Clinical applications of OCT

Patient 1

Normal findings of CTA, MRI and ultrasound Doppler despite 2 previous ischemic strokes in right ICA territory, new TIA now

- searching for the etiology 

- OCT 

- thrombosed carotid web with thrombus attenuation

Patient 2

Chronic total occlusion with recurrent watershed infarcts, total carotid artery reconstruction in 2020, CTA in 2021 showing focal intimal hyperplasia

- discussion regarding antiplatelet regimen

- OCT

- stent not fully covered by the endothelium cells (stent fracture) + neointimal hyperplasia 

• the decision to continue with DAPT

• sometimes angioplasty or another stent may be required

Patient 3

2 episodes of transient right side dysesthesia, MRI showing right carotid occlusion with normal brain perfusion raising suspicion of right ICA dissection sequelae, aspirin treatment + clinical follow up, then another episode of left sided infarct with left ICA occlusion but spontaneous recanalization during hospitalization +normal findings in CTA, scintigraphy, MRI, ultrasound Doppler, PET

- searching for the etiology

- OCT

- fibrodysplasia (thick media and intima, may be bilateral)

• treatment decision based on this result

Bothering problem in total carotid occlusion: timing – often it is difficult to evaluate when the occlusion has occurred

Imaging findings to predict if the occlusion is subacute or chronic:

Subacute (weeks):

- No brain atrophy

- Recent ischemia that may be territorial or embolic

- Occlusion level - petrous segment opacification on late CTA

- Few ECA collaterals 

- Flair negative

- Origin of ICA is irregular 

Chronic (late):

- Brain atrophy

- Watershed sequelae

- Cognitive impairment

- Occlusion level - very high occlusion, no petrous segment opacification 

- Flair positive

- Origin of ICA is smooth

To distinguish you need to perform: angiogram, MR, CT perfusion, cognitive impairment evaluation, CTA late phase 

Short treatment protocol:

Evidence of total carotid occlusion -> 3 weeks of medical therapy (DAPT or anticoagulation)

If there is still occlusion -> CT perfusion -> if there is hypoperfusion + stress test positive: 

- subacute occlusion: perform the revascularization 

- chronic occlusion: consider medical therapy first and perform the revascularization only if persisting symptoms and salvageable brain tissue to preserve