| 摘要 |
<p>A catheter (10) for accessing a target site along a tortuous, small-vessel pathway. The catheter (10) includes a flexible distal segment (26) which is composed of a flexible polymer tube (12) and a low-friction internal tubular surface (38). The surface allows the catheter to be advanced over sharp bends and small-diameter loops in a guidewire (14), in advancing the catheter along a small-vessel pathway. Various embodiments of the catheter (10) are disclosed wherein the internal tubular surface (38) of a distal portion of the catheter include a variety of different constructions and are comprised of a variety of different materials so as to best avoid the jamming, sticking or locking of the distal end or any part of the guidewire against the surface. Braided sleeve-like constructions (38), surfaces embedded with a plurality of small particles and surfaces comprised of various anti-friction materials are used in order to obtain the object of the invention.</p> |
