A new catheter combined with endoscope and intravascular ultrasound (CVIS) was developed for laser mitral valve commissurotomy. The catheter also had the lumen for laser fiber and the mitral guide wire for toucing the laser tip to the commissure. In the animal experiment, after the left thoracotomy, the catheter was inserted from the left atrium. Scanning the leaflet of the mitral valve with the CVIS, the laser tip was guided to the commissure. After reaching the commissure, the position of the laser tip was confirmed by both endoscope and CVIS. At this point, the laser ablation to the commissure was performed under the observation of the endoscope. The pathological finding showed that the commissure was correctly ablated and there were no thermal damage to the commissure and coronary artery and veins. In conclusion, this newly developed catheter considered to have a remarkable ability to make the stenotic valve area wider safely and correctly.
