Angiographic characteristics of the patients
| No | Right VA | Left VA | Course of ASA | Perfusion via ASA | Collateral Supply from PcomA | VBJ Patency | Comment |
|---|---|---|---|---|---|---|---|
| 1 | Occlusion | Occlusion | L VA → R VA | R AICA & PICA | Both SCAs filling from L PcomA | Yes | Reversed flow of ASA disappeared after recanalization; reappearance of ASA |
| 2 | Occlusion | Severe stenosis | R VA → L VA | Part of BA | Nil | Yes | BA filling from L VA; reversal of ASA flow direction after recanalization |
| 3 | Occlusion | Occlusion | L VA → R VA | Not profuse | BA trunk filling from L PcomA | No | |
| 4 | Severe stenosis | Occlusion | R & L VA → L VA | Not profuse | Both SCAs filling from R PcomA | Yes | Reversal of ASA flow direction after recanalization |
| 5 | Occlusion | Occlusion | R VA → both VAs | R AICA & PICA; L AICA | Nil | Yes | Increased perfusion through ASA after occlusion of L VA |
| 6 | Occlusion | Severe stenosis | R VA → R VA | Not profuse | Nil | Yes | Reversal of ASA flow direction after recanalization |
Note:—VA, vertebral artery; ASA, anterior spinal artery; PcomA, posterior communicating artery; VBJ, vertebrobasilar junction; L, left; R, right; AICA, anterior inferior cerebellar artery; PICA, posterior inferior cerebellar artery; SCA, superior cerebellar artery; BA, basilar artery.