| 摘要 |
<p>A small diameter balloon dilatation catheter (10) having a shaft (12) formed from hypodermic tubing is provided with a detachable luer fitting (18) on its proximal end. The luer fitting may be removed and an extension wire (52) attached to the proximal end of the catheter. A larger diameter catheter (56) then may be advanced over the smaller catheter (51) utilizing the smaller catheter to guide the larger catheter to the stenosis (59) being treated. In another aspect of the invention, a guiding sheath assembly (60) is provided which permits catheter exchanges involving such small diameter catheters having integral guidewires. In one protocol such a catheter may be exchanged for a conventional balloon dilatation catheter with a movable guidewire by removing the dilatation catheter, advancing the sheath over the guidewire, then removing the guidewire and inserting the replacement catheter. Similarly, a catheter having an integral guidewire may be exchanged for a similar catheter by first removing the luer fitting at the proximal end of the catheter, then attaching a wire extension to the proximal end of the catheter, then advancing a sheath over the extension and catheter to locate the distal end of the sheath in proximity to the stenosis, then removing the catheter through the sheath and replacing that catheter with a new catheter inserted through the sheath.</p> |
