New mechanical devices for treatment of coronary artery disease

Percutaneous high-speed coronary rotablation allows to remove arterio-sclerotic material from the vessel wall. A diamond-coated (15-30 microns) brass burr drill fastened to a flexible drive shaft rotating and tracking along a drill coaxial guide wire is used. The turbine rotates the drive shaft at 150,000-190,000 rpm. High-frequency rotational angioplasty was successful in 27 of 28 patients, but in about 34% additional PTCA was necessary. Only one patient went to bypass surgery, and myocardial infarction (CK less than 150 u/l) occurred in only one of 28 patients. No vessel perforation was observed. All vessels were open at 24 h control. The restenosis rate was not increased. The main indication for high-speed rotational angioplasty seems to be rigid sclerotic lesions that cannot be passed by a conventional balloon catheter. Whether restenosis rate can be reduced by this method will be judged in future studies. In order to avoid acute complications of PTCA and to reduce restenosis rate, coronary stents were developed. Self-expandable and balloon-expandable stents are available. It could be demonstrated that these stents can be used as a bail-out system and can block elastic recoil of coronary arteries. The major remaining problem is that of subacute closure of coronary vessels. In order to prevent this, treatment with coumarine, acetylsalicylic acid, and dipyridamol is necessary. Coronary stents can be successfully delivered in more than 90% of the patients, as demonstrated by a cooperative study. In a highly selective patient group using single stents, restenosis rate measured 15%, but was higher in patients with multiple stents.