Subclavian artery Stenting

Subclavian artery Stenting

Etiology Atherosclerosis Takayasu s arteritis Fibromuscular dysplasia Giant Cell Arteritis Radiation-induced Vascular Injury Thoracic Outlet Syndrome Neurofibromatosis

Incidence Incidence of 0.5-2% (1) Left : Right = 3-4 : 1 ratio The stenosis is usually focal and in the proximal segment of the vessel Predictors: Hypertension, Tobacco use, Dyslipidemia, and Diabetes.

Clinical manifestation Subclavian-steal syndrome Coronary subclavian steal syndrome

Clinical diagnosis Obstruction of the subclavian artery is suspected when there is a blood pressure difference > 20mm Hg between the two arms If there is a clinical suggestion of vasculitis: an ESR or CRP should be measured

Noninvasive diagnosis Duplex Ultrasonography Moderately high sensitivity (80% range) and an excellent negative predictive value (> 95%) Highly useful in clinical follow-up of patients after revascularization procedures

Noninvasive diagnosis Diagnostic Imaging work-up should include Magnetic resonance imaging (MRI) with or without arteriography (MRA) CT scan of the brain with close evaluation of the posterior fossa and brainstream. Arteriography Ascending aortography Selective arteriography of supra-aortic vessels

Indication of revascularization Symptomatic ischemia of the posterior fossa Symptomatic subclavian steal syndrome Disabling upper extremity claudication Preservation of flow to LIMA/RIMA Pre-CABG, where LIMA/RIMA will be used Post-CABG LIMA/RIMA with ischemia (with or without coronary-subclavian steal syndrome) Preservation of inflow to axillary graft or dialysis conduit Blue-digit syndrome (embolization to fingers) Inability to measure blood pressure Progressive stenosis or thromboembolus threatening cerebral blood supply

Indication of revascularization in Asx pts Angioplasty of the subclavian stenosis before other cardiovascular intervention and preservation of the vasculature for other angioplasty procedures Preservation of the cerebral perfusion. If other arterial lesions exist at the level of the supra-aortic vessels, to improve cerebral flow.

Treatment options PTA PTA with balloon angioplasty followed by stent placement is the treatment of choice. Prevertebral Portion of Subclavian Artery: Balloon expandable or self expanding stents with good radial force Postvertebral Portion of Subclavian Artery: Self expanding stents to avoid possibility of postvertebral compression by extravascular structures at the thoracic outlet

Indication of covered stent Aneurysm or pseudoaneurysm Traumatic artery injury Spontaneous arterial rupture or dissecti

Associated Vertebral artery stenosis Kissing balloon technique Complication: brain embolization Cerebral protection devices, protection balloons, or filters could be us

Treatment options Surgery Carotid-subclavian bypass Aortosubclavian bypass Axilloaxillary bypass

Approach Femoral Approach It is used at first intention in the majority of the cases Brachial Approach Recanalization of an occluded Subclavian artery (SA) When the occlusion begins at the ostium of the SA Severe tortuosity of the aorta Bilateral occlusion of the iliac arteries

Complications Hematomas Subclavian thrombosis Axillary artery thrombosis Stent Migration Arterial rupture Dissection Distal embolization Restenosis Neurologic complications Transient ischemic attack, stroke, hemiplegia, diplopia.

In-hospital outcomes Total group (n=89) Direct stenting (n=22) Predilatation (n=54) 6 4 3.7 2 2.2 1.9 1.9 1.2 1.2 0 0 0 0 Distal embolization TIA Major stroke Amor M, et al. CCI 2004;63:364-370

Long-term outcomes Mean follow-up duration: 3.51±1.98 years Total group (n=89) Direct stenting (n=22) Predilatation (n=54) 100 95.4 80 P=0.003 80 75.9 60 40 20 0 28.5 19.4 4.7 In-stent restenosis Primary patency Amor M, et al. CCI 2004;63:364-370

Favorable predictors of prognosis Presence of subclavian steal syndrome : it prevents the risk of vertebral embolization Isolatated stenosis Recurrent angina following an internal mammary coronary bypass