Method of making a temporary medical lead having biodegradable electrode mounting pad loaded with therapeutic drug

• US 6,748,653 B2
• Filed: 09/07/2001
• Issued: 06/15/2004
• Est. Priority Date: 10/04/1999
• Status: Expired due to Fees

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Lindemans, Fredric W., Gebhardt, Ursula, Hendriks, Marc
• Primary Examiner(s): Vo, Peter
• Assistant Examiner(s): NGUYEN, DONGHAI D
• Application Number:
  US09/947,433
• Publication Number:
  US 20020035388A1
• Time in Patent Office: 1,012 Days
• Field of Search: 298/42, 298/54, 298/57, 298/59, 298/68, 298/76, 295/921, 298/81, 298/83, 424/422, 424/423, 424/424, 424/425, 424/426, 424/428, 424/484, 600/374, 600/375, 607/116, 607/119, 607/120, 607/122, 607/129, 607/130, 607/131, 607/132
• US Class Current: 29/854
• CPC Class Codes: A61N 1/0587 Epicardial electrode systems; Endocardial electrodes piercing the pericardium
• CPC Class Codes: Y10T 29/49147 Assembling terminal to base
• CPC Class Codes: Y10T 29/49169 Assembling electrical component directly to terminal or elongated conductor
• CPC Class Codes: Y10T 29/49174 Assembling terminal to elongated conductor
• CPC Class Codes: Y10T 29/49208 by assembling plural parts

Abstract

A method of making a temporary medical electrical lead for pacing or defibrillating a heart of a patient. The method comprises providing at least one electrical conductor having proximal and distal ends; providing an insulating sheath formed of biocompatible material extending over and covering at least portions of the at least one electrical conductor, attaching an electrical connector assembly to the proximal end of the at least one electrical conductor for attachment to a device capable of providing pacing or defibrillation pulses; providing an electrode mounting pad in the form of a cast matrix structure made of a biodegradable, biocompatible material soluble in human body fluids and having an outer heart non-contacting surface and an inner heart contacting surface, the outer surface being less permeable to passage of body fluids than the inner surface and wherein the inner surface of the pad has larger interstices and is less dense than the outer surface; providing a drug for treating for treating a medical condition of the patient'"'"'s heart; loading the drug into the matrix of the pad; and attaching at least portions of the distal end of the at least one electrical conductor or of the electrode member to the electrode mounting pad.

Claims

1. A method of making a temporary medical electrical lead for pacing or defibrillating a heart of a patient, the lead comprising a lead body having proximal and distal ends, the lead body comprising at least one electrical conductor having proximal and distal ends, an insulative sheath formed of biocompatible and electrically insulative material, the sheath extending over and covering at least portions of the at least one electrical conductor, an electrical connector assembly attached to the proximal end of the at least one electrical conductor for attachment to a device capable of providing pacing or defibrillation pulses therethrough, and an electrode mounting pad disposed near the distal end of the lead body, at least one of the distal end of the at least one electrical conductor and an electrode member secured to the distal end of the at least one electrical conductor being attached to or integrated into the electrode mounting pad, the electrode mounting pad comprising a biodegradable, biocompatible material soluble in human body fluids, the material forming a matrix having open voids or spaces disposed therein, and a drug for treating a medical condition of the patient'"'"'s heart, the drug being incorporated in, or disposed on or in at least portions of the matrix, the drug being released to body fluids following implantation of the pad within the patient'"'"'s body adjacent the heart, the method comprising:

(a) providing the at least one electrical conductor;

(b) providing the insulative sheath;

(c) providing the electrode mounting pad in the form of a cast matrix structure having an outer heart non-contacting surface and an inner heart contacting surface, a collagenous material forming the outer surface of the collagen mounting pad being less permeable to passage of body fluids than a collagenous material forming the inner surface of the collagen mounting pad and wherein the collagenous material of the inner surface of the pad has larger interstices and is less dense than the collagenous material of the outer surface of the pad;

(d) providing the connector assembly;

(e) providing the drug;

(f) loading the drug into the matrix of the pad;

(g) disposing the insulative sheath over the at least portions of the electrical conductor;

(h) attaching the connector assembly to the proximal end of the at least one electrical conductor, and

(i) attaching at least portions of the distal end of the at least one electrical conductor or of the electrode member to the electrode mounting pad.

2. The method of claim 1, wherein loading the drug in the pad is accomplished by placing microspheres in the collagen pad, the microspheres containing a predetermined amount of a desired drug and releasing same at a predetermined rate upon contacting the body fluids of the patient.

3. The method of claim 1, wherein loading the drug in the pad is accomplished by suspending collagen in a solution, adding a desired water soluble drug in an appropriate quantity to the solution, dehydrating the solution, freeze drying the resulting material and forming the drug loaded collagen electrode mounting pad therefrom.

4. The method of claim 1, wherein loading the drug in the pad is accomplished by suspending collagen in a solution, adding a desired non-water-soluble drug in an appropriate quantity to the solution, dehydrating the solution, freeze drying the collagen pad, and forming the drug loaded collagen electrode mounting pad therefrom.

5. The method of claim 1, wherein loading the drug in the pad is accomplished by soaking the collagen pad in a solution containing a desired drug suspended in solution therein, removing the pad from the solution and drying it, and repeating the soaking and drying steps a sufficient number of times until a desired amount of drug has been imbibed into the electrode mounting pad.

6. The method of claim 1, wherein loading the drug in the pad is accomplished by co-valently coupling or bonding the desired drug into the matrix of the collagen electrode mounting pad, where the drug has a desired functional grouping which bonds to a corresponding functional grouping of the collagen.

7. The method of claim 1, wherein loading the drug in the pad is accomplished by disposing a paste or cream loaded with the desired drug on and into the matrix of the collagen electrode mounting pad.

8. The method of claim 7, wherein the cream or paste is disposed on a side of collagen electrode mounting pad configured to contact the heart.

9. The method of claim 1, wherein the collagen is crosslinked prior to being attached to the distal end of the at least one electrical conductor.

10. The method of claim 1, wherein the collagen is freeze dried prior to being attached to the distal end of the at least one electrical conductor.

11. The method of claim 1, wherein the collagen ETO-sterilized prior to being attached to the distal end of the at least one electrical conductor.

12. The method of claim 1, wherein providing the drug is preceded by selecting the drug from the group consisting of an anti-arrhythmic drug, an anti-inflammatory drug, an anti-biotic drug, a local anesthetic, and a pain relief agent.

13. The method of claim 1, wherein providing the drug is preceded by selecting the drug from the group consisting of quinidine, procalnamide, disopyramide, lidocaine, mexiletine, propafenone, fiencainide, a beta-adrenergic antagonist, bretyllum, sotalol, amiodarone, ibutilide, verpamil, diltazem, and andenosine.

14. The method of claim 1, wherein providing the drug is preceded by selecting the drug from the group consisting of dexamethazone, dexamethazone phosphate, a steroid, ibuprofen, aspirin, and baclomethazone.

15. The method of claim 1, wherein providing the drug is preceded by selecting the drug from the group consisting of genamyacin, penicillin, methacillin and tertracycline.