Extending the time window for endovascular procedures according to collateral pial circulation

Area of Science:

• Neurology
• Interventional Radiology
• Vascular Medicine

Background:

• Good pial collateral circulation (CPC) is crucial for favorable outcomes in patients undergoing intra-arterial procedures for stroke.
• Assessing CPC status can inform treatment decisions regarding recanalization efforts.

Purpose of the Study:

• To determine if collateral pial circulation (CPC) status can guide decisions on pursuing recanalization efforts in stroke patients.
• To evaluate the impact of CPC on clinical outcomes and infarct volume in relation to time to recanalization.

Main Methods:

• Pial collateral score (0-5) was assessed on initial angiograms; a score <3 defined good CPC.
• Total time of ischemia (TTI) was defined as onset-to-recanalization time.
• Clinical improvement was measured as a >4-point decline in NIH Stroke Scale score from admission to discharge.

Main Results:

• Good CPC (n=21) was associated with significantly lower discharge NIH Stroke Scale scores (7 vs. 21) and smaller infarct volumes (56 mL vs. 238 mL).
• In poor CPC patients, a TTI cutoff of <300 minutes predicted clinical improvement (66.7%).
• Good CPC patients showed a 3-fold higher likelihood of clinical improvement after 300 minutes (90.1%) and significantly reduced infarct volumes (33 mL) compared to poor CPC patients (23.1% and 217 mL, respectively) when TTI > 300 minutes.

Conclusions:

• Good collateral pial circulation (CPC) predicts a better clinical response to intra-arterial treatment, extending beyond 5 hours from stroke onset.
• Identifying good CPC in stroke patients undergoing endovascular treatment can aid physicians in deciding whether to pursue recanalization in later time windows.