Collateral circulation status-guided mechanical thrombectomy in pediatric stroke with an extended ghost infarct core: illustrative case

Abstract

Background: Mechanical thrombectomy (MT) has been proved to be a highly effective therapy to treat acute ischemic stroke due to large vessel occlusion. Often, the ischemic core extent on baseline imaging is an important determinant for endovascular treatment eligibility. However, computed tomography (CT) perfusion (CTP) or diffusion-weighted imaging may overestimate the infarct core on admission and, consequently, smaller infarct lesions called "ghost infarct cores."

Observations: A 4-year-old, previously healthy boy presented with acute-onset, right-sided weakness and aphasia. Fourteen hours after the onset of symptoms, the patient presented with a National Institutes of Health Stroke Scale (NIHSS) score of 22, and magnetic resonance angiography demonstrated a left middle cerebral artery occlusion. MT was not considered because of a large infarct core (infarct core volume: 52 mL; mismatch ratio 1.6 on CTP). However, multiphase CT angiography indicated good collateral circulation, which encouraged MT. Complete recanalization was achieved via MT at 16 hours after the onset of symptoms. The child's hemiparesis improved. Follow-up magnetic resonance imaging was nearly normal and showed that the baseline infarct lesion was reversible, in agreement with neurological improvement (NIHSS score 1).

Lessons: The selection of pediatric stroke with a delayed time window guided by good collateral circulation at baseline seems safe and efficacious, which suggests a promising value of vascular window.

Keywords: collateral circulation; ghost infarct core; mechanical thrombectomy; pediatric; stroke.

FIG. 1.

mCTA (3 phases) maximum-intensity projection images indicate a score of 4 (a validated 6-point pial arterial filling ordinary score established at the University of Calgary).

FIG. 2.

Axial DWI (A) demonstrates areas of restricted diffusion in the left temporal, frontal, and parietal lobes 8 hours after the onset of symptoms. Perfusion CT (B) showed the infarct core in the same area 14 hours after the onset of symptoms (red region, infarct core; green region, perfusion deficit; MIStar, Apollo Medical Imaging Technology). Follow-up fluid-attenuated inversion recovery (FLAIR) imaging 14 days later was normal (C).