PTA of left subclavian artery stenosis

Clinical History

Stenosis of proximal left subclavian artery

Imaging Findings

Patient presented with recurrent pain during exercising her left arm. Clinical investigation revealed a weakened brachial pulse on the left and a systolic pressure difference of 50 mm Hg between right and left arm. No neurological symptoms were present. She was a heavy smoker but no other risk factors were known. The location of the lesion is not typical for a thoracic outlet syndrome and shows morpholical appearance of an atherosclerotic lesion. Angiography via a transfemoral approach demonstrated a high-grade but short stenosis of the left subclavian artery . The left vertebral artery is not seen (Fig. 1 a). After traversing the stenosis and selective catheterization of the left vertebral artery (Fig. 1 b), contrast injection proves retrograde flow through the patent left vertebral artery proving a subclavian steal effect. Since the patient was symptomatic, PTA of the lesion was recommended.

Discussion

After selective catheterization of the left subclavian artery, a coated guidewire (0.035 in) was guided over the stenosis into the left axillary artery I.a. heparin (5000 IU) had been administered at the beginning of the intervention. Then a 110 cm long 4 F Headhunter I catheter was passed over the guidewire which was exchanged for a 200 cm long 0.035 in noncoated guidewire. After removal of the headhunter catheter, a 7 mm large balloon was advanced over the wire across the lesion and was inflated for 45 seconds with a pressure of 8 atm (Fig. 2 a). After deflation of the balloon and retrieval, a long 6 F guiding catheter was advanced over the wire which had been kept in place. Angiography via the guiding catheter shows sufficient opening of the lesion with only minor residual stenosis (Fig. 2 b) and good antegrade flow. Note that the vertebral artery is now perfused in an antegrade fashion. PTA of subclavian lesions is effective. It can be recommended as a treatment of choice in symptomatic patients. Some authors recommend treatment only in case of neurological deficits, other in case of brachial claudication. Severity of the symptoms and the individual activity of each patient are important for the decision process; a general rule is difficult to define. However, asymptomatic patients should not undergo treatment. Subclavian lesions with a proximal stump are more easy to attack via a transfemoral approach because the catheter tip can be easily stabilized within that stump as it was possible in the case presented. Lesions of the very proximal segment are more difficult to overcome via a transfemoral approach. Then a transbrachial approach is feasible to pass the lesion but the wire should be guided out at the transfemoral access, allowing a through-and-through manoeuver. If possible, balloon dilation alone should be used. Stents have been proven to do a good job in the subclavian location and both self-expanding and balloon-expandable devices have been used. Most crucial is not to cover the vertebral artery orifice by the stent which can be sometimes difficult if the lesion is to close to the origin of the vertebral artery. There have been older publications, that the vertebral artery will not perfused immediately in an antegrade fashion after PTA. In that very case, full antegrade flow was however present immediately

Differential Diagnosis List

Final Diagnosis

Balloon dilation of subclavian artery stenosis

URL:	https://eurorad.org/case/592
DOI:	10.1594/EURORAD/CASE.592
ISSN:	1563-4086