Subclavian artery stenosis

Radiologically demonstrable stenosis of the subclavian artery or innominate artery is present in approximately 17%. Of these, 2.5% have angiographic flow reversal in vertebral artery. Only 5.3 % of those with angiographic steal have neurologic symptoms ¹⁾.

The 5 D’s of VBI i.e.,diplopia, dysarthria, defective vision, dizziness and drop attacks. Other symptoms include headache, nystagmus, hearing loss and focal seizures ^{2) 3)}.

The arterial stenosis is proximal to the origin of VA. Symptoms are induced by exercise or exertion using the arm ipsilateral to the stenosis. The increased flow demand due to the exertion results in retrograde blood flow through the VA. The neurological symptoms may be because of continuous brainstem ischemia or more commonly, ischemia due to ipsilateral arm exercise or exertion ⁴⁾.

Symptomatic subclavian artery stenosis i.e., stenosis resulting in subclavian steal syndrome.

This includes angioplasty and stenting. A balloon mounted stent e.g., Express LD may be used, as the stent is deployed concurrently with angioplasty ⁵⁾.

However, if the stenosis is particularly severe (e.g., <2 mm), pre-dilatation may be performed by a smaller balloon to achieve a caliber of 4 mm at site of stenosis. Normal antegrade blood flow is restored following successful angioplasty and stenting.

The patient is monitored at least overnight in NSICU.

After stenting, the patient remains on dual antiplatelet therapy (ASA+Plavix) for at least 1 month, and ASA alone indefinitely.

Follow-up study in 3–6 months, which could be CTA, Doppler ultrasonography or catheter angiogram.

The frequency of complications is 17.8% (of 73 procedures) for innominate and VA angioplasty and stenting. These include access-site bleeding and distal embolization ⁶⁾.