Vertebral Artery Stenting VIST meeting 12 th October Dr Andrew Clifton Atkinson Morley Wing St George’s Hospital

Technical Aspects l Patients should be pre-medicated with antiplatelet agents –Recommended with aspirin 75mg a day for at least 7 days prior to the procedure, or a 600mg loading dose the day before the procedure and 75mg on the day, –plus clopidogrel 75mg a day for at least 7 days before the procedure, or a 600mg loading the dose the day before the procedure and 75mg on the day of the procedure. l 75mg of both agents continued for 6 weeks and one agent, usually aspirin, 75mg a day for life. l If a platelet functional analyser such as VerifyNow is available antiplatelet function should be tested prior to the procedure and dosages adjusted accordingly.

Extracranial Stenting l Most stenoses at origin. Stenting within the foramina is not generally recommended as neck movement can cause stent fracture and occlusion. l Stenting at the origin can be performed under local anaesthesia +/- (plus or minus) sedation. 5 or 6 French groin puncture depending on the size of the guiding sheath needed. l Full angiography to both subclavian arteries to look at both vertebral origins and collateral flow and views of intracranial circulation. l 5000 units of heparin given intravenously before insertion of the guiding catheter. l Appropriate ACT levels obtained prior to inserting the guiding catheter.

Extracranial Stenting l Usual practice is for balloon mounted stents under road mapping, the lesion is crossed with an 014 or 018 wire, depending on the stent used, and a balloon mounted stent deployed across the stenosis leaving a few millimetres of stent in the subclavian artery. l Post dilatation a check angiogram is performed and if satisfactory appearances the delivery system is removed. l Rarely the lesion needs to be pre-dilated. l Technical tip: access to the right vertebral can often be difficult and sometimes using a 7 French sheath with a wire into the subclavian stabilises the system to gain access. l Brachial artery puncture using a 5 French sheath is sometimes necessary for access. l Stent types: Monorail preferred, various stent types are available including cardiac, renal, and specific intracranial stents such as the Pharos.

Intracranial Stenting l Premedication as above. Heparinisation as above. l Procedure is ideally preformed under general anaesthesia. l Both balloon mounted Pharos and self expanding stents are used. Self expanding stents usually require pre-dilatation of the lesion using a gateway balloon to approximately 75% of the diameter of the normal vessel before deployment of the stent.

Intracranial Stenting l Post procedure care:- l Extracranial can be managed in a high dependency unit over night. Heparinisation is not necessary for extracranial stents. l Intracranial stenting:- essential the patient has access to an HDU or even an ITU bed overnight for close monitoring of blood pressure and other neurological parameters. Heparinisation is usually continued for 24 hours after the procedure. l It goes without saying that all these patients have atheromatous disease and will be managed by a Neurologist or Stroke Physician with control of risk factors such as hypertension, glucose, cholesterol etc.

Imaging Follow Up l Unless follow up is prescribed as part of a trial non-invasive imaging such as ultrasound, particularly to look at flow through an origin stenosis, or CTA or MRA would be indicated. Angiography we reserve for those who become symptomatic or as follow up as part of a trial.