What is the treatment for posterior cerebral artery (PCA) disease?

Treatment of Posterior Cerebral Artery (PCA) Disease

The treatment of posterior cerebral artery disease should follow the same guidelines as those for carotid artery disease, with aspirin (75-325 mg daily) as the primary antiplatelet therapy for patients with vertebral artery atherosclerosis. 1, 2

Medical Management

Antiplatelet Therapy

• First-line therapy: Aspirin 75-325 mg daily 1, 2
• For aspirin-intolerant patients: Clopidogrel 75 mg daily or ticlopidine 250 mg twice daily 1, 2
• Superior combination therapy: Aspirin plus extended-release dipyridamole has shown better outcomes (5.7% vs 10.8% event rate with placebo) for secondary prevention in patients with vertebrobasilar territory stroke or TIA 1, 2

Anticoagulation

• For patients with acute ischemic syndromes involving the vertebral artery territory with angiographic evidence of thrombus, anticoagulation with warfarin is generally recommended for at least 3 months 1, 2
• The WASID trial found aspirin and warfarin to be equally efficacious after initial non-cardioembolic ischemic stroke 1

Risk Factor Modification

• Aggressive management of atherosclerotic risk factors following the same standards as for carotid atherosclerosis 2:
  • Target blood pressure <140/90 mmHg
  • High-intensity statin therapy
  • Diabetes management if applicable
  • Smoking cessation

Revascularization Options

Indications for Revascularization

• Symptomatic patients who have failed medical therapy
• Recurrent ischemic events despite optimal medical management
• Clearly attributable symptoms to vertebral artery disease 1, 2

Surgical Approaches

• Operations for vertebral artery occlusive disease are rarely performed 1
• Surgical options for proximal vertebral artery stenosis include:
  • Trans-subclavian vertebral endarterectomy
  • Transposition of the vertebral artery to the ipsilateral common carotid artery
  • Reimplantation of the vertebral artery with vein graft extension 1, 2
• Reported complication rates:
  • Proximal vertebral artery reconstruction: 2.5-25% early complications, 0-4% perioperative mortality 1
  • Distal vertebral artery reconstruction: 2-8% mortality 1

Endovascular Treatment

• Recent evidence from the ATTENTION and BAOCHE trials supports endovascular thrombectomy for basilar artery occlusion 1
• Techniques include:
  • Aspiration
  • Stent retriever
  • Combined techniques
  • Angioplasty and stenting (particularly effective in populations with high rates of intracranial atherosclerosis) 1

Imaging and Monitoring

Initial Assessment

• CTA or MRA is recommended as the initial imaging modality for detection of vertebral artery disease 1, 2
• Neither MRA nor CTA reliably delineates the origins of the vertebral arteries, so catheter-based contrast angiography is typically required before revascularization 1
• For basilar artery occlusion, PC-ASPECTS (Posterior Circulation Alberta Stroke Program Early CT Score) can help assess ischemic injury 1

Follow-up Monitoring

• Serial noninvasive imaging of the extracranial vertebral arteries is reasonable to assess progression of atherosclerotic disease 1, 2
• Regular neurological assessments (every 3 months initially)
• Carotid and vertebral artery imaging surveillance (every 6 months for the first year, annually thereafter if stable) 2

Special Considerations

• Vertebrobasilar stenosis is associated with a higher risk of early recurrent stroke compared to carotid stenosis 2
• When one vertebral artery is patent and dominant, intervention on a stenotic non-dominant vertebral artery may not be necessary 2
• Symptoms of vertebrobasilar insufficiency (dizziness, vertigo, diplopia, ataxia) can be caused by other conditions, including cardiac arrhythmias and vestibular disorders 1, 2
• PCA atherostenosis is rarer than PCA embolic occlusion and presents more commonly with TIAs than infarcts 3
• Visual and sensory symptoms predominate in PCA disease, with visual field defects, difficulty seeing to one side, flashing lights, and paresthesias being common presentations 3, 4

Treatment Algorithm

1. Confirm diagnosis with CTA or MRA
2. Initiate medical therapy:
   • Aspirin 75-325 mg daily (first-line)
   • If aspirin contraindicated: clopidogrel 75 mg daily
   • Consider aspirin plus extended-release dipyridamole for secondary prevention
3. Aggressive risk factor modification
4. For acute thrombosis: Consider anticoagulation for 3 months
5. If symptoms persist despite medical therapy:
   • Evaluate for revascularization with catheter angiography
   • Consider endovascular treatment for basilar artery occlusion
   • Consider surgical options for proximal vertebral artery disease only when clearly indicated
6. Regular monitoring with serial imaging and neurological assessments

By following this evidence-based approach, clinicians can optimize outcomes for patients with posterior cerebral artery disease, reducing the risk of stroke and improving quality of life.