Method for treatment of obstructive portions of urinary passageways

• US 5,224,953 A
• Filed: 05/01/1992
• Issued: 07/06/1993
• Est. Priority Date: 05/01/1992
• Status: Expired due to Fees

• Current Assignee: BETH Israel Medical Center (Mount Sinai Beth Israel)
• Original Assignee: BETH Israel Medical Center (Mount Sinai Beth Israel)
• Inventors: Morgentaler, Abraham
• Primary Examiner(s): Kruter, J. L.
• Application Number:
  US07/877,412
• Time in Patent Office: 431 Days
• Field of Search: 623/1, 623/12, 604/53, 604/54, 606/108, 606/191, 606/192
• US Class Current: 606/192
• CPC Class Codes: A61F 2/95 Instruments specially adapted for placement or removal of stents or stent-grafts
• CPC Class Codes: A61F 2/966 with relative longitudinal movement between outer sleeve and prosthesis, e.g. using a push rod
• CPC Class Codes: A61F 2002/048 Ureters
• CPC Class Codes: A61M 27/008 pre-shaped, for use in the urethral or ureteral tract

Abstract

A method for the treatment of an obstructive portion of a urinary passageway of a mammal, comprising the steps of providing a stent thermally self-movable between a first condition in which the stent is rigid and generally tubular, and a second condition in which the stent is flexible and compressible, moving the stent in the second condition through a catheter to the obstructive portion of the urinary passageway while maintaining the stent in its second condition by flowing a cool solution through the stent, moving the stent out of the catheter and into the obstructive portion of the urinary passageway, and discontinuing the flow of cool solution, whereby the stent is caused by body temperature, or by the flow of a warm solution, to assume its first condition to hold open the obstructive portion of the urinary passageway.

Claims

1. A method for treatment of an obstructive portion of a urinary passageway of a mammal, said method comprising of the steps of:

measuring the length of said obstructive portion of said passageway,

providing a stent adapted to assume a first condition when exposed to body temperature of said mammal, and adapted to assume a second condition when exposed to a transition temperature less than said body temperature, said stent in said first condition being rigid and generally tubular in configuration, and having a selected length substantially equal to the measured length of said obstructive portion, and in said second condition being flexible and compressible to a size substantially smaller in diameter than the size of said stent in said first condition,

carrying said stent through said passageway to said obstructive portion,

flowing a cool solution through a carrier containing said stent, said cool solution being of a temperature no greater than said transition temperature,

separating said stent from said carrier in said passageway in said obstructive portion, and

discontinuing said flow of said cool solution,

whereby said stent is caused by said body temperature to assume said first condition to hold open said obstructive portion.

2. The method for treatment of an obstructive portion of a urinary passageway in accordance with claim 1, including the additional step of flowing warm solution through said stent after said stent has been disposed in said obstructive portion and after discontinuance of said flow of cool fluid through said stent, said warm solution being at a temperature sufficient to cause said stent to assume said first condition, whereby said stent is caused at least in part by said warm solution to assume said first condition to hold open said obstructive portion.

3. The method for treatment of an obstructive portion of a urinary passageway in accordance with claim 2, including the additional steps of flowing said cool solution through said stent to cause said stent to reassume said second condition, moving said stent to a selected second location while said stent is in said second condition, and discontinuing said flow of said cool solution, whereby said stent is caused by said body temperature to reassume said first condition to hold open said second location of said urinary passageway.

4. A method for treatment of obstructive urethra portions in a mammal, said method comprising the steps of:

inserting a cystoscope in said urethra,

moving said cystoscope in said urethra to dispose a distal end of said cystoscope proximate a furthest end of the obstructive portion,

measuring the length of the obstructive portion of said urethra through said cystoscope,

providing a stent adapted to assume a first condition when exposed to body temperature of said mammal, and adapted to assume a second condition when exposed to a transition temperature less than said body temperature, said stent in said first condition being rigid and generally tubular in configuration, and having a selected length substantially equal to the measured length of said obstructive portion, and in said second condition being flexible and compressible to a size substantially smaller in diameter than the size of said stent in said first condition,

inserting said stent in said second condition into a catheter,

moving said stent to a distal end of said catheter,

inserting said catheter in said cystoscope,

moving said catheter through said cystoscope to position said stent adjacent said obstructive portion of said urethra;

flowing a cool solution through said catheter, said cool solution being at a temperature no more than said transition temperature,

moving said stent out of said catheter and into said obstructed portion of said urethra, and

discontinuing said flow of said cool solution through said catheter,

whereby said stent is caused by said body temperature to assume said first condition to hold open said urethra obstructive portion.

5. The method in accordance with claim 4, including the further step of ascertaining visually the location of said stent in said first condition in said urethra, through said cystoscope.

6. The method in accordance with claim 5, including the further steps of flowing said cool solution through said stent to cause said stent to reassume said second condition, moving said stent to a selected second location in said urethra, and discontinuing said flow of said cool solution, whereby said stent is caused by said body temperature to again assume said first condition to hold open said urethra obstructed portion.

7. The method in accordance with claim 4, including the additional step of flowing a warm solution through said catheter, said warm solution being at a temperature sufficient to cause said stent to assume said first condition, whereby said stent is caused at least in part by said warm solution to assume said first condition.

8. The method in accordance with claim 6, including the additional step of flowing a warm solution through said catheter, said warm solution being at a temperature sufficient to cause said stent to assume said first condition, whereby said stent is caused at least in part by said warm solution to assume said first condition.

9. The method in accordance with claim 6, wherein said moving of said stent to said selected second location is accomplished by use of endoscopic forceps.

10. A method for treatment of obstructive prostatism in a mammal having a bladder and a urethra with a prostatic portion, said method comprising the steps of:

inserting a cystoscope in said urethra,

moving said cystoscope in said urethra to dispose a distal end of said cystoscope proximate said bladder,

measuring said prostatic portion of said urethra through said cystoscope,

providing a stent adapted to assume a first condition when exposed to body temperature of said mammal, and adapted to assume a second condition when exposed to a transition temperature less than said body temperature, said stent in said first condition being rigid and generally tubular in configuration, and having a selected length substantially equal to the measured length of said prostatic portion, and in said second condition being flexible and compressible to a size substantially smaller in diameter than the size of said stent in said first condition,

inserting said stent in said second condition into a catheter,

moving said stent to a distal end of said catheter,

inserting said catheter through said cystoscope to position said stent adjacent said prostatic portion of said urethra;

flowing a cool solution through said catheter, said cool solution being at a temperature no more than said transition temperature,

moving said stent out of said catheter and into said prostatic portion of said urethra, and

discontinuing said flow of said cool solution through said catheter,

whereby said stent is caused by said body temperature to assume said first condition to hold open said urethra prostatic portion.

11. The method in accordance with claim 10, including the further step of ascertaining visually the location of said stent in said first condition in said urethra, through said cystoscope.

12. The method in accordance with claim 11, including the further steps of flowing said cool solution through said stent to cause said stent to reassume said second condition, moving said stent to a selected second location in said prostatic portion of said urethra, and discontinuing said flow of said cool solution, whereby said stent is caused by said body temperature to again assume said first condition to hold open said urethra prostatic portion.

13. The method in accordance with claim 10, including the additional step of flowing a warm solution through said catheter, said warm solution being at a temperature sufficient to cause said stent to assume said first condition, whereby said stent is caused at least in part by said warm solution to assume said first condition.

14. The method in accordance with claim 12, including the additional step of flowing a warm solution through said catheter, said warm solution being at a temperature sufficient to cause said stent to assume said first condition, whereby said stent is caused at least in part by said war solution to assume said first condition.

15. The method in accordance with claim 12, wherein said moving of said stent to said selected second location is accomplished by use of endoscopic forceps.

16. A method for treatment of obstructive ureter portions in a mammal, said method comprising the steps of:

measuring the length of the obstructive portion of the ureter,

providing a stent adapted to assume a first condition when exposed to body temperature of said mammal, and adapted to assume a second condition when exposed to a transition temperature less than said body temperature, said stent in said first condition being rigid and generally tubular in configuration, and having a selected length substantially equal to the measured length of said obstructive portion, and in said second condition being flexible and compressible to a size substantially smaller in diameter than the size of said stent in said first condition,

extending a wire between a bladder at a first end of said ureter and a renal pelvis at a second end of said ureter, said wire extending through said obstructive portion of said ureter,

placing a catheter with said stent therein in said second condition around said wire,

moving said catheter along said wire until said catheter is disposed in said obstructive portion of said ureter,

flowing a cool solution at a temperature no greater than said transition temperature through said catheter and through said stent to maintain said stent in said second condition,

separating said catheter from said stent, terminating said flow of said cool solution, and withdrawing said catheter and said wire from said ureter, leaving said stent in said obstructive portion of said ureter,

whereby said stent is caused by said body temperature to assume said first condition to hold upon said obstructive portion of said ureter.

17. The method in accordance with claim 16 wherein said wire is passed through a ureteral orifice in said bladder and to said renal pelvis.

18. The method in accordance with claim 17 wherein measuring said length of said obstructive portion of said ureter is accomplished by a pyeloureterogram.

19. The method in accordance with claim 18 including the step of inserting a cytoscope through a urethra in communication with said bladder, moving said cytoscope in said bladder to a ureteral orifice, and moving said wire through said cytoscope, through said ureteral orifice and through said ureter to said renal pelvis.

20. The method in accordance with claim 19 wherein positioning of said stent in said ureter is determined by fluoroscopy.

21. The method in accordance with claim 20 wherein said stent is releasably connected to a grasping tool, such as that said positioning of said stent is accomplished by manipulation of said grasping tool, and including the additional step of releasing said stent from said tool and withdrawing said tool.

22. The method in accordance with claim 16 and including the additional step of flowing warm solution of at least said body temperature through said catheter upon movement of said stent into said obstructive portion of said ureter, whereby said stent is caused at least in part by said warm solution to assume said first condition.

23. The method in accordance with claim 16 and including the further steps of flowing said cool solution through said stent to cause said stent to reassume said second condition, moving said stent to a selected second location in said ureter, and discontinuing said flow of said cool solution, whereby said stent is caused by said body temperature to again assume said first condition to hold open said ureter obstructive portion.

24. A method for treatment of obstructive ureter portions in a mammal, said method comprising the steps of:

moving a ureteroscope into a ureter and through said ureter to gain visual access to the obstructive portion of the ureter,

visually measuring the length of said obstructive portion of said ureter,

providing a stent adapted to assume a first condition when exposed to body temperature of said mammal, and adapted to assume a second condition when exposed to a transition temperature less than said body temperature, said stent in said first condition being rigid and generally tubular in configuration, and having a selected length substantially equal to the measured length of said obstructive portion, and in said second condition being flexible and compressible to a size substantially smaller in diameter that the size of said stent in said first condition,

placing said stent in said second condition in a catheter,

passing said catheter with said stent therein through a working channel of said ureteroscope until a distal end of said catheter is at or beyond a furthest boundary of said obstructive portion,

expelling said stent from said catheter and into said ureter in said obstructive portion,

whereby said stent is caused by said body temperature to assume said first condition to hold open said ureter obstructive portion.

25. The method in accordance with claim 24 including the additional step of flowing a warm solution through said catheter as said stent is expelled from said catheter, the warm solution being of a temperature equal to at least said body temperature, whereby said stent is cased at least in part by said warm solution to assume said first condition.

26. The method in accordance with claim 24, and including the additional step of flowing a cool solution through said catheter and through said stent, said cool solution being of a temperature no greater than said transition temperature to cause said stent to reassume said second condition, advancing endoscopic forceps through said ureteroscope to grasp said stent and move said stent in said ureter, and flowing said warm solution through said catheter.