Impact of intra-arterial clot location on tissue-level collaterals and venous outflow


  • Patients with a distally located vessel occlusion (DVO) had more favorable tissue-level collateral and venous outflow profiles compared to patients with proximally located occlusions (PVO) in acute ischemic stroke due to large vessel occlusion (AIS-LVO). DVO, favorable tissue-level collaterals, and favorable venous outflow were predictors of good functional outcome.

Why this matters

  • In patients with AIS-LVO, robust collateral blood flow can help to maintain perfusion and prevent infarction until thrombolytic treatment. Collateral blood flow can be measured using computed tomographic angiography (CTA).

  • However, CTA collaterals do not fully describe the status of cerebral perfusion. CTA is unable to assess tissue-level collaterals (which instead require computed tomography or magnetic resonance perfusion imaging) and does not account for venous outflow.

  • Investigating the relationship between AIS-LVO location, tissue-level collaterals and venous outflow, and functional outcomes should help to clarify the importance of cerebral perfusion measures.