A NEW PLATINUM BALLOON-EXPANDABLE STENT (ANGIOSTENT(R)) MOUNTED ON A HIGH-PRESSURE BALLOON - ACUTE AND LATE RESULTS IN AN ATHEROGENIC SWINEMODEL

Background. Randomized studies have proven the efficacy and safety of stent placement to treat de novo coronary stenosis. However, the poor radio-opacity and the use of an additional high-pressure balloon to fu lly expand the stent are the major limitations of the currently clinic ally-approved stents. Objective. We evaluated the safety, efficacy, an giographic and histologic effect of a new platinum balloon expandable stent mounted on a high-pressure balloon in Yucatan miniature swine fe d high cholesterol diet. Methods. Fifteen Angiostents(R) (NuMED, Inc., Hopkinton, NY and Angiodynamics, Glens Falls, NY) (coronary stent was 3, 3.5, or 4 mm in diameter and 12 mm long; renal and carotid stents were 5 mm in diameter and 13 mm long) mounted on a high-pressure ballo on were placed percutaneously in blood vessels of 10 pigs [5 in circum flex (CX), 2 in left anterior descending (LAD), 5 in renal and 3 in ca rotid arteries]. The stent was 10-20% larger than the native vessel di ameter. All animals received 5000 I.U. of heparin during the procedure and were maintained on 325 mg aspirin daily. Follow-up angiography an d histology in the animals was performed at 2, 4, 12, 20, 26 and 52 we eks. Results. The stents were easily visualized with fluoroscopy and p laced in all animals without episodes of balloon rupture or embolizati on. There was no episode of acute thrombosis. Follow-up angiography in the animals revealed patency of all renal and carotid stents, however , 2/7 coronary stents in the animals revealed angiographic lumen narro wing (>20%) at 20 and 52 weeks. Histologic examination revealed neoint imal formation at the stent site with an average neointimal thickness ranging from 325-650 mu m. Conclusion. This stent was safe in this ani mal model, easily deployed, had excellent radio-opacity and with good short-term patency without anticoagulation. Clinical trials and experi ence is underway.