| 摘要 |
<p>A balloon dilatation catheter that may be used for percutaneous transluminal coronary angioplasty includes a coaxial construction of an inner tube and an outer tube. The inner tube extends distally beyond the distal end of the outer tube. A dilatation balloon, which may be compliant, is mounted on the distal end of the catheter and is connected at its proximal end to the distal end of the outer tube and at its distal end to the distal end of the inner tube. The lumen of the inner tube is adapted to receive a guidewire. An annular inflation lumen is defined between the inner and outer tubes. The distal end of the outer tube extends into the balloon. The inner diameter of the outer tube closely approximates but is larger than the outer diameter of the inner tube and is slidable relative to the inner tube. An abutment member is fixed to the inner shaft and is engageable by an abutment surface at the distal region of the outer tube. The abutment of the two prevents proximal movement of the inner tube into the outer tube to provide increased column strength and resistance to balloon bunching thereby avoiding distortion of the distal segment of the inner tube that extends distally beyond the anchor joint. The inner tube may move with respect to the outer tube in a distal direction to accommodate longitudinal stretching of the inner tube, as may occur in response to balloon inflation. <IMAGE></p> |
