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Updated: Apr 12, 2026
Optimized Management of Endovascular Treatment for Acute Ischemic Stroke
Published on: January 18, 2018
Acute ischemic stroke treatment, part 1: patient selection "the 50% barrier and the capillary index score"
Firas Al-Ali1, John J Elias2, Danielle E Filipkowski2
1Summit Neurovascular Specialists , Akron, OH , USA.
Insights
A new Capillary Index Score (CIS) may identify stroke patients with sufficient collateral blood supply for successful intra-arterial treatment (IAT). This could extend the treatment window for eligible patients, improving outcomes in acute ischemic stroke care.
Area of Science:
- Neurology
- Vascular Medicine
- Medical Imaging
Background:
- Current intra-arterial treatment (IAT) for acute ischemic stroke prioritizes speed and revascularization, yet outcomes remain suboptimal.
- Collateral blood supply is crucial for brain tissue viability during ischemic events.
- A genetic predisposition, termed the '50% barrier,' suggests only half of patients possess adequate collaterals for good outcomes.
Purpose of the Study:
- To introduce the Capillary Index Score (CIS) as a tool to assess collateral blood supply.
- To identify patients with favorable CIS (f CIS) who may benefit from IAT beyond standard time windows.
- To propose a patient treatment algorithm incorporating the CIS.
Main Methods:
- Development of the Capillary Index Score (CIS) using diagnostic cerebral angiograms.
- Proposed algorithm: Head CT followed by CT angiography (CTA) for large stroke patients without aphasia.
- CTA to confirm vascular occlusion and assess irreversible ischemia, followed by CIS assessment.
Main Results:
- The CIS can identify patients with sufficient collateral circulation (f CIS).
- Patients with f CIS may achieve good outcomes with IAT, potentially outside conventional timeframes.
- The proposed algorithm integrates CIS for optimized treatment selection.
Conclusions:
- The CIS is a valuable tool for stratifying acute ischemic stroke patients for intra-arterial treatment.
- Incorporating CIS into treatment algorithms may improve patient selection and outcomes.
- This approach addresses the '50% barrier' by identifying suitable candidates for extended IAT eligibility.
Abstract:
The current strategy for intra-arterial treatment (IAT) of acute ischemic stroke focuses on minimizing time from ictus to revascularization and maximizing revascularization. Employing this strategy has yet to lead to improved rates of successful outcomes. However, the collateral blood supply likely plays a significant role in maintaining viable brain tissue during ischemia. Based on our prior work, we believe that only approximately 50% of patients are genetically predisposed to have sufficient collaterals for a good outcome following treatment, a concept we call the 50% barrier. The Capillary Index Score (CIS) has been developed as a tool to identify patients with a sufficient collateral blood supply to maintain tissue viability prior to treatment. Patients with a favorable CIS (f CIS) may be able to achieve a good outcome with IAT beyond an arbitrary time window. The CIS is incorporated into a proposed patient treatment algorithm. For patients suffering from a large stroke without aphasia, a non-enhanced head CT should be followed by CT angiography (CTA). For patients without signs of stroke mimics or visible signs of structural changes due to large irreversible ischemia, CTA can help confirm the vascular occlusion and location. The CIS can be obtained from a diagnostic cerebral angiogram, with IAT offered to patients categorized as f CIS.
