Mechanical Thrombectomy in Pediatric Stroke: Report of Three New Cases

Prognostic significance of age within the adolescent and young adult acute ischemic stroke population after mechanical thrombectomy: insights from STAR

OBJECTIVE

Although younger adults have been shown to have better functional outcomes after mechanical thrombectomy (MT) for acute ischemic stroke (AIS), the significance of this relationship in the adolescent and young adult (AYA) population is not well defined given its undefined rarity. Correspondingly, the goal of this study was to determine the prognostic significance of age in this specific demographic following MT for large-vessel occlusions.

METHODS

A prospectively maintained international multi-institutional database, STAR (Stroke Thrombectomy and Aneurysm Registry), was reviewed for all patients aged 12-18 (adolescent) and 19-25 (young adult) years. Parameters were compared using chi-square and t-test analyses, and associations were interrogated using regression analyses.

RESULTS

Of 7192 patients in the registry, 41 (0.6%) satisfied all criteria, with a mean age of 19.7 ± 3.3 years. The majority were male (59%) and young adults (61%) versus adolescents (39%). The median prestroke modified Rankin Scale (mRS) score was 0 (range 0-2). Strokes were most common in the anterior circulation (88%), with the middle cerebral artery being the most common vessel (59%). The mean onset-to-groin puncture and groin puncture-to-reperfusion times were 327 ± 229 and 52 ± 42 minutes, respectively. The mean number of passes was 2.2 ± 1.2, with 61% of the cohort achieving successful reperfusion. There were only 3 (7%) cases of reocclusion. The median mRS score at 90 days was 2 (range 0-6). Between the adolescent and young adult subgroups, the median mRS score at last follow-up was statistically lower in the adolescent subgroup (1 vs 2, p = 0.03), and older age was significantly associated with a higher mRS at 90 days (coefficient 0.33, p < 0.01).

CONCLUSIONS

Although rare, MT for AIS in the AYA demographic is both safe and effective. Even within this relatively young demographic, age remains significantly associated with improved functional outcomes. The implication of age-dependent stroke outcomes after MT within the AYA demographic needs greater validation to develop effective age-specific protocols for long-term care across both pediatric and adult centers.

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.

Expanding indications for endovascular thrombectomy-how to leave no patient behind

Endovascular thrombectomy (EVT) has become standard of care for large vessel occlusion strokes but current guidelines exclude a large proportion of patients from this highly effective treatment. This review therefore focuses on expanding indications for EVT in several borderline indications such as patients in the extended time window, patients with extensive signs of infarction on admission imaging, elderly patients and patients with pre-existing deficits. It also discusses the current knowledge on intravenous thrombolysis as an adjunct to EVT and EVT as primary therapy for distal vessel occlusions, for tandem occlusions, for basilar artery occlusions and in pediatric patients. We provide clear recommendations based on current guidelines and further literature.

Clinical Diffusion Mismatch to Select Pediatric Patients for Embolectomy 6 to 24 Hours After Stroke: An Analysis of the Save ChildS Study

OBJECTIVE

To determine whether thrombectomy is safe in children up to 24 hours after onset of symptoms when selected by mismatch between clinical deficit and infarct.

METHODS

A secondary analysis of the Save ChildS Study (January 2000-December 2018) was performed, including all pediatric patients (<18 years) diagnosed with arterial ischemic stroke who underwent endovascular recanalization at 27 European and United States stroke centers. Patients were included if they had a relevant mismatch between clinical deficit and infarct.

RESULTS

Twenty children with a median age of 10.5 (interquartile range [IQR] 7-14.6) years were included. Of those, 7 were male (35%), and median time from onset to thrombectomy was 9.8 (IQR 7.8-16.2) hours. Neurologic outcome improved from a median Pediatric NIH Stroke Scale score of 12.0 (IQR 8.8-20.3) at admission to 2.0 (IQR 1.2-6.8) at day 7. Median modified Rankin Scale (mRS) score was 1.0 (IQR 0-1.6) at 3 months and 0.0 (IQR 0-1.0) at 24 months. One patient developed transient peri-interventional vasospasm; no other complications were observed. A comparison of the mRS score to the mRS score in the DAWN and DEFUSE 3 trials revealed a higher proportion of good outcomes in the pediatric compared to the adult study population.

CONCLUSIONS

Thrombectomy in pediatric ischemic stroke in an extended time window of up to 24 hours after onset of symptoms seems safe and neurologic outcomes are generally good if patients are selected by a mismatch between clinical deficit and infarct.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that for children with acute ischemic stroke with a mismatch between clinical deficit and infarct size, thrombectomy is safe.

Endovascular Thrombectomy for Pediatric Acute Ischemic Stroke: A Multi-Institutional Experience of Technical and Clinical Outcomes

BACKGROUND

Endovascular thrombectomy is a promising treatment for acute ischemic stroke in children, but outcome and technical data in pediatric patients with large-vessel occlusions are lacking.

OBJECTIVE

To assess technical and clinical outcomes of thrombectomy in pediatric patients.

METHODS

We undertook a retrospective cohort study of pediatric patients who experienced acute ischemic stroke from April 2017 to April 2019 who had immediate, 30-, and 90-d follow-up. Patients were treated with endovascular thrombectomy at 5 US pediatric tertiary care facilities. We recorded initial and postprocedural modified Thrombolysis in Cerebral Infarction (mTICI) grade ≥ 2b, initial and postprocedural Pediatric National Institutes of Health Stroke Scale (PedNIHSS) score, and pediatric modified Rankin scale (mRS) score 0 to 2 at 90 d.

RESULTS

There were 23 thrombectomies in 21 patients (mean age 11.6 ± 4.9 yr, median 11.5, range 2.1-19; 52% female). A total of 19 (83%) thrombectomies resulted in mTICI grade ≥ 2b recanalization. The median PedNIHSS score was 13 on presentation (range 4-33) and 2 (range 0-26) at discharge (mean reduction 11.3 ± 6.1). A total of 14 (66%) patients had a mRS score of 0 to 2 at 30-d follow-up; 18/21 (86%) achieved that by 90 d. The median mRS was 1 (range 0-4) at 30 d and 1 (range 0-5) at 90 d. One patient required a blood transfusion after thrombectomy.

CONCLUSION

In this large series of pediatric patients treated with endovascular thrombectomy, successful recanalization was accomplished via a variety of approaches with excellent clinical outcomes; further prospective longitudinal study is needed.

Pediatric Middle Cerebral Artery Occlusion with Dissection Following a Trampoline Trauma

BACKGROUND

Owing to the rarity of acute ischemic stroke in the pediatric population, evidence supporting the efficacy in children of the various treatments used in adults is scanty. This included mechanical thrombectomy for acute ischemic stroke.

CASE 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.