An Overview of Meta-Analyses of Endovascular Bridging Therapies for Acute Ischemic Stroke

Table 2

Basic characteristics and major conclusions of included meta-analysis.

Author (year)	Basic information: number, age	Quality of primary studies and meta-analysis	Outcome measure	Results of included meta-analysis	Major conclusions of included meta-analysis
ET + IVT versus IVT
Singh et al. 2013	5 studies, 711/486 (1197); NA	Mostly good (Jadad scale) and 10/11 points	(1) mRS (3 months); (2) Mortality, sICH rate	No significant improvement in patients receiving ET compared with those receiving IVT; ET was found to have better outcomes in patients with severe stroke (NIHSS > 20)	ET is not superior to IV thrombolysis for acute ischemic strokes. ET may lead to a better outcome for patients with severe strokes (−)
Balami et al. 2015	8 studies, 1313/1110 (2423); 65 to 71 years	All good (Cochrane collaboration) and 9/11 points	(1) mRS (3 months); (2) Mortality, sICH rate	ET had a greater chance of a favorable primary outcome (OR 1.56, ).; There was a tendency toward decreased; mortality (OR 1.56, ), and sICH was not increased	Clear evidence for improvement in functional independence with ET compared with IVT, suggesting that ET should be considered for AIS (+)
Elgendy et al. 2015	9 studies, 1363/1047 (2410); NA	All good and 10/11 points	(1) mRS (3 months); (2) Mortality, sICH rate; (3) Recanalization	ET was associated with a higher incidence of achieving good functional outcome (43.7% versus 30.9%, ). ET was relevant to a trend toward reduction in the risk of all-cause mortality and improved recanalization . The risk of in-hospital sICH was similar	ET could improve functional outcomes compared with IVT and was found to be relatively safe, with no excess in intracranial hemorrhage. There was a trend for reduction in all-cause mortality with ET (+)
Badhiwala et al. 2015	8 studies, 1313/1110 (2423); 64 to 72 years	All good (Cochrane collaboration) and 10/11 points	(1) mRS (3 months); (2) Function independence; (3) Mortality, sICH rate; (4) Recanalization	ET was benefit across mRS scores ; functional independence occurred more in the ET group (44.6% versus 31.8%); ET had higher rates of angiographic revascularization at 24 hours, but no significant difference in rates of sICH or all-cause mortality at 90 days	ET versus IVT was associated with improved functional outcomes and higher rates of angiographic revascularization, but no significant difference in symptomatic intracranial hemorrhage or all-cause mortality at 90 days (+)
Goyal et al. 2016	5 studies, 634/653 (1287); 57 to 77 years	All good and 10/11 points	(1) mRS (3 months); (2) Mortality, sICH rate; (3) NIHSS	ET led to significantly reduced disability at 90 days compared with control; mortality at 90 days and risk of sICH did not differ between populations	ET is of benefit to most patients with AIS caused by occlusion of the proximal anterior circulation. These findings will have global implications on structuring systems of care to provide timely treatment to patients with AIS (+)
Bush et al. 2016	5 studies, 634/653 (1287); NA	All good (Cochrane collaboration) and 9/11 points	(1) mRS (3 months); (2) Mortality, sICH rate	Patients received ET experienced 2.22 times greater odds of better functional outcome compared to IVT ; ET was not associated with mortality or symptomatic intracerebral hemorrhage	This meta-analysis showed superior functional outcomes in patients receiving ET Further, this analysis showed that AIS patients may receive enhanced functional benefit from earlier ET (+)
Campbell et al. 2016	4 studies, 401/386 (787); years	All good (Cochrane collaboration) and 10/11 points	(1) mRS (3 months); (2) Independent outcome; (3) Mortality, sICH rate; (4) Recanalization	The common odds ratio for mRS improvement was 2.7; successful revascularization occurred in 77% treated with ET; sICH rate and overall mortality did not differ	ET for large vessel ischemic stroke was safe and highly effective with substantially reduced disability (+)
IAT versus IVT
Lee et al. 2010	5 studies, 224/171 (395); 61 to 68 years	Mostly good (Cochrane collaboration) and 10/11 points	(1) mRS (3 months); (2) NIHSS; (3) Barthel Index; (4) Recanalization; (5) Mortality, sICH rate	IAT was associated with good and excellent outcome and could ameliorate NIHSS, Barthel Index, and increase recanalization.; IAT was associated with increased sICH; no difference in mortality between groups	Formal meta-analysis suggests that IAT substantially increases recanalization rates and good clinical outcomes in AIS patients (+)
Fields et al. 2011	3 studies, 261/134 (395); 64 to 68 years	All good (Cochrane collaboration) and 8/11 points	(1) mRS (3 months); (2) NIHSS; (3) Mortality, sICH rate	IAT were significantly more likely to have a good mRS and NIHSS. There was no effect on mortality at 90 days (20% versus 19%). The risk of SICH was significantly increased in the IAT groups	These meta-analyses support endovascular treatment of acute ischemic stroke due to MCA occlusion with IAT (+)
EBT versus IVT
Fargen et al. 2015	6 studies, 1071/832 (1903); 18 to 85 years	All good (Cochrane collaboration) and 9/11 points	(1) mRS (3 months); (2) Mortality, sICH rate	EBT was associated with significantly improved outcomes compared with medical management (OR 1.67, ) for patients with LVO	This meta-analysis suggested that EBT produce superior clinical outcomes compared to medical management in AIS patients from LVO (+)

EBT: endovascular bridging therapies; IAT: intra-arterial pharmacologic thrombolysis; ET: endovascular thrombectomy; IVT: intravenous rt-PA; NA: not available; mRS: modified Rankin scale; sICH: symptomatic intracranial hemorrhage; OR: odds ratio; AIS: acute ischemic stroke; NIHSS: National Institutes of Health Stroke Scale Score; and LVO: large vessel occlusion.