Proximal Vertebral Artery Stenosis Research Articles

Diagnosis and management of vertebral artery stenosis.

Approximately one‐quarter of ischaemic strokes involve the posterior or vertebrobasilar circulation.1,,2 Stenosis of the vertebral artery can occur in either its extra‐ or intracranial portions, and may account for up to 20% of posterior circulation ischaemic strokes.3–,6 Stenotic lesions, particularly at the origin of the vertebral artery, are not uncommon. In an angiographic study of 4748 patients with ischaemic stroke, some degree of proximal extracranial vertebral artery stenosis was seen in 18% of cases on the right and 22.3% on the left.7 This was the second most common site of stenosis after internal carotid artery stenosis at the carotid bifurcation. Such stenotic lesions are now potentially treatable by endovascular techniques.8 In marked contrast with carotid artery stenosis, the optimal management of vertebral artery stenosis has received limited attention, and is poorly understood. This partly reflects difficulties in imaging the vertebral artery adequately, and limited surgical treatment options. Recent improvements in imaging and the arrival of vertebral artery angioplasty, however, have opened up new opportunities for intervention in this disease. We review vertebral artery anatomy, what is known of the natural history of vertebral artery disease, the role of imaging in the diagnosis of vertebral artery stenosis, and treatments for vertebral artery stenosis. The vertebral artery arises from the supraposterior aspect of the first part of the subclavian artery. In 6% of cases, the left vertebral artery arises directly from the aortic arch. Unlike the internal carotid artery, which is an almost direct extension of its parent vessel the common carotid artery, the vertebral artery branches almost at right angles to its feeding vessel. The vertebral artery, being 3–5 mm in diameter, is of much smaller relative calibre than the subclavian, with only a small amount of subclavian blood flow normally being directed into …

Treatment of proximal vertebral artery stenosis vertebral to subclavian transposition: Ogawa A, Yoshimoto T, Sakurai Y. Acta Neurochir (Wien) 1991;112:13-8

Treatment of proximal vertebral artery stenosis vertebral to subclavian transposition: Ogawa A, Yoshimoto T, Sakurai Y. Acta Neurochir (Wien) 1991;112:13-8

鎖骨下動脈および椎骨動脈起始部の狭窄性病変に対する percutaneous transluminal angioplasty (PTA) の有用性

Percutaneous transluminal angioplasty (PTA) was performed on the stenotic lesions of subclavian and proximal vertebral arteries. Successful dilatation was achieved in 14 of 14 cases of subclavian artery stenosis and in 6 of 8 cases of proximal vertebral artery stenosis. Re-stenosis occurred one year after PTA in one case of subclavian artery stenosis, but no other complications occurred. In these 7 cases, vascular endoscopy was applied before PTA and all occlusive lesions were found to be round smooth-surfaced lumen. Therefore, we conclude that PTA is a very safe alternative method of immediate treatment for stenotic lesions of subclavian and proximal vertebral arteries.

Treatment of proximal vertebral artery stenosis

For vascular reconstruction in cases of atherosclerotic stenosis at the origin of the vertebral artery, we use vertebral to subclavian artery transposition. We discuss the advantages and effectiveness of such treatment based on a study of 32 cases. We have experienced neither surgical mortality nor morbidity and the outcome at the time of discharge has been favourable. Follow-up revealed no deaths, however, three cases exhibited symptoms of cerebral ischaemia. One had a supratentorial completed stroke, and the other two hat TIA or RIND, but without any notable lesion in the angiograms. There were no cases of cerebral infarction of the posterior fossa. We believe that this method should be the first choice for treatment of cases without lesions of the subclavian artery for the following reasons: serious operative complications have not been encountered, surgical invasion is minimal, temporary occlusion of the common carotid artery is unnecessary, the operation can be done by occluding only the vertebral artery, and unlike various bypass operations, anastomosis is required at only one location and is consequently technically uncomplicated. Following anastomosis the cerebral blood pathway is physiological.

Surgical reconstruction of the proximal vertebral artery

The authors have reviewed their experience in the management of 55 patients admitted to Henry Ford Hospital with symptoms of vertebrobasilar insufficiency and associated proximal vertebral artery stenosis or occlusion. In 48 patients, the symptoms occurred as multiple repeated events, five of which resulted in permanent deficits. The remaining seven patients had single events, four of which caused permanent deficit. These patients had been treated unsuccessfully with antiplatelet agents (37 cases) and with anticoagulant drugs (15 cases) before surgery. Most patients had multiple angiographic abnormalities, including bilateral vertebral stenosis in 19 cases, unilateral vertebral stenosis and contralateral occlusion in 18, unilateral vertebral hypoplasia and contralateral stenosis in 10, subclavian artery stenosis with steal in seven, and bilateral vertebral artery occlusion in one case. Posterior communicating arteries could not be demonstrated angiographically in 18 patients. Thirty-four patients had associated stenotic or occlusive lesions of the internal carotid artery. Forty-eight underwent a vertebral-to-carotid artery transposition. Of these, 18 had an associated carotid endarterectomy and seven had a vertebral artery endarterectomy immediately before the transposition. Two patients had saphenous vein grafts, one from the subclavian and one from the common carotid artery to the vertebral artery. Other surgical procedures included vertebral artery ligation in one case, transposition of the vertebral artery to the thyrocervical trunk in two cases and to the subclavian artery in one case, and endarterectomy of the origin of the vertebral artery in one case. All but two patients had complete resolution of their symptoms: one had persistent dizziness and the other had syncopal episodes. Complications included transient Horner's syndrome (30 cases) which became permanent in four cases, vocal cord paralysis (three cases), elevated hemidiaphragm without respiratory difficulty (two cases), and superficial would infection (one case). There were no deaths. Although the presentation of patients with vertebrobasilar insufficiency is generally characteristic, we believe that a specific diagnosis can be established only by angiographic means. Anticoagulants have been used to alleviate symptoms in some cases but are ineffective in solving the primary hemodynamic problem. Surgical reconstruction of the affected area deserves further evaluation in the management of these patients.

Cardiac cycle-dependent alternating flow in vertebral arteries with subclavian artery stenoses.

Continuous-wave Doppler sonography is a reliable method for detecting severe subclavian stenosis and occlusion as well as subclavian steal. Intermediate stages leading to subclavian steal can also be detected. These are characterized by a cardiac-phase-dependent alternating flow direction in the vertebral artery. Some cases of proximal subclavian or proximal vertebral artery stenosis produce a systolic deceleration of flow in the vertebral artery. Stenosis and occlusion of the subclavian artery as well as stenosis of the subclavian and vertebral arteries can be distinguished. The pulse curve changes described can be reversed by a vascular by-pass. Alternating flow direction or systolic deceleration of flow in the radial artery could also be observed or induced in a iatrogenic model using Cimino's a-v fistula in the arm in patients on dialysis. The results in beginning subclavian steal situations can be applied in principle to other collateral circulations, and in particular to the hemodynamics in the region of watersheds.