Which statement is true for the 6-24 hour thrombectomy eligibility criteria?

Which statement is true for the 6-24 hour thrombectomy eligibility criteria?

• A. Age >=18
• B. Infarct involving less than 1/3 of MCA on CT or MRI
• C. NIHSS 30
• D. Pre-stroke mRS 4

Answer: (B)

In the 6-24 hour thrombectomy window, the emphasis is on tissue viability shown on imaging. A relatively small infarct core—such as infarction involving less than a third of the MCA territory on CT or MRI—suggests there is still salvageable brain tissue (penumbra) that can benefit from reperfusion even after several hours. This imaging-based criterion helps identify patients who are likely to gain meaningful improvement from thrombectomy, which is why this statement best fits the late-window eligibility concept. The other options aren’t the defining late-window criterion. Age being at least 18 is a general inclusion factor in many trials, but the late-window eligibility centers on imaging findings rather than age alone. A very high NIHSS score or a poor pre-stroke functional status can affect prognosis and decisions in practice, but they do not establish the core eligibility rule for 6-24 hours.

In the 6-24 hour thrombectomy window, the emphasis is on tissue viability shown on imaging. A relatively small infarct core—such as infarction involving less than a third of the MCA territory on CT or MRI—suggests there is still salvageable brain tissue (penumbra) that can benefit from reperfusion even after several hours. This imaging-based criterion helps identify patients who are likely to gain meaningful improvement from thrombectomy, which is why this statement best fits the late-window eligibility concept.

The other options aren’t the defining late-window criterion. Age being at least 18 is a general inclusion factor in many trials, but the late-window eligibility centers on imaging findings rather than age alone. A very high NIHSS score or a poor pre-stroke functional status can affect prognosis and decisions in practice, but they do not establish the core eligibility rule for 6-24 hours.