| 摘要 |
A stent for assistance in draining urine from the kidney into the bladder through the ureter which may be partially or totally occluded. The stent has the capability to selectively inject a liquid, such as a dye, into the renal system. The stent is fabricated from a biocompatible tube, preferably of silicone rubber. The proximal and distal ends of the tube are preformed into a pigtail or other shape to secure in the renal and bladder cavities, respectively. The proximal and distal ends of the tube are perforated to provide for ingress and egress of the urine. During the implantation procedure, a guide wire is first advanced to provide a path for positioning the stent. The stent is advanced over the guide wire by pushing with a multiple diameter injection catheter. The smaller diameter proximal end of the injection catheter is positioned within the distal end of the stent at a predetermined fixed distance which occludes the distal perforations. The larger diameter distal portion of the injection catheter pushes against the distal end of the stent. Following positioning of the stent and injection of the fluid, if any, the injection catheter is released from frictional engagement with the distal end of the stent using a release catheter which slides over the injection catheter and pushes against the distal end of the stent. After removal of the injection catheter, the release catheter, and the guide wire, the stent assumes its preformed shape.
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