To optimize the safety of endovascular treatment and to prevent embolic complications, Théron's technique of carotid stenting under balloon protection was applied successfully to 31 patients with high grade extracranial
carotid stenoses. Dilatation of the
stenosis and
stent deployment are performed under temporary balloon occlusion of the distal internal carotid artery. Blood flow is restored after aspiration as well as
flushing of potential emboli from the external carotid territory. Initially a hand-mounted non-steerable protection balloon
catheter caused technical difficulties in the passage of some
stenoses with irregular plaque surfaces. Steerable guide wires with integrated balloons improved the technical feasibility of the protection technique. Up to now no periprocedural
strokes were observed. Microscopic examination of the aspirated blood showed numerous
cholesterol crystals and fat particles with sizes up to 600 mu which in model experiments with the use of pulsatile perfused
silicone carotids showed the effectiveness of aspiration and
flushing in the elimination of embolic particles. We assume that the meshwork of the
stent, antiplatelets and periprocedural anticoagulation provide no sufficient protection against materials released from the necrotic core of the
atherosclerotic plaque. The proven presence of micro-emboli as well as low clinical rates are arguments for further use and development of the protection technique.