NEW DEVICES IN INTERVENTIONAL CARDIOLOGY

Balloon coronary angioplasty for coronary stenosis has a success rate of over 90%, but secondary restenosis occurs in 30 to 40% of the patients. In addition, long calcified, ulcerated and distal lesions cannot be treated with the balloon technique. New techniques are thus needed and are currently under clinical evaluation. Stents are metallic meshes designed as vascular prostheses to maintain the arterial lumen open. Currently, stents are indicated in case of acute coronary occlusion during the angioplasty procedure and more rarely in case of elastic recoil after dilatation. First intention stents can reduce the rate of restenosis by about one-fourth, although use is limited due to the risk of thrombosis. The rotablator has a fine elliptoid tip which rotates at 180,000 rpm. When inserted into the area of stenosis, the rotablator attacks preferentially hard resistant material and is thus indicated for calcified lesions. It should not be used in large arteries or if a thrombus is visible on the angiography. Primary success rate is 95% and recoil does not exceed 5%. But this method still is not the final solution since the rate of restenosis is 44%, and even 54% for calcified lesions. In directional arthrectomy the tip of the catheter carries a metal cylinder with a lateral window which can be positioned on the lesion. Atheromatous material is then cut off with a rotating knife and trapped in the catheter's reservoir. This new system gives results which are currently similar to those for conventional angioplasty. The potential role of transluminal laser atherectomy, an effective but costly technique, is yet to be established. These new devices offer great potential, but their impact will depend to a great extent on the experience of the cardiology team and must be evaluated in comparison with the results of the classical balloon angioplasty.