WO2025011915A1

WO2025011915A1 - Catheter device for tethering a hitch of an implantable medical device during explanting the medical device

Info

Publication number: WO2025011915A1
Application number: PCT/EP2024/067206
Authority: WO
Inventors: Nicholas DEVICH; Eric Austin; Julia Khoury Valentine
Original assignee: Biotronik SE and Co KG
Current assignee: Biotronik SE and Co KG
Priority date: 2023-07-07
Filing date: 2024-06-20
Publication date: 2025-01-16
Anticipated expiration: 2026-01-07

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.

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. As a result of such configuration, each wire together with its associated tube and its associated neighboring tube forms a loop such that, upon the mandrel being pulled to the proximal position relative to the shaft, the loop is pulled into a closed configuration having a minimum lateral dimension, and, upon the mandrel being pushed to the distal position relative to the shaft, the loop is pushed into an opened configuration having a maximum lateral dimension.

Proximal is to be understood as close to the physician handling the catheter within the frame of the application. In contrast distal means away from the physician.

Briefly summarised and without limiting the scope of the invention, basic ideas underlying embodiments of the invention and associated possible advantages will be roughly described as follows:

The catheter device described herein differs from conventional catheter devices mainly with regards to its specific hitch grabbing mechanism. This hitch grabbing mechanism includes wires and tubes which are configured and interoperating in a specific manner such as to enable precisely opening and closing a loop controlled by a simple longitudinal motion of a mandrel. Furthermore, the hitch grabbing mechanism cooperates with the shaft and the inner catheter of the catheter device such that the loop may first be opened while keeping it stationary relative to the inner catheter and, subsequently, the opened loop may be pushed in a distal direction away from the inner catheter in order to then catch a hitch of an implanted medical device with the protruding loop. Subsequently, the hitch grabbing mechanism may be operated such as to first close its loop before then retracting the loop together with the medical device towards the inner catheter. In order to correctly operate the hitch grabbing mechanism, the catheter device may comprise a specific handle including a grabber mechanism control which is specifically configured for displacing the mandrel relative to the shaft and displacing the shaft relative to the inner catheter, wherein such displacement motions are specifically executed in a predetermined sequence. Furthermore, the catheter device may comprise an outer catheter enclosing the inner catheter and being longitudinally displaceable relative to the inner catheter, wherein the outer catheter may be specifically configured for re-sheathing the explanted medical device.

In the following, possible features of embodiments of the invention and associated possible advantages will be described in more detail.

The catheter device comprises an elongate catheter. This elongate catheter is named herein inner catheter as the catheter device may comprise another catheter enclosing this inner catheter and therefore being named herein outer catheter. Alternatively, the inner catheter could be named first catheter and the outer catheter could be named second catheter. The inner catheter is adapted for example with regards to its length, diameter and bending capability for being introduced into vessels of the patient and being forwarded until reaching an implantation site for example within a cardiac chamber, particularly within a ventricle or an atrium. For example, a length may typically be in a range of between 20 cm and 2 m, in particular between 1,00 m and 1,60 m, a diameter may typically be in a range of between 2 mm and 2 cm, in particular between 2 mm and 8 mm, and a bending capability may enable a bending radius of down to a few centimeters.

The catheter device further comprises an elongate shaft extending through an inner volume of the inner catheter. I.e., an outer diameter of the shaft is smaller than an inner diameter of the inner catheter. The shaft may be displaced linearly in a longitudinal direction within the inner catheter. Particularly, the shaft may be displaced between a retracted position in which it (i.e. its geometrical center) is closer to a proximal end of the inner catheter than in a protruding position and the protruding position in which it is closer to a distal end of the inner catheter than in the retracted position.

The catheter device further comprises a hitch grabbing mechanism. The hitch grabbing mechanism is arranged at, i.e. may be fixed to, a distal end of the shaft. The hitch grabbing mechanism comprises a mandrel, plural tubes and plural wires which interact with each other such as to form a loop which may be suitably opened and closed upon displacing the mandrel relative to the shaft. The hitch grabbing mechanism may comprise at least two tubes, in particular 3 to 5 tubes, and a corresponding number of wires.

The mandrel is an elongate and preferably metallic member like a wire, cable, rod, etc. which may be bent and which may transfer pulling forces as well as pushing forces along its longitudinal direction upon being guided within the shaft. An outer diameter of the mandrel is generally smaller than an inner diameter of the shaft such that the mandrel may be accommodated within the shaft and may be longitudinally displaced relative to the shaft. Particularly, the mandrel may be pulled to a proximal position in which it (i.e. its geometrical center) is closer to a proximal end of the shaft than in a distal position and may be pushed to the distal position in which it is closer to a distal end of the shaft than in the proximal position.

The tubes are arranged at and extend from the distal end of the shaft. The tubes are elongate, hollow and bendable. However, the tubes are preferably substantially non-compressible along their longitudinal direction. The tubes may be made with various materials such as plastics, metals, etc. The tubes may be pre-formed and/or pre-stressed into an intended shape, wherein such shape may be linear or curved.

The wires are also arranged at and extend from the distal end of the shaft. The wires are elongate and bendable. The wires are preferably substantially non-compressible along their longitudinal direction. The wires generally have an outer diameter being smaller than an inner diameter of the tubes such that at least a first portion of each of the wires may extend throughout the inner volume of an associated one of the tubes and may be displaced longitudinally relative to the associated tube. The wires may be made with a metal material. Preferably, the wires comprise or consist of a metal material enabling some form setting. For example, the wires may comprise or consist of Nitinol. Nitinol wires are usually kink resistant and super elastic. These properties in combination with a set form of the wires lead to loops very suitable for snaring the hitch of an ILP. The wires may be pre-formed and/or pre-stressed into an intended shape, wherein such shape may be linear or curved.

The wires may comprise some radio-opaque material to make them more visible under fluoroscopy. Although nitinol wires are explicitly mentioned above, the wires may be made of any fluoroscopically visible material or non-fluoroscopically visible material which enables form setting and provides some kink resistance and/or super elasticity.

The wires, the tubes and the mandrel are coupled to each other and/or to the shaft and/or are displaceable relative to each other and/or to the shaft in a specific manner. Particularly, each wire extends with its first portion throughout an inner volume of the associated tube while being displaceable relative to the associated tube, whereas its second portion generally extends distant to the associated tube and towards an associated neighboring one of the tubes. Accordingly, the associated tube and the associated neighboring tube are interconnected with each other via the wire connecting both. Thereby, the two neighboring tubes together with the interconnecting wire form a loop.

Therein, a first end of each wire is fixed relative to the shaft, i.e. the first end of such wire is stationary at the shaft or is arranged with a predetermined distance with respect to the shaft as long as the shaft is stationary and the first end of the wire may be moved together with the shaft. The second end of the wire is fixed to the mandrel and may be displaced relative to the shaft.

Due to such configuration and fixation of the first and second ends, the wire together with the associated tube and the associated neighboring tube forms a loop which may be closed by pulling the mandrel to its proximal position relative to the shaft and which may be opened by pushing the mandrel to its distal position relative to the shaft. Therein, in its closed configuration, the loop has a minimum lateral dimension. Particularly, by withdrawing the mandrel to its proximal position, the wire attached thereto is pulled such that it pulls the associated tube and the associated neighboring tube in a direction towards each other, thereby reducing the distance between both tubes and, accordingly, reducing the lateral dimension of the loop to its closed configuration. In the other direction, by pushing the mandrel to its distal position, the wire attached thereto is pushed such that it pushes the associated tube and the associated neighboring tube in a direction away from each other, thereby increasing the distance between both tubes and accordingly increasing the lateral dimension of the loop to its opened configuration.

Accordingly, in such specific hitch grabbing mechanism, the loop may be precisely opened or closed by suitably displacing the mandrel relative to the enclosing shaft, while the shaft itself together with its loop at its distal end may remain substantially stationary. In other words, as a result of the specific arrangement of plural tubes and plural wires extending through the tubes and being fixed at one end relative to the shaft and at the other end relative to the mandrel, the hitch grabbing mechanism is able to precisely open and close the loop, wherein the opening and closing motion may be precisely controlled by a simple linear displacement of the mandrel relative to the shaft.

According to an embodiment, at least one of the wires and the tubes is mechanically preformed for deflecting radially away from a longitudinal axis of the shaft.

In other words, at least one of the wires and/or at least one of the tubes is mechanically preformed such as, upon no external forces being applied to the respective wire or tube, to deflect in a direction away from the longitudinal axis of the shaft. In particular, the wires are pre-formed in a way that they form a circle at the distal end that expands radially from a longitudinal axis of the shaft. Accordingly, upon the wires are no longer forced to a straight shape along the longitudinal axis of the shaft, i.e. upon the mandrel being in its distal position, the wires and/or tubes deflect into the opened (pre-formed) configuration having the maximum lateral dimension. However, upon the wires being pulled by pulling the mandrel in its proximal position, the wires pull their associated tubes and neighboring tubes towards each other and therefore deflect against the wire’ s intrinsic pre-formed configuration into the closed configuration having the minimum lateral dimensions. According to an embodiment, the first end of each wire is fixed to the associated neighboring tube. The wire may be glued or fastened to the distal end of the neighboring tube, inserted into a lumen of the neighboring tube and fixed there and/or passed through a lumen of the neighboring tube and fixed somewhere proximally to the shaft.

Generally, the first end of the wire may be attached to any component as long as it is fixed relative to the shaft such that, in contrast to the second end of the wire, this first end of the wire is not displaced together with the mandrel. However, it has been found to be beneficial to attach the first end of the wire fixedly to an associated neighboring tube. In other words, while a portion of the wire extends through the associated tube, another portion of the wire extends from the associated tube to the associated neighboring tube and is fixed with its distal (first) end to or within the neighboring tube or it is passed through the neighboring tube and fixed to the shaft. Such fixation may be established easily and reliably.

According to an embodiment, at least one of the wires and the tubes comprises radiopaque material.

In other words, at least one of the wires and/or at least one of the tubes may comprise or may consist of radiopaque material. Due to the provision of such radiopaque material, the respective wire or tube may be visible via fluoroscopy taken during the explantation procedure. This may simplify correctly positioning the hitch grabbing mechanism with its loop for tethering the hitch of the implanted medical device. Furthermore a physician may be able to observe the hitch grabbing mechanism and its interaction with the medical device, which eases the attempt to catch the medical device with the grabbing mechanism.

According to an embodiment, the inner catheter is steerable.

A steerable catheter may generally be bent laterally into a curved shape. Due to such bending capability, the steerable catheter may be precisely navigated and displaced for example throughout vessels and may follow a course of the vessels. Particularly, upon reaching a cardiac chamber, a distal end of the steerable catheter may be precisely positioned relative to a cardiac wall defining the chamber. Accordingly, as the catheter may be precisely steered, the shaft extending through the catheter and particularly the hitch grabbing mechanism arranged at the distal end of this shaft may be precisely navigated and arranged for example relative to an implanted medical device to be explanted.

According to an embodiment, the inner catheter comprises an alignment cone at its distal end for accommodating and/or aligning at least an end portion of the implantable medical device upon being pulled towards the inner catheter.

The alignment cone is generally formed by a portion of the inner catheter at or close to the distal end of the inner catheter, such portion having an increased inner diameter in comparison to the inner diameter of the rest of the inner catheter. Due to such increased inner diameter and is due to its cone shape, the alignment cone may have a shape which is substantially complementary to a shape of the end portion of the implanted medical device (i.e. hitch). Accordingly, during the explantation procedure, the medical device may be grabbed at its end portion with the hitch grabbing mechanism and the inner catheter may be advanced toward the medical device such as to be finally aligned with and/or at least partially accommodated within the alignment cone. In such configuration, the explanted medical device is securely held at the distal end of the inner catheter.

According to an embodiment, the alignment cone comprises radiopaque material.

Due to the provision of such radiopaque material, at least a portion of the alignment cone may be visible in a fluoroscopy during the explantation procedure. Accordingly, correct explantation of the medical device and accommodation of the medical device in the alignment cone may be monitored.

According to an embodiment, the catheter device further comprises a handle coupled to a proximal end of the inner catheter. Therein, the handle comprises a housing coupled to the inner catheter, and a grabber mechanism control. The grabber mechanism control includes an actuator being displaceable relative to the housing. The actuator is mechanically coupled to the mandrel as well as to the shaft in a manner such that an initial actuation of the actuator induces changing the loop between its closed configuration and its opened configuration whereas a subsequent actuation of the actuator induces displacing the shaft between its retracted position and its protruding position.

The handle may be used for displacing the inner catheter together with its shaft and its hitch grabbing mechanism to an intended explantation site. Having reached such site, the actuator for the grabber mechanism control may be used for suitably bringing the loop of the hitch grabbing mechanism to its opened configuration before then displacing the shaft together with the opened loop towards its protruding position in order to approach the hitch of the implanted medical device.

Therein, it is beneficial that the actuator is coupled to the mandrel and to the shaft in a specific manner such that, upon actuating the actuator, first, the loop is brought to its opened configuration and, only subsequently, the shaft and the opened loop are then displaced towards the medical device. Due to such sequential loop-opening and loop-displacement, catching the hitch of the medical device may be substantially simplified. Furthermore, due to the specific mechanical coupling between the actuator and the mandrel as well as the shaft, upon having caught the hitch, first, the loop is brought to its closed configuration and, only subsequently, the shaft together with the loop are then pulled back to the retracted position. Again, due to such sequential loop-closing and loop-displacement, the explantation procedure may be substantially simplified.

According to a further specified embodiment, the grabber mechanism control is configured such that, upon the actuator being initially actuated in a first actuation direction, the mandrel is displaced from its proximal position to its distal position while the shaft is held stationary relative to the inner catheter and such that, upon the actuator being subsequently actuated in the first actuation direction, the shaft is displaced from its retracted position to its protruding position.

In other words, the grabber mechanism control may be specifically functionally adapted such that, when the actuator is actuated, as a first action, the mandrel is displaced from its proximal position to its distal position, and only after such first action, as a second action, the shaft is displaced from its retracted position to its protruding position. Therein, the actuation direction may be a linear direction, i.e. the actuator may be linearly pushed from an initial position to a final position, and during such linear actuation, first, the mandrel is displaced and, then, the shaft is displaced. Alternatively, the actuation direction may be nonlinear. For example, the grabber mechanism control may be configured such that its actuator is to be displaced along a curved path and/or is to be rotated. Also, in such alternative approaches, actuating the actuator shall first result in displacing the mandrel and only subsequently in displacing the shaft. Due to such functional implementation, the loop is first opened by the displaced mandrel before then being displaced together with the displacing shaft towards the medical device to be explanted.

In a similar way, according to another further specified embodiment, the grabber mechanism control is configured such that, upon the actuator being initially actuated in a second actuation direction, the mandrel is displaced from its distal position to its proximal position while the shaft being held stationary relative to the inner catheter and such that, upon the actuator being subsequently actuated in the second actuation direction, the shaft being displaced from its protruding position to its retracted position.

In this case, the actuator is actuated in the second actuation direction being generally opposite to the first actuation direction. Therein, again, the mandrel is first displaced, thereby bringing it to its proximal position and, as a result, closing the loop of the hitch grabbing mechanism, before then pulling back the loop together with the shaft towards the retracted position, thereby pulling back and explanting the medical device caught by the loop.

According to an embodiment, the grabber mechanism control comprises a mandrel carriage and a shaft carriage. Therein, the mandrel carriage is fixedly coupled to the actuator and to the mandrel, and the mandrel carriage is displaceable relative to the shaft carriage between a first position and a second position. The shaft carriage is fixedly coupled to the shaft, and the shaft carriage is displaceable relative to the housing between a third position and a fourth position. The mandrel carriage interacts with the shaft carriage such that upon the mandrel being pushed in a first direction from the first position to the second position, no displacement forces are transferred from the mandrel carriage to the shaft carriage, thereby leaving the shaft carriage stationary relative to the housing, and such that, upon the mandrel carriage being pushed from the second position further in the first direction, displacement forces are transferred from the mandrel carriage to the shaft carriage, thereby pushing the shaft carriage from its third position towards its fourth position. Alternatively or additionally, the mandrel carriage interacts with the shaft carriage such that upon the mandrel being pulled in a second direction from the second position to the first position, no displacement forces are transferred from the mandrel carriage to the shaft carriage, thereby leaving the shaft carriage stationary relative to the housing, and such that, upon the mandrel carriage being pulled from the first position further in the second direction, displacement forces are transferred from the mandrel carriage to the shaft carriage, thereby pulling the shaft carriage from its fourth position towards its third position.

According to such structural implementation, the grabber mechanism control comprises at least two components, i.e. the mandrel carriage and the shaft carriage. These components interact with each other and are displaceable with respect to each other. Furthermore, the components interact with the actuator, on the one hand, and with the mandrel and the shaft, respectively, on the other hand. Such structural implementation may realize the functional characteristics described in the preceding paragraphs. In such an implementation the loop- opening/closing and the loop-displacement (distally or proximally) could be controlled with the same actuator which would simplify the extraction procedure for the physician. The actuator, in particular a slider, could be used single-handedly by physician. Possible details of such structural implementation will be described further below with respect to the enclosed figures.

According to an embodiment, the catheter device further comprises an elongate outer catheter. Therein, the inner catheter extends throughout an inner volume of the outer catheter and is longitudinally displaceable relative to the outer catheter.

Expressed differently, additionally to the inner catheter, the catheter device generally includes an outer catheter enclosing the inner catheter. The outer catheter generally has a substantially larger diameter than the inner catheter and may be adapted for accommodating the medical device upon having explanted it.

According to an embodiment, the outer catheter is non-steerable.

Particularly, the outer catheter may be relatively simple as it may not necessarily be steerable. Instead, in an explantation procedure, first, the steerable inner catheter may be guided towards the explantation site and, then, the non-steerable outer catheter may be displaced along the inner catheter and follow the course of the inner catheter.

According to an embodiment, the outer catheter comprises a protector cup at its distal end, the protector cup having a widened inner diameter for accommodating at least a portion of the implantable medical device.

According to an embodiment, the outer catheter comprises a fluoroscopic marker at its distal end, and/or a visible marker at a position distant to its distal end.

Possible details of the aforementioned embodiments and characteristics of the outer catheter will be described below with respect to the enclosed figures.

It shall be noted that possible features and advantages of embodiments of the invention are described herein partly with respect to catheter device and partly with respect to a method of using such catheter device. One skilled in the art will recognize that the features may be suitably transferred from one embodiment to another and features may be modified, adapted, combined and/or replaced, etc. in order to come to further embodiments of the invention.

In the following, advantageous embodiments of the invention will be described with reference to the enclosed drawings. However, neither the drawings nor the description shall be interpreted as limiting the invention.

Fig. 1 shows a total view of a catheter device according to an embodiment of the present invention. Fig. 2 shows a partial view of a distal portion of the catheter device of Fig. 1.

Fig. 3 shows a partial view of a proximal portion of the catheter device of Fig. 1.

Fig. 4A, B shows an enlarged view of a hitch grabbing mechanism of the catheter device of Fig. 1 with a loop in its opened configuration and its closed configuration, respectively.

Fig. 5 shows a cross-sectional view of some major components of the hitch grabbing device located at the distal end of the catheter of Fig. 1.

Fig. 5a shows a more detailed schematic of some selected components of the hitch grabbing device of Fig. 1

Figs. 6A-E visualize a sequence of operating the catheter device of Fig. 1 during an explantation procedure.

Fig. 7 visualizes another operating step during an explantation procedure.

The figures are only schematic and not to scale. Same reference signs refer to same or similar features.

Fig. 1 shows a catheter device 1 in its entirety. Fig. 2 and Fig. 3 represent enlarged views of a distal portion and a proximal portion, respectively, of this catheter device 1. Figs. 4A and 4B show enlarged views of a hitch grabbing mechanism 7 of the catheter device 1. Fig. 5 shows a cross-sectional view representing some the hitch grabbing device located at the distal end of the catheter 1.

The catheter device 1 is configured for tethering a hitch 65 of an implantable medical device 61 (see Fig. 6D) such as an implantable leadless pacemaker 63 during a procedure for explanting the medical device 61. The catheter device 1 comprises an elongate inner catheter 3, an elongate shaft 5 and a hitch grabbing mechanism 7. Furthermore, the catheter device 1 comprises an outer catheter 51 and a handle 33. The shaft 5 extends along an inner volume of the inner catheter 3 and may be displaced longitudinally relative to the inner catheter 3. The inner catheter 3 is steerable. A motion of the inner catheter 3 may be steered using a steering knob 71 provided at the handle 33. The inner catheter 3 comprises an alignment cone 29 at its distal end 31, wherein, upon being pulled towards the inner catheter 3, the implantable medical device 61 may be accommodated in and/or aligned with the alignment cone 29. The alignment cone 29 comprises radiopaque material. The inner catheter 3 may be flushed with a fluid via a catheter flushing port 73. The inner catheter 3 extends through an inner volume of the outer catheter 51 and is displaceable longitudinally relative to the outer catheter 51. The outer catheter 51 is non-steerable. The outer catheter 51 comprises a protector cup 53 at its distal end 55. Due to its locally increased inner diameter, such protector cup 53 may accommodate at least a portion or preferably an entirety of the implantable medical device 61. A fluoroscopic marker 57 is provided at the distal end 55 of the outer catheter 51. Furthermore, a visible marker 59 is provided at a position distant to the distal end 55 and may serve as a visual introducer marker band.

In another embodiment (not shown), a flushport may be attached to the grabber mechanism shaft 5 and then through the shaft one may have some holes so that when one flushes the grabber mechanism, the holes are interconnected into the inner catheter and thereby enabling both shafts to be flushed simultaneously. Another embodiment (not shown) would be a flush port attached to all three shafts (shaft, inner catheter, outer catheter) so that they could each be flushed independently.

The hitch grabbing mechanism 7 is arranged at a distal end 9 of the shaft 5. It comprises a mandrel 11, plural tubes 13 and plural wires 15. The mandrel 11 extends throughout the inner volume of the shaft 5 and is displaceable longitudinally relative to the shaft 5. Particularly, the mandrel 11 may be displaced longitudinally between a proximal position and a distal position via an interaction with the handle 33, as described further below. The plural tubes 13 extend longitudinally from the distal end 9 of the shaft 5. Each of the wires 15 extends partially throughout an inner volume of an associated tube 13 ’and towards an associated neighboring tube 13”. Particularly, a first portion 17 of each of the wires 15 extends throughout the associated tube 13’, whereas a second portion 19 of the wire is exposed from the associated tube 13’ and extends to the associated neighboring tube 13”. Therein, a first end 21 of each wire 15 is fixed relative to the shaft 5. In the example shown in Fig. 5, such first end 21 is fixedly attached to a distal end 27 of the associated neighboring tube 13” and is therefore held at a predetermined distance with respect to the shaft 5, such predetermined distance corresponding to a length of the associated neighboring tube 13”. An opposite second end 23 of each wire 15 is fixed to the mandrel 11 and is displaceable relative to the shaft 5.

Fig 5a schematically shows two exemplary tubes 13’ and 13” of the grabber mechanism in in the transfer from the closed (left) to the open (right) configuration in more detail. Both tubes 13’, 13” comprise two lumens 50a and 50b. The first end 21 of wire 15 is fixedly attached (e.g. glued) in one lumen 50b of tube 13” and connected via the corresponding lumen 50a of the neighboring tube 13’ to mandrel 11. Wire 15 is fixed to mandrel 11 via a crimping connection I la.

As a result of such structural configuration, each wire 15 together with its associated tube 13’ and its associated neighboring tube 13” forms a loop 25. This loop 25 can be opened and closed by suitably displacing the mandrel 11. Specifically, upon the mandrel 11 being pulled to its proximal position relative to the shaft 5, the loop 25 is pulled into a closed configuration having a minimum lateral dimension, as shown in Fig. 4B. Upon the mandrel 11 being pushed in the other direction to its distal position relative to the shaft 5, the loop 25 is pushed into an opened configuration having a maximum lateral dimension, as shown in Fig. 4A.

In order to enable suitably operating the hitch grabbing mechanism 7, the handle 33 comprises a housing 37 and a grabber mechanism control 39 including an actuator 41. The handle 33 is coupled with a proximal end 35 of the inner catheter 3. Particularly, the housing 37 is coupled to the inner catheter 3. The grabber mechanism control 39 comprises a mandrel carrier 47 and a shaft carriage 49. The mandrel carrier 47 is fixedly coupled to the actuator 41 such that any actuation of the actuator 41 results in a direct displacement of the mandrel carrier 47. The mandrel carrier 47 is further fixedly coupled to the mandrel 11 such that any displacement of the mandrel carriage 47 results in a corresponding displacement of the mandrel 11. Furthermore, the mandrel carriage 47 is displaceable relative to the shaft carriage 49 between a first position and a second position. The shaft carriage 49 is fixedly coupled to the shaft 5 such that any displacement of the shaft carriage 47 results in a corresponding displacement of the shaft 5. Furthermore, the shaft carriage 49 is displaceable relative to the housing 37 between a third position and a fourth position.

An operation of the handle 33 and its cooperation with other components of the catheter device 1 is represented in Figs. 6A-E. Therein, a sequence of processing steps is represented for a process in which the implanted medical device 61 is grabbed using the catheter device’s hitch grabbing mechanism 7 and is explanted. Fig. 7 represents a final stage of the process in which the tethered medical device 61 is accommodated within the protector cup 53 of the outer catheter 51.

The actuator 41 at the handle 33 may be actuated by a physician during the explantation process. The actuator 41 is displaceable relative to the housing 37 in a linear first actuation direction 43 and in an opposite linear second actuation direction 45. The actuator 41 is mechanically coupled to the mandrel 11 as well as to the shaft 5 in a specific manner such that an initial actuation of the actuator 41 actuates the hitch grabbing mechanism 7 such as to change the loop 25 from its closed configuration to its opened configuration, or vice versa, whereas a subsequent actuation of the actuator 41 induces a displacement of the shaft 5 between its retracted position and its protruding position, or vice versa. Various displacement actions at the actuator 41 and resulting reactions at the hitch grabbing mechanism 7 are visualized in the sequence of Figs. 6A-E and are further emphasized by arrows included in the respective partial figures.

Specifically, the sequence starts when the inner catheter 3 has been correctly arranged with its distal end being close to an explantation site (see Fig. 6A). In such situation, the actuator 41 is in its initial position with the mandrel carriage 47 being in its first position and the shaft carriage 49 being in its third position. Starting from such initial configuration, the actuator 41 is initially pushed in the first actuation direction 43 (see Fig. 6B). During such initial actuation, the mandrel carriage 47 is pushed from its first position to its second position relative to the shaft carriage 49 and the mandrel 11 is pushed in a distal direction corresponding to the first actuation direction 43 and thereby changes the configuration of the hitch grabbing mechanism 7 from its closed loop configuration, as shown in Fig. 6A, to its opened loop configuration, as shown in Fig. 6B. Therein, the mandrel carriage 47 interacts with the shaft carriage 49 such that no substantial displacement forces are transferred from the mandrel carriage 47 to the shaft carriage 49. Accordingly, the shaft carriage 49 remains stationary relative to the housing 37.

Upon further pushing the actuator 41 in the first actuation direction 43 (see Fig. 6C), the mandrel carriage 47 does not only displace the mandrel 11 further in the distal direction but, additionally, 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. Such displacement of the shaft carriage 49 results in displacing the shaft 5 in the distal direction towards the medical device 61. Particularly, the hitch grabbing mechanism 7 may be pushed together with the shaft 5 towards the medical device 61 such that its opened loop 25 approaches the hitch 65 of the medical device 61.

Subsequently, the actuator 41 is pulled in the second actuation direction 45 (see Fig. 6D). As a result of such pulling action, the mandrel carriage 47 displaces from its second position back to its first position relative to the shaft carriage 49 and initially does only displace the mandrel 11 in the proximal direction, while no substantial displacement forces are transferred from the mandrel carriage 47 to the shaft carriage 49, thereby leaving the shaft carriage 49 stationary in its fourth position. Accordingly, the mandrel 11 is displaced relative to the shaft 5 in the second actuation direction 45. As a result of such displacement action, the mandrel 11 pulls the hitch grabbing mechanism 7 such as to bring the previously opened loop 25 to its closed configuration. Thereby, the closed loop 25 may tether and grab the hitch 65 of the medical device 61.

Upon pulling the actuator 41 further in the second actuation direction 45 (see Fig. 6E), the mandrel carriage 47 begins to transfer displacement forces onto the shaft carriage 49. Accordingly, both carriages 47, 49 are displaced together and the shaft carriage 49 is brought from its previous fourth position back to its third position. Due to such displacement action, the shaft 5 together with the hitch grabbing mechanism 7 and the medical device 61 grabbed thereby are displaced towards the inner catheter 3. Upon sufficiently approaching the inner catheter 3, the rear side of the medical device 61 comes into contact with the alignment cone 29 and is therefore aligned with the inner catheter 3.

Finally, the outer catheter 51 is pushed towards the distal end of the inner catheter 3 (see Fig. 7) by suitably displacing the outer catheter control hub 67. Thereby, the protector cup 53 at the distal end 55 of the outer catheter 51 is pushed over the medical device 61. Accordingly, the medical device 61 accommodated within the protector cup 53 may then be explanted from the patient.

Subsequently, some further background and some further explanations and details with regards to embodiments of the catheter device disclosed herein are given in slightly alternative wording:

As an introduction, a short summary is given as follows:

An invention is disclosed for a novel catheter design that facilitates explantation of a leadless pacemaker.

This design provides a superior means of navigating to and recapturing leadless pacemakers acutely placed either in the septum or the apex of the right ventricle or in the atrial appendage of the heart. Note that acute implantation means days, weeks, and potentially months (not exceeding 6 months) following initial implantation of the leadless pacemaker. It is recognized that once a leadless pacemaker is encapsulated, it is no longer acutely implanted.

Furthermore, this leadless pacemaker explantation catheter design provides a superior means of establishing a connection between the catheter and the leadless pacemaker by using a custom grabbing mechanism that has been mechanically incorporated into the catheter’s handle design in a novel manner. This grabbing mechanism and its incorporation into the catheter’ s handle design may be interpreted as forming the core of the ideas presented herein. In summary, the disclosed approach provides high usability, reliability, and a means for a user to navigate successfully up to and establish a secure connection to a leadless pacemaker placed in either the apex or septum of the right ventricle or in the atrial appendage, resheathe it if it was implanted, and remove the device and catheter safely and reliably from the patient anatomy.

Some background information is now given as follows:

Implantation of leadless pacemakers requires proper positioning and delivery of the implant to a specific location of the heart. During this procedure, the device is implanted into the heart where it is anchored by a suitable fixation mechanism (for example, a multitude of flexible metal tines). Electrical and fixation measurements are performed by the user to confirm that an implantation site is suitable prior to release of the implant.

However, in some cases, even after determining suitability of an implantation site and releasing the implant, it may be determined that the site location of the implant is no longer acceptable for the implant to function properly. This assessment may arise hours, days, weeks, and potentially months following leadless pacemaker implantations. It is in these situations, where ingrowth and encapsulation of the implant have not yet taken place that a physician would need to remove the implant from the patient.

The disclosure detailed herein is thus specific to the design of a catheter tool that allows a user the means to navigate easily and reliably up to a leadless pacemaker implanted in either the apex or septum of the right ventricle or in the atrial appendage, resheathe it, and remove the implant and catheter from the patient anatomy.

There is currently one known solution that exists in the field that features a catheter that is used specifically for explantation of a leadless pacemaker. Therein, a dedicated explantation catheter is used to remove a screw-based fixation leadless pacemaker from the right ventricle. This design solution utilizes either a triple loop or single loop snare within its catheter to grab the implant, before the catheter then utilizes handle mechanisms to unscrew the implant from the anatomy, resheathe it, and remove it from the anatomy.

A different approach does not have a dedicated explantation catheter, but instead uses an implantation catheter pre-loaded with a snare to resheathe a tine-based leadless pacemaker. However, the implantation catheter with snare is not able to explant a leadless pacemaker in an easy, safe, or reliable manner which resulted in the majority of users abandoning this explantation approach in favor of using an off-the shelf steerable sheath to navigate up to an implant, establishing a connection to the implant using an off the shelf snare roughly 10-20mm in diameter, pulling the implant out from the heart wall, and dragging it back out of the right ventricle, across the tricuspid valve, and down through the introducer in order to explant the implant from the anatomy.

Lastly, there are presently no known atrial appendage explantation catheter solutions as there are presently no atrial appendage leadless pacemaker implants in the field.

Some drawbacks of known solutions are as follows:

One of the known approaches must utilize a significant number of controls and actuators on its catheter’ s handle to manipulate a snare to establish a tethered connect to a screw-based fixation implant. Then this approach must utilize additional controls to unscrew the implant from the anatomy that it is fixated to before it can ultimately be resheathed into the catheter and removed from the anatomy. Due to the significant quantity of controls and actuators necessary to perform these steps and procedure, the catheter has a high degree of complexity and low degree of usability. It is also only to be used for explantation from the right ventricle.

A different approach does not have a dedicated explantation catheter, but instead uses its implantation catheter pre-loaded with a snare to resheathe the tine-based leadless pacemaker in acute situations. However, the implantation catheter with snare is not able to explant a leadless pacemaker in an easy, safe, or reliable manner. Due to the length of the implant catheter, only a micro loop snare can be used with the implant catheter and the use of a micro snare loop makes it incredibly difficult to establish a connection to the implant. This is because the loop diameter is so small that it requires the user to be ultra-precise while trying to establish a connection between it and the implant. Furthermore, the steering and navigation of the implant catheter is very difficult for the purposes of explantation because of the long stiff not-deflectable cup at the distal end of their implant catheter. These usability issues have resulted in the majority of the users abandoning this explantation approach in favor of using an off-the shelf steerable sheath to navigate up to an implant, establishing a connection to the implant using an off the shelf snare roughly 10-20mm in diameter, pulling the implant out from the heart wall, and dragging it back out of the right ventricle, across the tricuspid valve, and down through the introducer in order to explant the implant from the anatomy. This leaves the implant’s fixation mechanism exposed throughout the removal process which can allow for excessive force to be applied on the heart wall (which could potentially tear the heart wall open) during the removal process and for the fixation mechanism to get caught on structures in the heart while it is being pulled out of the anatomy (which could lead to damage to the anatomy).

Accordingly, it is an object to design a catheter tool that allows a user the means to navigate easily and reliably up to a leadless pacemaker implanted in either the apex or septum of the right ventricle or in the atrial appendage, establish a connection between the implant and catheter easily and reliably, resheathe the implant into the catheter, and remove the implant and catheter from the patient anatomy.

As seen in Figs. 1 - 4, the design solution consists of a non-steerable straight but flexible outer catheter that is connected to a Protector Cup that is used to resheathe the implant and its fixation mechanism so that it can be safely removed from the anatomy. The Outer Catheter is connected to a Control Hub that is used to advance and retract the Outer Catheter over a steerable inner catheter. The OC Control Hub also has a flush port/tube to flush air out of the Outer Catheter.

The design solution also consists of the steerable catheter that is used for navigating up to an implant placed in either the Apex or Septum of the right ventricle or into the Atrial Appendage. The Steerable Catheter has a fluoroscopic Alignment Cone at its distal tip used for protecting the implant’s hitch from damaging interactions with the Protector Cup on the Outer Catheter during the resheathing process. The handle also has a steering control knob that steers the steerable catheter. The handle is mechanically designed so that when the user removes their hand from the handle or handle steering actuator, that the steering position remains fixed and does not relax or return to its nominal/starting position. The outer non- steerable catheter has a hub that is used to advance the outer steerable catheter distally over the steerable catheter to resheathe the implant. The steerable catheter has no pre-shape curve and is completely straight for its zero position in order to facilitate navigation up to both the atrial appendage and also across the tricuspid valve into the right ventricle. In a second embodiment, the steerable catheter could have a pre-shape curve to facilitate navigation solely across the tricuspid valve and into the right ventricle. In this second embodiment, the explant catheter would only be used for explanting leadless pacemakers from the right ventricle rather than both the right ventricle and atrial appendage.

There is also a non-steerable catheter-based hitch grabbing mechanism running longitudinally from the catheter’ s main handle through the steerable catheter and terminating at the distal end of the steerable catheter. This hitch grabbing mechanism is used to establish a connection between the catheter and the implant so it can be removed from the anatomy.

The hitch grabbing mechanism is controlled via a singular actuator on the catheter’s handle. The distal end of the hitch grabbing mechanism consists of three or more tubes through which nitinol wires are woven to create a loop (see, inter alia, Figs. 4 and 5). One end of each of the nitinol wires is fixated to the mechanism’s shaft while the other end of each of the nitinol wires is connected to a mandrel. The mandrel is used to push the wires distally to open the loop and to pull the wires proximally to close the loop. The mandrel is connected to the actuator on the handle that is used to control the grabber mechanism.

The hitch grabbing mechanism is operated via the singular actuator on the handle. The actuator has two independent functions. The first function is to open and close the loop. The second function is to telescopically advance and retract the mechanism distally and proximally. Advancing the slider distally will always open the loop first before it can then be telescopically advanced distally by continuing to advance the slider distally. Retracting the slider proximally will always close the loop first before it can then be telescopically retracted proximally by continuing to retract the slider proximally. This can be seen in Figs. 6A - E.

Due to the design of this mechanism, the loop will always be open when it is advanced outside from the steerable catheter, and it will always be closed when it is retracted back inside of the steerable catheter. This is a key design element for this novel design solution. Another key design element of this design is that the loop is able to close down on the hitch first prior to being retracted. This prevents issues with having to advance or retract the entire catheter assembly while trying to perform the actuations to establish a connection between the catheter and the implant.

Once the implant hitch grabbing mechanism has successfully established a connection between the catheter and implant and the slider has been fully retracted such that the implant’s hitch is seated inside of the Alignment Cone (see Fig. 6D), the Outer Catheter Hub can be advanced distally, which pushes the Outer Catheter and Protector cup over the Steerable Catheter (as if it was a guide rail) and up over the implant so that the implant can be resheathed inside of it. This can be seen in Fig. 7.

The proposed design solution may incorporate one of the following features:

1.) A visual marker on the Outer Catheter to signify when the catheter has been inserted into its introducer sufficiently and fluoroscopy needs to start being used. This can be seen in Fig. 1 above as “Introducer marker band” or visible marker.

2.) An inner steerable catheter that it is fully deflectable along its distal end resulting in enhanced control and maneuverability and for a user to easily navigate across the tricuspid valve into the right ventricle from the atrium and navigate up to the implantation location in the right ventricle and also be able to navigate up to an implant placed in the atrial appendage.

3.) A fluoroscopically visible Alignment Cone attached to the distal end of the inner steerable catheter that is used to seat the implant’s hitch and protect the hitch from damaging interactions with the Protector Cup during the resheathing process.

4.) An outer non-steerable catheter with a shape set curve that can be advanced distally and proximally over the inner steerable catheter, even when the inner steerable catheter has been articulated over tight angles and geometries.

5.) A novel inner non-steerable catheter-based implant hitch grabbing mechanism that has a loop at its distal end which is controlled by a singular actuator on the catheter’s handle.

6.) A hitch grabbing mechanism is comprised of three or more “fingers” that are used to form the loop by advancing and retracting nitinol wires running inside the fingers that are attached to a mandrel that is attached to the catheter’s handle/actuator. 7.) A hitch grabbing mechanism that is fluoroscopically visible via the inclusion of fluoroscopically visible wires and / or tubes that comprise the loop and fingers.

8.) When actuated on the handle, distal advancement of the actuator for the grabbing mechanism will always open the loop prior to advancing the loop distally.

9.) When actuated on the handle, proximal retraction of the actuator for the grabbing mechanism will always close the loop prior to retracting the loop proximally.

10.) The loop will always either open or close completely with its location staying static during the process of each, prior to the hitch grabbing mechanism telescopically advancing distally or retracting proximally.

11.) A hitch grabbing mechanism with a loop that will always be open when it is advanced outside from the steerable catheter, and will always be closed when it is retracted back inside of the steerable catheter.

12.) An open loop diameter of the hitch grabbing mechanism ranging from 10-25mm in diameter.

13.) A hitch grabbing handle mechanism which is comprised of two components (seen in

Figs. 6A-E) with the following functions. a. A mandrel carriage which is connected to wires at the distal end of the hitch grabbing mechanism. When advanced forward the wires push the loop open. When retracted proximally the wires pull the loop closed. When advancing the actuator distally, the mandrel carriage (directly connected to the actuator) will advance with the actuator until the loop has been opened up. b. A shaft carriage which is advanceable or retractable only after the loop has been opened or closed following the movement of the mandrel carriage. For instance, after the loop has been opened up, the mandrel carriage will come into contact with the shaft carriage and begin pushing both the shaft and loop wires distally which telescopically advances the entire assembly distally (see Figs. 6A-C). When retracting the actuator proximally, the mandrel carriage will retract proximally independently of the shaft carriage until the loop has been closed. At that point, the mandrel carriage will come into contact with the shaft carriage again and begin pulling both the shaft and loop wires proximally which retracts the entire assembly telescopically (see Figs. 6D-E). 14.) A steering mechanism or actuator that allows the user a high degree of steering control over the inner steerable catheter. The steering mechanism or actuator maintains the fixed steering position of the catheter whenever the user removes his or her hands from the mechanism or actuator.

15.) The ability for the user to resheathe the implant into the outer catheter’s implant protector cup safely and reliably.

16.) The ability to remove the implant and catheter tooling safely from the anatomy.

The present approach presents a dedicated tool specifically designed to safely and reliably navigate up to a leadless pacemaker placed in either the Septum or Apex of the Right Ventricle or a leadless pacemaker placed in the Atrial Appendage, establish a connection to the implant’s hitch via a novel grabbing mechanism, explant the implant by recapturing it into a Protector Cup located on the distal end of the explant catheter’s Outer Catheter, and remove the implant and catheter safely from the patient’s anatomy.

Embodiments of the present invention provide at least one of the following advantages:

1.) An inner steerable catheter which is utilized as the means to navigate safely, reliably, and easily up to the implantation location. This is accomplished because the inner steerable catheter does not have the implant Protector Cup attached to it. The implant Protector Cup acts as a long linear and non-articulatable component that can prohibit movement through tight geometries and radiuses. When a leadless pacemaker has been implanted, it is important to allow the user as much control as possible to navigate the catheter up to the implant.

2.) A hitch grabbing mechanism used to establish a connection between the catheter and the implant in an easy, safe, and reliable manner so that the implant can be resheathed into the catheter and removed from the anatomy. The major advantages of the hitch grabbing mechanism are: a. When actuated on the handle, distal advancement of the actuator for the grabbing mechanism will always open the loop prior to advancing the loop distally. b. When actuated on the handle, proximal retraction of the actuator for the grabbing mechanism will always close the loop prior to retracting the loop proximally. c. All actuations are controlled via a singular actuator (which in this embodiment is a slider). d. The act of grabbing the implant’ s hitch requires less precise steering because the loop can be advanced over the hitch in an open state, increasing the viable area the hitch can be in for the loop to capture it. If the loop were to arrive at the hitch in a closed state, the act of opening the loop could result in the loop opening without the hitch being in the inner radius of the loop, thus missing the hitch and requiring additional actuation and steering. e. The act of opening the loop does not impact the location of the implant by nudging the hitch out of the intended path because the loop always exits the catheter inner steerable catheter in an open position. f. Since the loop closes completely prior to being retracted, the user does not need to advance any part of the grabbing mechanism distally towards the implant during the act of closing the loop down on the implant. Normally when users are attempting to grab an object while using a snare, the snare is being advanced or retracted simultaneously while a cinch tube is being advanced or retracted over it in order to accurately control the snare during the snaring process. The advantage of the hitch grabbing mechanism presently disclosed does not require a user to advance/retract multiple objects simultaneously in order to establish a connection to an object (like an implant’s hitch). An Outer Catheter (non-steerable) with a Protector Cup at the distal end of it that is used to navigate up to the implant once a connection to the implant has been established, and resheathe the implant and its fixation mechanism back into it in a safe and reliable manner. a. The outer (non-steerable) catheter can easily be advanced over the OD of the inner steerable catheter and up to the implant without impacting the position of the implant. b. Since a connection to the implant has already been established, the long linear length of the implant protector cup is easily tracked over the inner steerable catheter’s OD as if it was a guide rail, and no additional steering is required to perform this action. c. Once the implant protector cup arrives at the implant, the implant is then easily resheathed into the cup.

It is at this point that the user can remove the implant and tooling from the patient anatomy. No other tool yet exists that allows a user to be able to perform a procedure to explant an implanted leadless pacemaker with a tine based fixation mechanism from either the right ventricle or the atrial appendage, especially in such an easy, safe, and reliable manner.

Finally, it should be noted that the term “comprising” does not exclude other elements or steps and the “a” or “an” does not exclude a plurality. Also elements described in association with different embodiments may be combined. It should also be noted that reference signs in the claims should not be construed as limiting the scope of the claims.

List of Reference Numerals

I catheter device

3 inner catheter

5 shaft

7 hitch grabbing mechanism

9 distal end of the shaft

I I mandrel

13 tube

13’ associated tube

13 ’ associated neighboring tube

15 wire

17 first portion of the wire

19 second portion of the wire

21 first end of the wire

23 second end of the wire

25 loop

27 distal end of the associated neighboring tube

29 alignment cone

31 distal end of the inner catheter

33 handle

35 proximal end of the inner catheter

37 housing

39 grabber mechanism control

41 actuator

43 first actuation direction

45 second actuation direction

47 mandrel carriage

49 shaft carriage

51 outer catheter

53 protector cup

55 distal end of the outer catheter 57 fluoroscopic marker

59 visible marker

61 medical device

63 implantable leadless pacemaker 65 hitch

67 outer catheter control hub

69 outer catheter flushing port

71 steering knob

73 catheter flushing port

Claims

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. 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. 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. The catheter device (1) of claim 1, wherein at least one of the wires (15) and the tubes (13) comprises radiopaque material.

5. The catheter device (1) of claim 1, wherein the inner catheter (3) is steerable.

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. The catheter device (1) of claim 6, wherein the alignment cone (29) comprises radiopaque material.

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. 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. 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. 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. 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. The catheter device (1) of claim 12, wherein the outer catheter (51) is non-steerable.

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. 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).