This disclosure pertains in general to the field of medical implants. More particularly, the disclosure relates to occluding devices or occluders. In particular the disclosure relates to left atrial appendage occluders and a method of manufacturing thereof.
An occluder is a medical product or implant used for occluding, i.e. closing, defects e.g. in the human heart. Defects may occur in various regions of the heart and have different forms. The occluders can be inserted using minimally invasive cardiac catheter techniques, more precisely by means of a transvenous, catheter-interventional access. One example of a defect is a left atrial appendage (LAA). Thus a left atrial appendage occluder can be placed into such defect in order to prevent thrombus caused by the defect that could transfer to the brain to result in stroke. The occluder is placed into the LAA in order to occlude the LAA and block the blood flow entering the LAA, so that this may eliminate the risk of thrombus. The anatomy of the LAA varies significantly, as seen in
Prior art LAA occluders are not suitable for all of these type of LAA geometries, and there is a challenge to achieve sufficient occlusion and stability of the occluder over time for the great variance in the LAA geometry.
Thus, it would be advantageous to provide an improved LAA occluder that increases occlusion and have sufficient stability over time, as well as a method of manufacturing such LAA occluder.
Accordingly, embodiments of the present disclosure preferably seek to mitigate, alleviate or eliminate one or more deficiencies, disadvantages or issues in the art, such as the above-identified, singly or in any combination by providing an LAA occluder according to the appended patent claims.
According to a first aspect of the disclosure an occluder for a left atrial appendage is disclosed comprising a proximal portion comprising a braiding of at least one thread being radially self-expandable in a radial direction, to an expanded state, substantially perpendicular to a surface of inner walls of the left atrial appendage, whereby said braiding is engageable with said inner walls of a proximal end of said left atrial appendage, whereby in said expanded state, said proximal portion has a defined stiffness and resilience to be deformable by, and conformable to, said inner walls, whereby said braiding is configured to form a sealing connection, upon expansion in said radial direction, with said inner walls along a sealing portion of said braiding extending in a longitudinal direction of said occluder, substantially perpendicular to said radial direction. Said occluder comprising further a distal anchoring portion comprising an anchoring wire being radially expandable from a reduced diameter shape to an expanded diameter shape, said anchoring portion having a higher defined stiffness than said proximal portion, and a flexing element connecting said anchoring portion and said proximal portion and allowing movement between said anchoring portion and said proximal portion from a relaxed configuration to a deployed configuration.
According to a second aspect of the disclosure a method of manufacturing an occluder is disclosed. The method comprises; braiding a tubular or bell-shaped proximal portion of at least one thread; providing a distal anchoring portion comprising a distal anchoring wire and a proximal elongate flexing element; joining said proximal portion and said distal anchoring portion by connecting said flexing element to said proximal portion.
Further embodiments of the disclosure are defined in the dependent claims, wherein features for the second and any other aspects of the disclosure are as for the first aspect mutatis mutandis.
Some embodiments of the disclosure provide for improved anchoring of the occluder in the LAA.
Some embodiments of the disclosure provide for improved anchoring of the occluder in the LAA while maintaining a high flexibility to adapt to various LAA geometries.
Some embodiments of the disclosure provide for an improved occlusion.
It should be emphasized that the term “comprises/comprising” when used in this specification is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.
These and other aspects, features and advantages of which embodiments of the disclosure are capable of will be apparent and elucidated from the following description of embodiments of the present disclosure, reference being made to the accompanying drawings, in which;
Specific embodiments of the disclosure now will be described with reference to the accompanying drawings. This disclosure may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. The terminology used in the detailed description of the embodiments illustrated in the accompanying drawings is not intended to be limiting of the disclosure. In the drawings, like numbers refer to like elements.
The following description focuses on embodiments of the present disclosure applicable to occluders such as an left atrial appendage occluders. However, it will be appreciated that the disclosure is not limited to this application but may be applied to many other medical implants including for example Stents, Vascular Occluders, Products for treatment of aneurysm, Plugs and Occlusion systems for other applications, and various other occluders such as a atrial septal defect (ASD) occluder, a Patent foramen ovale (PFO) occluder, a paravalvular leakage (PLD) occluder, a PDA occluder, a ventricular septal defect (VSD) occluder, or a transapical occluder.
By having a sealing surface 104 of the braiding 102 extending in the longitudinal direction 108 and being configured to expand against the inner walls 900 of a LAA, and being conformable to the inner walls to form a sealing connection thereto, the proximal portion 101 provides an optimal occlusion of the proximal end 901 of a LAA. Independent of the geometry of the proximal portion 101 of the LAA, the proximal portion, i.e. the braiding 102, has sufficiently low stiffness to conform the inner walls 900 of the LAA to form a sealing connection thereto. Prior art devices, such as illustrated in
Thus the sealing portion 104 of the present embodiments of the occluder 100 extending in the longitudinal direction 108 and configured for expanding radially outwards in the radial direction 103 against the inner walls 900 of the LAA and having a stiffness so as to be deformed by said walls form a sealing connection thereto has improved tolerances in positioning an is less traumatic to the tissue.
Further, the proximal portion 101 may have such sufficiently low stiffness to be conform the inner walls of the LAA due to the distal anchoring portion 105 having a higher defined stiffness than the proximal portion 101. Thus the distal anchoring portion 105 makes sure the proximal sealing portion 101 is fixated in the proximal end 901 of the LAA. Thus, since the proximal portion 101 does not need to provide a counter force to such degree such that it anchors against the inner walls 900—which instead is the function of the distal anchoring portion 105—the proximal portion can have a lower stiffness than the distal anchoring portion 101, and be defined in the heat setting step of the manufacturing thereof to be sufficiently low to be deformed by the force exerted by the inner walls 900 of the LAA to conform and seal thereto.
The anchoring wire 106 is radially expandable to an expanded diameter shape, as illustrated in e.g.
The flexing element 107 of the present embodiments of the occluder 100 allows angling between the proximal portion 101 and a distal anchoring portion 105 for the occluder 100 to adapt to the different geometries of the LAA as seen in
The occluder 100 thus provides for the above synergetic features to provide a synergetic effect of being easily conformable to the proximal end 901 of the LAA for sealing thereof, while having a pivotable anchoring portion 105 of higher stiffness than the proximal sealing portion 101 that allows for the proximal portion to be highly conformable, as explained above, while providing secure anchoring in various LAA geometries, such as varying “branches” or “lobes” of the LAA that may be angled relative the entrance opening of the LAA, due to the pivoting flexing element 107 between the two portions.
The braiding 102 of the proximal portion 101 may have a closed or open distal end, i.e. the end opposite connecting unit 111, seen in e.g.
The anchoring portion 105 may thus be freely pivotably movable relative the proximal portion, whereby the anchoring portion 105 is positionable at an angle relative the proximal portion, and the longitudinal direction 108, in the deployed configuration, whereby the flexible element 107 is bendable and conformable to the geometry of the left atrial appendage.
The frictional force between the anchoring portion 105 in the expanded diameter shape and the inner walls 900 may accordingly be higher than the frictional force between the proximal portion 101 in the expanded state and the inner walls 900. This improves the anchoring of the proximal portion 101.
The anchoring wire 106 may be stiffer than the at least one thread of the braiding 102. The anchoring wire 106 may thus be of a different material, and/or have a different diameter, and/or have been subjected to a different treatment procedure during manufacturing, than the thread of the braiding 101, in order to be more stiff. Alternatively, or in addition, the geometry of the distal anchoring portion 105 is configured so that the distal anchoring portion 105 has a higher stiffness, e.g. by having a more densely wound structure by the anchoring wire 106
The flexing element 107 may be substantially non-extendable in the longitudinal direction 108 and freely pivotable in the radial direction 103. Thus, this may provide for a substantially fixed separation between the proximal 101 and distal portion 105, while allowing angling therebetween, which may be desired in certain geometries.
The flexing element 107 may comprises a series of linkage section being movable with respect to each other (not shown). This may provide for having a substantially fixed distance between the proximal and distal portions in the longitudinal direction. This may also provede for improved pushability of the occluder while maintaining a high pivoting action.
The flexing element 107 may be resiliently movable in the longitudinal direction and freely pivotable in the radial direction. It may also be desired to have a spring like effect in the longitudinal direction 108, e.g. to provide a tractive force from the distal portion to the proximal portion to draw the latter in a direction further inside the LAA. It may also be desired to have flexibility to reach different branches or lobes of different depths inside the LAA with the distal anchoring portion 105.
The flexing element 107 may comprises a spring 109 or another resilient element, see
The proximal portion 101 may be substantially tubular- or bell-shaped. The sealing portion 104 may extends along substantially the entire length of the proximal portion in the longitudinal direction 108. This provides for a larger sealing interface between the occluder and the inner walls 900 of the LAA, while maintaining a compact device. Also pressure is distributed on a larger surface, as compared to a disk shaped device which is more traumatic.
The proximal portion 101 may comprise an occluding membrane 121, as illustrated in
The proximal portion 106 may comprise tissue retention members 110, see
The proximal portion 101 may be resilient such that it is deformable to a non-circular shape by the inner walls 900, such as to an at least partly oval shape, and/or to an at least partly concave shape at a peripheral portion of the proximal portion 101. The stiffness of the proximal portion 101, and/or of the threads thereof, may thus be adapted such that it is readily deformable to a non-circular shape as may be required by the particular geometry of the LAA for optimal sealing.
The occluder may comprise a connecting unit 111 for connecting to a delivery tool, wherein the connecting unit collects and fixates ends of the threads at a proximal end of said the proximal portion 101. The flexing element 107 may be attached to the connecting unit 111 and extend distally therefrom in the longitudinal direction 108, see
Alternatively, or in addition, the flexing element 111 may be connected to the braiding 102.
The proximal portion 101 may comprise an outer and inner braiding 112, see
The occluder may comprise at least two anchoring portions 113, 113′, see
The occluder may comprise at least two flexing elements 114, 114′, see
The anchoring portion 105 may comprise at least one wire loop 116, see
The anchoring wire 106 of the anchoring portion may be braided, i.e. comprising a braid 120, see
The anchoring portion 105 may comprise an at least partly concave shape 118 being concave in a direction towards said proximal portion, see e.g.
The flexing element 107 may be a separate connecting element between the proximal portion 101 and the anchoring portion 106, whereby the flexing element 107 is freely bendable or pivotable independent of, or unaffected by, movement of the threads of the proximal portion 101 and/or movement of the anchoring wire 106 of the anchoring portion 106. This provides for optimal and independent positioning of the anchoring portion 105 relative the proximal portion 101, in the various geometries of the LAA.
As explained above the anchoring wire 106 may also be a separate wire that is unaffected by movement of the threads of the braid of the proximal portion 101, for allowing optimised anchoring function, independent of the movement of the threads of the braiding 102 which move to conform to the internal wall of the LAA for optimal sealing.
The anchoring portion 105 may be radially expandable to a larger diameter than the proximal portion 101. Thus the anchoring of the proximal portion 101 may be further improved.
The distal anchoring portion 105 may comprise the flexing element 107 such that the anchoring wire 106 and the flexing element 107 are joined as an integrated unit. This may provide for a simple to manufacture device while still having the above mentioned advantages.
braiding (201) a tubular or bell-shaped proximal portion 101 of at least one thread;
providing (202) a distal anchoring portion 105 comprising a distal anchoring wire 106 and a proximal elongate flexing element 107;
joining (203) said proximal portion and said distal anchoring portion by connecting said flexing element to said proximal portion. This may provide for a particularly easy manufacturing method of the occluder 100 while achieving the above mentioned advantages.
Connecting the flexing element to the proximal portion may comprise;
collecting (204) ends of the at least one thread of said braided proximal portion and an end of said flexing element at a collection point;
attaching (205) said ends of the at least one thread of said braided proximal portion and said end of said flexing element at the collection point.
Attaching said ends of the at least one thread of said braided proximal portion and said end of said flexing element at the collection point may comprise;
welding (206) a connection unit (111) that connects said ends of the at least one thread of said braided proximal portion to said end of said flexing element at the collection point. This provides for a compact and easy to manufacture occluder 100 having the above mentioned advantages.
The present disclosure has been described above with reference to specific embodiments. However, other embodiments than the above described are equally possible within the scope of the disclosure. Different method steps than those described above, may be provided within the scope of the disclosure. The different features and steps of the disclosure may be combined in other combinations than those described. The scope of the disclosure is only limited by the appended patent claims. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the teachings of the present disclosure is/are used.
Filing Document | Filing Date | Country | Kind |
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PCT/EP2015/063011 | 6/11/2015 | WO | 00 |
Number | Date | Country | |
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62010768 | Jun 2014 | US |