Can neurointervention be used in posterior circulation?

Neurointervention in Posterior Circulation Stroke

Neurointervention is strongly recommended for posterior circulation large vessel occlusions, particularly basilar artery occlusions, as it significantly improves functional outcomes and reduces mortality compared to medical therapy alone. 1

Indications for Posterior Circulation Neurointervention

Neurointervention in the posterior circulation is indicated for:

• Basilar artery occlusion (strongest evidence)
• Vertebral artery occlusion
• Symptomatic intracranial aneurysms of the posterior circulation
• Space-occupying cerebellar strokes requiring decompression

Diagnostic Evaluation

Imaging

• Non-contrast CT: Initial assessment to rule out hemorrhage and evaluate for posterior fossa edema/mass effect 2
• CT/MR Angiography: Essential for identifying vertebral or basilar artery occlusion 1
• DWI MRI: Most sensitive for early ischemic changes; pc-ASPECTS score ≥8 is associated with better outcomes 2
• CT Perfusion: Adds diagnostic value with higher sensitivity (74%) compared to non-contrast CT (31%) 2

Clinical Assessment

• NIHSS has limitations for posterior circulation strokes - patients may present with low scores despite severe pathology 2
• Key symptoms: Loss of consciousness, headache, nausea, vomiting, dizziness, double vision, vertigo, ataxia, nystagmus, and visual field defects 2
• "Locked-in syndrome" may occur with proximal basilar occlusions 2

Interventional Techniques

Mechanical Thrombectomy

• Suction Thrombectomy (ADAPT): Achieves higher rates of complete reperfusion (OR 2.59) with shorter procedure duration and fewer complications compared to stent retrievers 2
• Stent Retriever Thrombectomy: Effective for basilar occlusions, though associated with higher complication rates than ADAPT 2
• Technical Success: Similar recanalization rates between anterior and posterior circulation (OR = 1.02) 3

Access Routes

• Transradial Approach: Safe and feasible alternative to transfemoral access, with successful use in 23% of posterior circulation cases in one series 4
• Transfemoral Approach: Traditional access route, may be preferred for complex anatomy 4

Outcomes and Prognosis

• Successful reperfusion is a strong predictor of favorable outcome (OR 4.57) 2
• Posterior circulation thrombectomy achieves similar recanalization rates as anterior circulation but with:
  • Lower rates of 90-day functional independence (OR = 1.26 in favor of anterior circulation) 3
  • Higher 90-day mortality (OR = 0.58 in favor of anterior circulation) 3
• Predictors of poor outcome: Older age, higher NIHSS, lack of recanalization, atrial fibrillation, intracranial hemorrhage, and pc-ASPECTS ≤8 2

Special Considerations

Basilar Artery Occlusion

• Historically considered fatal with mortality rates of 40-86% without treatment 2
• Mechanical thrombectomy now shows improved outcomes with newer devices achieving recanalization rates up to 92% 1
• Recent ATTENTION and BAOCHE trials demonstrate clear benefit of thrombectomy for basilar artery occlusion 5

Posterior Circulation Aneurysms

• Higher surgical risk than anterior circulation, particularly for giant aneurysms (mortality 9.6%, morbidity 37.9%) 2
• Basilar apex aneurysms require special consideration due to intimate association with midbrain perforating arteries 2
• Endovascular coiling is a viable alternative to surgical clipping 2

Cerebellar Stroke Management

• Approximately 25% of patients develop mass effect causing rapid clinical deterioration 2
• Up to 20% develop hydrocephalus requiring intervention 2
• Decompressive suboccipital craniectomy should be considered early for patients with mass effect and hydrocephalus 2, 1
• External ventricular drainage alone carries risk of upward herniation 2

Post-Procedure Management

• Blood pressure: Maintain systolic 121-200 mmHg and diastolic 81-110 mmHg 2, 1
• Close neurological monitoring with assessments every 15-30 minutes during initial hours 1
• Early mobilization to prevent complications 1
• Swallowing assessment before initiating oral feeding 1

Common Pitfalls to Avoid

1. Delayed Recognition: Posterior circulation strokes often present with non-specific symptoms, leading to delayed diagnosis and treatment 2
2. Relying solely on NIHSS: Patients may have low NIHSS scores despite severe posterior circulation pathology 2
3. Inadequate Imaging: Posterior fossa structures may be obscured by beam hardening artifact on CT; consider MRI when available 2
4. Overlooking Mass Effect: Failure to monitor for and treat cerebellar edema and hydrocephalus can be fatal 2
5. Inappropriate Patient Selection: Not all posterior circulation strokes benefit equally from intervention; pc-ASPECTS ≥8 predicts better outcomes 2

Neurointervention for posterior circulation pathology requires specialized expertise but offers significant benefits for appropriately selected patients, particularly those with basilar artery occlusion.