Failure of a clot retrieval device in an adolescent stroke patient

Extended time window mechanical thrombectomy for pediatric acute ischemic stroke

Endovascular thrombectomy (EVT) for the treatment of acute ischemic stroke (AIS) remains an off-label procedure seldom utilized in the pediatric population; this holds especially true for patients presenting outside the standard 6-hour time window. In this review we describe the published literature regarding usage of the extended time window EVT in pediatric stroke. We searched PubMed for all pediatric AIS cases and case series that included patients treated with extended time window EVT. We found data from 38 cases found in 27 publications (15 case reports and 12 case series). The median age was 10 years; 60.5% males. The median NIHSS before EVT was 13 with a median time-to-treatment of 11 hours. The posterior circulation was involved in 50.0%. Stent retrievers were used in 68.5%, and aspiration in 13.2%. Angiographic outcome TICI ≥2B was achieved in 84.2%, whereas TICI˂2B was reported in 10.6%. A favorable clinical outcome (NIHSS score ≤4, modified Rankin score ≤1, or Pediatric Stroke Outcome measure score ≤1) occurred in 84.2%. Eight cases that did not report the clinical outcome employing a standardized scale described mild to absent neurological residual deficits. This study found data that supports that extended window EVT produces high recanalization rates and good clinical outcomes in pediatric patients with AIS. Nevertheless, the source materials are indirect and contain substantial inconsistencies with an increased risk of bias that amount to low evidence strength.

Higher-Quality Data Collection Is Critical to Establish the Safety and Efficacy of Pediatric Mechanical Thrombectomy

BACKGROUND AND PURPOSE

Because children often have lifelong morbidity after stroke, there is considerable enthusiasm to pursue mechanical thrombectomy in childhood stroke based on literature reports. However, current published data may reflect inconsistent reporting and publication bias, which limit the ability to assess safety and efficacy of mechanical thrombectomy in childhood stroke.

METHODS

This retrospective cohort study compared reporting quality and clinical outcomes for mechanical thrombectomy between a trial-derived cohort of 42 children treated with mechanical thrombectomy for acute stroke at study sites and 133 patients reported in the literature. National Institutes of Health Stroke Scale at baseline, 24 hours after mechanical thrombectomy, and at discharge were compared between study site patients and literature patients. Odds ratios (ORs) were used to compare reporting frequencies. Proportional odds logistic regression was used to compare outcomes.

RESULTS

Premechanical thrombectomy National Institutes of Health Stroke Scale was available in 93% of study patients compared with 74% of patients in the literature (OR, 4.42 [95% CI, 1.47-19.89]). Postmechanical thrombectomy National Institutes of Health Stroke Scale was available in 69% of study patients compared with 29% of literature cases at 24 hours (OR, 5.48 [95% CI, 2.62-12.06]), and 64% of study patients compared with 32% of cases at discharge (OR, 3.85 [95% CI, 1.87-8.19]). For study sites, median scores were 12 at baseline, 9 at 24 hours, and 5 at discharge. Median scores in case reports were 15 at baseline, 4 at 24 hours, and 3 at discharge. ORs for differences in outcomes between groups were 5.97 (95% CI, 2.28-15.59) at 24 hours and 3.68 (95% CI, 1.45-9.34) at discharge.

CONCLUSIONS

Study site patients had higher rates of National Institutes of Health Stroke Scale reporting and worse short-term outcomes compared with literature reports. Rigorous data collection is needed before treatment guidelines for pediatric mechanical thrombectomy can be developed.

A rare cause of ischemic stroke in childhood: spontaneous long segment intracranial dissection

Craniocervical arterial dissection is an important cause of arterial ischemic stroke in children. Recognition of dissections is of particular importance both in determining the risk of recurrence and in bringing about different treatment alternatives. We report a 10-year-old girl who presented with acute ischemic stroke due to spontaneous long segment dissection involving the parasellar internal carotid artery up to the distal M1 portion of the middle cerebral artery. Three-dimensional digital subtraction angiography with flat panel detector revealed the presence of major vessels originating from both true and false lumens and had a critical role in the treatment decision of the case.

Mechanical thrombectomy in pediatric stroke: systematic review, individual patient data meta-analysis, and case series

OBJECTIVE

The role of mechanical thrombectomy in pediatric acute ischemic stroke is uncertain, despite extensive evidence of benefit in adults. The existing literature consists of several recent small single-arm cohort studies, as well as multiple prior small case series and case reports. Published reports of pediatric cases have increased markedly since 2015, after the publication of the positive trials in adults. The recent AHA/ASA Scientific Statement on this issue was informed predominantly by pre-2015 case reports and identified several knowledge gaps, including how young a child may undergo thrombectomy. A repeat systematic review and meta-analysis is warranted to help guide therapeutic decisions and address gaps in knowledge.

METHODS

Using PRISMA-IPD guidelines, the authors performed a systematic review of the literature from 1999 to April 2019 and individual patient data meta-analysis, with 2 independent reviewers. An additional series of 3 cases in adolescent males from one of the authors' centers was also included. The primary outcomes were the rate of good long-term (mRS score 0-2 at final follow-up) and short-term (reduction in NIHSS score by ≥ 8 points or NIHSS score 0-1 at up to 24 hours post-thrombectomy) neurological outcomes following mechanical thrombectomy for acute ischemic stroke in patients < 18 years of age. The secondary outcome was the rate of successful angiographic recanalization (mTICI score 2b/3).

RESULTS

The authors' review yielded 113 cases of mechanical thrombectomy in 110 pediatric patients. Although complete follow-up data are not available for all patients, 87 of 96 (90.6%) had good long-term neurological outcomes (mRS score 0-2), 55 of 79 (69.6%) had good short-term neurological outcomes, and 86 of 98 (87.8%) had successful angiographic recanalization (mTICI score 2b/3). Death occurred in 2 patients and symptomatic intracranial hemorrhage in 1 patient. Sixteen published thrombectomy cases were identified in children < 5 years of age.

CONCLUSIONS

Mechanical thrombectomy may be considered for acute ischemic stroke due to large vessel occlusion (ICA terminus, M1, basilar artery) in patients aged 1-18 years (Level C evidence; Class IIb recommendation). The existing evidence base is likely affected by selection and publication bias. A prospective multinational registry is recommended as the next investigative step.

Mechanical thrombectomy using a Solitaire stent retriever in the treatment of pediatric acute ischemic stroke

OBJECTIVE Mechanical thrombectomy using a Solitaire stent retriever has been widely applied as a safe and effective method in adult acute ischemic stroke (AIS). However, due to the lack of data, the safety and effectiveness of mechanical thrombectomy using a Solitaire stent in pediatric AIS has not yet been verified. The purpose of this study was to explore the safety and effectiveness of mechanical thrombectomy using a Solitaire stent retriever for pediatric AIS. METHODS Between January 2012 and December 2017, 7 cases of pediatric AIS were treated via mechanical thrombectomy using a Solitaire stent retriever. The clinical practice, imaging, and follow-up results were reviewed, and the data were summarized and analyzed. RESULTS The ages of the 7 patients ranged from 7 to 14 years with an average age of 11.1 years. The preoperative National Institutes of Health Stroke Scale (NIHSS) scores ranged from 9 to 22 with an average of 15.4 points. A Solitaire stent retriever was used in all patients, averaging 1.7 applications of thrombectomy and combined balloon dilation in 2 cases. Grade 3 on the modified Thrombolysis In Cerebral Infarction scale of recanalization was achieved in 5 cases and grade 2b in 2 cases. Six patients improved and 1 patient died after thrombectomy. The average NIHSS score of the 6 cases was 3.67 at discharge. The average modified Rankin Scale score was 1 at the 3-month follow-up. Subarachnoid hemorrhage after thrombectomy occurred in 1 case and that patient died 3 days postoperatively. CONCLUSIONS This study shows that mechanical thrombectomy using a Solitaire stent retriever has a high recanalization rate and excellent clinical prognosis in pediatric AIS. The safety of mechanical thrombectomy in pediatric AIS requires more clinical trials for confirmation. ABBREVIATIONS ACA = anterior cerebral artery; AIS = acute ischemic stroke; CTA = CT angiography; ICA = internal carotid artery; MCA = middle cerebral artery; mRS = modified Rankin Scale; mTICI = modified Thrombolysis In Cerebral Infarction; NIHSS = National Institutes of Health Stroke Scale; rt-PA = recombinant tissue plasminogen activator.

Primary versus secondary mechanical thrombectomy for anterior circulation stroke in children: An update

This review of the literature on the use of mechanical thrombectomy (MT) in children with acute ischemic stroke from occlusion of the internal carotid artery and the proximal middle cerebral artery (MCA) compares the efficacy and safety of primary and secondary MT. We analyzed the data reported for 24 case reports from 20 relevant articles published up to 31 December 2016 and the data of a patient treated at our institution. Eighteen cases received primary MT and 7 received secondary MT. The proportions of complete MCA recanalization, small infarcts, and asymptomatic intracranial hemorrhage were similar in both MT groups (73% [11/15] vs. 67% [4/6], 58% [7/12] vs. 60% [3/5], and 15% [2/13] vs. 17% [1/6], respectively). The proportion of favorable neurological outcomes was higher for the primary MT group (69% [11/16] vs. 43% [3/7]). We found no substantial differences in efficacy and safety between primary and secondary MT for anterior circulation stroke in children.

Successful Manual Aspiration Thrombectomy in a Pediatric Patient

BACKGROUND

Timely recognition of stroke at major pediatric medical centers is improving, and although treatment guidelines for pediatric stroke exist, no extensive study establishing the efficacy of surgical or thrombolytic treatment has been completed. Extrapolation of adult guidelines to pediatric patients remains the mainstay of treatment in the absence of adequate information regarding safety and efficacy in children. Recent trials have demonstrated revascularization and clinical improvement after endovascular retrieval therapy in adults with acute large vessel occlusive stroke. Furthermore, successful mechanical thrombectomy using a variety of techniques has been documented in numerous children and adolescents.

PATIENT DESCRIPTION

We present a 15-year-old boy with altered mental status and left hemiparesis due to acute ischemic stroke secondary to blockage of the right internal carotid artery terminus, most likely precipitated by end-stage heart failure and cardiac embolism. Mechanical aspiration thrombectomy using the Penumbra aspiration catheter without any adjunct surgical equipment or thrombolytic therapy was used to remove thrombus and treat the patient's acute ischemic stroke. He experienced complete artery recanalization with a Thrombolysis in Cerebral Infarction (TICI) score of 2C after the procedure. He also exhibited an 8 point improvement in his pediatric National Institutes of Health Stroke Scale score within 24 hours.

CONCLUSIONS

Mechanical aspiration thrombectomy is commonly used in adult hospitals but infrequently employed in pediatric patients with arterial ischemic stroke. Given its efficacy in our patient, we encourage a larger systematic trial to evaluate the use of mechanical thrombectomy in pediatric patients with acute ischemic stroke.

Mechanical thrombectomy in pediatric acute ischemic stroke: Clinical outcomes and literature review

There are limited data on outcomes of mechanical thrombectomy for pediatric stroke using modern devices. In this study, we report two cases of pediatric acute ischemic stroke treated with mechanical thrombectomy, both with good angiographic result (TICI 3) and clinical outcome (no neurological deficits at 90 days). In addition, we conducted a literature review of all previously reported cases describing the use of modern thrombectomy devices. Including our two cases, the aggregate rate of partial or complete vessel recanalization was 100% (22/22), and the aggregate rate of favorable clinical outcome was 91% (20/22). This preliminary evidence suggests that mechanical thrombectomy with modern devices may be a safe and effective treatment option in pediatric patients with acute ischemic stroke.

Considerations in Applying a New Stent Retriever in Pediatric Endovascular Cerebral Thrombectomy for Acute Ischemic Stroke

Acute ischemic stroke (AIS) in children has been difficult to diagnose, treat and study, due to atypical clinical presentation, imaging challenges and the rarity of large-vessel embolic occlusion as the etiology of acute neurological change in children. With endovascular thrombectomy showing success in randomized trials of adult AIS, the technique is increasingly being extrapolated to pediatric stroke. However, there is little evidence regarding the safety or efficacy of applying in children these devices developed and tested in adults. There is concern about a vessel-to-device size mismatch that may result in a different complication and benefit profile than typically seen. We report on the successful application in pediatric stroke of a newer-generation, smaller stent retriever, designed to be delivered through relatively smaller and more navigable microcatheters than the prior generation of this device.

Experience of mechanical thrombectomy for paediatric arterial ischaemic stroke

BACKGROUND

Paediatric arterial ischaemic stroke (AIS) is an important cause of acute neurological symptoms in children, it causes significant morbidity and is one of the top ten causes of childhood deaths. Consensus papers have suggested guidelines for the management of AIS in childhood, although none recommend thrombectomy. Despite this, children within our institution have undergone mechanical thrombectomy for large vessel occlusion. This is the first series of mechanical thrombectomy and outcomes performed in children in the U.K.

METHODS

We describe the endovascular management of paediatric arterial ischaemic stroke (AIS) in four children (5-15 years) with PedNIHSS > 17.

RESULTS

Three had basilar artery (BA) occlusion and one left middle cerebral artery (MCA) occlusion. All underwent uncomplicated thrombectomy followed by intravenous heparin. One had a successful second attempt. The BA cases underwent thrombectomy 17-36 h after symptom onset; the left MCA case <6 h after symptom onset. Modified Rankin Scale (MRS) was 0-3, 50% had MRS 0.

DISCUSSION

Adult AIS guidelines recommend IV recombinant tissue plasminogen activator (r-tPA) within 4.5 h of onset and intra-arterial r-tPA within 6 h; thrombectomy being reserved for carefully selected patients. Paediatric AIS recognition is problematic, often with delayed imaging. There is little evidence regarding efficacy of thrombectomy for paediatric AIS. Our experience suggests there may be a role for endovascular clot retrieval in selected patients managed by an experienced multidisciplinary team. Careful data collection is mandatory.

Successful mechanical thrombectomy in a 2-year-old male through a 4-French guide catheter

A 2-year-old boy with hypoplastic left heart syndrome that required multiple cardiovascular surgeries and a heterozygous prothrombin G20210A mutation with resulting thrombophilia maintained on warfarin presented with acute right middle cerebral artery (MCA) infarction manifesting as a left hemiplegia. An MRI revealed a complete occlusion of the right M1 segment with an area of restricted diffusion in the right basal ganglia representing only a small area of acute infarction. Patchy areas of subacute infarction were also present in the right MCA territory. He underwent endovascular mechanical thrombectomy with a stent retriever. This is an account of a successful mechanical thrombectomy performed in the youngest patient reported in the English literature to date.

Modern endovascular treatments of occlusive pediatric acute ischemic strokes: case series and review of the literature

PURPOSE

Literature on the endovascular treatment of occlusive acute ischemic stroke (AIS) in the pediatric population remains nebulous. Clinical trials evaluating the role of systemic and intra-arterial thrombolysis, and mechanical thrombectomy have been strictly isolated to the adult population and largely unknown in their safety and efficacy in the pediatric group.

METHODS

The authors present a review of the literature and their own two cases of occlusive acute ischemic stroke in children younger than the age of 10 years who were treated with modern endovascular devices, specifically with stent retrievers, and discuss their clinical and technical considerations as well as their limitations.

RESULTS

In both pediatric patients, a combination of stent retriever and Penumbra aspiration were used to achieve Thrombolysis In Cerebral Infarction (TICI) 2a or greater with reduction of overall stroke burden. A reduction of National Institutes of Health Stroke Scale (NIHSS) of 8 or greater was achieved at discharge. At 3-month follow-up, the patients had a NIHSS of 6 and 2, respectively. One patient continued to improve from NIHSS of 6 to 3 at 6 months.

CONCLUSION

In carefully, selected pediatric patients, modern endovascular techniques may be used to treat occlusive pediatric AIS. However, larger clinical trials are needed to evaluate the overall safety and effectiveness.

Basilar artery strokes in children: good outcomes with conservative medical treatment

AIM

To describe outcomes and outcome predictors in childhood basilar artery stroke (BAS).

METHOD

We prospectively enrolled children with BAS with or without basilar artery occlusion (BAO) in the Toronto Children's Stroke Registry from 1992 to 2009. We assessed presenting features and outcomes including Pediatric Stroke Outcome Measure scores.

RESULTS

Among 578 children with acute arterial ischemic stroke, 27 had BAS (4.6% including neonates, 6% excluding neonates). Twenty-four (14 males, 10 females) children met study criteria (mean age at stroke was 8 y 10 mo; range 0-17 y). Eleven children had BAO. Aspirin or anticoagulation was given to 15 children. None received tissue plasminogen activator or endovascular treatments. At mean follow-up (3 y 2 mo, range 1 mo-11 y 8 mo), 12 had a 'good outcome' (seven normal, five insignificant deficit) and 12 had 'poor outcome' (10 moderate or severe deficit, two acute deaths). Larger infarct size (≥50% of axial brainstem diameter) independently predicted poor outcome (p=0.02; odds ratio 21.2, 95% confidence interval 1.6-274.9) but not BAO, altered level of consciousness, or age.

INTERPRETATION

Compared with adults, in childhood BAS death is rare and survivors frequently have good outcomes. Aggressive endovascular interventions may not be justifiable in this population.

Craniocervical arterial dissection in children: diagnosis and treatment

OPINION STATEMENT

Diagnosis of craniocervical arterial dissection (CCAD) in children begins with a careful history and physical in a child with a transient ischemic attack (TIA) or arterial ischemic stroke (AIS). The extent of radiologic evaluation for suspected CCAD is based upon careful consideration of the risks associated with the best imaging techniques, weighed against the benefits of enhanced vascular imaging with better diagnostic sensitivity. Although conventional angiography (CA) and CT angiography (CTA) have a higher sensitivity than magnetic resonance angiography (MRA), they are accompanied by risks: for CA, femoral hematoma, femoral arterial pseudoaneurysm, recurrent AIS, and radiation exposure; for CTA, radiation. For children (non-neonates) with suspected CCAD, MRI with MRA is recommended as the first-line imaging study. MRI usually includes diffusion-weighted, FLAIR, and T1 images of the brain, and T1 or T2 fat-saturation axial imaging through the neck. MRA should include 3D time-of-flight MRA of the head and neck (from the aortic arch through the circle of Willis). Contrast-enhanced MRA should be highly considered in neck imaging. If MRI/MRA is equivocal, CCAD is strongly suspected but not detected on MRI/MRA (especially in the posterior circulation), or the child has recurrent events, additional imaging of the craniocervical vasculature is likely warranted. Individual clinical circumstances warrant careful, case-by-case consideration. Treatment of CCAD in children is challenging and differs for intracranial and extracranial dissections. In extracranial CCAD, we most commonly use anticoagulation for 6 weeks to 6 months in patients with TIA or AIS. Typically, unfractionated heparin is used in the acutely ill patient at heightened risk for bleeding (because of its short half-life), whereas low-molecular-weight heparin (LMWH) or warfarin are reserved for the stable patient. If the history is suspicious for dissection (head and neck trauma, recent cervical chiropractic manipulation, recent car accident, or neck pain), we consider treatment for dissection even with normal MRI/MRA. For patients with CCAD with a stroke size greater than one third to one half of the middle cerebral artery territory (or other bleeding risk factors) and extracranial CCAD, in whom there is concern about heightened risk for hemorrhagic conversion, we commonly use aspirin therapy during the acute phase. Regardless of their treatment in the initial weeks to months, we subsequently treat all patients with aspirin for 1 year after their event, and sometimes longer if they have other risk factors. Interventional techniques, such as extracranial cerebral arterial stent placement or selective occlusion, are understudied in children. Interventional techniques are typically reserved for patients who fail aggressive medical management and have recurrent TIA or AIS. The diagnosis and treatment of intracranial dissection is extraordinarily challenging in children, in whom inflammatory intracranial arteriopathies are common. When intracranial arteriopathy is clearly associated with dissection, the clinician should look for the presence of subarachnoid hemorrhage and/or dissecting aneurysm. Treatment decisions should be made by a multidisciplinary pediatric stroke team, given the lack of data in this area. Intracranial cerebral artery stent placement carries high risk and is not recommended for intracranial CCAD in children. Most importantly, we educate all children with CCAD and their parents about the paucity of evidence in the treatment of this disease, the risks of enhanced imaging techniques such as CTA or CA, and the challenges involved in weighing the risks of aggressive therapies and interventions against the costs of unclear diagnosis and potentially ineffective treatments. We also educate our patients with CCAD about the signs and symptoms of recurrence and the importance of emergent evaluation.

American childhood football as a possible risk factor for cerebral infarction

Three adolescent football players who had ischemic stroke associated with football practice and play are described. The literature on stroke associated with childhood sports and football in particular is reviewed, and the multiple mechanisms by which football can contribute to ischemic stroke are discussed.