Enhanced chronic lead removal

• US 6,966,322 B2
• Filed: 04/19/2002
• Issued: 11/22/2005
• Est. Priority Date: 04/20/2001
• Status: Expired due to Fees

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Anderson, James M., Ebert, Michael J., McVenes, Rick D., Stokes, Kenneth B.
• Primary Examiner(s): Schaetzle, Kennedy
• Application Number:
  US10/126,747
• Publication Number:
  US 20030028224A1
• Time in Patent Office: 1,313 Days
• Field of Search: 607/36, 607/63, 607/96, 607/98, 607/99, 607/104, 607/105, 607/116, 607/119, 607/121, 607/122, 607/126, 607/153, 128/898, 128/899, 606/108, 606/21, 606/22, 606/24, 606/27
• US Class Current: 128/899
• CPC Class Codes: A61L 2400/18 Modification of implant surfaces in order to improve biocompatibility, cell growth, fixation of biomolecules, e.g. plasma treatment
• CPC Class Codes: A61L 31/10 Macromolecular materials
• CPC Class Codes: A61N 1/056 Transvascular endocardial electrode systems
• CPC Class Codes: A61N 1/37512 Pacemakers
• CPC Class Codes: C08L 33/26 Homopolymers or copolymers of acrylamide or methacrylamide

Abstract

An implantable medical device, perhaps a pacemaker lead, has a medical unit and a casing at least partially enclosing the medical unit. The casing is formed of a base polymer having surface modifying pendant groups formed of an acrylamide polymer or an acrylamide copolymer, perhaps polyisopropyl acrylamide. The base polymer may be a polyurethane, polyimide, fluoropolymer or polyolefin, for example.

Claims

1. A method of extracting a chronically implanted medical device, comprising:

changing the temperature of an implanted medical device having a medical unit and a casing at least partially enclosing the medical unit, the casing being formed of a base polymer having surface modifying pendant groups; and

extracting the implanted medical device.

2. A method according to claim 1, wherein the temperature of the implanted medical device is changed through a thermally active device included in the implanted medical device.

3. A method according to claim 1, wherein changing the temperature of the implanted medical device involves heating the implanted medical device to denature collagen surrounding the implanted medical device.

4. A method according to claim 3, wherein the implanted medical device is heated to a temperature of at least 40°

C.

5. A method according to claim 1, wherein the surface modifying end groups of the casing form a hydrogel within a patient.

6. A method according to claim 5, wherein the surface modifying end groups are formed of an acrylamide polymer or an acrylamide copolymer.

7. A method according to claim 5, wherein changing the temperature of the implanted medical device involves cooling the implanted medical device to change the water content of the hydrogel.

8. A method according to claim 7, wherein the implanted medical device is cooled to a temperature of at least 30°

C.