Ureteral stent

• US 4,790,809 A
• Filed: 05/14/1987
• Issued: 12/13/1988
• Est. Priority Date: 08/29/1985
• Status: Expired due to Term

• Current Assignee: Cabot Corporation
• Original Assignee: Medical Engineering Corporation
• Inventors: Kuntz, David H.
• Primary Examiner(s): Pellegrino, Stephen C.
• Application Number:
  US07/050,509
• Time in Patent Office: 579 Days
• Field of Search: 604/43, 604/8, 604/55, 604/264, 604/280, 604/281, 128/1.3, 128/656, 128/657
• US Class Current: 604/8
• CPC Class Codes: A61M 25/0045 multi-layered, e.g. coated coating materials A61L29/08
• CPC Class Codes: A61M 25/0069 Tip not integral with tube
• CPC Class Codes: A61M 25/0127 Magnetic means; Magnetic markers
• CPC Class Codes: A61M 27/008 pre-shaped, for use in the urethral or ureteral tract

Abstract

An ureteral stent comprises an elongated, flexible tubular member which has one end with a magnetically attractable tip. Both ends of the stent are preferably both set in the form of hooks. A method of removing the stent from the bladder of a patient comprises introducing a retrieving catheter with a magnet at its proximal tip into the urethra, advancing the proximal tip of the catheter into the bladder which is signalled by urine flowing into the catheter, catching the magnetically attractable tip of the stent with the magnet and removing the stent by withdrawing the catheter with the magnetically attractable tip of the stent held by the magnet of the catheter.

Claims

1. In a ureteral stent comprising an elongated, flexible, tubular member of substantially uniform outside diameter throughout its length and having at one end a hook for placement in the kidney and at the other end a hook for placement in the bladder, the improvement which comprises having a magnetically attractable tip at the other end of the stent, said tip being a cylinder of magnetically attractable material having a lumen through which a guidewire can be introduced into the tubular member.

2. A retrieving catheter for removing a ureteral stent with a magnetically attractable tip, said catheter being a tubular member having a lumen and one end which is of a size which can be introduced into the urethra of a patient, said catheter having a portion including said one end which is bent at an obtuse angle to the rest of the catheter, said bent portion including an opening through which urine can flow and means for magnetically attracting the magnetically attractable tip of a stent.

3. A retrieving catheter of claim 2 in which the means for attracting the tip of the stent includes a magnet which is protected from urine by a fluid tight seal that is between the magnet and the lumen of the catheter.

4. A method of retrieving from the urinary tract of a patient a ureteral stent which includes a magnetically attractable end which is in the patient'"'"'s bladder, said method comprising introducing into the urethra of the patient a retrieving catheter having means at its leading end for magnetically attracting the magnetically attractable end of the stent, advancing said catheter until is reaches the bladder of the patient, bringing said means into contact with the magnetically attractable end of the stent and then withdrawing the catheter with the stent attracted thereto through the urethra and out of the patient.