What is the management for high grade stenosis in the left P2 (posterior cerebral artery) segment?

Management of High-Grade Stenosis in Left P2 Segment of Posterior Cerebral Artery

For high-grade stenosis in the left P2 segment of the posterior cerebral artery, medical management with aspirin 325 mg daily, high-dose statin therapy, and blood pressure control targeting <140 mmHg systolic is strongly recommended over angioplasty and stenting. 1

Medical Management Algorithm

First-Line Therapy

1. Antiplatelet therapy

   • Aspirin 325 mg daily 1
   • Note: Anticoagulation is NOT recommended unless there is another indication such as atrial fibrillation 1

2. Lipid management

   • High-dose statin therapy 1
   • Target LDL-cholesterol of 1.8 mmol/L (70 mg/dL) 1

3. Blood pressure control

   • Target systolic blood pressure <140 mmHg 1
   • Regular monitoring and medication adjustment as needed

4. Lifestyle modifications

   • At least moderate physical activity 1
   • Smoking cessation
   • Diabetes control (if applicable)
   • Weight management

Dual Antiplatelet Consideration

While single antiplatelet therapy is the standard recommendation, dual antiplatelet therapy (DAPT) may be considered in specific circumstances:

• In patients with recent minor ischemic stroke (NIHSS ≤3) or high-risk TIA (ABCD2 ≥4), short-term DAPT with aspirin and clopidogrel for 21 days followed by long-term single antiplatelet therapy may be reasonable 1
• The CLAIR trial showed DAPT was associated with a 54.4% relative risk reduction in microembolic signals on transcranial Doppler ultrasound in patients with symptomatic intracranial atherosclerotic disease 1

Interventional Management

Angioplasty and stenting are NOT recommended for high-grade intracranial atherosclerotic stenosis (50-99%) 1. This recommendation is based on evidence from the SAMMPRIS trial, which showed that aggressive medical management was superior to stenting for preventing stroke in patients with symptomatic intracranial stenosis.

Monitoring and Follow-up

• Serial non-invasive imaging of the posterior cerebral artery is reasonable to assess disease progression 1
• Regular monitoring of blood pressure, lipid levels, and other vascular risk factors
• Ongoing assessment for symptoms of posterior circulation ischemia

Special Considerations

• If the patient has symptoms of posterior cerebral or cerebellar ischemia, MRA or CTA is preferred over ultrasound for evaluation of the vertebral and posterior cerebral arteries 1
• In patients with recurrent symptoms despite optimal medical therapy, catheter-based contrast angiography may be useful to better define the pathoanatomy when non-invasive imaging is insufficient 1

Clinical Pitfalls to Avoid

1. Do not use anticoagulation unless there is a specific indication such as atrial fibrillation 1
2. Do not rush to interventional procedures - medical management is the first-line approach for intracranial stenosis 1
3. Do not neglect comprehensive risk factor modification - addressing all modifiable risk factors is essential for preventing stroke progression
4. Do not overlook the possibility of other stroke mechanisms - ensure a thorough evaluation for other potential causes of posterior circulation symptoms

While some case reports have described successful angioplasty and stenting for posterior cerebral artery stenosis 2, 3, 4, 5, these represent isolated cases and do not override the strong guideline recommendations against routine stenting for intracranial stenosis.