Is neurointervention (neurointerventional surgery) best suited for anterior or posterior circulation?

Neurointervention for Posterior Circulation Stroke

Neurointervention is particularly beneficial for posterior circulation strokes, especially basilar artery occlusions, with recent trials demonstrating superior outcomes compared to medical management alone. 1

Effectiveness of Neurointervention by Circulation

Posterior Circulation

• Recent evidence from the ATTENTION and BAOCHE trials demonstrates that mechanical thrombectomy significantly improves outcomes in basilar artery occlusion (BAO) patients compared to medical therapy alone 1
• Suction thrombectomy (ADAPT) achieves higher rates of complete reperfusion with shorter procedure duration and fewer complications compared to stent retrievers in posterior circulation 1
• Posterior circulation interventions often require additional techniques:
  • Intracranial angioplasty/stenting in 55% of cases
  • Tirofiban administration in 54% of cases 1

Anterior Circulation

• Class I evidence exists for mechanical thrombectomy in anterior circulation large vessel occlusion (LVO) 2
• Anterior circulation interventions typically have:
  • Lower mortality rates (5.8% vs 16.6% in basilar occlusions) 1
  • Better 90-day modified Rankin Scale scores (3.0 vs 4.2 in basilar occlusions) 1

Key Differences Between Anterior and Posterior Circulation Interventions

1. Technical Considerations:

   • Posterior circulation often requires more complex approaches:
     • Higher rates of angioplasty and stenting due to higher frequency of intracranial atherosclerosis 1
     • Radial access may be advantageous for basilar thrombectomy due to anatomical advantages 1

2. Outcomes:

   • Mortality is significantly higher in posterior circulation interventions 1, 3
   • Symptomatic intracranial hemorrhage is less common in posterior circulation (0% vs 3% in anterior circulation) 3

3. Patient Selection:

   • Posterior circulation patients benefit from intervention even with:
     • Low NIHSS scores (may underestimate posterior circulation deficits) 4
     • Longer time windows (up to 24 hours from last known well) 1
     • pc-ASPECTS ≥8 associated with better outcomes 4

Procedural Approach for Posterior Circulation

1. Imaging Assessment:

   • CT/CTA for initial assessment to rule out hemorrhage and identify occlusion 4
   • DWI MRI for early ischemic changes when available 4
   • pc-ASPECTS scoring to guide patient selection 1

2. Thrombectomy Technique:

   • Primary aspiration technique (ADAPT) is recommended as first-line approach 2
     • Achieves higher rates of complete reperfusion (OR 2.59) 1
     • Shorter procedure duration (median 45 min vs 56 min) 1
     • Lower periprocedural complications (4.3% vs 25.9%) 1

3. Management of Underlying Pathology:

   • Consider angioplasty/stenting for persistent stenosis after thrombectomy 1
   • Tirofiban administration may be beneficial, particularly with stenting 1

Predictors of Good Outcome in Posterior Circulation Intervention

• Successful reperfusion (OR 4.57) 1, 4
• Low initial NIHSS score (OR 0.82) 1
• High DWI pc-ASPECTS (OR 1.854) 1
• Primary aspiration technique 2
• Early intervention (though benefit extends to 24 hours) 1

Special Considerations

• Mass Effect Management: Early surgical decompression for cerebellar infarcts with mass effect is critical, as 85% of patients progressing to coma die without intervention 1

• Hydrocephalus: Up to 20% develop hydrocephalus requiring intervention 4

• Blood Pressure Management: Maintain between 140-180 mg/dL in accordance with American Diabetic Association guidelines 1

• Beyond 24 Hours: Limited evidence suggests thrombectomy may be feasible beyond 24 hours in select cases, but outcomes are generally poor when recanalization is achieved >9 hours after onset 1

Common Pitfalls

1. Underestimating Posterior Circulation Strokes:

   • Patients may present with low NIHSS scores despite severe pathology 4
   • Non-specific symptoms (dizziness, nausea, headache) may delay diagnosis 1

2. Overreliance on Time Windows:

   • Unlike anterior circulation, posterior circulation benefits from intervention up to 24 hours 1

3. Inadequate Technique Selection:

   • Failure to use primary aspiration technique may lead to futile revascularization 2

4. Delayed Recognition of Mass Effect:

   • Approximately 25% develop mass effect causing rapid clinical deterioration 1
   • Early surgical intervention is critical when indicated 1