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 patie nts. 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 meshe s designed as vascular prostheses to maintain the arterial lumen open. Currently, stents are indicated in case of acute coronary occlusion d uring the angioplasty procedure and more rarely in case of elastic rec oil after dilatation. First intention stents can reduce the rate of re stenosis by about one-fourth, although use is limited due to the risk of thrombosis. The rotablator has a fine elliptoid tip which rotates a t 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% a nd recoil does not exceed 5%. But this method still is not the final s olution since the rate of restenosis is 44%, and even 54% for calcifie d 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 an d trapped in the catheter's reservoir. This new system gives results w hich are currently similar to those for conventional angioplasty. The potential role of transluminal laser atherectomy, an effective but cos tly technique, is yet to be established. These new devices offer great potential, but their impact will depend to a great extent on the expe rience of the cardiology team and must be evaluated in comparison with the results of the classical balloon angioplasty.