Patent Application
20200360687
The present invention generally relates to an implantable medical device and a delivery arrangement comprising a delivery system for delivering such an implantable medical device.
An implantable medical device of this kind may, for example, be a leadless pacemaker for implantation into the human heart, for example in the right ventricle or the right atrium.
In recent years, leadless pacemakers have received increasing attention. Leadless pacemakers, in contrast to pacemakers implanted subcutaneously using leads extending transvenously into the heart, avoid the need for leads in that the pacemaker device itself is implanted into the heart, the pacemaker having the shape of a generally cylindrical capsule for implantation into cardiac tissue, in particular the right ventricular wall of the right ventricle. Such leadless pacemakers exhibit the inherent advantage of not using leads, which can reduce risks for the patient involved with leads transvenously accessing the heart, such as the risk of pneumothorax, lead dislodgement, cardiac perforation, venous thrombosis and the like.
When placing an implantable medical device such as a leadless pacemaker device, for example in the human heart, one challenge lies in designing an anchoring device allowing a fixation of the implantable medical device, for example on cardiac tissue such that the implantable medical device is securely received and held on cardiac tissue. For this, the anchoring device on the one hand shall provide for a secure fastening of the implantable medical device on the cardiac tissue, on the other hand however shall avoid a damaging of cardiac tissue and structures within the cardiac tissue.
A typical anchoring device comprises anchoring members in the form of tines which, when placing the implantable medical device on cardiac tissue, pierce the cardiac tissue and in this way provide for an anchoring of the implantable medical device on the cardiac tissue. For placing the implantable medical device on the cardiac tissue, the implantable medical device typically is received within a sheathing device of a delivery catheter, the delivery catheter being used to access the human heart and to deliver the implantable medical device towards a location of interest by removing the sheathing device and by in this way placing the implantable medical device on cardiac tissue at the location of interest. When received in the sheathing device, anchoring members of the anchoring device are deformed from a relaxed, pre-shaped first configuration to assume a strained second configuration within the sheathing device. The anchoring members reset to their pre-shaped first configuration upon delivering the implantable medical device from the sheathing device such that the anchoring members engage with cardiac tissue to fasten the implantable medical device to the cardiac tissue.
There is a general desire to provide for an anchoring device that allows an easy, reliable delivery from a sheathing device, while providing for a secure and reliable fastening when placing the implantable medical device on an object, in particular on cardiac tissue.
U.S. Pat. No. 9,844,659 describes an assembly of an implantable medical device comprising an anchoring device having a set of active fixation tines. The active fixation tines in the set are deployable from a spring-loaded position in which distal ends of the fixation tines point away from the implantable medical device to a hooked position in which the active fixation tines bend back towards the implantable medical device.
United States Publication No. 2015/0051616 discloses an implantable leadless pacing device including a pacing capsule having a housing. Anchoring members are coupled to a distal region of the housing, the anchoring members including a region with a compound curve.
There are inherent issues with the anchoring devices identified above, which the present invention is directed at overcoming.
It is an object to provide an implantable medical device and a delivery arrangement for delivering such implantable medical device which allow for a reliable and secure delivery of an implantable medical device to a location of interest, for example, in the human heart and a reliable fastening of the implantable medical device at a location of interest, for example to cardiac tissue.
An implantable medical device according to claim 1 and a delivery arrangement according to claim 11 are provided. Further embodiments are subject matter of dependent claims.
At least the above object is addressed by an implantable medical device comprising a housing having a proximal end and a distal end, an electrode device arranged in the region of the distal end, and an anchoring device fixedly attached to the housing in the region of the distal end.
The anchoring device comprises at least one anchoring member having a pre-shaped first configuration, the at least one anchoring member being deflectable from the pre-shaped first configuration into a strained second configuration (where it may be held within an implantation tool) for placement of the implantable medical device on an object. The at least one anchoring member comprises a tip section and a connection section extending in between the tip section and the distal end of the housing, wherein at least in the pre-shaped first configuration the tip section comprises a straight portion adjoining the connection section at a transition location by forming a bend (or a kink) in between the straight portion and the connection section.
The implantable medical device comprises an anchoring device configured to fasten the implantable medical device on an object, in particular cardiac tissue, upon placement of the implantable medical device for example in the human heart. An implantable medical device of this kind may for example be a leadless pacemaker device configured to provide a pacing action, the implantable medical device comprising an electrode device for emitting a simulation signal towards the cardiac tissue in order to stimulate cardiac activity.
The anchoring device comprises at least one anchoring member. The at least one anchoring member assumes a pre-shaped first configuration when it is in a relaxed state. From this pre-shaped first configuration the at least one anchoring member may be (elastically) deformed, in particular for receiving the implantable medical device in a sheathing device of a delivery system. When received in a delivery system, the at least one anchoring member hence is strained in a spring-loaded fashion and is held in said second configuration, wherein upon placement of the implantable medical device on an associated object, in particular on cardiac tissue of the human heart, and upon delivery out of the delivery system the at least one anchoring member elastically resets towards its pre-shaped first configuration, the at least one anchoring member thus piercing cardiac tissue as it returns to the relaxed, pre-shaped first configuration.
The at least one anchoring member within the delivery device assumes a predefined shape corresponding to the second configuration, which may be such that a scratching of a sheathing device by a free end of the at least one anchoring member is avoided when delivering the implantable medical device out of the sheathing device. For this, the at least one anchoring member comprises different sections, namely a tip section forming the far end of the at least one anchoring member and a connection section for connecting the tip section to the housing of the implantable medical device. The tip section comprises a straight portion adjoining the connection section at a transition location by forming a bend in between the straight portion and the connection section.
At its tip section the at least one anchoring member hence at least partially is formed straight. At a position in between the straight portion of the tip section and the connection section herein a bend is formed of small radius. In this way it is possible to shape the tip section such that it, with its free end, does not scratch on an inner wall of a sheathing device upon delivering the implantable medical device out of the sheathing device for placing the implantable medical device on an object, in particular on cardiac tissue of the human heart. Because a scratching of the sheathing device is avoided, a risk of releasing material of the delivery catheter potentially into the bloodstream of a patient is reduced, reducing the danger of potentially hazardous effects such as a risk for thrombi and/or lung emboli. In one embodiment, the connection of the tip section to the connection section may be discontinuous in that no smooth transition from the straight portion of the tip section to the connection section is formed, but the tip section is joined to the connection section at a sharp-angled kink.
In addition, because the tip section at least partially is formed straight, the tip section may be shaped such that it may engage with tissue at an advantageous angle, in particular at substantially 90°, when placing the implantable medical device on the tissue, hence allowing for an initially deep penetration of the tissue at a substantially perpendicular penetration direction, which may allow the use of an anchoring member of comparatively short length. In particular, the tip section initially penetrates into the tissue at a substantially perpendicular angle, upon which it transitions from its (spring-loaded) strained second configuration into the relaxed pre-shaped first configuration and in this way pierces through the tissue and exits from the tissue by means of the tip section to form a hook-like connection for the implantable medical device on the tissue. Because the at least one anchoring member may have a rather large curvature at its connection section the overall length of the anchoring member may be comparatively short.
In one embodiment, the connection section of the at least one anchoring member, at least in the pre-shaped first configuration, comprises at least one of at least one curved portion and at least one straight portion. The connection section hence may have a generally curved shape, wherein the connection section may be formed by a single curved portion or multiple different portions which adjoin each other and which may have a curved or straight shape.
In one embodiment, the connection section may be formed by a single curved portion having a single, constant radius of curvature.
In another embodiment, the connection section may be formed by a single curved portion adjoined by a single straight portion, the straight portion of the connection section, for example, forming the transition location with the straight portion of the tip section.
In another embodiment, the connection section may be formed by multiple curved portions. For example, the connection section may be formed by multiple different curved portions, the curved portions adjoining each other and having different radii of curvature. In another example, the connection section may be formed by curved portions in between which straight portions are arranged, the curved portions each having the same radius of curvature or different radii of curvature.
In yet another embodiment, the connection section may be formed by a first curved portion having a first curvature and a second curved portion having a second curvature opposite to the first curvature. The different curved portions hence are curved into different directions, wherein, for example, the second curved portion may form the transition location with the straight portion of the tip section.
The tip section may be formed entirely straight such that the tip section is made up by the straight portion. In yet another example, the tip section may have a curved portion adjoining the straight portion, the curved portion, for example forming the far end of the at least one anchoring member.
The tip section adjoins the connection section at a transition location by forming a bend in between the straight portion and the connection section. At least in the pre-shaped first configuration, herein, the straight portion of the tip section may form an angle with respect to a straight portion of the connection section extending from the transition location. Alternatively, the straight portion of the tip section may form an angle with a tangent to a curved portion of the connection section extending from the transition location. The angle herein may be in the range between 90° and 160° beneficially in between 120° and 150°.
If the connection section adjoins the tip section by means of a curved portion, the angle is measured in between a tangent to the curved portion, the tangent being placed at the transition location such that it is tangential to the curved portion of the connection section. The angle to the straight portion of the tip section herein differs from 180° such that (in mathematical terms) a discontinuously differentiable connection in between the tip section and the connection section is formed at the transition location.
In one embodiment, the anchoring device comprises a ring element for fixing the anchoring device to the housing of the implantable medical device. The at least one anchoring member herein is fixed to the ring element, for example by forming the at least one anchoring member integrally with the ring element. The ring element provides for a fixation of the anchoring device on the housing of the implantable medical device such that the at least one anchoring member is held at the distal end of the housing of the implantable medical device.
The anchoring device may comprise a multiplicity of anchoring members, for example, two, three, four or more anchoring members, each anchoring member having a pre-shaped first configuration and a strained second configuration and each anchoring member having a tip section and a connection section as described previously.
The at least one anchoring member may, for example, be made of a wire, a sheet, or a tube. The at least one anchoring member or the anchoring device as a whole may, for example, be made from a super-elastic metal material, in particular a Nickel Titanium alloy, also denoted as Nitinol.
At least the above object is also addressed by a delivery arrangement comprising a delivery system having a sheathing device, and an implantable medical device. The implantable medical device comprises a housing having a proximal end and a distal end, an electrode device arranged in the region of the distal end, and an anchoring device fixedly attached to the housing in the region of the distal end, the anchoring device comprising at least one anchoring member having a pre-shaped first configuration, the at least one anchoring member being deflectable from the pre-shaped first configuration into a strained second configuration for placement of the implantable medical device on an object. The at least one anchoring member herein comprises a tip section and a connection section extending in between the tip section and the distal end of the housing, wherein at least in the pre-shaped first configuration the tip section comprises a straight portion adjoining the connection section at a transition location by forming a bend in between the straight portion and the connection section. The at least one anchoring member, for placement of the implantable medical device on an object by means of delivery system, is received in the sheathing device of the delivery system in said strained second configuration.
For placement of the implantable medical device on an object, the implantable medical device is received within the sheathing system of the delivery system. For arranging the implantable medical device, for example, within the human heart the implantable medical device is guided through a venous access by means of the delivery system, in particular comprising a delivery catheter. Once a location of interest is reached, the implantable medical device is delivered from the sheathing device of the delivery system by withdrawing the sheathing device or by pushing the implantable medical device out of the sheathing system, such that the implantable medical device with its distal end comes to rest on tissue at the location of interest and by means of the anchoring device is fastened to the tissue.
Within the sheathing device the at least one anchoring member of the anchoring device of the implantable medical device is held in the strained second configuration, which is such that the at least one anchoring member by means of its tip section (which at least partially is formed flat) may engage with the tissue when delivering the implantable medical device out of the sheathing device. During the placement, the at least one anchoring member resets from its strained second configuration to the relaxed, pre-shaped first configuration, in the course of which the at least one anchoring member penetrates through the tissue and exits from the tissue by means of its tip section, such that a hook connection in between the implantable medical device and the tissue is formed. In an implanted state the connection section extends through tissue such that by means of the connection section the implantable medical device is securely fastened to the tissue.
In one embodiment, the implantable medical device generally extends along a longitudinal axis, the implantable medical device, for example, having a generally cylindrical shape with the longitudinal axis forming a cylinder axis of the implantable medical device. The proximal end and the distal end of the implantable medical device herein are displaced with respect to each other along the longitudinal axis, wherein the implantable medical device is deliverable from the sheathing device for placement on said object in a placement direction aligned with the longitudinal axis. When delivering the implantable medical device from the sheathing device the implantable medical device hence, with its distal end, approaches associated tissue along the placement direction, causing the at least one anchoring member to engage with the tissue in order to fasten the implantable medical device on the tissue.
In the strained second configuration, the straight portion of the tip section of the at least one anchoring member may, in one embodiment, extend substantially parallel to the longitudinal axis and may point in the placement direction. The at least one anchoring member is hence held within the sheathing device in its strained second configuration such that it points forward in the placement direction and hence may engage with the tissue at an angle of substantially 90°, which allows for a beneficial, deep penetration in particular at an initial penetration phase by means of the tip section. This may allow the use of anchoring members of rather short length, because the connection section may be formed with a rather large curvature, as the fixation of the implantable medical device may be achieved by a comparatively deep, but laterally short penetration (as compared to a shallow, but laterally spread-out penetration).
In one embodiment, in the pre-shaped first configuration the straight portion extends substantially parallel or at an obtuse angle with respect to the longitudinal axis. The straight portion herein may, in the pre-shaped first configuration, point in a direction generally opposite to the placement direction. In the relaxed, pre-shaped first configuration, the tip section of the at least one anchoring member, by means of its straight portion, hence points away from the tissue such that by means of the connection section a hook-like connection of the anchoring member to the tissue is established. The connection section herein penetrates through the tissue and curves laterally outwards from the housing, such that the tip section exits from the tissue at a laterally remote location from the housing, the tip section being formed to extend parallel to the housing (i.e., parallel to the longitudinal axis) or at an obtuse angle with respect to the longitudinal axis such that the tip section with its free end points away from the housing.
Additional features, aspects, objects, advantages, and possible applications of the present invention will become apparent from a study of the exemplary embodiments and examples described below, in combination with the Figures, and the appended claims.
The various features and advantages of the present invention may be more readily understood with reference to the following detailed description and the embodiments shown in the drawings. Herein,
Subsequently, embodiments shall be described in detail with reference to the drawings. In the drawings, like reference numerals designate like structural elements.
It is to be noted that the embodiments are not limiting for the present disclosure, but merely represent illustrative examples.
For implantation, the implantable medical device 1, by means of a delivery system, is placed in the right ventricle RV and is delivered from the delivery system such that it comes to rest on myocardial tissue M and is fastened to myocardial tissue M.
During implantation, the implantable medical device 1 is to be placed on myocardial tissue M and is to be fastened to the myocardial tissue M. For this, the implantable medical device 1 comprises an anchoring device 2 having a multiplicity of anchoring members 20 fabricated from wires, sheets or tubes or the like, the anchoring members 20 extending from the housing 10 of the implantable medical device 1 at the distal end 100 in order to engage with myocardial tissue M for securely fastening the implantable medical device 1 to the myocardial tissue M.
The anchoring members 20 are fixedly arranged on the distal end 100 of the housing 10 of the implantable medical device 1. In a relaxed state, the anchoring members 20 assume a pre-shaped first configuration, as shown in
The anchoring members 20 of the anchoring device 2 may assume a strained, second configuration in which they are deflected from their relaxed, pre-shaped first configuration, as it is schematically illustrated in
When having reached the myocardial tissue M at a point of interest, the implantable medical device 1 is delivered from the sheathing device 30 in the placement direction A such that the implantable medical device 1 exits from the sheathing device 3 at a front opening 300, in the course of which the anchoring members 20 with their tip sections 21 engage with myocardial tissue M and penetrate into the myocardial tissue M.
As the anchoring members 20 are received within the sheathing device 30 in a spring-loaded, strained second configuration, the anchoring members 20, when the implantable medical device 1 is delivered from the sheathing device 30, relax from their second configuration towards the pre-shaped first configuration as illustrated in
Whereas each anchoring member 20 at its tip section 21 is substantially formed straight, the connection section 22 of each anchoring member 20 has a substantially curved shape in order to form a loop through myocardial tissue M for fastening the implantable medical device 1 on the myocardial tissue M when the implantable medical device 1 is removed from the sheathing device 30 and the anchoring members 20 relax from their second configuration towards the pre-shaped first configuration.
Each anchoring member 20 herein generally has the same shape, wherein it also is conceivable that different anchoring members 20 of the anchoring device 2 have different shapes.
Different embodiments of anchoring members 20 of an anchoring device 2 are shown in
The anchoring device 2 may, as illustrated in
The anchoring device 2 with its anchoring members 20 and the ring element 23 may be integrally formed, for example, from a super-elastic Nickel Titanium alloy material. The anchoring members 20 herein are elastically deformable from their pre-shaped first configuration, which the anchoring members 20 assume when they are relaxed and are not received within the delivery system 3.
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The anchoring members 20 of the anchoring device 2 may, in particular, be shaped such that in the strained second configuration, as illustrated in
As the straight portions 212 of the tip sections 21 of the anchoring members 20 point straight along the placement direction A when the implantable medical device 1 is received in the delivery system 3, the tip sections 21 may engage with myocardial tissue M at a substantially perpendicular angle, which may help to achieve a defined, deep penetration in particular at an initial phase of delivering the implantable medical device 1 from the sheathing device 30. This may allow designing the connection sections 22 with a relatively large curvature, such that in the implanted state (corresponding to the relaxed, pre-shaped first configuration of the anchoring members 20) the anchoring members 20 extend through the myocardial tissue M at a defined, narrow curve, allowing forming the anchoring members 20 with a comparatively small axial length.
In particular, the implantable medical device may be configured to act as a leadless pacemaker device, whereas the implantable medical device may also be designed to provide a different function. The implantable medical device may be configured to be implanted into the right ventricle of the human heart or into another location of, e.g., the human heart or another body part.
It will be apparent to those skilled in the art that numerous modifications and variations of the described examples and embodiments are possible in light of the above teachings of the disclosure. The disclosed examples and embodiments are presented for purposes of illustration only. Other alternate embodiments may include some or all of the features disclosed herein. Therefore, it is the intent to cover all such modifications and alternate embodiments as may come within the true scope of this invention, which is to be given the full breadth thereof. Additionally, the disclosure of a range of values is a disclosure of every numerical value within that range, including the end points.
