Table 1.
Baseline characteristics of included studies.
| Study name | Year | Country | No of AIS patients | Mean age ± SD (years) | Males (%) | Total prevalence of VAH (%) | VAH/PCI (%) | VAH/ACI (%) | Vessel diameter for VAH definition | Imaging modality | Time from symptom onset to imaging |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Chuang et al.6 | 2006 | Taiwan | 191 | 55.8 ± 14.0 | 68 | 11.51 | 54.5 | 2.5 | <2 mm | MRA | ≤72 h |
| Gaigalaite et al.7 | 2016 | Lithuania | 367 | – | – | 51.1 | 58.3 | 30.5 | <3 mm | MRA/CTA | – |
| Hu et al.8 | 2013 | China | 841 | 64.6 ± 13.5 | 68.6 | 10.8 | 17.0 | 8.5 | <2 mm | CE-MRA/(CTA) | – |
| Park et al.9 | 2007 | Korea | 529 | – | – | 26.5 | 45.6 | 27.1 | ≤2 mm | TOF-MRA | 2.9 ± 1.8 days |
| Perren et al.10 | 2007 | Switzerland | 725 | 67.1 | 61.1 | 7.4 | 13.0 | 4.6 | ≤2.5 mm or difference to contralateral side> 1:1.7 | CDU | – |
| Sauer et al.11 | 2016 | Germany | 815 | 70 ± 14 | 52.8 | 13.6 | 17.1 | 11.7 | ≤2.5 mm or difference to contralateral side > 1:1.7 | TOF-MRA | – |
| Yang et al.12 | 2015 | China | 235 | 42.9 ± 6.3 | 64.7 | 16.1 | 25.0 | 12.9 | <2 mm | DSA | – |
| Zhang et al.13 | 2016 | China | 172 | 61.3 | 54.6 | 33.1 | 44.8 | 27.2 | ≤2 mm or difference to contralateral side > 1:1.7 | CE-MRA | ≤5 days |
ACI: anterior circulation ischaemia; AIS: acute ischemic stroke; CDU: colour duplex ultrasound; CE: contrast enhanced; CTA: computed tomography angiography; DSA: digital subtraction angiography; MRA: magnetic resonance angiography; PCI: posterior circulation ischaemia; SD: standard deviation; TOF: time of flight; VAH: vertebral artery hypoplasia.