CHRONICALLY IMPLANTABLE MEDICAL DEVICES CONFIGURED FOR EXTRACTION AND EXTRACTION DEVICES FOR EXTRACTING CHRONICALLY IMPLANTED MEDICAL DEVICES

• US 20170281261A1
• Filed: 03/30/2017
• Published: 10/05/2017
• Est. Priority Date: 03/31/2016
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Shuros, Allan Charles, Sharma, Arjun D., Soltis, Brian
• Granted Patent: US 10,639,097 B2
• Time in Patent Office: Days
• CPC Class Codes: A61B 17/320016 Endoscopic cutting instruments, e.g. arthroscopes, resectoscopes A61B10/0233, A61B17/29, A61B17/3207 take precedence
• CPC Class Codes: A61B 17/32056 Surgical snare instruments for removing or smashing calculi A61B2017/2212; tonsillotomes A61B17/26
• CPC Class Codes: A61B 17/3209 Incision instruments
• CPC Class Codes: A61B 18/1445 at the distal end of a shaft, e.g. forceps or scissors at the end of a rigid rod
• CPC Class Codes: A61B 18/148 having a short, rigid shaft for accessing the inner body transcutaneously, e.g. for neurosurgery or arthroscopy
• CPC Class Codes: A61B 2017/00358 Snares for grasping
• CPC Class Codes: A61B 2017/320004 abrasive
• CPC Class Codes: A61B 2017/32006 with a cutting strip, band or chain, e.g. like a chainsaw
• CPC Class Codes: A61B 2018/00351 Heart
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2018/00601 Cutting
• CPC Class Codes: A61B 2018/141 Snare
• CPC Class Codes: A61N 1/056 Transvascular endocardial electrode systems
• CPC Class Codes: A61N 1/0573 chacterised by means penetrating the heart tissue, e.g. helix needle or hook
• CPC Class Codes: A61N 1/362 Heart stimulators heart defibrillators A61N1/39
• CPC Class Codes: A61N 1/372 Arrangements in connection with the implantation of stimulators
• CPC Class Codes: A61N 1/37205 Microstimulators, e.g. implantable through a cannula
• CPC Class Codes: A61N 1/3756 Casings with electrodes thereon, e.g. leadless stimulators
• CPC Class Codes: A61N 1/3787 from an external energy source
• CPC Class Codes: A61N 2001/0578 having means for removal or extraction

Abstract

Extraction devices for extracting chronically implanted devices such as leadless cardiac pacemakers (LCP). In some cases, the extraction devices may be configured to cut, tear or ablate through at least some of the tissue ingrowth around and/or over the chronically implanted device such that a retrieval feature on the chronically implanted device may be grasped for removal of the chronically implanted device. Implantable medical devices such as LCPs may include features that facilitate their removal.

Claims

1. An implantable medical device (IMD) configured for deployment within a chamber of a patient'"'"'s heart, the chamber including a chamber wall, the IMD comprising:

a housing configured to be positioned within the chamber of the patient'"'"'s heart proximate the chamber wall once the IMD is implanted, the housing extending from a distal end to a proximal end;

a power source disposed within the housing;

circuitry disposed within the housing and operatively coupled to the power source;

an electrode fixed relative to the housing and positioned to contact the chamber wall once the IMD is implanted, the circuitry configured to pace the patient'"'"'s heart via the electrode;

a fixation element for extending into the chamber wall at the implantation site to fix the IMD relative to the chamber wall at the implantation site, the fixation element disposed at or near the distal end of the housing;

a retrieval feature for retrieving the IMD after implantation, the retrieval feature disposed at or near the proximal end of the housing; and

the retrieval feature including an ablating region that is operatively coupled to the circuitry, wherein the circuitry is configured to selectively provide sufficient energy from the power source to the ablating region to cause tissue proximate the retrieval feature to ablate and to expose the IMD to a surrounding blood pool.

2. The IMD of claim 1, wherein the retrieval feature comprises a tether ring, and the tether ring forms at least part of the ablating region.

3. The IMD of claim 1, further comprising a cutting feature disposed at or near the proximal end of the housing.

4. The IMD of claim 3, wherein the cutting feature is actuatable from a retracted position in which the cutting feature is disposed within the housing and an extended position in which at least a portion of the cutting feature extends and faces proximally.

5. The IMD of claim 3, wherein the cutting feature forms at least part of the ablating region.

6. The IMD of claim 1, wherein the power source has sufficient stored energy to provide sufficient energy to the ablating region of the retrieval feature to cause the ablating region to be heated sufficiently to ablate tissue proximate the retrieval feature.

7. The IMD of claim 1, further comprising an antenna operably coupled to the circuitry, the antenna configured to receive radiated energy directed towards the IMD from a location exterior to the patient and to provide the energy to the circuitry, and wherein the circuitry is configured to direct at least some of the energy to the power source and ultimately to the ablating region.

8. The IMD of claim 7, wherein the radiated energy comprises ultrasound.

9. The IMD of claim 7, wherein the radiated energy comprises RF energy.

10. The IMD of claim 1, wherein the IMD comprises a leadless cardiac pacemaker (LCP).

11. An implantable medical device (IMD) configured for deployment within a patient, the IMD comprising:

a housing configured to be implantable within the patient at an implantation site;

a fixation element for fixing the IMD to the patient at the implantation site;

a retrieval feature secured relative to the housing for facilitating retrieval of the IMD from the implantation site; and

an extraction element secured relative to the housing, the extraction element configured to expose at least part of the retrieval feature from tissue overgrowth.

12. The IMD of claim 11, wherein the extraction element is configured to expose at least part of the retrieval feature from tissue overgrowth by ablating at least some of the tissue overgrowth.

13. The IMD of claim 11, wherein the extraction element is configured to expose at least part of the retrieval feature from tissue overgrowth by cutting at least some of the tissue overgrowth.

14. The IMD of claim 11, wherein the extraction element comprises a heating element that is selectively operatively coupled to a power source to ablate tissue away from the retrieval feature.

15. The IMD of claim 14, wherein the heating element comprises one or more heating elements that extend along an outer surface of the housing.

16. The IMD of claim 14, wherein the heating element comprises one or more heating elements that extend along an outer surface of the housing in a spiral shape.

17. The IMD of claim 11, wherein the extraction element comprises an energy-absorbable material that is sufficiently heated by an incident energy beam emanating from exterior to the patient to ablate or cut tissue overgrowth adjacent the extraction element.

18. An extraction device for removing a previously implanted Implantable Medical Device (IMD), the extraction device having a proximal region and a distal region, the extraction device comprising:

a retrieval cavity at the distal region of the extraction device that is sized to fit over at least a proximal region of the IMD, the retrieval cavity configured to fit at least partially over tissue overgrowing the proximal region of the IMD; and

one or more electrodes disposed within the retrieval cavity, the one or more electrodes positioned adjacent the proximal region of the IMD when the proximal region of the IMD is positioned within the retrieval cavity, the one or more electrodes are electrically coupled to one or conductors that can be connected to a source of ablating energy for ablating at least some of the tissue overgrowing the proximal region of the IMD.

19. The extraction device of claim 18, further comprising a retrieval loop extendable into the retrieval cavity and manipulatable from the proximal region of the extraction device by an operator, the retrieval loop configured to selectively engage a retrieval feature of the IMD once at least some of the tissue overgrowing the proximal region of the IMD has been ablated, and to pull the IMD into the retrieval cavity of the extraction device.

20. The extraction device of claim 18, wherein the one or more electrodes extend partially around a circumference of the retrieval cavity such that the tissue overgrowing the IMD is only partially cut away by ablation, leaving a flap that prevents the cut tissue from migrating away.