Basilar artery occlusion in a child treated successfully with mechanical thrombectomy using ADAPT

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.

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.