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Basilar Artery - thrombectomy vs. thrombolysis

Synthesis

Manuscript

Qualitative

Quantitative

Critical Appraisal

PRISMA

Abstract

Kevin Kallmes, John Pederson, Kathryn Cowie, Nicole Hardy, Kristen Hutchison, Hassan Kobeissi, Gautam Adusumilli, Ranita Tarchand, Daniel Heiferman, Jeremy J HeitLast Edited: 2022-09-26

Background

Endovascular thrombectomy (EVT) is an effective treatment for acute ischemic stroke attributable to the anterior circulation large‐vessel occlusion. Randomized trials of patients with posterior circulation large‐vessel occlusion (PC‐LVO) have failed to show a benefit of EVT over medical therapy (MEDT). We performed a systematic review and meta‐analysis to understand better whether EVT is beneficial for PC‐LVO.

Methods

Using the Nested Knowledge AutoLit living review platform, we identified randomized control trials and prospective studies that reported functional outcomes in patients with PC‐LVO treated with EVT versus MEDT. The primary outcome variable was 90‐day modified Rankin scale score of 0 to 3, and secondary outcome variables included 90‐day modified Rankin scale score of 0 to 2, 90‐day mortality, and rate of symptomatic intracranial hemorrhage. A separate random effects model was fit for each outcome measure to calculate pooled odds ratios.

Results

Three studies with 1248 patients, 860 in the EVT arm and 388 in the MEDT arm, were included in the meta‐analysis. The favorable outcome rate (modified Rankin scale score of 0–3) in patients undergoing EVT was 39.9% (95% CI, 30.6%–50.1%) versus 24.5% in patients undergoing MEDT (95% CI, 9.6%–49.8%). Patients undergoing EVT had higher modified Rankin scale score of 0 to 2 rates (31.8% [95% CI, 25.7%–38.5%] versus 19.7% [95% CI, 7.4%–42.7%]) and lower mortality (42.1% [95% CI, 35.9%–48.6%] versus 52.8% [95% CI, 33.3%–71.5%]) compared with patients undergoing MEDT, but neither result was statistically significant. Patients undergoing EVT were more likely to develop symptomatic intracranial hemorrhage (odds ratio, 10.36; 95% CI, 3.92–27.40).

Conclusions

EVT treatment of PC‐LVO trended toward superior functional outcomes and reduced mortality compared with MEDT despite a trend toward increased symptomatic intracranial hemorrhage in patients undergoing EVT. Existing randomized and prospective studies are insufficiently powered to demonstrate a benefit of EVT over MEDT in patients with PC‐LVO.

Study information:

PMID: N/A

DOI: 10.1161/svin.121.000147

Key Insights:

Evidence quality difference? Registry vs. RCTs does not impact findings

Two included studies were RCTs, while the third (the BASILAR study) reported a prospective registry. While mortality was much higher in this registry for the Medical Therapy arm, and mRS 0-2 and 0-3 were much lower (potentially indicated worse general performance of Medical Therapy), removing the registry did not change the findings of this review.

Possible trend: Endovascular Therapy improves Neurological Outcome over Standard Medical Therapy

Patients undergoing EVT had higher rates of mRS 0-3 (39.9% vs. 24.5%), but this finding was not significant (OR, 2.17; 95% CI, 0.41–11.52; P=0.185). Patients undergoing EVT also had higher rates of mRS 0-2 (31.8% vs. 19.7%). However, this finding was also not significant (OR, 2.05; 95% CI, 0.31–13.67; P=0.246), and further research is needed.

Endovascular Therapy significantly increases symptomatic hemorrhage over Standard Medical Therapy

The rate of sICH for the EVT group was 6.8% vs. 0.7% in the medical therapy group. This difference was significant (OR, 10.36; 95% CI, 3.92–27.40; P=0.009), but should not be surprising, since EVT requires devices to be advanced directly into the occluded vessel, and the clot retrieval (regardless of technique) can damage the vessel.