| 摘要 |
A catheter with a heater mounted on its distal end is used to melt atherosclerotic plaque to clear an obstruction within an artery. The catheter heater is a tapered cone that emits heat from its outer, leading edges. Several embodiments are disclosed in which the power for the heater is generated by electrical resistance heating or by laser energy absorption. In the disclosed method of use, the guidewire is inserted into the lumen of the catheter so that the distal tip of the guidewire extends a few centimeters beyond the heater tip. The catheter is directed into the proper coronary branch by means of the guidewire and the wire is advanced until it meets the obstruction. If the wire can be advanced through the obstruction, the catheter is advanced over the wire until the heater contacts the plaque. The heater is then operated and the catheter is advanced as the plaque melts. If the guidewire cannot be pushed through the obstruction, the guidewire and catheter are advanced together until the obstruction is breached and the guidewire can be extended down the artery. Once a suitable channel has been opened, the catheter is removed and a conventional balloon dilatation catheter is slid over the guidewire to enlarge the stenosis in a conventional manner. |
