Myocardial steroid releasing lead

• US 5,324,325 A
• Filed: 03/26/1993
• Issued: 06/28/1994
• Est. Priority Date: 06/27/1991
• Status: Expired due to Term

• Current Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Siemens Pacesetter, Inc. (Abbott Laboratories Incorporated)
• Inventors: Moaddeb, Shahram
• Primary Examiner(s): Cohen, Lee S.
• Assistant Examiner(s): GILBERT, SAMUEL G
• Application Number:
  US08/038,564
• Time in Patent Office: 459 Days
• Field of Search: 128/642, 128/785, 128/786, 128/419 P, 607/119, 607/120, 607/121, 607/126, 607/127, 607/130, 607/131
• US Class Current: 607/120
• CPC Class Codes: A61N 1/0575 with drug delivery

Abstract

A lead for delivering electrical stimulation pulses to pace the cardiac muscle and for sensing electrical signals occurring in the cardiac muscle is disclosed which as a rigid helix disposed at the extreme distal end thereof which rigid helix may be operated by the implanting physical to extend the tip of the rigid helix from a stored position within the distal end of the lead to a deployed position projecting from the distal end of the lead. The rigid helix pierces and engages the heart tissue to anchor the lead in place within the heart. The tip of the rigid helix has an axial bore therein which is filled with a therapeutic medication such as a steroid or steroid-based drug for inhibiting inflammation and promoting tissue growth. After the tip of the helical screw is disposed in the heart tissue, the therapeutic medication will be slowly eluted into the surrounding tissue, thereby minimizing the trauma of implantation and assisting in the anchoring of the lead.

Claims

1. A pacing lead comprising:

a flexible cable containing at least one electrical conductor, said flexible cable having a proximal end and a distal end;

an electrode housing member made of nonconductive material and having a proximal end and a distal end, said distal end of said flexible cable entering said electrode housing member at said proximal end of said electrode housing member;

at least one electrode located at said distal end of said electrode housing member, said electrode being in electrical communication with said electrical conductor;

active fixation means for actively fixing said electrode in close proximity to heart tissue, said active fixation means having a proximal end and a distal end, said proximal end of said active fixation means being connected to said electrode housing; and

storing means for storing a therapeutic medication to be dispensed into heart tissue, said storing means being located entirely within said active fixation means and communicating with the outside of said active fixation means only at the distal end thereof.

2. A pacing lead, as defined in claim 1, wherein said active fixation means extends from said distal end of said electrode housing member.

3. A pacing lead, as defined in claim 2, wherein said electrode comprises:

an annular member located at said distal end of said electrode housing member, said active fixation means being located at least partially within said annular member.

4. A pacing lead, as defined in claim 1, wherein said active fixation means is deployable from said distal end of said electrode housing member, said active fixation means being moveable between a first position in which it does not extend beyond said electrode, and a second position in which it extends beyond said electrode.

5. A pacing lead, as defined in claim 1, wherein said active fixation means is in electrical communication with said electrical conductor.

6. A pacing lead, as defined in claim 1, wherein said active fixation means is electrically insulated from said electrical conductor.

7. A pacing lead, as defined in claim 1, wherein said distal end of said active fixation means comprises:

a sharpened tip.

8. A pacing lead as defined in claim 7, wherein said active fixation means comprises:

a helix.

9. A pacing lead, as defined in claim 8, wherein said storing means additionally comprises:

an internal bore located within said helix, said internal bore having an opening adjacent to and in communication with the exterior of said sharpened tip.

10. A pacing lead, as defined in claim 1, wherein said therapeutic medication comprises:

steroids or steroid-based drugs.

11. A pacing lead, as defined in claim 1, wherein said therapeutic medication is compounded into a solid material.

12. A pacing lead, as defined in claim 1, wherein said therapeutic medication is compounded into a material selected from the group consisting of silicone rubber, polyurethane, polyethylene, polysulphone, and a ceramic material.

13. A pacing lead comprising:

a flexible cable containing at least one electrical conductor, said flexible cable having a proximal end and a distal end;

an electrode housing member made of nonconductive material and having a proximal end and a distal end, said distal end of said flexible cable entering said electrode housing member at said proximal end of said electrode housing member;

at least one electrode located at said distal end of said electrode housing member, said electrode being in electrical communication with said electrical conductor;

a helix having a sharpened distal tip, for actively fixing said electrode in close proximity to heart tissue, said helix having a proximal end and a distal end, said proximal end of said helix being connected to said electrode housing; and

storing means for storing a therapeutic medication to be dispensed into heart tissue, said storing means being located entirely within said helix and communicating with the outside of said helix only at the distal end thereof.

14. A pacing lead, as defined in claim 13, wherein said storing means is in communication with said sharpened distal tip of said helix.

15. In a body implantable lead for the delivery of stimulation energy to a desired body site of the type having at least one electrode carried by said lead which is adapted for positioning adjacent to said desired body site, and an active fixation member for maintaining said electrode adjacent said desired body site, the lead and the active fixation member each having la proximal end and a distal end, the improvement wherein said lead further comprises:

drug dispensing means for dispensing a drug, said drug dispensing means being carried by said active fixation member, including means disposed entirely within said active fixation member for storing a drug to be dispensed while allowing dispensing of said drug only at the distal end of said active fixation member to counter undesirable interactions between said lead and the body site.

16. The body implantable lead of claim 15, wherein said drug is compounded into a solid material, said solid material being carried by said lead entirely within said active fixation member.

17. A pacing lead comprising:

a flexible cable containing at least one electrical conductor, said flexible cable having a proximal end and a distal end; and

an anchoring and energy delivery structure having a proximal end and a distal end, said proximal end of said structure being connected to said distal end of said cable, said structure comprising;

a rigid helix having a sharpened tip adapted to pierce heart tissue and contained within an opening in said distal end of said structure;

means for mechanically advancing said helix to cause said helix to project from said distal end and to screw said helix into heart tissue to anchor said pacing lead; and

means, contained entirely within said helix and in open communication with the outside of said helix only at said sharpened tip, for storing a therapeutic medication and for releasing said therapeutic medication directly through said sharpened tip after said helix has been screwed into heart tissue.

18. A pacing lead, as defined in claim 17, wherein said therapeutic medication is selected from the group consisting of steroids and steroid-based drugs.

19. A pacing lead comprising:

a flexible cable containing at least one electrical conductor, said flexible cable having a proximal end and a distal end; and

an anchoring and energy delivery structure having a proximal end and a distal end, said proximal end of said structure being connected to said distal end of said cable, said structure comprising;

a rigid helix having a sharpened tip adapted to pierce heart tissue and contained within an opening in said distal end of said structure;

means for mechanically advancing said helix to cause said helix to project from said distal end and to screw said helix into heart tissue to anchor said pacing lead; and

a bore located entirely within said helix and in open communication with the outside of said helix only at said sharpened tip of said helix, said bore containing a therapeutic drug so that after said helix has been screwed into said heart tissue said therapeutic drug is in direct contact with said heart tissue and is directly released into said heart tissue through said sharpened tip of said helix.

20. A pacing lead, as defined in claim 19, wherein said therapeutic drug is selected from the group consisting of steroids and steroid-based drugs.