Table 2.
Angiographical findings suggestive of branching-site and truncal-type occlusions on catheter or digital subtraction angiography (DSA) and computed tomography angiography (CTA).
| Branching-site occlusion | Truncal-type occlusion | |
|---|---|---|
| Principle | Involvement of the bifurcation site | Intact bifurcation site and all distal major branches beyond occlusion |
| DSA | (1) Failure of advancement of ACOM collateral flow to ipsilateral MCAa (T-occlusion) (2) Direct visualization of Y- or T-shaped filling defectb, c, d (Y- or T-shaped clot) (3) Absence or partial visualization of another branchd (branch-missing sign) |
(1) Advancement of ACOM collateral flow to ipsilateral MCAa (below T-occlusion) (2) Clearly-visible distal major branches and bifurcation site beyond occlusionb, c, d |
| CTA | Vague or invisible major distal branches and bifurcation site beyond occlusion | Clearly-visible distal major branches and bifurcation site beyond occlusion |
a
By contralateral ICA angiogram.
b
By any angiography, including microcatheter angiography.
c
By minimal or partial recanalization using a thrombectomy procedure.
d
By post-deployment angiogram with stent-through flow.
ICA, internal carotid artery; ACOM, anterior communicating artery; MCA, middle cerebral artery.