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EP-4739384-A1 - CATHETER DEVICE FOR TETHERING A HITCH OF AN IMPLANTABLE MEDICAL DEVICE DURING EXPLANTING THE MEDICAL DEVICE

EP4739384A1EP 4739384 A1EP4739384 A1EP 4739384A1EP-4739384-A1

Abstract

A catheter device (1) is presented for tethering a hitch (65) of an implantable medical device (61) during explanting. It comprises a catheter (3), a shaft (5) and a hitch grabbing mechanism (7). The hitch grabbing mechanism comprises a mandrel (11), plural tubes (13) and plural wires (15) each of the wires being longitudinally displaceable relative to the associated tube, the wire further partially extending to an associated neighboring tube (13''), wherein a first end (21) of each wire is fixed relative to the shaft and a second end (23) of each wire is displaceable relative to the shaft and is fixed to the mandrel, such that each wire together with its associated tube and its associated neighboring tube forms a loop (25) that can be pulled into a closed configuration, and pushed into an opened configuration.

Inventors

  • DEVICH, Nicholas
  • Austin, Eric
  • KHOURY VALENTINE, JULIA

Assignees

  • BIOTRONIK SE & Co. KG

Dates

Publication Date
20260513
Application Date
20240620

Claims (15)

  1. 1. A catheter device (1) for tethering a hitch (65) of an implantable medical device (61) during explanting an implantable medical device (61), wherein the catheter device (1) comprises: an elongate inner catheter (3), an elongate shaft (5) extending throughout an inner volume of the inner catheter (3) and being longitudinally displaceable relative to the inner catheter (3) between a retracted position and a protruding position, and a hitch grabbing mechanism (7) arranged at a distal end (9) of the shaft (5), wherein the hitch grabbing mechanism (7) comprises: - a mandrel (11) extending throughout an inner volume of the shaft (5) and being longitudinally displaceable relative to the shaft (5) between a proximal position and a distal position, - plural tubes (13) extending longitudinally from the distal end (9) of the shaft (5), - plural wires (15), each of the wires (15) extending with a first portion (17) of its length throughout an inner volume of an associated one (13’) of the tubes (13) and being longitudinally displaceable relative to the associated tube (13’), a second portion (19) of the wire (15) extending to an associated neighboring one (13”) of the tubes (13), wherein a first end (21) of each wire (15) is fixed relative to the shaft (5) and an opposite second end (23) of each wire (15) is displaceable relative to the shaft (5) and is fixed to the mandrel (11), such that each wire (15) together with its associated tube (13’) and its associated neighboring tube (13”) forms a loop (25) and such that, upon the mandrel (11) being pulled to the proximal position relative to the shaft (5), the loop (25) is pulled into a closed configuration having a minimum lateral dimension, and, upon the mandrel (11) being pushed to the distal position relative to the shaft (5), the loop (25) is pushed into an opened configuration having a maximum lateral dimension.
  2. 2. The catheter device (1) of claim 1, wherein at least one of the wires (15) and the tubes (13) is mechanically pre-formed for deflecting radially away from a longitudinal axis of the shaft (5).
  3. 3. The catheter device (1) of claim 1, wherein the first end (21) of each wire (15) is fixed to a distal end (27) of the associated neighboring tube (13”).
  4. 4. The catheter device (1) of claim 1, wherein at least one of the wires (15) and the tubes (13) comprises radiopaque material.
  5. 5. The catheter device (1) of claim 1, wherein the inner catheter (3) is steerable.
  6. 6. The catheter device (1) of claim 1, wherein the inner catheter (3) comprises an alignment cone (29) at its distal end (31) for at least one of accommodating and aligning at least an end portion of the implantable medical device (61) upon being pulled towards the inner catheter (3).
  7. 7. The catheter device (1) of claim 6, wherein the alignment cone (29) comprises radiopaque material.
  8. 8. The catheter device (1) of claim 1, further comprising a handle (33) coupled to a proximal end (35) of the inner catheter (3), the handle (33) comprising - a housing (37) coupled to the inner catheter (3), and - a grabber mechanism control (39) including an actuator (41) being displaceable relative to the housing (37), the actuator (41) being mechanically coupled to the mandrel (11) as well as to the shaft (5) in a manner such that an initial actuation of the actuator (41) induces changing the loop (25) between its closed configuration and its opened configuration whereas a subsequent actuation of the actuator (41) induces displacing the shaft (5) between its retracted position and its protruding position.
  9. 9. The catheter device (1) of claim 8, wherein the grabber mechanism control (39) is configured such that, upon the actuator (41) being initially actuated in a first actuation direction (43), the mandrel (11) is displaced from its proximal position to its distal position while the shaft (5) being held stationary relative to the inner catheter (3) and such that, upon the actuator (41) being subsequently actuated in the first actuation direction (43), the shaft (5) being displaced from its retracted position to its protruding position.
  10. 10. The catheter device (1) of claim 8, wherein the grabber mechanism control (39) is configured such that, upon the actuator (41) being initially actuated in a second actuation direction (45) , the mandrel (11) is displaced from its distal position to its proximal position while the shaft (5) being held stationary relative to the inner catheter (3) and such that, upon the actuator (41) being subsequently actuated in the second actuation direction (45), the shaft (5) being displaced from its protruding position to its retracted position.
  11. 11. The catheter device (1) of claim 8, wherein the grabber mechanism control (39) comprises a mandrel carriage (47) and a shaft carriage (49), wherein the mandrel carriage (47) is fixedly coupled to the actuator (41) and to the mandrel (11) and wherein the mandrel carriage (47) is displaceable relative to the shaft carriage (49) between a first position and a second position, wherein the shaft carriage (49) is fixedly coupled to the shaft (5) and wherein the shaft carriage (49) is displaceable relative to the housing (37) between a third position and a fourth position, wherein the mandrel carriage (47) interacts with the shaft carriage (49) such that upon the mandrel (11) being pushed in a first actuation direction (43) from the first position to the second position, no displacement forces are transferred from the mandrel carriage (47) to the shaft carriage (49), thereby leaving the shaft carriage (49) stationary relative to the housing (37), and such that, upon the mandrel carriage (47) being pushed from the second position further in the first direction, displacement forces are transferred from the mandrel carriage (47) to the shaft carriage (49), thereby pushing the shaft carriage (49) from its third position towards its fourth position, and/or wherein the mandrel carriage (47) interacts with the shaft carriage (49) such that upon the mandrel (11) being pulled in a second actuation direction (45) from the second position to the first position, no displacement forces are transferred from the mandrel carriage (47) to the shaft carriage (49), thereby leaving the shaft carriage (49) stationary relative to the housing (37), and such that, upon the mandrel carriage (47) being pulled from the first position further in the second direction, displacement forces are transferred from the mandrel carriage (47) to the shaft carriage (49), thereby pulling the shaft carriage (49) from its fourth position towards its third position.
  12. 12. The catheter device (1) of claim 1, further comprising an elongate outer catheter (51), wherein the inner catheter (3) extends throughout an inner volume of the outer catheter (51) and is longitudinally displaceable relative to the outer catheter (51).
  13. 13. The catheter device (1) of claim 12, wherein the outer catheter (51) is non-steerable.
  14. 14. The catheter device (1) of claim 12, wherein the outer catheter (51) comprises a protector cup (53) at its distal end (55), the protector cup (53) having a widened inner diameter for accommodating at least a portion of the implantable medical device (61).
  15. 15. The catheter device (1) of claim 12, wherein the outer catheter (51) comprises at least one of - a fluoroscopic marker (57) at its distal end (55), and - a visible marker (59) at a position distant to its distal end (55).

Description

CATHETER DEVICE FOR TETHERING A HITCH OF AN IMPLANTABLE MEDICAL DEVICE DURING EXPLANTING THE MEDICAL DEVICE The present invention relates to a catheter device. Particularly, the invention relates to an explantation catheter for tethering a hitch of an implantable medical device. The phrase “tethering a hitch of an implantable medical device” is to be understood within the frame of this application as establishing a connection between a tether and a hitch of the medical device, which is sometimes also referred to as snaring the medical device. Various medical devices may be implanted into a patient’s body. As an example, which is mainly discussed hereinafter, a miniaturized implantable leadless pacemaker (ILP sometimes referred as intracardiac pacemaker) may be implanted directly into a cardiac chamber in the patient’s heart. Typically, such medical devices are implanted using a catheter device. Therein, an elongate catheter may carry the medical device at its distal end. The catheter together with the medical device may be introduced and guided along vessels. In the case of an ILP, the catheter is guided towards the heart such that the ILP at its end is introduced into one of the cardiac chambers and may be fixed at an inner surface of a cardiac wall using a fixation mechanism including for example tines. Therein, the ILP is to be located at a suitable implantation site such that its electrode may correctly induce electric pacing pulses for stimulating cardiac tissue. However, in some cases, an implanted medical device may have to be explanted. For example, if the ILP has not been implanted at a suitable site or if it does not operate properly, the ILP may have to be explanted and replaced by a new device in these situations. This may occur particularly in acute situations after implanting the medical device, i.e. as long as no substantial in-growth and encapsulation of the implant has taken place. As an alternative, the catheter device may be used to explant an ILP at the end of its life time. Various techniques and technologies have been developed for explanting an implanted medical device. For example, a conventional implantation catheter may be used for attempting to catch an implanted medical device and withdraw it from its former implantation site. Therein, the implantation catheter may be preloaded with a snare to resheathe for example a tine-based ILP. However, such approach is generally complex and may often not be applied in an easy, safe and reliable manner. Further approaches have been described for example in WO 2020/187666 Al disclosing a catheter device for repositioning or explanting an implantable medical device or in WO 2019/166230 Al disclosing a recapture assembly for a catheter system, a catheter system and a method for retrieval of an implant. It is an object of the present invention to provide an alternative catheter device which is configured for advantageous capturing and explanting an implantable medical device. Particularly, it is an object of the present invention to provide a catheter device which is specifically configured for tethering a hitch of an implanted medical device during explanting the same in an easy, safe and/or reliable manner. Furthermore, it is an object of the present invention to provide a catheter device which may serve for explanting an ILP upon being implanted in one of a ventricle or an atrium of a heart. Such objects may be met with the subject-matter of the independent claim. Advantageous embodiments are defined in the dependent claims as well as the corresponding specification and figures. According to an aspect of the invention, a catheter device is presented, the catheter device being specifically configured for tethering a hitch of an implantable medical device during the explanting of the implantable medical device. The catheter device comprises an elongate inner catheter, an elongate shaft and a hitch grabbing mechanism. The elongate shaft extends throughout an inner volume of the inner catheter and is longitudinally displaceable relative to the inner catheter between a retracted position and a protruding position. The hitch grabbing mechanism is arranged at a distal end of the shaft. Therein the hitch grabbing mechanism comprises a mandrel, plural tubes and plural wires. The mandrel extends throughout an inner volume of the shaft and is longitudinally displaceable relative to the shaft between a proximal position and a distal position. The tubes extend longitudinally from a distal end of the shaft. Each of the wires extends with a first portion of its length throughout an inner volume of an associated one of the tubes and is longitudinally displaceable relative to the associated tube, with a second portion of the wire extending to an associated neighboring one of the tubes. Therein, a first end of each wire is fixed relative to the shaft and an opposite second end of each wire is displaceable relative to the shaft and is fixed to the mandrel.