Patent Application
20240041599
The field of the invention concerns catheter devices for implanting a medical implant, particularly self-expanding implants such as an occluding device, aortic grafts, a prosthetic heart valve, more particularly an aortic heart valve prosthesis (TAVI/TAVR), but also e.g., for an implantable leadless pacemaker.
Such a catheter device usually includes a capsule for receiving the implant when the latter is in a collapsed state, e.g., a crimped prosthetic heart valve such as a prosthetic aortic heart valve. The capsule covers the implant (e.g. a prosthetic aortic heart valve) that is positioned on a support element connected to an inner sheath of the catheter device while the capsule is connected to an outer sheath (the inner and outer sheaths may also be denoted as inner and outer shafts of the catheter).
Retraction of the outer sheath with respect to the inner sheath allows displacing the capsule with respect to the inner sheath and the support element so as to deploy and release said implant. With the catheter device of the present invention, an implant like a prosthetic aortic heart valve may be, e.g., only partially released and can be retracted into the capsule for the purpose of re-positioning the implant so that it can be deployed at a proper implantation site in a next attempt. Reinserting the implant into the capsule is commonly termed “resheathing” and is for example achievable by providing a connection of the implant to a connector connected to the inner sheath of the catheter device.
Catheter devices of the aforementioned kind, particularly for implantation of a self-expanding transcatheter aortic valve replacement (TAVR) prosthesis (or TAVI prosthesis), are challenging in multiple aspects. A typical drawback is the fact that during recapturing of the TAVI/TAVR implant the catheter is exposed to high axial loads. In challenging anatomies or disadvantageous circumstances, these loads can plastically deform the sheaths of the catheter, which can affect a resheathing of the implant to the extend that the capsule can no longer completely cover the implant. However, the withdrawal of the device from the implantation site/body is only considered safe if the capsule is fully closed, i.e., properly aligned with the catheter tip so that no gap is present between the tip and a distal edge of the capsule.
Typically, safety buttons are known in the prior art which are used to limit the uncovering of the prosthesis. Mechanisms of this kind are for instance described in U.S. Pat. Nos. 9,782,257 B2, 9,545,308 B2, 9,615,924 B2, 8,814,931 B2, 8,778,019 B2 and 8,926,693 B2.
A preferred catheter device for implanting a medical implant, particularly a TAVI/TAVR catheter device for a self-expanding aortic valve prosthesis, allows implanting an implant, particularly a prosthetic heart valve, in particular a self-expanding aortic valve prosthesis, with the ability to allow proper closing of the capsule for the purpose of covering the implant during a resheathing procedure even in case of a permanent compression of the outer sheath and/or a permanent elongation of the inner sheath due to axial loads that have acted on the catheter device during implantation of the implant.
A preferred catheter device for implanting a medical implant has a handle that includes a locking element configured to be moved from a first to a second state. The locking element limits a movement of a traveler and therewith of a capsule in a distal direction (D) in the first state. The locking element allows further movement of the traveler and therewith of the capsule in the distal direction in the second state.
In the following, further features and advantages of the present invention are described in detail with reference to the Figures which show preferred embodiments of the catheter device according to the present invention, wherein
A preferred embodiment provides a catheter device for implanting a medical implant is disclosed, wherein the catheter device includes:
During recapturing of the TAVI/TAVR implant, the catheter is exposed to high axial loads. In challenging anatomies or disadvantageous circumstances, these loads can plastically deform the sheaths of the catheter, particularly said inner and outer sheaths. To ensure that the entire implant can still be covered by the capsule, additional travel of the potentially deformed outer sheath is required. Advantageously, this additional travel can be locked and enabled using the locking element. In addition, the mechanism preferably enables automatic resetting of the locking element after use and it may also provide feedback to the user that the locking element has been deactivated or reactivated.
Advantageously, the invention enables a further movement of the capsule in the distal direction so as to compensate the resulting length mismatch between the outer and inner sheath. With this additional travel, that is also denoted as “overtravel”, the outer sheath can be moved further in the distal direction than its original start position.
Furthermore, in the case that the sheaths do not deform in the procedure, the user could potentially close the capsule too far which would result in a sharp edge on the distal end. Therefore, the present invention includes a locking element so that the overtravel is only available when the locking element is moved to the second state. The activation and deactivation of the compensation feature is thus safe, detectable and reversible.
In the framework of the present invention, the notion “distal” refers to a portion or components of the catheter device that is remote from the handle or from the physician that operates the catheter device while the notion “proximal” refers to those portions or components that are closer to the handle or closer to the physician. According to a preferred embodiment of the catheter device according to the present invention, the locking element is configured to set a limit to the movement of the traveler in the distal direction such that the capsule completely covers the implant when the traveler has reached this limit and the inner and the outer sheath have not yet been permanently deformed during usage of the catheter and each include their initial length in the direction of the longitudinal axis.
According to a further preferred embodiment, in the second state, the locking element is configured to allow further movement of the traveler and therewith of the capsule in the distal direction such that the implant is completely coverable by the capsule despite a permanent compression of the outer sheath or a permanent elongation of the inner sheath. Without the possibility of said further movement (i.e. overtravel) of the capsule, a gap between the catheter tip and the capsule could not be closed properly so that a resheathing procedure could not be successfully completed or would bear the risk of injuring the patient.
Furthermore, according to an embodiment of the present invention, the handle of the catheter device includes an elongated rod that is slidable along the longitudinal axis, wherein when the locking element is in its first state, the rod is configured to be pressed by the traveler against the locking element to limit the movement of the traveler (and therefore of the capsule) in the distal direction, wherein a first spring element connected to the traveler is arranged between the traveler and the rod and is pretensioned against the rod when the traveler presses against the locking element.
Preferably, the rod includes a proximal end portion having a concave face side to enclose a front side of the traveler in a form-fitting fashion when the traveler presses against the rod via said face side of the proximal end portion of the rod.
According to a further embodiment, the locking element is configured to release the rod when the locking element is moved from the first state to the second state, wherein the rod is pushed in the distal direction by the pretensioned first spring element that is allowed to expand when the locking element sets the rod free in the second state.
Furthermore, according to an embodiment, when the locking element is in the second state, the further movement (so-called overtravel) of the traveler in the distal direction caused by further rotation of the deployment knob in the first rotation direction pushes the rod against a stop provided on the handle which prevents any further movement of the traveler and therewith of the capsule in the distal direction. Now, the first spring element is pretensioned by the traveler against the rod, and a second spring element is pretensioned by the rod against a guiding member of the handle, which guiding member is configured to guide the sliding movement of the rod along the longitudinal axis and also forms said stop for the rod.
According to a further embodiment of the catheter device, the handle includes an actuating element configured to be manually actuated by a user, wherein the actuating element is operatively connected to the locking element, wherein the locking element is moved from the first state to the second state when the actuating element is actuated by the user. Particularly, the actuating element can be integrally connected to the locking element. Particularly, the actuating element can be a pushable button, wherein actuating the actuating element corresponds to manually pushing the button which causes the locking element to transition from the first state to the second state.
According to yet another embodiment of the catheter device, the handle includes a third spring element, wherein the third spring element is configured to be pretensioned against the locking element when the latter is moved from the first state to the second state. The third spring element thus provides a restoring force that allows moving the locking element back from the second state to the first state as will be described further below.
According to a further embodiment, the locking element includes an opening having a narrow portion and an adjacent wider portion, wherein the rod includes a distal portion including a narrow section having a diameter that is smaller than a diameter of an adjacent proximal portion of the rod (that connects to the proximal end portion of the rod) so that the rod forms a step, particularly a circumferential step, at said narrow section, wherein when the locking element is in the first state said narrow section of the rod is arranged in the narrow portion of the opening of the locking element and the rod is configured to be pressed by the traveler against the locking element with said step to prevent the movement of the traveler in the distal direction.
According to a further embodiment, when the locking element is moved from the first state to the second state, the rod becomes arranged in the wider portion of the opening of the locking element so that the step of the rod is allowed to move through the wider portion of the opening of the rod by the action of the pretensioned first spring element when the latter expands.
The deactivated locking element that allows movement of the rod in the distal direction in the second state can be automatically transferred back into the first state using the pretensioned third spring element when the capsule is opened again, i.e. by moving the outer sheath via the traveler in the proximal direction.
Particularly, when the traveler pushes the rod against the stop (which means that the maximal overtravel of the capsule has been realized) or when the second spring element is pretensioned, moving the traveler and therewith the capsule in the proximal direction (to again deploy the implant) causes the pretensioned second spring element to move the rod in the proximal direction, too, such that said narrow section of the rod moves back into the opening of the locking element at a certain position of the traveler which allows the third spring element to move the locking element back into the first state in which said section of the rod is in turn arranged in the narrow portion of the opening of the locking element.
The locking element has now returned to the first state and will limit further movement of the capsule in the distal direction until it is again moved to the second state by manually actuating, e.g. pushing, the actuating element (e.g. pushable button).
According to a further embodiment of the present invention, the deployment knob is rotatably supported on the guiding member of the handle that forms the stop for the rod and is also configured to guide the movement of the rod along the longitudinal axis.
The present invention enables further travel of a capsule 40 of a catheter device 1 so that the capsule 40 can properly resheath a partially deployed implant 100 even in case an outer and inner sheath 10, 20 of the catheter device 1 have been permanently deformed due to axial loads during the implantation procedure.
The principle mechanism of the invention is illustrated in
Particularly,
Particularly, the handle 70 can be adapted to manipulate, particularly steer, four sheaths 20, 10, 60, and 90 as shown in
As indicated in
The inner and the outer sheath 20, 10 can be moved relative to the deflection sheath 60 (and relative to the stabilizing sheath 90). Additionally, the outer sheath 10 can be moved relative to the inner sheath 20. The stabilizing sheath 90 is stationary and fixed to a grip portion 71 of the handle 70 (cf.
For delivery using the catheter device 1, the medical implant 100, here an aortic prosthetic heart valve 100, is placed on a support element 30 that is connected to a distal end section 20a of the inner sheath 20 and covered by the capsule 40. The support element 30 can be connected to the inner sheath 20 via a connector 50 to which the heart valve prosthesis 100 is releasably connectable for delivery to an implantation site when it is arranged in the capsule 40. The guidewire lumen 21 can be formed by a tubing 22 that protrudes out of the inner sheath 20 at the distal end 20a of the inner sheath 20, extends through the connector 50 and support element 30, and connects to a catheter tip 24 to which the tubing 22 is connected. Furthermore, the catheter tip 24 can include an opening 25 formed in a distal end 24a of the catheter tip 24, so that the guidewire can exit the guidewire lumen 21 via said opening 25 (cf.
The movements and functions of the catheter device 1 can be realized with the handle 70 of the catheter device 1 (cf.
The handle 70 can further include actuating means for achieving a simultaneous movement of the inner and outer sheath 20, 10 as well as for deflecting the sheaths 10, 20 using the deflection sheath 60 and pull wire 62.
Preferably, the knob 72 is rotatable about the longitudinal axis x of the catheter device 1, along which axis x the handle 70 extends.
Furthermore, the grip portion 71 includes an opening 71c at a distal end 71a of the grip portion 71 through which all sheaths 10, 20, 60, 90 extend into the handle 70 at the distal end 71a of the grip portion 71 (the sheaths are not shown in
For deflecting the deflection sheath 60, an actuating means such as a deflection knob can be provided on the handle 70 that can be operatively connected to a distal end section 60a of the deflection sheath 60 via the pull wire 62, so that the deflection sheath 60 and thereby the inner and the outer sheath 20, 10 are deflected, i.e. bent, to adjust an angular orientation of the medical implant 100 when the deflection knob is rotated about the longitudinal axis x which causes tensioning or loosening of the pull wire 62 depending on the direction of the rotation.
Further, for moving the inner and the outer sheath 20, 10 simultaneously, the handle 70 can include a guiding member (also denoted as handle core) 75 (cf.
Further, the handle 70 includes a traveler 76 (also denoted as outer sheath hub), wherein the outer sheath 10 is connected to the traveler 76, and wherein the deployment knob 72 is operatively connected to the traveler 76 such that the traveler 76 and thereby the outer sheath 10 are moved along the longitudinal axis x with respect to the inner sheath 20, and so as to deploy the medical implant 100 when the deployment knob 72 is rotated in a first rotation direction of the deployment knob 72 (cf.
If the physician is satisfied with the positioning of the catheter device 1, deployment of the prosthesis 100 is started by the physician. In this regard, an axial movement of the outer sheath 10 (and therewith of the capsule 40 and implant 100) in the proximal direction P relative to all other sheaths 20, 60, 90 and the grip portion 71 of handle 70 releases the implant 100; e.g. a prosthetic aortic heart valve. This movement of the outer sheath 10 can be controlled by the deployment knob 72 (cf.
For releasing the implant 100 based on the above-described movement of the outer sheath 10 and capsule 40, the connector 50 connected to a distal end 20a of the inner sheath 20 can include a recess 51, wherein the at least one fastening element 102 of the medical implant 100 is engaged with the at least one recess 51 as long as the capsule 40 covers the at least one recess 51 of the connector 50 and the at least one fastening element 102 that engages with the at least one recess 51 when the prosthetic heart valve 100 is arranged on the support 30 (cf.
Once the capsule 40 is completely removed from the implant 100 and does no longer cover the at least one fastening element 102 and the corresponding recess 51 of the connector 50 (cf. lower part of
In case the implant 100 is only partially deployed and still connected to the connector 50, resheathing of the implant 100 is possible. However, due to high axial loads acting on the inner and outer sheath 20, 10 during the implantation procedure, the sheaths 20, 10 can become permanently deformed in the direction of the longitudinal axis x during operation of the catheter device 1. This usually corresponds to a compression of the outer sheath 10 and an elongation of the inner sheath 10; which means that it is no longer possible to properly close the capsule 40, i.e., to completely cover the implant 100 with the capsule 40. Typically, a gap can result between the tip 24 and a distal edge of the capsule 40 which means that the resheathing cannot be properly completed.
In order to prevent this outcome, the present invention provides the capsule 40 with an additional travel which is denoted as overtravel and corresponds to a further movement of the capsule 40 in the distal direction D past the initial limit of the capsule 40.
As shown in
With the axial movement in the distal direction D during closing of the capsule 40, the rod 80 is reaching a rigid barrier in form of a locking element 80 which is inhibiting further axial travel of the rod 81 and therewith of the traveler 76 in the distal direction D. A first spring element 706 between the traveler 76 and the rod 81 is loaded in this position (cf.
The locking element 80 can be configured to allow passage of the rod 81 through an opening 802 and can be configured to include a push button 800 for moving the locking element 80 perpendicular to the longitudinal axis x/distal direction D. The pushing of the locking element 80 loads the third spring element 801. Once the barrier 80 is removed, the rod 81 is pushed forward by the pretensioned first spring element 760. According to an embodiment of the present invention, the unloading of the first spring element 760 is audible and the change in position of the push button 800 is visible (cf.
Subsequently, the user can move the traveler 76 and therewith the outer sheath 10 and capsule 40 forward in the distal direction D and the rod 81 moves further through the opening 802 of the locking element/barrier 80. Using this overtravel, the user carefully closes the capsule 40 (capsule 40 properly aligned with the atraumatic tip 24 in a gapless fashion) and thereby pretensions the first spring element 760 as well as the second spring element 810 (cf.
In the next step, in case the user is satisfied with the repositioned implant, the user is releasing the implant 100 again. The outer sheath 10 is moved in the opposite direction (proximal direction P) and the implant 100 is deployed. After this second deployment it is possible that the user needs to resheath the prosthesis again. Therefore, the already used locking mechanism must be re-activated.
This lock reactivation is achieved by the second and third spring element 810, 801. Starting from
This mechanism can be integrated in various ways into a handle 70 of a catheter device 1. In the following an embodiment of such an integration is described with reference to
As shown in
As stated above, the deploy traveler 76 is connected to the outer sheath 10 and is moved in axial direction x by the rotation of the deployment knob 72. On the front side 76a of the traveler 76, a first spring element 706 is connected to the traveler 76 that protrudes from the front side 76a in the distal direction D and moves with the traveler 76 (cf.
Particularly, the traveler 76 moves in the distal direction D (to the right) until it reaches an elongated slidable rod 81 that is also denoted as overtravel traveler. The state depicted in
When the traveler 76 has reached the rod 81 as shown in
Particularly, the locking element 80 includes an opening 802 having a narrow portion 802a and an adjacent wider portion 802b. Correspondingly, the rod 81 includes a distal portion including a narrow section 81b having a diameter that is smaller than a diameter of an adjacent proximal portion of the rod 81 so that the rod 81 forms a step 81c (e.g. a circumferential step) at said section 81b, wherein when the locking element 80 is in the first (locked) state said narrow section 81b of the rod 81 is arranged in the narrow portion 802a of the opening 802 and the rod 81 cannot be moved further through the opening 802 since the step 81c butts against the locking element 80, namely against an edge of the narrow portion 802a of the opening 802.
According to
Now, with the locking element 80 being in the second (open) state, the traveler's 76 first spring element 706 pushes the rod 81 forward through the opening 802 of the locking element 80. Particularly, the user can hear/feel the jump of the rod 81 as feedback for successful unlocking. Due to the button 800/locking element 80 being pushed into the second state, the third spring element 801 is now loaded.
The elongated rod 81 can now travel freely through the wider portion 802b of the opening 802 of the locking element 80. The distal movement of the deploy traveler 76 (overtravel) can be used by rotating the deployment knob 72 further in the first rotation direction R1 until the first spring element 760 and the second spring element 810 are fully compressed or the rod 81 hits a stop 83 provided on the handle 70.
Particularly, the locking element 80 being in the second (unlocked) state allows a specific extra overtravel. According to an embodiment, this overtravel is in the range from 10 mm to 30 mm. Particularly, the overtravel amounts to 20 mm in an embodiment.
Particularly, as shown in
After successful recapturing of the implant 100 with the help of the overtravel of the capsule 40, the user opens the capsule 40 (i.e. moves it proximal) for a second deploy attempt. The deploy traveler 76 then moves in the proximal direction (to the left in
Particularly, the movement of the locking element 80 is visible as well as audible.
The solution according to the present invention combines increased safety with good usability. Particularly, the locking element can be operated in a stable manner and its states can be detected either visually and/or acoustically.
In view of all the foregoing disclosure, the present invention also provides for the following embodiments:
| Number | Date | Country | Kind |
|---|---|---|---|
| 21161475.5 | Mar 2021 | EP | regional |
This application is a 35 U.S.C. 371 US National Phase and claims priority under 35 U.S.C. § 119, 35 U.S.C. 365(b) and all applicable statutes and treaties from prior PCT Application PCT/EP2022/053512, which was filed Feb. 14, 2022, which application claimed priority from U.S. Provisional Application 63/150,324, filed Feb. 17, 2021, and from European Patent Application Number 21161475.5, filed Mar. 9, 2021.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2022/053512 | 2/14/2022 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63150324 | Feb 2021 | US |
