclerosis (fatty deposits in the walls of blood vessels) is the most common cause of this condition. The risk factors associated with atherosclerosis are hypertension, smoking, obesity, dislipidemia, diabetes.
Other etiologies include arteritis (inflammation of the artery walls, i.e. Takayasu arteritis, giant cell arteritis), inflammation due to radiation exposure, compression syndromes, fibromuscular dysplasia, and neurofibromatosis.
Frequently, patients with subclavian artery stenosis have concomitent lesions of other vessels (coronary arteries – the heart vessels, carotid arteries – the main vessels of the neck, the arteries of the legs), so the patients affected with this disease are at increased risk of developing symptomatic coronary artery disease (angina – chest pain, or heart attack) and cerebrovascular events (eg. stroke).
The left subclavian artery is more likely to be affected (3-4 times more frequently), close to its origin from the aorta.
If there is an isolated stenosis, the symptoms may lack due to the collaterals (new vessels that open and facilitate blood supply to the affected areas).
The symptoms include muscle fatigue, arm pain (claudication), rest pain and finger necrosis (blocking the blood supply of the fingers caused by pieces of the atherosclerosis plaque), bleeding in the nails.
Neurologic symptoms may occur (due to coronary-subclavian “steal”, the blood is redirected from normal vessels that originate in the subclavian artery to the affected area): visual disturbances, syncope (loss of consciousness), ataxia, vertigo, dysarthria (difficulty in speaking), ataxia (inability to maintain balance), vertigo (dizziness) and facial sensory deficits. In patients with internal mammary artery (IMA) grafts as a result of coronary artery bypass graft (CABG) surgery, the symptoms of ischemic heart disease may be recurrent.