A catheter with two balloons for implanting a stent without flaring at the ends of the stent during implantation has an outer balloon overlying an inner balloon. The length of the inner balloon is shorter than the length of the outer balloon and shorter than a stent which is mounted over both balloons....http://www.google.es/patents/US7052510?utm_source=gb-gplus-sharePatente US7052510 - Two Balloon staged stent expansion
