Case Report Pediatric Middle Cerebral Artery Occlusion with Dissection Following a Trampoline Trauma Nimer Adeeb, Christopher Storey, Alexis J. Vega, Asala Aslan, Bharat Guthikonda, Hugo Cuellar-Saenz Key words - BACKGROUND: Owing to the rarity of acute ischemic stroke in the pediatric - Aspirin population, evidence supporting the efficacy in children of the various treatments used in adults is scanty. This included mechanical thrombectomy for acute ischemic stroke. - Dissection - Heparin - Middle cerebral artery - Pediatric - CASE - Stroke - Thrombectomy Abbreviations and Acronyms AIS: Acute ischemic stroke CT: Computed tomography ICA: Internal carotid artery MCA: Middle cerebral artery TICI: Thrombolysis in Cerebral Infarction Department of Neurosurgery, Ochsner-Louisiana State University, Shreveport, Louisiana, USA To whom correspondence should be addressed: Nimer Adeeb, M.D. [E-mail: Nimer_adeeb@hotmail.com] Citation: World Neurosurg. (2020) 143:428-433. https://doi.org/10.1016/j.wneu.2020.07.175 Journal homepage: www.journals.elsevier.com/worldneurosurgery Available online: www.sciencedirect.com 1878-8750/$ - see front matter ª 2020 Elsevier Inc. All rights reserved. INTRODUCTION The incidence of childhood stroke ranges from 1.3 to 13 per 100,000, with a mortality of approximately 3%e6% and up to 70% of survivors debilitated with significant deficits.1 Because of this low incidence, there is a lack of evidence on the safety and efficacy of various initial therapies for acute ischemic stroke (AIS) in the pediatric population.2 Mechanical thrombectomy, which has become a standard of care for large-vessel occlusion in adults, has not been included in guidelines for treating pediatric stroke owing to the lack of level 1 evidence.3 This has led to long-term management based on recommendations and expert opinion, which are typically based on treatment of the adult population. However, recent retrospective studies and multiple case reports have shown 428 www.SCIENCEDIRECT.com DESCRIPTION: we present the case of an 11-year-old female with acute left hemiparesis, numbness, and left facial droop occurring after tumbling on a trampoline. Computed tomography angiography revealed an 11-mm nonfilling defect in the right middle cerebral artery. She underwent thrombectomy approximately 8.5 hours after the onset of symptoms, and a Thrombolysis in Cerebral Infarction (TICI) scale score of 2b was achieved. She had an uneventful postoperative recovery. - CONCLUSION: Pediatric patients likely have more reserve and collateral flow and benefit from a longer therapeutic window following acute ischemic stroke. favorable outcomes with high recanalization rates in the pediatric population.2,4,5 Those previous studies evaluated different types of mechanical thrombectomy, including stent retrievers and aspiration. Here we report a patient who underwent thrombectomy of the right middle cerebral artery (MCA) as a result of arterial dissection occurring after jumping on a trampoline, which was treated with a stent retriever. CASE PRESENTATION Diagnosis The patient is a 11-year-old female who was jumping on a trampoline performing her usual tumbles when she felt she could no longer support herself with her left leg. She was carried inside for a bath and began experiencing left hemiparesis and numbness with left facial droop. She developed slurred speech and complained of right frontal headache. She was then brought to a hospital. A computed tomography (CT) scan of the head done approximately 90 minutes after the onset of symptoms did not show any fracture or intracranial bleeding. The patient was emergently transferred to our center, where neurosurgery was consulted for possible spinal cord injury. The left facial droop noted on examination ruled out spinal cord injury. Out of concern for developing ischemic stroke, CT angiography was performed and showed an w11-mm nonfilling defect of the M1-M2 segment of the right MCA (Figure 1). Because of her age, the patient was not a candidate for tissue plasminogen activator therapy; therefore, after discussion with her family, she was taken for thrombectomy. Management A 6 Fr sheath was placed, and a 6 Fr guide catheter was used to access the right internal carotid artery. The CT angiogram showed a delayed arterial phase indicating retrograde flow through collateral vessels and a string sign through the occlusion, suggesting a dissection with large-vessel occlusion (Figure 2A and B). The MCA territory WORLD NEUROSURGERY, https://doi.org/10.1016/j.wneu.2020.07.175 CASE REPORT NIMER ADEEB ET AL. PEDIATRIC MCA OCCLUSION WITH DISSECTION Figure 1. (A) Preoperative computed tomography (CT) angiogram, axial maximum intensity projection reconstruction, showing occlusion of the right middle cerebral artery (MCA) (arrow) (B) Preoperative CT was receiving flow from leptomeningeal branches of the anterior cerebral artery. The superior M3 MCA branch was cannulated with a microwire, and the true lumen was verified on injection. Using a stent retriever (Trevo; Stryker, Kalamazoo, MI), we were able to achieve a Thrombolysis In Cerebral Infarction (TICI) 2b revascularization at 8.5 hours after the onset of symptoms, but there appeared to be some remaining clot along the MCA (Figure 2C). Thus, 8 mg of tissue plasminogen activator was pushed intra-arterially, which revealed an intimal flap, narrowed lumen, and stagnation of contrast within the false lumen of the dissection (Figure 2D). No extracranial dissection was noted that could have propagated. An immediate postoperative CT showed an ASPECTS score of 9 with hypodensity in the right lenticular nucleus and no signs of hemorrhage. The patient was started on a heparin drip with a target partial thromboplastin time of 40e60. The patient remained left hemiplegic immediately after thrombectomy. At w5 hours after thrombectomy, she remained plegic in the left upper extremity, but had regained strength in left lower extremity to 4/5. On postoperative angiogram, coronal maximum intensity projection reconstruction, showing occlusion of the right MCA (arrow). day 2, she returned to 4/5 in her left upper extremity and 5/5 in her left lower extremity. Magnetic resonance angiography revealed no stenosis to the right MCA (Figure 3A). Magnetic resonance imaging showed a small temporal infarct (Figure 3B) and an infarct with some hemorrhagic conversion of the right corpus striatum. On postoperative day 3, the heparin drip was stopped, and she was started on enoxaparin. She was discharged home on postoperative day 5 on enoxaparin with a target anti-Xa value of 0.5e1 for 3 months. Prognosis and Outcomes The patient did well, progressing with outpatient physical therapy, but due to problems with compliance with enoxaparin, she was switched to aspirin 325 mg after her coagulopathy workup was negative on postoperative day 15. Magnetic resonance angiography performed at 3 months and 1 year showed no signs of stenosis or dissection of the right MCA (Figure 3C). Magnetic resonance imaging revealed stable old initial infarcts without new hemorrhage or edema. Connective tissue disease was ruled out clinically as a possible etiology, given no family history and no other signs on physical examination. She initially had some WORLD NEUROSURGERY 143: 428-433, NOVEMBER 2020 trouble returning to schoolwork, which improved with time. At 14 months, she was changed to aspirin 81 mg in stable condition with minimal left-sided deficits. DISCUSSION Here we present the case of an 11-yearold female who sustained an AIS. This was a unique presentation of an MCA dissection with large vessel occlusion occurring after trampoline jumping. Using a stent retriever, we were able to achieve a TICI score of 2b at 8.5 hours after the onset of symptoms. For an adult patient, treatment would have included a self-expanding stent across the dissection to prevent propagation of the intimal flap. However, in pediatric patients, the required antiplatelet regimen would have sentenced them to a lifelong risk of stroke due to lack of compliance. Instead, we chose to administer an immediate heparin drip followed by a short course of enoxaparin followed by aspirin. On follow-up imaging, the flap had resolved, and the patient has had no further ischemic events. A review of the literature identified 20 case reports of pediatric patients with AIS in the anterior circulation who underwent www.journals.elsevier.com/world-neurosurgery 429 CASE REPORT NIMER ADEEB ET AL. PEDIATRIC MCA OCCLUSION WITH DISSECTION Figure 2. Cerebral angiography, anteroposterior (AP) view of the right internal carotid artery (ICA) injection in the early arterial phase, showing occlusion of the right middle cerebral artery (MCA) (arrow) (A); in the late arterial phase, showing the string sign across the thrombectomy with a stent retriever (Table 1).6-22 Only initial revascularization attempts were analyzed. Overall, the 430 www.SCIENCEDIRECT.com occluded portion of the right MCA (arrow), indicating dissection (B); after thrombectomy, showing TICI 2b reperfusion (C); and after intra-arterial tPA administration postthrombectomy, showing TICI 2b reperfusion with dissection, the string sign (arrow) (D). median time from symptom onset to revascularization was 5 hours; 6 out of 16 patients (37.5%) had recanalization beyond 6 hours due to delayed diagnosis. The mean time of reperfusion for TICI 2b or better was 5 hours. Six of the 14 WORLD NEUROSURGERY, https://doi.org/10.1016/j.wneu.2020.07.175 CASE REPORT NIMER ADEEB ET AL. PEDIATRIC MCA OCCLUSION WITH DISSECTION Figure 3. (A) Magnetic resonance angiography (MRA) 3D reconstruction on postoperative day 2 showing no right middle cerebral artery (MCA) stenosis. (B) Diffusion-weighted magnetic resonance imaging on patients (42.9%) who achieved a TICI of 2b or better were outside of the 6-hour window suggested for mechanical thrombectomy and without direct complications, likely due to better collateral flow in the pediatric population. Similarly, our patient had an impressive outcome after achieving TICI 2b at 8.5 hours. Hemiplegia resolving to a pronator drift overnight validated her good collateral flow. Resolution of the drift and affect changes demonstrates the remarkable plasticity of pediatric patients in healing after stroke. postoperative day 2 showing right basal ganglia stroke. (C) MRA 3D reconstruction at 1 year postthrombectomy showing no right MCA stenosis. The risk of hemorrhagic conversion after thrombectomy is widely reported in the literature, with concerns that it might increase with increasing time between stroke onset and reperfusion; however, a recent study by Boisseau et al23 showed no significant correlation. The current literature suggests that mechanical thrombectomy may be considered for AIS due to large vessel occlusion (internal carotid artery terminus, M1, basilar artery) in patients age 1e18 years (level C evidence; class IIb recommendation).5 WORLD NEUROSURGERY 143: 428-433, NOVEMBER 2020 With continued research and more evidence, mechanical thrombectomy may one day become a standard of care. CONCLUSIONS As shown in this case, dissection in pediatric patients due to trauma may be safely treated with enoxaparin and aspirin after mechanical thrombectomy. Mechanical thrombectomy has been shown to be beneficial in the adult AIS population with an extended window. Pediatric patients www.journals.elsevier.com/world-neurosurgery 431 CASE REPORT NIMER ADEEB ET AL. PEDIATRIC MCA OCCLUSION WITH DISSECTION Table 1. Reports of Pediatric Large Vessel Occlusion Thrombectomy Using Stent Retrievers Study NIHSS Age (years) Score Vessels Etiology Device TICI Scale Medications Time from Symptom Onset to Intervention (hours) Alnaami et al., 20136 8 >9w MCA Cardiac Solitaire 3 Heparin 1.5 Sainz de la Maza et al., 20147 12 18 ICA Dissection Solitaire 2b NA 8 Hu et al., 20148 9 16 MCA, ICA Cardiac Solitaire* 2a NA NA Hu et al., 20148 7 17 MCA, ICA Infection Solitaire*,y 2a NA NA Stidd et al., 20149 2 mRS 4z MCA Cardiac, hematologic Trevo 2b Heparin, warfarin 7 Bodey et al., 201410 15 21 MCA Unknown Solitaire NA Heparin, aspirin 6 11 Rhee et al., 2014 9 6 ICA, MCA, ACA Cardiac Solitaire 3 Aspirin, dipyridamole, heparin 7 Van den Wijngaard et al., 201412 14 21 MCA Cardiac Soltaire 2b NA 5 Vega et al., 201513 11 16 MCA Cardiac Trevo* 3 Aspirin 3 14 Mittal et al., 2015 17 12 MCA Cardiac Solitaire 2a NA NA Chung et al., 201615 4 16 MCA Cardiac Solitaire 3 NA 5 Buompadre et al., 201716 8 7 ACA/MCA NA Trevo 2b Heparin dipyridamole 5 9 7 MCA Cardiac Trevo 3 Dabigatran 8.5 Stowe et al., 2018 9 23 MCA Cardiac Trevo 2b Heparin, warfarin 4.5 Kim et al., 201819 14 2 ICA, MCA Intracranial arteriopathy Trevo NA NA 8.4 Bhogal et al., 201820 17 9 ICA NA pRESET/Lite 2b NA 7.4 20 11 2 MCA NA Prowler/Solitaire 3 Heparin, aspirin 5.9 Bhogal et al., 201820 16 15 MCA NA ReFlex/Solitaire 2b Aspirin 4 Souto Silva et al., 201921 4 14 MCA Cardiac Trevo 2b Warfarin 3.5/4 Gervalis et al., 202022 16 13 ICA, MCA, ACA Cardiac Solitaire NA Aspirin, heparin NA Kulhari et al., 201717 18 Bhogal et al., 2018 NIHSS, National Institutes of Health Stroke Scale; TICI, Thrombolysis in Cerebral Infarction; MCA, middle cerebral artery; ICA, internal carotid artery; NA, not applicable; ACA, anterior cerebral artery. *Penumbra-assisted. yBalloon angioplasty performed. zModified Rankin Scale score. should be directly incorporated into the expanded window not only because of their better collateral flow and fewer comorbidities, but also because of their likely delayed diagnosis. 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(2020) 143:428-433. https://doi.org/10.1016/j.wneu.2020.07.175 Journal homepage: www.journals.elsevier.com/worldneurosurgery Available online: www.sciencedirect.com 1878-8750/$ - see front matter ª 2020 Elsevier Inc. All rights reserved. www.journals.elsevier.com/world-neurosurgery 433