Vertebral artery ectasia

Vertebral artery ectasia refers to an abnormal dilatation of the vertebral artery. It is also known as a dolichoarterial loop (of Danziger).

Clinical presentation

Symptoms occur due to radicular compression or pathologic fracture (rare) from extensive bone erosion. Generally, patients present with headache, dizziness, suboccipital pain, nausea and vomiting. 

Pathology

Vertebral arterial wall thinning and elongation (usually age-related); the majority are unilateral.

Occlusion of the carotid arteries (bilaterally) may precipitate vertebral artery dilatation as a compensatory mechanism for maintaining cerebral perfusion ¹.

Radiographic features

Plain radiograph

• enlargement of the transverse foramen
• erosion of pedicle and posterolateral vertebral body expanding the intervertebral foramen
• extrinsic bone erosion seen in the mid cervical segments, usually at C4-C5 level (Hadley’s erosive defect)

CT

Allows better visualization of plain film findings

MRI

MRA is best method to confirm the presence of a dolichoectatic loop or dolichoarterial loop.

Differential diagnosis

Consider other vascular causes of pedicle erosion:

• arteriovenous malformation
• pseudoaneurysm
• aortic coarctation
• subclavian steal syndrome
• carotid obstruction