Replay Day 2 - Slice WW 2021 - Stroke Game 6
Chronic carotid revascularization – its pros, cons and the technique
Presentations of case resolutions in the form of a “serious game”. Step by step, from the emergency call to the resolution on high fidelity silicon models in the angiosuite, the members of the SLICE Academy will work along with faculty members to solve these real cases reconstitutions.
DIAGNOSIS:
CTP in chronic asymptomatic ICA occlusion:
CTP in chronic symptomatic ICA occlusion (hemodynamic changes due to hypoperfusion):
Sometimes severe stenosis (near-occlusion) can present as an occlusion, so to be sure, you should confirm the diagnosis in DSA. DSA may reveal “string sign” in that cases.
Be aware of carotid “pseudostring sign” from vasa vasorum collaterals in case of total chronic carotid occlusion (its presence is a positive predictive value of successful recanalization).
SYMPTOMS:
Patients may be: asymptomatic, periodically symptomatic with hemispheric neurological symptoms (symptoms induced during physical effort) or constantly symptomatic.
Stress-test with acetazolamide (mimicking physical effort) is usually performed under scintigraphy (quantitative method), but may also be used during MRI imaging.
Patient may have cognitive impairment in neuropsychological testing due to focal cognitive deficits attributed to affected hemisphere.
TECHNIQUE:
- Start with 3D-angiography of the stump
- If there is vasa vasorum supplying the lumen of ICA at some point above the occlusion, perform the intramural dissection:
*procedure is safe until this moment (no connection to the patent lumen of ICA above = no risk of distal emboli neither reperfusion injury)
*continuing with intramural dissection on the level of ophthalmic branch of ICA can jeopardize cerebral and ophthalmic supply – re-entry point should be below the ophthalmic segment
- once you manage to enter the proper lumen of ICA, aspire with small 3cc syringe to see whether you have blood backflow and then do microangiography (on BCG deflated) to confirm the proper position of the microcatheter in the true lumen
- push 300 cm wire into the MCA and do the over-the-wire-exchange (remove microcatheter and 5F catheter)
- perform “full metal jacket” reconstruction of ICA on bare wire (with overlap of the stents, under inflated BCG) :
- evaluate the patency of intracranial vessels and confirm good apposition of the stents by performing vaso-CT
Note: if it is possible to stay from the beginning in the true lumen, it is even better (no need for re-entry, lower rate of re-occlusion, better chance of reendothelialization of created channel).
CRUCIAL POINTS:
The keys are:
*before the revascularization high blood pressure is recommended
Please note that there is a need for further investigation and safety evaluation of the procedure.