Chronically implantable medical devices configured for extraction and extraction devices for extracting chronically implanted medical devices

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.

What is claimed is: 
     
         1 . 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 defined by the distal region of the extraction device, the retrieval cavity is sized to fit over at least a proximal region of the IMD, the retrieval cavity further configured to fit at least partially over tissue overgrowing the proximal region of the IMD; and   one or more electrodes in the distal region of the extraction device, the one or more electrodes are positioned in the distal region to be 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 extend to the proximal region of the extraction device for connection to a source of ablating energy for ablating at least some of the tissue overgrowing the proximal region of the IMD.   
     
     
         2 . The extraction device of  claim 1 , further comprising a retrieval loop extendable into the retrieval cavity and having a proximal region extending out of the proximal region of the extraction device, the retrieval loop is manipulatable from the proximal region of the retrieval loop by an operator, the retrieval loop is 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   pull the IMD into the retrieval cavity of the extraction device.   
     
     
         3 . The extraction device of  claim 1 , 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. 
     
     
         4 . The extraction device of  claim 1 , further comprising a source of ablating energy operatively coupled to the one or more conductors. 
     
     
         5 . The extraction device of  claim 4  further comprising:
 a vacuum source operably coupled to the retrieval cavity for extracting debris that is dislodged in the ablation process. 
 
     
     
         6 . The extraction device of  claim 1  further comprising:
 a vacuum source operably coupled to the retrieval cavity for extracting debris that is dislodged in the extraction process. 
 
     
     
         7 . The extraction device of  claim 6 , comprising:
 a shaft extending from the proximal region of the extraction device to the distal region, the shaft defining one or more lumen extending from the proximal region of the extraction device to the retrieval cavity.   
     
     
         8 . The extraction device of  claim 7 , wherein the vacuum source is fluidly coupled to one of the one or more lumen in the proximal region of the extraction device. 
     
     
         9 . The extraction device of  claim 8 , further comprising:
 a retrieval loop extending through one of the one or more lumen and into the retrieval cavity, the retrieval loop having a proximal region extending out of the proximal region of the extraction device, the retrieval loop is manipulatable from the proximal region of the retrieval loop by an operator, the retrieval loop is 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   pull the IMD into the retrieval cavity of the extraction device.   
     
     
         10 . The extraction device of  claim 1 , wherein the one or more electrodes are positioned on an inner surface of the retrieval cavity facing the proximal region of the IMD when the proximal region of the IMD is positioned within the retrieval cavity. 
     
     
         11 . An extraction system comprising:
 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 extending to the proximal region of the extraction device; 
   an ablation energy source operatively connected to the one or more electrodes of the extraction device via the one or conductors, the ablation energy source configured to provide ablating energy to the one or more electrodes to ablate at least some of the tissue overgrowing the proximal region of the IMD.   
     
     
         12 . The extraction system of  claim 11 , further comprising a vacuum source operably coupled to the retrieval cavity of the extraction device for extracting debris being dislodged in the extraction process of the IMD. 
     
     
         13 . The extraction system of  claim 11 , 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. 
     
     
         14 . The extraction system of  claim 11 , 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. 
     
     
         15 . The extraction system of  claim 11 , wherein the proximal region of the extraction device is configured to remain outside of a body of a patient, and the ablation energy source is also configured to remain outside of a body of a patient. 
     
     
         16 . A method for removing a previously implanted Implantable Medical Device (IMD) from an implant site within a body of a patient, the method comprising:
 guiding a distal region of an extraction device to the implant site, the distal region of the extraction device defining a retrieval cavity that is configured to fit over a proximal region of the IMD and also over tissue overgrowing the proximal region of the IMD;   maneuvering the distal region of the extraction device such that at least part of the proximal region of the IMD is received by the retrieval cavity;   ablating at least some of the tissue overgrowing the proximal region of the IMD using one or more ablating electrodes of the extraction device, the one or more ablating electrodes of the extraction device are positioned adjacent to at least part of the proximal region of the IMD when the proximal region of the IMD is received by the retrieval cavity;   pulling the IMD further into the retrieval cavity; and   removing together the extraction device and the IMD from the body of the patient.   
     
     
         17 . The method of  claim 16  further comprising:
 after at least some of the tissue overgrowing the proximal region of the IMD has been ablated, thereby exposing a retrieval feature of the IMD, capturing the retrieval feature with a retrieval loop and pulling the IMD further into the retrieval cavity using the retrieval loop. 
 
     
     
         18 . The method of  claim 17 , further comprising manipulating the retrieval loop from outside the body to capture the retrieval feature and to pull the IMD further into the retrieval cavity. 
     
     
         19 . The method of  claim 16 , further comprising applying a vacuum to the retrieval cavity while ablating at least some of the tissue overgrowing the proximal region of the IMD, the vacuum for extracting at least some debris that is dislodged during the ablation process. 
     
     
         20 . The method of  claim 19 , wherein the vacuum is applied to a lumen outside of the body, wherein the lumen is in fluid communication with the retrieval cavity.