Implantable shunt system and method of assembly

• US 4,861,331 A
• Filed: 04/22/1988
• Issued: 08/29/1989
• Est. Priority Date: 03/24/1988
• Status: Expired due to Term

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Pudenz-Schulte Medical Research Corporation
• Inventors: Laguette, Stephen W., Lintula, Leanne M., East, Gary P., Heindl, Alfons
• Primary Examiner(s): Pellegrino, Stephen C.
• Application Number:
  US07/184,749
• Time in Patent Office: 494 Days
• Field of Search: 604/8-10, 604/175, 604/185, 604/247, 137/854, 137/614.2, 285/332, 285/339
• US Class Current: 604/9
• CPC Class Codes: A61M 27/006 Cerebrospinal drainage; Accessories therefor, e.g. valves
• CPC Class Codes: F16K 15/148 the closure elements being fixed in their centre
• CPC Class Codes: Y10T 137/789 Central mount

Abstract

A surgically implantable shunt system, including a flow control valve and an antechamber, is provided for controlling the release of entrapped body fluids. The flow control valve includes a pair of molded plastic bases situated, respectively, adjacent to an inlet and an outlet of the valve, which bases are situated within a flexible encasement. Each base includes an outer housing, a valve membrane carrier positioned within the housing, and a flow control member. The flow control members each include a rigid nail-like central support and a separate flexible resilient membrane positioned on the central support. A first flow control member is capable of selectively occluding the valve inlet, but is normally spaced from its base to permit free fluid flow through the inlet. The second flow control member is generally arch-shaped and resiliently biased to contact its respective base generally along the outer edge of the membrane in a manner permitting only controlled one-way flow through the valve. The antechamber permits injection of medication into the shunt between a proximal catheter and the distal flow control valve, and pumping of the medication in either direction. Additionally, a method for assembling the shunt system in a quick and economical manner is provided, which utilizes tapered grommets to anchor components in place prior to adhesively securing tubing to the flexible encasement.

Claims

1. A surgically implantable shunt system, comprising:

an inlet;

an outlet;

a first base adjacent to the inlet, the first base including an inlet fluid passageway therethrough and a first valve seat surrounding a portion of the inlet fluid passageway;

a first flow control member attached to the first base and being positioned with respect to the first valve seat to normally permit free fluid flow through the inlet fluid passageway, and alternately, to selectively contact the first valve seat in a manner to occlude the inlet fluid passageway;

a second base adjacent to the outlet, the second base including an outlet fluid passageway therethrough and a second valve seat surrounding a portion of the outlet fluid passageway; and

a second flow control member attached to the second base so that the second flow control member contacts the second valve seat in a manner normally occluding the outlet fluid passageway but selectively opening to permit controlled unidirectional flow therethrough.

2. A shunt system as set forth in claim 1, including an intermediate fluid passageway between the inlet and outlet fluid passageways, and means for flushing fluid from the intermediate fluid passageway through the outlet fluid passageway by application of percutaneous manual pressure to the shunt system.

3. A shunt system as set forth in claim 2, wherein the flushing means comprises a flexible encasement generally surrounding the first and second bases, wherein the encasement is deformable by external pressure to facilitate manual flushing of the valve and defines the intermediate fluid passageway, and further wherein deformation of the flexible encasement causes the first flow control member to temporarily engage the first valve seat and occlude the inlet fluid passageway.

4. A shunt system as set forth in claim 1, wherein each flow control member includes a central support and a resilient membrane, the central support being attached to the respective base and extending therefrom to support the resilient membrane, the resilient membrane being generally arch-shaped and having a portion thereof capable of engaging the respective valve seat to occlude the respective fluid passageway.

5. A shunt system as set forth in claim 4, wherein each central support comprises a rigid nail which is anchored to its respective base, and wherein each resilient membrane comprises a flexible valve seat-engaging member.

6. A shunt system as set forth in claim 5, wherein the central support is formed of a polypropylene material, and the membrane is formed of an elastomer material.

7. A shunt system as set forth in claim 4, wherein the first base includes a first outer housing and a first valve membrane carrier securely positioned within the first outer housing, the first valve membrane carrier including means for positioning the central support of the first flow control member.

8. A shunt system as set forth in claim 7, wherein the first base includes a rigid recess in which the resilient membrane of the first flow control member is positioned.

9. A shunt system as set forth in claim 4, wherein the second base includes a rigid second outer housing and a second valve membrane carrier securely positioned within the second outer housing, the second valve membrane carrier including means for positioning the central support of the second flow control member so that the outer edges of the second resilient membrane contact the second valve seat.

10. A shunt system as set forth in claim 9, wherein the second outer housing forms an outlet chamber between the second valve membrane carrier and the outlet, and wherein the second resilient membrane is positioned within the outlet chamber.

11. A shunt system as set forth in claim 9, wherein the second valve membrane carrier defines a plurality of channels comprising a part of the outlet fluid passageway, and wherein the second valve seat is situated on the second valve membrane carrier.

12. A shunt system as set forth in claim 1, including means for injecting medication into the shunt system, the injecting means including an antechamber having an inlet, an outlet, a flexible encasement which defines an injection chamber, and a rigid needle shield situated within the injection chamber, the needle shield extending generally the length of the injection chamber and including needle stop means for preventing a tip of a needle from inadvertently slipping off the needle shield during injection of medication into the injection chamber, and means for preventing occlusion of the antechamber inlet and outlet by the needle shield, and further including tubing means for connecting the antechamber outlet with the first base.

13. A shunt system as set forth in claim 12, including grommet means for non-adhesively attaching an end of the tubing means to the first base.

14. A shunt system as set forth in claim 1, including distal tubing means for channeling fluid from the outlet, the distal tubing means being attached to the second base by grommet means for forming a non-adhesive attachment between the second base and the distal tubing means.

42. A method as set forth in claim 4-, wherein each base includes a rigid base outer housing and a valve membrane carrier, the valve membrane carrier being fixed to the rigid base outer housing after the rigid base outer housing is secured to the respective segment of tubing.

15. An implantable flow control valve for controlling the flow of fluid from one portion of the human body to another, said valve comprising:

an inlet;

an outlet;

a first base adjacent to the inlet and including a first outer housing and a first valve membrane carrier securely positioned within the first outer housing, the first outer housing and the first valve membrane carrier defining an inlet fluid passageway and a first valve seat surrounding a portion of the inlet fluid passageway;

a second base adjacent to the outlet and including a second outer housing and a second valve membrane carrier securely positioned within the second outer housing, the second outer housing and the second valve membrane carrier defining an outlet fluid passageway and a second valve seat surrounding a portion of the outlet fluid passageway, wherein the second outer housing forms an outlet chamber;

a flexible encasement generally surrounding the first and second bases, wherein the encasement is deformable by external pressure to facilitate manual flushing of the valve, the flexible encasement defining an intermediate fluid passageway between the inlet and outlet fluid passageways;

a first flow control member including a first rigid central support and a first arch-like flexible resilient membrane, the first central support being attached to the first valve membrane carrier and extending therefrom to support the first resilient membrane with respect to the first valve seat to normally permit free fluid flow through the inlet fluid passageway, the first resilient membrane further being positioned so that upon deformation of the encasement to flush the valve, the membrane temporarily contacts the first valve seat in a manner to occlude the inlet fluid passageway; and

a second flow control member including a second rigid central support and a second arch-like resilient membrane, the second central support being attached to the second valve membrane carrier and extending therefrom to support the second resilient membrane adjacent to the second valve seat, the second resilient membrane being resiliently biased to contact the second valve seat in a manner normally occluding the outlet fluid passageway but selectively opening to permit controlled unidirectional flow therethrough.

16. A valve as set forth in claim 15, wherein the first valve membrane carrier defines a plurality of channels comprising at least a part of the inlet fluid passageway, wherein the channels are collectively occluded in a controlled manner upon engagement by the first resilient membrane of the first valve seat.

17. A valve as set forth in claim 15, wherein the second valve membrane carrier defines a plurality of channels comprising at least part of the outlet fluid passageway, wherein the channels are collectively occluded in a controlled manner by the second flow control member.

18. A valve as set forth in claim 15, wherein the first base includes a rigid recess in which the first resilient membrane is positioned.

19. A valve as set forth in claim 15, wherein the second base provides a non-deformable outlet chamber, and wherein the second resilient membrane is positioned within the outlet chamber.

20. A valve as set forth in claim 15, including grommet means for non-adhesively attaching the bases to tubing means for channeling fluids to the inlet and from the outlet.

21. A surgically implantable fluid shunt, comprising:

an inlet;

an outlet;

a rigid base which resists deformation, the base having an inlet surface in communication with the inlet and an outlet surface in communication with the outlet;

an aperture through the base for permitting flow of fluid through the shunt from the inlet to the outlet; and

a flow control member for controlling the flow of fluid from the inlet to the outlet, the flow control member including a rigid nail and an arch-like flexible resilient membrane fixed to the nail, wherein the nail is attached to the base adjacent to the aperture and extends therefrom to position the resilient membrane with a concave side thereof in facing relation with the inlet, the resilient membrane being resiliently biased such that outermost edges of the membrane contact the base in a manner normally preventing fluid flow through the shunt, the membrane selectively opening to permit controlled unidirectional flow through the shunt from the inlet to the outlet.

22. A shunt as set forth in claim 21, wherein the resilient membrane contacts the outlet side of the base in a manner surrounding the aperture to form a releasable seal between the outlet side of the base and the outermost edges of the membrane.

23. A shunt as set forth in claim 21 wherein the base is situated adjacent to the outlet and includes an outer housing and a valve membrane carrier securely positioned within the outer housing, the outer housing and the valve membrane carrier defining an outlet fluid passageway and a valve seat surrounding a portion of the outlet fluid passageway.

24. A shunt as set forth in claim 23, wherein the base forms a non-deformable outlet chamber, and wherein the flow control member is situated within the outlet chamber.

25. A shunt as set forth in claim 23, including a secondary base situated adjacent to the inlet and including a secondary outer housing and a secondary valve membrane carrier securely positioned within the secondary outer housing, the secondary outer housing and the secondary valve membrane carrier defining an inlet fluid passageway and a secondary valve seat surrounding a portion of the inlet fluid passageway.

26. A shunt as set forth in claim 25, including a flexible encasement generally surrounding the bases, wherein the encasement is deformable by external pressure to facilitate manual flushing of the shunt, the flexible encasement defining an intermediate fluid passageway between the inlet and outlet fluid passageways.

27. A shunt as set forth in claim 26, including a secondary flow control member including a rigid central support and an arch-like flexible resilient membrane, the central support being attached to the secondary valve membrane carrier and extending therefrom to support the resilient membrane with respect to the secondary valve seat to normally permit free fluid flow through the inlet fluid passageway, the resilient membrane further being positioned so that upon deformation of the encasement to flush the shunt, the membrane temporarily contacts the secondary valve seat in a manner to occlude the inlet fluid passageway.

28. A shunt as set forth in claim 21, including grommet means for non-adhesively attaching the bases to tubing means for channeling fluid to the inlet and from the outlet of the shunt.

29. A shunt as set forth in claim 21, including antechamber means for injecting medication into the shunt, the antechamber means having a relatively flexible encasement which defines an injection chamber, and a rigid needle shield situated within the injection chamber, wherein the needle shield includes needle stop means for preventing a tip of a needle from slipping off the needle shield during injection of medication into the injection chamber.

30. A shunt as set forth in claim 29, wherein the needle shield has a dog bone-like cross-section, and the ends of the needle shield are contoured to permit its abutment against the flexible encasement without occluding openings therethrough.

31. A flow control member for use with an implantable flow control valve for controlling the flow of fluid from one portion of the human body to another, the valve including a base invested within a valve housing, wherein the base forms a wall separating an inlet of the valve from an outlet of the valve, the base including at least one aperture therethrough for permitting flow of fluid through the valve from the inlet to the outlet, the flow control member comprising:

a rigid nail having an elongated shaft and an expanded head at an end of the shaft, the nail capable of being driven into the base and frictionally retained therein, or otherwise attached to the base, so that the head is suspended beyond the one side of the base; and

a flexible resilient membrane positioned and retained on the shaft adjacent to the head, the membrane being generally arch-shaped and resiliently biased for contacting the base in a manner preventing fluid flow through the aperture from the inlet of the valve to the outlet of the valve.

32. A flow control member as set forth in claim 31, wherein the head is suspended beyond the outlet side of the base, and wherein the flexible resilient membrane is resiliently biased to normally contact the outlet side of the base generally along the outer edges of the membrane in a manner surrounding the aperture through the base and forming a releasable seal between the outlet side of the base and the outer edges of the membrane.

33. A flow control member as set forth in claim 32, wherein the membrane includes a central reinforced section which surrounds and is adjacent to the nail, and a peripheral flexible section which engages the base to form the seal therebetween.

34. A flow control member as set forth in claim 33, wherein the thickness of the peripheral flexible section of the resilient membrane can be adjusted to alter the releasable seal characteristics of the flow control valve.

35. A flow control member as set forth in claim 34, wherein the nail is heat welded to the base.

36. A method for assembling an implantable shunt system including a flow control valve for controlling the flow of fluid from one portion of the human body to another, the valve including at least one base invested within a valve housing and at least one flow control member, wherein the at least one base forms a wall separating an inlet of the valve from an outlet of the valve, the at least one base including at least one aperture therethrough for permitting flow of fluid through the valve from the inlet to the outlet, the steps comprising:

fixing the at least one flow control member to the at least one base in a manner permitting only controlled unidirectional fluid flow through the shunt;

attaching a first section of tubing to the at least one base by sliding an end of the first section of tubing into the base, placing a first tubing grommet into the end of the first tubing section to expand the end thereof, and then pulling the first section of tubing so the expanded end of the first tubing section engages the at least one base and forms a frictional attachment therewith;

attaching a second section of tubing to the at least one base by sliding an end of the second section of tubing into the base, placing a second tubing grommet into the end of the second tubing section to expand the end thereof, and then pulling the second section of tubing so the expanded end of the second tubing section engages the at least one base and forms a frictional attachment therewith, wherein the first and second sections of tubing, when so attached, define, in part, the inlet and outlet of the valve;

sliding the housing over the tubing to envelope the at least one base and adjacent sections of the first and second sections of tubing; and

sealing the housing to respective adjacent portions of the first and second sections of tubing.

37. A method as set forth in claim 36, wherein the at least one base includes a first base defining a valve inlet fluid passageway, and a second base defining a valve outlet fluid passageway, the at least one flow control member including a first flow control member mounted to the first base, and a second flow control member mounted to the second base, and wherein the first section of tubing attaches to the first base and the second section of tubing attaches to the second base.

38. A method as set forth in claim 37, wherein the first flow control member is attached to the first base in a manner to normally permit free fluid flow through the inlet fluid passageway, but when the housing is deformed to flush the valve, the first flow control member is temporarily deformed to contact the first base in a manner to occlude the valve inlet fluid passageway.

39. A method as set forth in claim 37, wherein the second flow control member is attached to the second base to contact the second base in a manner normally occluding the outlet fluid passageway but selectively opening to permit controlled unidirectional flow therethrough.

40. A method as set forth in claim 37, wherein the first and second bases are spaced from one another within the housing to create, in connection with the housing, a flushing volume of fluid therebetween.

41. A method as set forth in claim 37, wherein each flow control member includes a rigid nail having an elongated shaft and an expanded head at an end of the shaft, and a flexible resilient membrane positioned and retained on the shaft adjacent to the head, the membrane being generally arch-shaped and wherein the membrane is fixed to the nail, and the nail is then press fit into its respective base until properly aligned, after which the nail is heat-welded to the respective base.

43. A method as set forth in claim 36, including the step of fixing a second end of the first tubing section to an antechamber.

44. A method as set forth in claim 43, including the steps of inserting a needle shield into the antechamber, and attaching a third section of tubing to the antechamber opposite the first section of tubing, to create a fluid flow pathway from the third section of tubing, through the antechamber, to the first section of tubing, and then through the valve to the second section of tubing.