Patent Publication Number: US-2021186539-A1

Title: System and method for lead extraction

Description:
FIELD OF THE DISCLOSURE 
     The present disclosure is of a system and method for removing an implanted lead from a patient and in particular, such a system and method that significantly improves the removal process of such a cardiac lead. 
     BACKGROUND OF THE DISCLOSURE 
     Pacemaker or ICD (implantable cardioverter-defibrillator) leads are fed into the heart through a large vein and connect the pacemaker to the implantation site of an electrode that terminates the lead which is implanted in the heart. Sometimes these inserted leads need to be removed due to one or more reasons including infection, malfunction, lead degradation, pacing system upgrade, or venous occlusion/stenosis. 
     Ideally (if the lead has been implanted for a short time) it should be possible to remove the lead by simple traction, however this is typically not the case. Lead removal is usually complicated by the lead&#39;s attachments to the patient&#39;s body at various places in the pathway from cardiac rhythm device to heart muscle, since the human body tends to incorporate foreign devices into tissue. These tissue growths (binding sites) thus hold the lead and pulling on the lead to remove it may actually endanger the patient by resulting in perforation of the heart or vein wall. 
     In these cases the most common method of removal uses a cutting device which threads over the lead and is moved along the lead to remove any tissue attachments with a cutting tube, cutting lasers or other cutting methods. These cutting sheath or laser sheath solutions also cause problems since the tissue that is dislodged by the sheath tends to build up in front of the sheath eventually clogging the pathway that the sheath was supposed to clear. 
     Another option is to leave the existing lead in position and insert a new lead but this is not a preferred solution as the unused lead provides additional obstruction to blood flow and heart valve function and may become infected. 
     Thus, there is an urgent need for an alternative solution for cardiac lead removal that significantly eases the process of lead removal and reduces the risk to patients. 
     SUMMARY OF THE DISCLOSURE 
     The present disclosure overcomes the deficiencies of the background art by providing an improved system and method for cardiac lead removal. The system comprises a lead removal stylet (LRS) that is inserted into the interior of the lead to be removed (hereinafter referred to as the lead). The LRS is moved through the lead&#39;s internal lumen and the LRS tip is extensively vibrated at tissue binding sites to dislodge the binding tissue. Alternatively the LRS is vibrated along the entire length of the LRS to simultaneously dislodge binding tissue at all binding sites allowing the lead to then be removed. 
     In order to detect a binding site the LRS is locked to a position against the inner walls of the lead, a low amplitude testing vibration is applied to the LRS, and the resistance to the vibration is measured. The level of resistance provides an indication as to whether the lead is stuck to local tissue. Where a binding site is detected, higher levels of vibration are applied to dislodge the binding tissue. If no tissue binding is detected then the LRS is moved to a next position in the lead and process is repeated until the lead is completely freed from tissue binding and can be removed. 
     The process of moving the LRS, checking for resistance, and applying tissue-disrupting vibration is preferably automated and controlled by an LRS controller which is a computing device. Alternatively the process is controlled by a human operator such as a medical professional operating the controller and making decisions about when and where to move the LRS, when to apply vibration, and how much to apply. Alternatively the process is controlled by a human operator with the controller providing automated assistance, for example allowing the controller to select the type and amplitude of vibration to apply. 
     According to some embodiments of the present disclosure, a method for extracting a lead from a patient comprises: providing a lead removal stylet; inserting the stylet into the lead; locking the stylet to a position inside the lead; and vibrating the stylet with tissue disrupting vibration to cause the lead to vibrate and to disconnect from binding tissue. Optionally the method further comprises vibrating the stylet with testing vibration to determine the resistance to the testing vibration. Preferably when the resistance to the testing vibration is high, applying tissue disrupting vibration. Optionally the method further comprises determining the resistance to testing vibration to determine whether further tissue disruption vibration is required. Optionally the method further comprises removing the lead. Preferably the method further comprises providing a controller for the LRS and wherein the locking the stylet to a position inside the lead, the vibrating the stylet with tissue disrupting vibration, the vibrating the stylet with testing vibration; and the determining the resistance to testing vibration to determine whether further tissue disruption vibration is required are performed by the controller. 
     According to some further embodiments of the present disclosure, a method for disconnecting a lead from binding tissue comprises: providing a lead removal stylet; inserting the stylet into the lead; locking the stylet to a position inside the lead adjacent to the binding tissue; and vibrating the stylet to cause the lead to vibrate and to disconnect from the binding tissue. 
     According to some further embodiments of the present disclosure, a system for cardiac lead extraction comprises: a lead removal stylet adapted for insertion into a lead and comprising a locking mechanism for locking the stylet to a portion of the inside wall of the lead; and means for vibrating the stylet. Preferably the system further comprises a controller, wherein the controller controls the movement of the stylet and the type of vibration applied. Optionally the type of vibration comprises vibration selected from the group consisting of: horizontal, rotational, vertical, a combination of directions; high amplitude; low amplitude; long period; short period; high frequency; low frequency; and a combination of the above. 
     Optionally the locking mechanism is adapted to transfer the vibrations from the stylet to the lead. Optionally the locking mechanism is radiopaque. Optionally the locking mechanism comprises a cable locking head formed of a flexible material manipulated by a locking cable. Optionally the locking mechanism comprises a balloon locking head comprising an inflatable material. Optionally the locking mechanism comprises a heated transform lock comprising a material that deforms when heated. Optionally the material that deforms comprises Nitinol. Optionally the locking mechanism comprises a wedge and dowel. Optionally the stylet is disposable. 
     According to some further embodiments of the present disclosure, a method for disconnecting a lead from binding tissue comprises: providing a lead removal stylet; inserting the stylet into the lead; locking the stylet inside the lead along the full length of the lead; and vibrating the stylet to cause the lead to vibrate and to disconnect from the binding tissue. Optionally the method further comprises providing a controller for the LRS and wherein the locking the stylet inside the lead, and the vibrating the stylet are performed by the controller. 
     According to some further embodiments of the present disclosure, a system for cardiac lead extraction comprising: a lead removal stylet adapted for insertion into a lead and comprising a locking mechanism for locking the stylet to a plurality of positions on the inside wall of the lead; and means for vibrating the stylet along its entire length. Preferably the system further comprises a controller, wherein the controller controls the movement of the stylet and the type of vibration applied. Preferably the locking mechanism transfers the vibrations from the stylet to the lead. Optionally the locking mechanism is radiopaque. 
     Optionally the locking mechanism comprises a plurality of cable locking heads each formed of a flexible material manipulated by a locking cable. Optionally the locking mechanism comprises a plurality of balloon locking heads comprising an inflatable material. Optionally the locking mechanism comprises a plurality of heated transform locks comprising a material that deforms when heated. Optionally the material that deforms comprises Nitinol. Optionally the locking mechanism comprises multiple wedge and dowel locks 
     Lead as used herein refers to a cardiac lead or cardiac catheter. Alternatively lead may also refer to other types of leads or catheters that are implanted in a patient and that require removal. As used herein distal refers to those parts of the lead or LRS that are furthest from the LRS controller and proximal refers to parts that are closest to the LRS controller. 
     Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The materials, methods, and examples provided herein are illustrative only and not intended to be limiting. 
     Implementation of the method and system of the present disclosure involves performing or completing certain selected tasks or steps manually, automatically, or a combination thereof. Moreover, according to actual instrumentation and equipment of preferred embodiments of the method and system of the present disclosure, several selected steps could be implemented by hardware or by software on any operating system of any firmware or a combination thereof. For example, as hardware, selected steps of the disclosure could be implemented as a chip or a circuit. As software, selected steps of the disclosure could be implemented as a plurality of software instructions being executed by a computer using any suitable operating system. In any case, selected steps of the method and system of the disclosure could be described as being performed by a data processor, such as a computing platform for executing a plurality of instructions. 
     Although the present disclosure is described with regard to a “computing device”, a “computer”, or “device”, or “mobile device” on a “computer network” or simply “network”, it should be noted that optionally any device featuring a data processor and the ability to execute one or more instructions may be described as a computer or one of the interchangeable terms listed above, including but not limited to any type of personal computer (PC), a server, a cellular telephone, an IP telephone, a smartphone, or a PDA (personal digital assistant). Any two or more of such devices in communication with each other may optionally comprise a “network”. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure will now be described in connection with certain preferred embodiments with reference to the following illustrative figures so that it may be more fully understood. With specific reference now to the figures in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present disclosure only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the disclosure. In this regard, no attempt is made to show structural details of the disclosure in more detail than is necessary for a fundamental understanding of the disclosure, the description taken with the drawings making apparent to those skilled in the art how the several forms of the disclosure may be embodied in practice. 
       In the drawings: 
         FIGS. 1A-1M  are schematic system diagrams showing a system for lead removal according to some embodiments of the present disclosure; 
         FIGS. 2A and 2B-2H  are respectively a flow diagram and illustrative drawings showing a method of use of a lead removal stylet according to at least some embodiments of the present disclosure; 
         FIGS. 3A-3C  are schematic system diagrams showing a system for lead removal according to some embodiments of the present disclosure; and 
         FIGS. 4A and 4B-4E  are respectively a flow diagram and illustrative drawings showing a method of use of a lead removal stylet according to at least some embodiments of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     In the detailed description, numerous specific details are set forth in order to provide a thorough understanding of the disclosure. However, it will be understood by those skilled in the art that these are specific embodiments and that the present disclosure may be practiced also in different ways that embody the characterizing features of the disclosure as described and claimed herein. In the drawings and descriptions set forth, identical reference numerals indicate those components that are common to different embodiments or configurations. 
     The present disclosure will be more fully understood from the following detailed description of the preferred embodiments thereof, taken together with the drawings. 
     Reference is now made to  FIGS. 1A-1D  which are schematic system diagrams showing a system for lead removal according to some embodiments of the present disclosure. As shown in  FIGS. 1A and 1B , a cardiac lead  30  has been implanted into a patient  80 . Lead  30  passes through veins  82  and terminates at its distal end  31  in an electrode  32  that is attached to the heart  84  of patient  80 . Lead  30  has an opening  36  at its proximal end that allows access to the interior  34  of lead  30 . For the purpose of lead removal it is assumed that lead  30  is disconnected from its source device (such as a pacing device which is not shown). 
     System  100  for lead removal comprises lead removal stylet (LRS)  110  which is a stylet adapted to fit into lead interior  34  via opening  36 . LRS  110  is preferably between 50-100 cm long. LRS  110  comprises a biocompatible material including but not limited to plastic, steel, titanium, or nitinol. 
     System  100  further comprises controller  120 . LRS  110  is attached at its proximal end  114  to controller  120 . Controller  120  is a computing device and preferably comprises a controller user interface  122  which comprises interface components as known in the art such as but not limited to a screen, keyboard, mouse or other components for use by an operator (not shown) such as a medical professional to control LRS  110  and to receive information about its activities or status. 
     Controller  120  also comprises vibration generator  124  which generates the vibrations used by LRS  110  which is attached thereto. Alternatively as shown in  FIG. 1B , LRS  110  comprises a vibration generator  118  which can be powered and controlled by controller  120 . Optionally system  100  comprises both of generators 124  and  118 . Generators  124  and/or  118  are capable of generating a range of vibration frequencies, amplitudes, and directions. Generators  124  and  118  are based on vibration generation mechanisms known in the art including electromagnetically induced vibration or vibration based on piezoelectric transducers. A non limiting example of a vibration generator  124  or  118  is shown in  FIG. 1M  where vibration generator  124  or  118  comprises a disc  126  attached to motor  127 . A vibration cord  129  is attached to disc  126  at attachment point  128 . As disc  126  is rotated in direction “A” by motor  127 , vibration cord  129  is alternately pushed and pulled in direction “B”. Vibration cord  129  is attached to LRS  110  and the mechanical movement “B” translates into a mechanical vibration of LRS  110 . Optionally vibration cord  129  is rigid. Optionally vibration cord  129  is rigid in a single plane. 
       FIGS. 1C-1N  show alternative embodiments of locking mechanism  113  used by LRS  110  to lock LRS  110  onto the inner wall  39  of lead  30 . The embodiments shown should not be considered limiting and potentially any suitable locking mechanism could be used. Locking mechanism  113  is preferably radiopaque. Locking mechanism  113  is adapted to transfer the vibrations, as described further below, of LRS  110  to lead  30  when locked to lead  30 . Locking mechanism  113  is preferably of the same or smaller diameter as outer wall  116  of LRS  110  when in “unlocked” mode allowing LRS  110  to pass through lead  30 . Locking mechanism  113  is preferably of a greater diameter than outer wall  116  of LRS  110  when in “locked” mode, pressing locking mechanism  113  against the inside wall  39  of lead  30  to lock LRS  110  to lead  30 . Locking mechanism  113  can then be unlocked so that LRS  110  can be removed from lead  30  or moved to another position in lead  30 . 
     In the embodiment of  FIGS. 1C and 1D  LRS  110  locking mechanism  113  comprises a cable locking head  144  formed of a flexible material. Locking head  144  is fixedly attached to locking cable  142  which extends from locking head  144  along cable lumen  143 . Locking cable  142  exits LRS  110  on its proximal side and can optionally be manipulated by a medical practitioner to lock or unlock LRS  110  to lead  30  or alternatively can be manipulated by controller  120  to lock or unlock LRS  110  to lead  30 .  FIG. 1C  shows locking mechanism  113  in an unlocked position and  FIG. 1D  shows locking mechanism in a locked position when locking cable  142  is pulled. When locking cable  142  is released, locking head  144  springs back to its original position to unlock from inner wall  39 . 
     In the embodiment of  FIGS. 1E and 1F  LRS  110  locking mechanism  113  comprises a balloon locking head  148  formed of an inflatable material. Locking head  148  is inflated via inflating lumen  149 . Inflating lumen  149  is connected on the proximal side of LRS  110  to an inflating device (not shown) and can optionally be manipulated by a medical practitioner to lock or unlock LRS  110  to lead  30  or alternatively can be manipulated by controller  120  to lock or unlock LRS  110  to lead  30 .  FIG. 1E  shows locking mechanism  113  in an unlocked position and  FIG. 1F  shows locking mechanism in a locked position when balloon  148  is inflated by a pressurized gas pumped into inflating lumen  149 . When the gas is allowed to escape from balloon  148 , balloon  148  deflates to unlock from inner wall  39 . 
     In the embodiment of  FIGS. 1G-1J  LRS  110  locking mechanism  113  comprises a heated transform lock  146  formed of a material that deforms when heated such as but not limited to Nitinol. Transform lock  146  is fixedly attached to heating wire  145  which extends from transform lock head  146  and exits LRS on its proximal side. Heating wire is heated to thereby heat transform lock  146  and to change the shape of lock  146  to press it against the inner wall  39  of lead  30  to lock LRS  110  at a chosen position. Heating wire  145  is connected at its proximal end to a heating mechanism (not shown) which can optionally be manipulated by a medical practitioner to lock or unlock LRS  110  to lead  30  or alternatively can be manipulated by controller  120  to lock or unlock LRS  110  to lead  30 . When heat is removed, lock  146  reverts to its original shape to unlock from inner wall  39 .  FIGS. 1G and 1I  show locking mechanism  113  in an unlocked position and  FIG. 1H and 1J  show locking mechanism in a locked position.  FIGS. 1G and 1H  show a transform lock  146  that curves when heated, and  FIGS. 1I and 1J  show a transform lock  146  that is cube shaped and expands when heated. 
     In the embodiment of  FIGS. 1K-1L  LRS  110  locking mechanism  113  comprises a wedge  147  and dowel  141 . In order to lock head  113  to lead  30 , dowel  141  is pulled onto wedge  147  or alternatively wedge  147  is driven into dowel  141  such as by rotating LRS  110 . When wedge  147  is driven into dowel  141 , dowel  141  is opened ( FIG. 1L ) so as to press against the inner wall  39  of lead  30  to lock LRS  110  at a chosen position. Wedge  147  can optionally be manipulated by a medical practitioner to lock or unlock LRS  110  to lead  30  or alternatively can be manipulated by controller  120  to lock or unlock LRS  110  to lead  30 .  FIG. 1K  shows dowel  141  in an unlocked mode. 
     Optionally LRS  110  is disposable such that it is used once for each patient. For a disposable LRS  110 , LRS  110  connects to controller  120  via interface  114  using a one-use connector (not shown). The one-use connector comprises a mechanism for one-time attachment of LRS  110  to controller  120 , such that the connector is damaged after removal from controller  120  preventing reuse. 
     In use, LRS  110  is inserted into lead interior  34  through opening  36  and then used to detach lead from binding tissue as will be described below. 
     Reference is now made to  FIGS. 2A and 2B-2H  which are respectively a flow diagram and illustrative drawings showing a method of use of a lead removal stylet according to at least some embodiments of the present disclosure. In step  202  of process  200  as shown in  FIG. 2B  LRS  110  is inserted into the interior of lead  30 . Steps  202 - 212  are preferably automated and performed by controller  120  or alternatively by controller  120  along with a human operator. 
     In step  204  and as in  FIG. 2B , LRS  110  is moved to a starting position inside lead  30  and as in  FIG. 2C ; LRS  110  is locked against the inner walls  39  of lead  30  by expanding locking mechanism  113 . This position is referred to herein as the locking position. The first locking position is preferably where distal end  112  of LRS  110  is adjacent to electrode  32  as in step  205  and as described further below. 
     It must now be determined whether lead  30  is held in place by binding tissue  88  or not. Therefore in step  206  and as shown in  FIG. 2C , low amplitude testing vibration  150  is activated in or applied to LRS by controller  120  and the resistance to the vibration is measured by controller  120  in step  208 . Depending on the measured resistance it is determined whether lead  30  is held in place by binding tissue  88  at the locking position. Test vibration  150  direction is horizontal, rotational, or vertical, or a combination of these in any or all planes. Vibration  150  direction, amplitude, period and frequency (collectively referred to as vibration type) are preferably predetermined based on experience with use of the system on a range of patients. Vibration  150  from LRS  110  is mechanically transferred to lead  30  at the locking position and thus lead  30  also vibrates based on the selected vibration type but to varying degrees depending on the presence of binding tissue  88 . 
     A low resistance to vibration indicates that lead  30  is not stuck in binding tissue  88  at the locking position. Therefore in step  212  and as in  FIG. 2D , LRS  110  is unlocked and insertion of LRS  110  continues until the next locking position. 
     Tissue binding typically occurs where lead  30  exposes a metallic surface to tissue. In these areas, which are visible on an x-ray showing lead  30 , locking positions may be 2-10 mm apart. In other parts of lead  30 , locking positions may be 10 mm or more apart. Once LRS  110  is locked to the next position, the process for checking resistance as in steps  206  and  208  is repeated ( FIGS. 2C, 2E, 2G ). 
     A high resistance to vibration in steps  206  and  208  indicates that lead  30  is stuck in binding tissue  88 .  FIG. 2E  illustrates a locking position where lead  30  is held in position by binding tissue  88 . Therefore if the resistance is high, LRS  110  is vibrated with a high amplitude tissue disrupting vibration  160  as at step  209  and as shown in  FIG. 2F . As described above, the vibration may be from internal generator  118  or controller generator  124  as in  FIGS. 1A and 1B . Tissue disrupting vibration  160  direction is horizontal, or vertical, or a combination of these. Vibration  160  direction, amplitude, period and frequency (collectively referred to as vibration type) are modified depending on the measured level of resistance. Vibration  160  type is preferably predetermined based on experience with use of the system on a range of patients. Vibration  160  from LRS  110  is mechanically transferred to lead  30  at the locking position and thus lead  30  also vibrates based on the selected vibration type. Vibration  160  ideally disrupts binding tissue  88  such as in  FIG. 2G . 
     After completion of the tissue disrupting vibration  160  period, steps  206  and  208  is repeated to determine whether there is still high resistance to testing vibration  150  from LRS  110 , in order to assess whether binding tissue  88  has been disrupted. If resistance remains high then step  209  is repeated and high amplitude tissue disrupting vibration  160  is again applied at the locking position. Subsequent applied tissue disrupting vibration  160  is typically of a greater type with increase in one or more of period, frequency or amplitude and also optionally a different vibration direction. 
     Following the vibration period, LRS  110  is again tested for resistance at the locking position as in steps  206  and  208 . Once it has been determined that resistance is lowered it is assumed that binding tissue  88  has been disrupted and that lead  30  is now disconnected from binding tissue  88 . Therefore in step  212  and as shown in  FIG. 2H , LRS  110  is now unlocked and moved to the next locking position. 
     The starting position for LRS  110  is preferably where locking mechanism  113  at distal end  112  of LRS  110  is positioned at lead distal end  31  where electrode  32  is located such as in step  205 . In such a case, it is known that electrode  32  must be removed from its attachment point in the heart  84  wall. Therefore LRS  110  is locked at the electrode  32  position and as in step  209 , LRS  110  is vibrated. As above, the vibration type  160  is adjusted by controller  120  or operator of controller  120 . The tissue disrupting vibration  160  of LRS  110  results in transmitted vibration to lead  30  at the locked electrode point. This vibration ideally results in electrode  32  detaching from attached tissue—in this case the heart  84  wall. 
     To confirm whether the electrode  32  has indeed been loosened, the resistance of LRS  110  at the electrode locking point is measured as in steps  206  and  208 . A high resistance indicates that electrode  32  is still attached and step  209  is repeated and tissue disrupting vibration  160  is again applied at the locking position. Subsequent applied tissue disrupting vibration  160  is typically of a greater type with increase in one or more of period, frequency or amplitude and also optionally a different vibration direction. Following the vibration period, LRS  110  is again tested for resistance at the locking position as in steps  206  and  208 . Once it has been determined that resistance is lowered it is assumed that electrode  32  has been dislodged. Therefore in step  212  LRS  110  is unlocked and moved to the next locking position. 
     Following the resistance measurement of steps  206  and  208  and determination that resistance is low, controller  120  or operator assess whether the final locking position has been reached in step  210 . If this is the case then in step  214  lead  30  is removed by pulling it out of patient  80 . 
     It should be appreciated from the above that LRS  110  is moved from locking position to locking position in a direction starting from proximal opening  36  of lead  30  and progressing till the distal end  31  of lead  30 . Alternatively and preferably, the first locking position of LRS  110  is the distal end  31  of lead  30  (to release electrode  32 ) followed by locking positions that are progressively closer to proximal opening  36  of lead  30 . Alternatively, the first locking position of LRS  110  is the distal end  31  of lead  30  (to release electrode  32 ) followed by LRS  110  being moved from locking position to locking position in a direction starting from proximal opening  36  of lead  30  and progressing till the distal end  31  of lead  30 . 
     Reference is now made to  FIGS. 3A-3C  which are schematic system diagrams showing a system for lead removal according to some embodiments of the present disclosure. As shown in  FIG. 3A  a cardiac lead  30  has been implanted into a patient  80 . The embodiment of  FIGS. 3A-3C  is the same as that shown in  FIG. 1A , including components with the same numbering. 
     In the embodiment of  FIGS. 3A-3C  LRS  310  comprises locking mechanism  313  that extends along the entire length of LRS  310  that is to be inserted into lead  30 . In the exemplary embodiment of  FIGS. 3B-3C , locking mechanism  313  comprises multiple balloons  370  formed of an inflatable material positioned along the outer surface of LRS  310 . Balloons  370  are inflated via inflating lumen  372 . Inflating lumen  372  is connected on the proximal side of LRS  310  to an inflating device (not shown) and can optionally be manipulated by a medical practitioner to lock or unlock LRS  310  to lead  30  or alternatively can be manipulated by controller  120  to lock or unlock LRS  310  to lead  30 .  FIG. 3B  shows locking mechanism  313  in an unlocked position (deflated) and  FIG. 3C  shows locking mechanism in a locked position when balloons  370  are inflated by a pressurized gas pumped into inflating lumen  372  to lock LRS  310  to the inner wall  39  of lead  30  along the entire length of insertion of LRS  310 . When the gas is allowed to escape from balloons  370 , balloons  372  deflate to unlock from inner wall  39  of lead  30 . Although the locking mechanism  313  of  FIGS. 3B-3C  uses a balloon locking mechanism, it should be appreciated that any type of locking mechanism, including but not limited to the full-length variations of the locking mechanisms described in  FIGS. 1C-1L  are possible, implemented with multiple locking points, and the specific embodiment of  FIGS. 1M-1N  should not be considered limiting. 
     Reference is now made to  FIGS. 4A and 4B-4E  which are respectively a flow diagram and illustrative drawings showing a method of use of a lead removal stylet according to at least some embodiments of the present disclosure. In step  402  of process  400  as shown in  FIG. 4B  LRS  310  is inserted into the interior of lead  30 . Steps  402 ,  405 ,  406 ,  408 , and  409  are preferably automated and performed by controller  140  or alternatively by controller  140  along with a human operator. 
     In step  405  and as in  FIG. 4B , LRS  310  is moved to a starting position inside lead  30  and as in  FIG. 4C ; LRS  310  is locked against a plurality of points of the inner walls  39  of lead  30  by expanding locking mechanism  313 . These positions are referred to herein as the locking positions. The starting locking position is preferably with LRS  310  pushed all the way into lead  30  such that the distal end  312  is adjacent to electrode  32 . 
     In step  409  LRS  310  is vibrated with a high amplitude tissue disrupting vibration  460  and as shown in  FIG. 4D . The vibration is generated from controller generator  124  as in  FIG. 3A . Tissue disrupting vibration  460  direction is horizontal, or vertical, or a combination of these. Vibration  460  direction, amplitude, period and frequency (collectively referred to as vibration type) are preferably predetermined based on experience with use of the system on a range of patients. Vibration  460  from LRS  310  is mechanically transferred to lead  30  at the plurality of locking positions where balloons  370  or other alternative locking mechanisms  313  lock against inner wall  39 , and thus lead  30  also vibrates based on the selected vibration type. Vibration  460  ideally disrupts binding tissue holding lead  30 . 
     It must now be determined whether lead  30  is still held in place by binding tissue or not. Therefore in step  406  and as shown in  FIG. 4E , low amplitude testing vibration  450  is activated in or applied to LRS  310  by controller  140  and the resistance to the vibration is measured by controller  140  in step  408 . Depending on the measured resistance it is determined whether lead  30  is still held in place by binding tissue. Test vibration  450  direction is horizontal, rotational, or vertical, or a combination of these in any or all planes. Vibration  450  direction, amplitude, period and frequency (collectively referred to as vibration type) are preferably predetermined based on experience with use of the system on a range of patients. Vibration  450  from LRS  310  is mechanically transferred to lead  30  at the plurality of locking positions where balloons  370  or other alternative locking mechanisms  313  lock against inner wall  39  and thus lead  30  also vibrates based on the selected vibration type but to varying degrees depending on the presence of binding tissue. 
     A high resistance to vibration in steps  406  and  408  indicates that lead  30  is stuck in binding tissue. In such cases, step  409  is repeated, and then steps  406  and  408  are repeated until a low resistance to vibration is detected. Subsequent reapplied tissue disrupting vibration  460  is optionally of a greater type with increase in one or more of period, frequency or amplitude and also optionally a different vibration direction. Optionally when a high resistance to vibration  450  is detected in steps  406  and  408 , LRS  310  is unlocked, shifted forward or backward within lead  30 , locked in position and step  409  is then repeated. 
     A low resistance to vibration  450  indicates that lead  30  is not stuck in binding tissue. Once it has been determined that resistance is lowered it is assumed that binding tissue has been disrupted and that lead  30  is now disconnected from binding tissue. Therefore in step  414  LRS  310  is now unlocked and lead  30  is removed by pulling it out of patient  80 . 
     It is appreciated that certain features of the presently disclosed subject matter, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the presently disclosed subject matter, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination. 
     It is to be understood that the disclosure is not limited in its application to the details set forth in the description contained herein or illustrated in the drawings. The disclosure is capable of other embodiments and of being practiced and carried out in various ways. Those skilled in the art will readily appreciate that various modifications and changes can be applied to the embodiments of the disclosure as hereinbefore described without departing from its scope, defined in and by the appended claims.