A sheath arrangement for spiral balloon catheters which permits improved perfusion during dilation of a body vessel. Methods of making the sheath and assembling the sheath onto a balloon and the resulting sheathed balloon catheter are included. A tube sized to fit over a spiral balloon is...http://www.google.com.hk/patents/US5749852?utm_source=gb-gplus-share專利 US5749852 - Sheath system for autoperfusion dilatation catheter balloon
