Chester K. Yarbrough, Charlene J. Ong, Alexander B. Beyer, Kim Lipsey, and Colin P. Derdeyn. Endovascular Thrombectomy for Anterior Circulation Stroke: Systematic Review and Meta-Analysis. Stroke. 2015
In addition to the five unequivocally positive trials this year (MR CLEAN, ESCAPE, SWIFT PRIME, EXTEND-IA and REVASCAT), they included IMS III and Synthesis. The latter two studies were limited by poor patient selection and use of first-generation devices.
Unsurprisingly, analysis of pooled data showed a favorable odds ratio for good outcome (mRS 0-2), especially in studies that required confirmation of large arterial occlusion (OR 2.00). In the latter trials, the number needed to treat to achieve one good outcome with mRS 0-2 was 5 patients.
Notably, younger and older subgroups (not explicitly defined) benefited from ET. For patients who had not received IV-tPA prior to ET, the OR for good outcome of 1.59 was not statistically significant. Patients with moderate or severe strokes benefited, though patients with higher NIHSS had greater benefit. Last, mortality and ICH were not modified by ET.
Overall, the results of this meta-analysis do not change practice. ET is already well-accepted. However, these data importantly encourage clinicians to not withhold ET from older patients and those with moderate deficits, as both groups, when appropriately selected, stand to benefit from ET. Additionally, the data suggest that patients receiving ET without having receiving IV-tPA may not derive benefit. Therefore, patients being considered for ET should still always expediently receive IV-tPA.