Childhood stroke, with an estimated incidence of 2 to 8 per 100,000 children per year, is a rare but devastating clinical event [1]. In terms of presentation, etiology, and response to therapeutic intervention, stroke in childhood differs from adulthood [2]. Nearly half of the childhood strokes are ischemic in nature and the common underlying mechanisms are arteriopathy, connective tissue disorders, infection, trauma, underlying structural cardiac disease, and rarely atherosclerosis [3]. Approximately 10% of cases are idiopathic and the tendency for recurrence is relatively high in pediatric cases, reaching up to 35% [3-6]. Since 2015, endovascular therapy has become the standard of care for eligible large vessel occlusion strokes in adults and has revolutionized the outcome of acute ischemic stroke (AIS). However, there are limited data on mechanical endovascular therapy in pediatric stroke [7]. Despite these limitations, mechanical thrombectomy alone or in combination with intravenous tissue plasminogen activator is increasingly performed in the pediatric population [8]. The safety and feasibility of aspiration thrombectomy is challenged by the compatibility of the aspiration devices with smaller pediatric intracranial vessels, but the stent retrieval technique may still be used, especially in older children, given the higher rates of recanalization [9].

In this case report, we describe an AIS in a 1-year-old child that was successfully treated by aspiration thrombectomy and report the patient’s outcome after this procedure.

A 12-month-old girl presented to the emergency department with acute right-sided hemiplegia and confusion for 6 hours, 2 days after a fall from stairs. Magnetic resonance imaging (MRI) of the brain was performed and showed an acute large ischemic infarction in the right middle cerebral artery (MCA) territory (Fig. 1A). Magnetic resonance angiography (MRA) of the head and neck showed occlusion of the right internal carotid artery (ICA) just above the carotid bulb. She was transferred to our institution approximately 12 hours after the onset of symptoms. After discussion among the multidisciplinary team and with the parents regarding the intended benefits and potential risks of the procedure, the decision was made to proceed with the procedure. In the neuroendovascular suite, she was intubated and under general anesthesia, right femoral artery access was accessed with a 5F radial sheath 13.5 hours after the onset of symptoms. Cerebral angiography of the right common carotid artery (CCA) showed occlusion of the right ICA just above the carotid bulb, possibly due to dissection (Fig. 1B). Next, the 5F short sheath was exchanged for a 6F Cook Shuttle 80 cm (Cook Inc.), which was parked in the right CCA. Using an Echelon 14 microcatheter (Medtronic) over a 0.014 Traxcess microwire (MicroVention), the dissected portion of the right ICA was easily crossed and the 5F Sofia catheter (MicroVention) was advanced over the Echelon 14 into the petrous segment of ICA through the true lumen and clot aspiration was done. Control angiography showed terminal ICA occlusion (Fig. 1C). The second round of aspiration thrombectomy was performed in the same fashion, resulting in proximal M1 segment occlusion on control angiography. The third pass of thrombectomy with Sofia 5F catheter resulted in distal posterior M2 segment occlusion. At this time, 0.6 mg of Integrilin (Millennium Pharmaceuticals, Inc.) was infused into the posterior branch of the right MCA over 2 minutes. Final angiography showed Thrombolysis in Cerebral Infarction (TICI) 2b with occlusion of distal M3 branches of the MCA vascular tree (Fig. 1D–F). She was transferred to the intensive care unit and remained intubated under sedation for the next 24 hours. The next day, a follow-up brain MRI/MRA showed patent right ICA and MCA branches without infarct progression or hemorrhage. She was extubated on the 2nd postoperativeday and discharged to a rehabilitation facility on 40 mg of aspirin daily. At discharge, there was some improvement in left lower extremity strength (2/5) but the right arm remained paralyzed. At the 12-month follow-up, there was a great improvement in the left lower extremity muscle strength, and she could walk 3–4 steps without assistance and the left upper extremity had muscle strength of 3/5.

To the best of our knowledge, this case is the youngest report in the literature of a child who successfully underwent aspiration thrombectomy for ischemic stroke possibly due to ICA dissection. ICA dissection is a common cause of AIS in the pediatric age group, considering that it is the etiology of 7.5–20% of ischemic stroke cases in children [10]. Except for history of head trauma, pain, and paralysis of cranial nerves, other signs, and symptoms would not be helpful to differentiate stroke due to ICA dissection from other causes [11,12]. Angiography is still the gold standard modality for the diagnosis of craniocervical arterial dissection, although it has its challenges in children [12].

Considering its low incidence, there is a lack of high-quality evidence to choose the appropriate treatment strategy for AIS in children. Endovascular treatment is the standard of care for the eligible adults with large vessel occlusion AIS but its role in the pediatric population is uncertain due to a lack of randomized clinical trials [7,13]. A review of the literature by Christi et al. [14] examined cases from 2016 to 2021, including 21 cases with a mean age of 12.8 years. The most common underlying mechanism of stroke was cardiac pathologies in 9 cases, followed by arterial dissection in 2 cases. This study found that the mean of the pediatric National Institute of Health Stroke Scale (NIHSS) was reduced by 8.07±5.47 after mechanical thrombectomy. In terms of recanalization, the final modified TICI score was reported as 3 in 6 cases, 2c in one case, and 2b in 9 cases. A retrospective analysis of all children presenting with AIS at 3 German tertiary care stroke centers was performed in 12 children [15]. The results showed good angiographic outcomes in all patients with mechanical thrombectomy (stent retrieval) with an improvement in neurological outcome with a median pediatric NIHSS of 3.5 at day 7 and a modified Rankin scale of 1 at 3 months.

Mechanical thrombectomy can be performed using retriever pulls, aspiration alone, or a combination of both techniques. However, due to the small intracranial vessels in children younger than 5 years of the age, the feasibility and efficacy of the aspiration-alone technique has been debated and controversial [16,17]. The majority of reported thrombectomy procedures in the pediatric population have been performed with stent retrievers due to the smaller crossing profile of the device. Fewer cases have been reported using the aspiration-only technique [18,19]. Mechanical thrombectomy was performed in our case despite the presence of a large infarct core in the right MCA territory on the initial brain MRI. Recent high-quality data support the use of endovascular mechanical thrombectomy in large vessel occlusion strokes with large infarct core [20,21]. Although such data are not available in the pediatric population due to the low incidence of stroke, we occasionally apply adult data to children in our practice. For effective aspiration thrombectomy, we need a large-bore catheter to reach the distal cranial vasculature and there is a risk of severe vasospasm or perforation. In this case, we were able to pass the 5F Sofia catheter to the distal MCA segment uneventfully with the assistance of a long sheath. We chose a 6F Cook Shuttle long sheath for support, as its outer diameter was smaller than the other available long sheath in our catheterization lab.

In conclusion, the aspiration-only method may be safe and technically feasible to treat AIS with large vessel occlusion in children as young as 12 months, although further prospective studies are needed.