Occluder with a stretchable waist

Abstract

The present invention discloses an occluder for structural heart defects, the occluder including a tubular interdigitated structure having a pitch that varies along the axial length of the occluder; a proximal element; a distal element; and an intermediate element extending between the proximal and distal elements. According to one embodiment, at least one transition in pitch from a first pitch to a second pitch is located closer to the intermediate element of the occluder than the circumferential surface of at least one of the proximal and distal elements when the occluder is in a relaxed state. According to another embodiment, the occluder is stretchable from a relaxed state to an axially stretched state, wherein the load-to-elongation ratio exerted by the occluder, measured in N / mm, is less than about 0.75 when stretched at least 2 mm.

Description

[Technical field]

[0001] The present invention relates to the field of intravascular and / or cardiac occluders and devices such as atrial septal defect (ASD) occluders, patent foramen ovale (PFO) occluders, PDA (patent ductus arteriosus) occluders, PLD (paravalvular leak devices), TAVI (transcatheter aortic valve implantation) PLD, VSD (ventricular septal defect) occluders, LAA (left atrial appendage) occluders, AFR (atrial flow regulators), fistula devices, and / or reciprocal atrial flow diverters such as VP (vascular plug) devices. In particular, these devices are manufactured from combined structures, preferably braided wire structures. [Background technology]

[0002] Occluders generally provide sufficient occlusion to allow minimally invasive procedures for a variety of structural cardiac or vascular diseases. When implanted, interatrial shunt devices such as AFRs allow controlled flow across the device, see, for example, WO 2016 / 038115 A1. Fistula devices may provide a passageway between two body cavities. Vascular plugs may provide vascular occlusion. Interventional procedures for the treatment of structural cardiac or vascular disease using endovascular and / or cardiac occluders and devices have become an established routine.

[0003] An occluder for treating structural heart disease may have one disk at one end of the device, or two disks, one at each opposite end of the waist. The disks may have an enlarged diameter relative to the waist. Typically, a disk is used as the occluding portion of the occluder.

[0004] An occluder with two discs may extend between two sides of a cardiac structure, such as the septal wall, a cardiac valve, a cardiac valve annulus, or between two blood vessels, such as the pulmonary artery and the aorta. A disc may be placed on each side of the cardiac structure, preferably as a holding unit that keeps the occluder in place when implanted. The waist may extend through the cardiac structure. Such cardiac structures may have a large variability. For example, occluders with a single disc are commonly used for the treatment of several diseases to accommodate the large variability of anatomical structures, such as length and shape. For a single disc occluder, either the disc or the waist may be used as the occluding portion. However, the anatomical structure may distort the occluding waist so that the occluding effect of the device is distorted. This may make it difficult to anchor the occluder securely to the anatomical structure.

[0005] In the case of anatomically adapted occluders designed for a specific clinical / anatomical length, if an occluder with two discs is used in a situation where the extensible length of the waist is actually required, the discs may be distorted by the stiffness of the waist. This may reduce the quality of the occlusion effect provided by the discs. Other structural heart diseases are treated with occluders having a fixed diameter or with only a single disc.

[0006] In WO 2017 / 139702 A1, a vascular occlusion device is disclosed having petals with varying pitch. In US 8313505 B2, a tubular occluder with one pitch is disclosed. In WO 2014 / 150288 A2, a vascular treatment device is disclosed that controls the braid angle to control the porosity of the device. In WO 2018 / 058033 A1, an LAA occluder is disclosed having multiple layers of braid with different pitches. In WO 2011 / 161136 A1, a medical implant is disclosed in which various braided segments are assembled. In WO 97 / 42878 A1, an occlusion device is disclosed made of a tubular braid with a single pitch. In EP 2063791 and corresponding WO 2008 / 036156 A1, a cerebrovascular device is disclosed in which the braid angle of the tubular braid is controlled to limit expansion of certain parts of the device but not at the ends of the device. In WO 2014 / 110589 A1, an occlusion device with variable pitch is disclosed, but the purpose and function of the variable pitch in the device is not disclosed. In WO 2017 / 214431 A1, a braided vaso-occlusion member is disclosed, and while a variable pitch of the braid is disclosed, the purpose and function of the variable pitch in the device is not disclosed. In WO 03 / 065934 A2, a braided modular stent is disclosed in which different braid angles provide different radial strengths of the stent. In WO 2018 / 112203 A1, a stent with a polymeric electrospun coating is disclosed. US Patent Publication US2015 / 238333 discloses a vascular aneurysm stent device.

[0007] Certain anatomical structures are not suitable for occlusion with any of the occluders mentioned above.

[0008] Also, the length of the anatomical structure occluded by the constriction may change during the life of the implanted occluder. For example, the structure may expand in structural heart disease. Also, contractions may occur, for example, during sinus rhythm of the heart or during fibrillation. For example, the atrial appendages may contract or expand. The heart wall may thicken. Generally, known occluders are unable to handle the tensions that create such changing anatomical conditions for the surrounding implant tissue, potentially leading to tissue rupture, unwanted leakage at the implant site, or even embolization of the device with dire consequences for the patient.

[0009] Thus, a need exists for an occluder with increased bending resistance for treatment of anatomical structures having greater variability, such as length and / or shape. Summary of the Invention

[0010] Accordingly, as described above, embodiments of the present invention seek to preferably mitigate, alleviate or eliminate the deficiencies, drawbacks or problems in the art singly or in any combination by providing an occluder as defined in the appended claims.

[0011] The present invention is defined solely by the appended claims, and in particular by the scope of the appended independent claims. References to "embodiments" throughout the detailed description that are not under the appended claims merely represent possible exemplary implementations and are therefore not part of the present invention. In one aspect, the present disclosure includes an occluder with a tubular interlocking structure having a pitch that varies along the axial length of the occluder, with at least one transition of the pitch being located closer to the central axis or intermediate member of the occluder than the outer circumferential surface of the proximal and / or distal elements when the occluder is in a relaxed state. The occluder includes a continuous tubular braided structure made of at least one wire integral base body and having a pitch that varies along the axial length of the base body with at least one pitch transition. The occluder is preferably heat set to have a shape that includes a proximal retention element having an outer circumferential surface and a distal inner diameter at a first transition in the relaxed state of the occluder. The shape preferably includes a distal retaining element having an outer circumferential surface and a proximal inner diameter at a second transition portion in the relaxed state of the occluder. The shape preferably includes an intermediate element extending between the first and second transition portions of the proximal and distal retaining elements. At least one pitch transition from a first pitch to a second pitch is preferably located closer to the intermediate element or central axis of the occluder than to an outer circumferential surface of at least one of the proximal and distal elements when the occluder is in the relaxed state. Preferably, the location of at least one of the transition portions is closer to the central axis, and the diameter of the intermediate element is reduced from its relaxed diameter when the occluder is in an axially extended state.

[0012] In another aspect, the present disclosure includes an occluder expandable from a relaxed state to an axially stretched state, said occluder being longer in a longitudinal direction of the occluder than the relaxed state, and a load-to-elongation ratio provided by the occluder, measured in N / mm, is less than about 0.75 when stretched at least 2 mm. The first and second aspects form mutually exclusive embodiments or may be combined into a single embodiment.

[0013] In a second aspect of the present disclosure, a method of manufacturing an occluder is provided. The method includes forming an integral platform body of at least one wire providing a continuous tubular braided interwoven structure having a pitch that varies along an axial length of the occluder platform body with at least one pitch transition. The method includes heat setting the platform body to have a shape in the relaxed state of the occluder, preferably including a proximal retention element having an outer circumferential surface and a distal inner diameter at a first transition. The shape preferably includes a distal retention element having an outer circumferential surface and a proximal inner diameter at a second transition in the relaxed state of the occluder. The shape preferably includes an intermediate element extending between the first and second transitions of the proximal and distal retention elements. At least one pitch transition from the first pitch to the second pitch is preferably located closer to the intermediate element or central axis of the occluder than to an outer circumferential surface of at least one of the proximal and distal elements when the occluder is in a relaxed state. Alternatively, or additionally, the occluder is stretchable from the relaxed state to a state of axial extension greater along the length of the occluder than in the relaxed state, wherein a load-to-extension ratio provided by the occluder, measured in N / mm, is less than about 0.75 when stretched at least 2 mm without distortion of the proximal or distal retaining elements.

[0014] An embodiment of the invention provides an occluder including at least one wire and a tubular interdigitated structure made from the at least one wire and having a pitch that varies along an axial length of the occluder, the occluder including a proximal element having an outer circumferential surface and an inner diameter in the relaxed state of the occluder, a distal element having an outer circumferential surface and an inner diameter in the relaxed state of the occluder, and an intermediate element extending between the proximal and distal elements.

[0015] According to a first aspect, at least one transition of the pitch from the first pitch to the second pitch is located closer to an intermediate element or central longitudinal axis of the occluder than to an outer circumferential surface of at least one of the proximal and distal elements when the occluder is in a relaxed state.

[0016] According to a second aspect, the occluder is stretchable in its longitudinal direction from a relaxed state to an axially stretched or elongated state that is longer in the longitudinal direction of the occluder than the relaxed state, the load to stretch ratio provided by the occluder, measured in N / mm, is less than about 0.75 when stretched at least 2 mm.

[0017] In various embodiments, the first and second aspects are mutually exclusive embodiments or may be combined into a single embodiment. Each of the first and second aspects may be combined separately or together with the next embodiment.

[0018] In one embodiment, when the occluder is in a relaxed state, at least one transition in pitch may be located between an outer periphery and an inner diameter of at least one of the proximal and distal elements.

[0019] In one embodiment, at least one of the proximal and distal elements includes at least a first pitch, and the intermediate element includes only a second pitch along the axial length of the intermediate element.

[0020] In one embodiment, at least one of the outer periphery of the proximal and distal elements remains substantially constant as the inner diameter decreases upon stretching the occluder longitudinally.

[0021] In one embodiment, at least one of the proximal and distal elements includes only the first pitch.

[0022] In one embodiment, the intermediate element includes a first pitch and a second pitch along an axial length of the intermediate element.

[0023] In one embodiment, the occluder is expandable from a relaxed state to a state that is axially elongated longer along the length of the occluder than the relaxed state.

[0024] In one embodiment, the load to elongation ratio provided by the occluder, measured in N / mm, is preferably less than 0.5 N / mm, preferably less than 0.75 N / mm, and more preferably less than 0.25 N / mm when stretched at least 2 mm up to about 6 mm.

[0025] In embodiments, when the occluder is stretched from the relaxed state to the extended state, the cross-sectional diameter of the intermediate component decreases by less than 60%, preferably by less than 40%.

[0026] In embodiments, the circumferential surface of at least one of the proximal and distal elements is substantially constant when the occluder is stretched to a length greater than 50% of its relaxed state and up to about 150% of its relaxed state.

[0027] In embodiments, when the occluder is in a relaxed state, the intermediate element is at least partially straight or has a centrally waisted shape relative to the longitudinal axis of the occluder, such as a cylindrical or conical, bell-shaped, or hourglass-shaped shape.

[0028] In an embodiment, the occluder is one of an interatrial shunt device, such as, for example, a PDA occluder, a PLD, a TAVI-PLD, a VSD occluder, an atrial septal defect (ASD) occluder, a patent foramen ovale (PFO) occluder, an LAA occluder, an AFR (atrial flow regulator), a fistula device, or a vascular plug (VP) device.

[0029] Embodiments of the present invention provide an occluder that can be used for occlusion of anatomical structures having a wide variety of shapes, where occlusion by a surgeon was previously the only option available. In particular, the extensibility of the present invention provides an occluder that can conform to a wide variety of shapes and is therefore very flexible. For example, an occluder may provide occlusion with proximal and distal elements at each end of an intermediate element when used with the proximal and / or distal elements expanded relative to the waist therebetween. Occlusion may be enhanced by suitable coatings and / or fabric patches known to those skilled in the art.

[0030] 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. [Brief description of the drawings]

[0031] These and other aspects, features, and advantages possible from embodiments of the present invention will become apparent and elucidated from the following description of embodiments of the invention, now referring to the accompanying drawings. [Figure 1a] FIG. 1a is a side view of an embodiment of a platform body with an example of the basic shape of the tubular interlocking structure prior to heat setting into a loosened occluder 1. FIG. [Figure 1b] FIG. 1b is a side view of the base body of FIG. 1a with an example relative representation, in which a portion of the base body is positioned in an occluder 1 when given a desired shape by a suitable heat setting process; [Figure 2a] FIG. 2a is a side view and a cross-sectional view, respectively, taken through the center of an embodiment of an occluder, looking across its length toward its proximal and distal ends when the occluder is in a relaxed state. [Figure 2b] FIG. 2b is a perspective view of the occluder of FIG. 2a in a relaxed state. [Figure 3a] FIG. 3a is a side view and a cross-sectional view taken through the center of the occluder of FIG. 2a looking across the longitudinal direction toward the proximal and distal ends when the occluder is in an axially extended or elongated state. [Figure 3b] FIG. 3b is a perspective view of the occluder of FIG. 2a in an axially stretched or elongated state. [Figure 4] FIG. 4a is a side view and a cross-sectional view, respectively, taken through the center of an embodiment of an occluder, looking across its length toward its proximal and distal ends when the occluder is in a relaxed state. [Figure 4b] FIG. 4b is a perspective view of the occluder of FIG. 2a in a relaxed state. [Figure 5a] 5a is a side view and a cross-sectional view taken through the center of the occluder of FIG. 4a looking across its length toward its proximal and distal ends when the occluder is in an axially extended or elongated state; and [Figure 5b] FIG. 5b is a perspective view of the occluder of FIG. 4a in the axially stretched or elongated state shown in FIG. 5a. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] Specific embodiments of the present invention will be described with reference to the accompanying drawings. However, because the present invention can be embodied in many different forms, it should not be construed as being 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 present invention, as defined by the appended claims, to those skilled in the art. The terms used in the detailed description of the embodiments illustrated in the accompanying drawings are not intended to be limiting of the present invention. In the drawings, like numerals refer to like elements.

[0033] This description of the invention is given with respect to occluder 1, which is illustrated in the embodiment of a PDA occluder. Other occluders of the present disclosure have similar shapes and functions, for example, VSDs, such as mVSD (muscular ventricular septum) occluders with the improvements of the present disclosure, where a conventional mVSD is described below for comparative measurements with an occluder without the improvements. However, it should be kept in mind that the present invention is not strictly limited to the illustrated embodiments, but includes additional embodiments that form a PDA occluder, a PLD, a TAVI-PLD, a VSD occluder, other types of occluders, such as atrial septal defect (ASD) occluders, patent foramen ovale (PFO) occluders, LAA occluders, interatrial shunt devices, such as AFR (atrial flow regulator) that allows inhibited left / right heart blood flow across the atrial wall, a fistula device, or a vascular plug (VP) device, an occluder that forms a fistula channel (occludes or directs flow at least partially across the fistula).

[0034] The present invention will be described with respect to a first aspect and a second aspect and their embodiments. The first aspect and the second aspect are mutually exclusive embodiments. In some embodiments, the first aspect and the second aspect are combined into a single embodiment, which may be further defined by the detailed embodiments described herein. The structures common to the first aspect and the second aspect will be described first.

[0035] As illustrated in Figures 1a and 1b, the substrate of the occluder 1 includes at least one wire 2 and may be formed into a tubular interwoven structure 3 (Figure 1a) made from at least one wire 2. The substrate is made from a single, integral, continuous interwoven structure 3, for example a single braid with two opposite ends. The interwoven structure 3 may also be made from a single wire. The wire 2 is also referred to as a strand. The wire may be made of a metal. The wire may be made of a suitable polymeric material. The strand may be made as a single core heavy filament or may be made of sub-elements forming a strand (multifilament), such as a braided multifilament strand similar to strand technology. The wire 2 may be made of a shape memory material, such as a shape memory metal (for example Nitinol). In particular, the wire 2 may be made of a shape memory material with high elastic properties.

[0036] The tubular interlocking structure 3 is generally interlocked by a weaving technique. Preferably, the tubular interlocking structure 3 is woven to provide the tubular interlocking structure 3 as a tubular braid. The tubular braid may be provided by known braiding techniques. However, the pitch and / or elasticity varying portions are provided by the improvements disclosed in this application. A suitable example of a braiding technique for a pouch-shaped substrate body with a single pitch is disclosed in International Application No. US2007 / 0225760A1 of the same applicant as the present application, which is incorporated herein by reference in its entirety for all purposes. A person skilled in the art will know how to modify the teachings of International Application No. WO2007 / 0225760A1 to produce a substrate body according to the improvements disclosed in this disclosure.

[0037] The wires of the tubular interlocking structure 3 are assembled to have a pitch, which is the longitudinal distance required for one revolution of the wires around the tubular interlocking structure 3. As can be seen in Figures 1a and 1b, the pitch may vary along the axial length of the occluder 1. In the first portion 3a, the pitch may be greater than the pitch of the second portion 3b. This provides for varying the extensibility or elasticity of the tubular interlocking structure 3 along its length. The first, second (and also, for example, third) portions of the tubular interlocking structure 3 may thus be provided with different extensibility by varying pitch. For example, the first portion may be provided with a pitch such that it is not as extensible as the second portion 3b. The third portion (if present) may be provided with a different pitch than the first portion 3a or the second portion 3b. The third portion may in one example be provided with the same pitch as the first portion 3a. Further portions may be defined by varying the pitch of the portions with respect to other portions in the base body of the tubular interlocking structure 3.

[0038] For example, the pitch of the wires (i.e., the angle defined between the turns of the wires and the axis of the interlocking structure) and the picks (i.e., the number of wire overlaps per unit length) of the tubular interlocking structure 3 can be adjusted as desired for a particular application. For example, the pitch of the wires can be about 90 degrees to 130 degrees, such as about 100 degrees. Also, by way of example, when the occluder 1 is in a relaxed configuration, the number of picks of the second portion 3b can be about 7 to 12 picks / 5 mm, such as about 9 picks / 5 mm. When the occluder is stretched about 4-6 mm, the pitch of the wires may be about 50 degrees-90 degrees and / or the number of picks in the second portion 3b may be about 12-16 picks / 5 mm, for example about 14 picks / 5 mm. At the same time, the pitch and / or picks of the first portion 3a of the thermoformed occluder 1 may be constant in both the relaxed and stretched shapes. Alternatively or in addition, the wires of the first portion 3a may combine to form a petal-like shape. Thus, when the occluder is in the relaxed shape as well as in the stretched state, the picks of the first portion 3a may be essentially constant, while the second portion has variable picks in the relaxed shape relative to the stretched state.

[0039] Figure 1a illustrates a tubular interlocked structure 3 made of multiple wire braids in its basic shape before heat treatment and before forming the occluder 1 into its relaxed shape. Additionally, the interlocked structure 3 in Figures 1a and 1b illustrates an embodiment in which the interlocked structure 3 includes a first portion 3a and a second portion 3b, with the first portion 3a distal to the second portion 3b. When the portions have varying (varying) pitch, a pitch transition 9 exists between the portions.

[0040] In other embodiments, the structure 3 combined with the base body includes a third portion (not shown in FIG. 1a or 1b) formed proximal to the second portion 3b. The third portion may have a different pitch than the pitch of the second portion 3b, for example a pitch larger than the pitch of the second portion 3b. In other embodiments, the pitch of the third portion is smaller than the pitch of the second portion 3b.

[0041] Thus, other embodiments may have additional portions.

[0042] Then, after heat setting the relaxed shape of the occluder 1, the heat-set occluder 1 has the same portion defined by the base body along its longitudinal axis. The portion of the structure 3 that is combined with the base body may not correspond 1:1 to the portion of the heat-set occluder. For example, the pitch transition 9 is secured along the base body and therefore also along the heat-set occluder 1. However, as described in more detail below, the transition from an occluder element such as the end disc 6 to an adjacent occluder element such as the middle portion 8 at the transition 9b (also referred to as the "waist" of the occluder) may be at a different transition or position 9a, 9b along the longitudinal axis of the heat-set occluder than the pitch transition 9. The position of the transition 9a, 9b along the longitudinal axis and / or axial position of the occluder 1 may further vary. For example, the variability of the position of the transition 9a, 9b may be determined by the state of elongation of the occluder 1. See below.

[0043] Thus, elements of the occluder 1, such as discs 4, 6, may have two or more portions with different pitch (such as 3a, 3b) along their extent. For example, an inner disc portion, such as distal disc 6, of a double folded disc may include a pitch transition 9 between portions of the base body, while transition 9b to waist 8 may be located more inwardly towards central axis 10 of the occluder 1, as can be seen in Figures 2-5.

[0044] Furthermore, the location of the transitions 9a, 9b may vary, see for example Figures 2a, 2b and 3a, 3b as well as 4a, 4b and 5a, 5b, respectively.

[0045] Thus, the length of the waist 8 can vary partly thanks to the variable position of the transitions 9a, 9b and partly thanks to the different pitch of the first and second portions 3a, 3b.

[0046] Moreover, the extensibility (stretchability) or elasticity of the waist 8 may be selected to further encourage the elongation of the waist to occur prior to deformation of the edge and / or outer diameter of the disc, see below.

[0047] In some embodiments, the pitch of the first portion 3a and the third portion are the same, which provides for essentially equal forces on the second portion 3b when the occluder 1 is stretched or lengthened, as described below. In other embodiments, the first portion 3a and optionally the third portion may be formed by petal-shaped wires, as illustrated in Figures 4b, 5b. Such shapes may also be utilized in the embodiments illustrated in Figures 2b, 3b.

[0048] The combined structure 3 of Figure 1a forms the shape of the occluder in a relaxed or unelongated state, and forms a basic shape that can be heat treated in one or more steps to obtain the occluder's properties as further described below. Heat treatment of shape memory materials such as Nitinol is known as such and will not be described further herein. The relative positions of parts of an example occluder can be seen in Figure 1b.

[0049] In addition to the varying pitch section, the extensibility or elasticity of the tubular interlocking structure 3 can be further defined by the heat-setting process, which can be performed in sections with various parameters as one skilled in the art would know how to perform. The extensibility or elasticity can thus be defined to vary along the longitudinal axis of the heat-set occluder 1. For example, the intermediate element 8 can have a higher extensibility than one or two end portions, such as the disks 4, 6.

[0050] After heat treatment, the occluder is generally self-expandable. When collapsed, e.g., during delivery in a catheter sheath, the occluder will elastically return to its heat-set, relaxed shape unless further restrained. The occluder can be fully or at least partially collapsed again and self-expand again. Desirably, a highly elastic material is provided, such as a wire strand of Nitinol.

[0051] 2a-2b illustrate the relaxed or un-elongated state of the occluder. The occluder 1 may include a proximal element 4 having an outer circumferential surface 5 and an inner diameter D1a in the relaxed state of the occluder 1. Additionally or alternatively, the occluder 1 may include a distal element 6 having an outer circumferential surface 7 and an inner diameter D1b in the relaxed state of the occluder 1. An intermediate element 8 may extend between the proximal element 4 and the distal element 6.

[0052] In particular, the distal element 6 may be a distal retaining element. In particular, the proximal element 4 may be a proximal retaining element. Retention means the ability to keep the occluder 1 in place when implanted. For example, the retaining element may be a retaining disc.

[0053] Each of the proximal and distal elements 4 , 6 may form a disc of the occluder 1 .

[0054] The occluder 1 comprises a proximal element 4 and / or a distal element 5, ie a proximal disc and / or a distal disc.

[0055] The proximal 4 / distal elements 6 can be, for example, substantially circular, oval, substantially square, kidney-shaped (eg, for a TAVI PLD), and the like.

[0056] Additionally, the proximal and / or distal elements may be cup-shaped, i.e., their periphery may be curved in the proximal and distal directions of the occluder 1 .

[0057] Additionally, the proximal / distal elements may be dome-shaped (convex outer surface at the end surface).

[0058] In some embodiments, the proximal elements 4 and / or the distal elements 6 are bent from their centers. In other embodiments, only a portion of the proximal elements 4 and / or the distal elements 6 are bent.

[0059] Furthermore, the proximal / distal elements may additionally and / or alternatively be provided with recesses to "hide" the connecting elements, such as welded or clamped ends of a wire, and to prevent them from protruding beyond the end surface, thus providing improved endothelialization and / or reduced risk of thrombosis for attachment to the occluder surface when implanted.

[0060] The intermediate member 8 may form a waist of the occluder 1. The maximum outer diameter of the intermediate member 8 may be less than the maximum outer diameters of the proximal and distal elements 4, 6.

[0061] In some embodiments, the intermediate member 8 includes a first pitch and a second pitch along the axial length of the intermediate member 8. Additionally, as seen in Figures 2b and 3b, the intermediate portion 8 may have a pitch that varies along its length, such as one or several portions with a greater pitch and a lesser pitch along its length. This further enhances the elastic properties of the intermediate portion 8. The intermediate portion 8 , in one example, has substantially more elasticity in the longitudinal direction of the occluder than the proximal and distal elements 4 , 6 .

[0062] According to a first embodiment, when the occluder 1 is in a relaxed or non-elongated state, at least one pitch transition 9 from a first pitch to a second pitch is located closer to the inner diameter D1 and / or central axis 10 of the occluder 1 than the outer peripheral surface 5, 7 of at least one of the proximal and distal elements 4 and 6. The pitch transition 9 occurs at an inner disk portion (oriented away from the end of the occluder and toward the longitudinal middle and / or center of the occluder) of the doubly folded distal element, which in one example has the shape of a disk element. The distal element may have an outer diameter or axial surface. The pitch transition 9 is located closer to the inner diameter D1 and / or central axis 10 of the occluder than the outer peripheral surface 5, 7. This contributes to a higher extensibility (stretchability) or elasticity of the intermediate member 8 than at least one of the proximal and distal elements 4 and 6.

[0063] According to a second embodiment, the occluder 1 may be extended or stretched from a relaxed state to an axially stretched state, the stretched state being longer in the longitudinal direction of the occluder than the relaxed state. The occluder 1 may have a load-to-stretch ratio measured in N / mm. The load-to-stretch ratio may be measured as described below. The load-to-stretch ratio provided by the occluder 1 may be less than about 0.75 N / mm when the occluder is stretched or stretched at least 2 mm in the axial direction along the center or longitudinal direction 10 of the occluder 1. This load-to-stretch ratio for this length stretch / occluder-stretch range may be provided without substantially distorting the proximal and / or distal elements 4. The proximal and / or distal elements 4 are generally not distorted when the disk shape is maintained and / or its outer diameter / circumferential surface is not altered from the relaxed heat-set shape. Thus, retention capability is provided by the distal elements to remain in the implanted location when the occluder 1 is implanted over a large range. This ratio thus defines a higher extensibility (stretchability) or elasticity of the intermediate member 8 than at least one of the proximal and distal elements 4 and 6, respectively. Thus, the occluder 1 is advantageously adaptable to anatomical variations even during implantation (long-term) periods, while maintaining retentiveness (as the proximal and / or distal elements 4 and / or 6 are not distorted). When stretched further, beyond the end of the axially stretched range, the occluder may distort shape (which is sometimes desired, for example, when folding the occluder into a delivery sheath for implantation).

[0064] In the following, embodiments will be described that combine only the first aspect, only the second aspect, or the first and second aspects in combination.

[0065] In some embodiments, the load-to-strain ratio provided by the occluder 1 is less than 0.5 N / mm, and preferably less than 0.75 N / mm. In some embodiments, it may even be less than 0.25 N / mm. The load-to-strain ratio is provided when the occluder 1 is stretched or extended to a predetermined longitudinal length. The predetermined length may be, for example, at least 2 mm and up to about 6 mm. The occluder 1 is highly stretchable over a large range compared to conventional devices before the above-mentioned strains occur.

[0066] FIG. 2a is a side view of the occluder 1 (central view) and a cross-sectional view taken across the middle portion 8, looking towards the proximal element 4 (bottom view), and looking towards the distal element 6 (top view). FIG. 3a includes a similar view looking towards the occluder 1 in an extended state. Each of the proximal element 4 and distal element 6 has Outside diameter or circumference 5, 7 2a。 Thus, as illustrated in the bottom view of FIG. 2a, the transition portion 9a of the proximal element 4 may be located distal to the proximal element 4. Similarly, as illustrated in the top view of FIG. 2a, the transition portion 9b of the distal element 6 may be located proximal to the distal element 6.

[0067] As can be seen in the figure, the transition sections 9a, 9b may have an axial position (distance to the longitudinal central axis 10) that may vary depending on the extension state of the occluder 1, while Outside diameter or circumference 5, 7 remains substantially constant as the occluder 1 stretches within its large elongation / extension range.

[0068] In general, the occluders of the present disclosure avoid transitions with small diameters. The occluders in certain embodiments do not have transitions with small diameters. In particular, the occluders do not have transitions between end elements, such as the distal element 6 or the proximal element 4, and the intermediate element 8. The varying pitch and / or portions of the flexible fabric improve the bending resistance of the portions of the occluder relative to each other. In particular, not only is the stretchability better than conventional devices, but possible improvements in pivoting or tilting movement of the occluder relative to each other are provided by the arrangement between the braid pitch transitions and the relative positions of the transitions 9a, 9b between the occluder elements. The transitions with small diameters may be omitted in this way, while in some embodiments they may be present.

[0069] In some embodiments, at least one transition 9 in pitch is located between the outer circumferential surface 5, 7 and at least one inner diameter D1a, D1b of the proximal and distal elements 4, 6 when the occluder 1 is in a relaxed state.

[0070] For example, at least one of the proximal element 4 and the distal element 5 can include at least a first pitch. The intermediate element 8 can include a second pitch only along the axial length of the intermediate element 8. Thus, the intermediate element 8 can, in one example, be formed only from the second portion 3b of the combined tubular structure 3. Similarly, the proximal element 4 and / or the distal element 5 can be formed only from the first portion 3a / third portion of the combined structure 3.

[0071] Thus, the transition section 9 may bridge the intermediate element 8 and the proximal element 4 / distal element 6. Thus, in some embodiments, at least one of the proximal element 4 and the distal element 6 includes only the first pitch.

[0072] Figures 3a - 3b illustrate the extended or elongated state of the occluder 1. In this state, the axial length of the occluder 1 is extended or elongated. In this state, the middle portion 8 of the occluder is extended / elongated. The occluder is extended longitudinally. However, the axial length or thickness in the longitudinal direction of the proximal element 4 and / or the distal element 6 remains substantially constant without being distorted. Further, the inner diameter D3 of the middle element 8 in the elongated state of the occluder 1 is reduced compared to the relaxed state. On the other hand, the outer peripheral surfaces of the proximal element 4 and / or the distal element 6 remain substantially constant without being distorted. When L2 > L1, D3 < D2, but D1 remains substantially unchanged. This is due to the variation in the rigidity of the middle element 8 and the proximal element 4 and / or the distal element 6, and thus their respective stretchabilities are different.

[0073] As illustrated in FIGS. 2a - 3b, when the inner diameters D1a, D1b are reduced when stretching or elongating the occluder 1 along its longitudinal direction or central axis 10, at least one of the outer peripheral surfaces 5, 7 of the proximal element 4 and the distal element 6 is substantially constant respectively. This is provided, for example, by providing varying pitches for the first part 3a, the second part 3b, and optionally the third part of the combined tubular structure 3.

[0074] In some embodiments, when the occluder is extended from the relaxed state to the extended state in terms of axial length, the diameter of the cross - section of the middle element 8 shrinks by less than 60%, preferably less than 40%, from diameter D2 to diameter D3 without the above - mentioned distortion occurring.

[0075] Similarly, in some embodiments, when the occluder 1 is extended or elongated in length from the non - extended or slack length L1 to a length L2 that exceeds 50% of the relaxed state and up to approximately 150% of the maximum of the relaxed state, the outer perimeter or diameter 7 of at least one of the proximal element 4 and the distal element 6 is substantially constant.

[0076] In the embodiment illustrated in Figures 2a-2b, the intermediate element 8 is at least partially straight or waisted in a shape such as cylindrical or conical. However, in other embodiments, when the occluder 1 is in a relaxed state, the intermediate element 8 assumes a bell-shaped or hourglass shape relative to the longitudinal or central axis 10 of the occluder 1. The shape of the proximal and / or distal elements 4 and / or 6 as well as the shape of the intermediate portion 8 can be molded by one or several molds using the same or different temperatures during the heat treatment in one or more steps and during the heat treatment of the shape memory material. The skilled person will select the appropriate curing temperature and setting time as well as the distribution of the heat set to obtain the desired device as disclosed herein depending on the actual material chosen for the occluder 1, the pitch chosen along the base body and their distribution, the distribution of the occluder elements along the longitudinal axis of the occluder, the flexibility or stiffness of the fabric in the desired part of the occluder 1. This contributes to the elasticity of the intermediate element 8 mentioned above being greater compared to at least the outer sides oriented towards the ends of the occluder 1 of the proximal element 4 and the distal element 6. The intermediate element can thus be heat set to have a softer weave than the elements 4, 6. The intermediate element 8 can have a portion with both a first pitch and a second pitch. Such an intermediate element can have a softer weave than the adjacent elements upon heat treatment. Thus, the intermediate element 8 can have two portions of pitch with the same braided flexibility / elasticity / stretchability that differs from the braided weave flexibility / elasticity / stretchability of the adjacent elements 4, 6. The distal element 6 and / or the proximal element 4 can have a portion with both a first and a second pitch. The first pitch can be the same as the third pitch. After heat treatment, the occluder 1 is removed from the molded element and substantially retains its relaxed shape after being deformed.

[0077] At least one of the ends of the occluder 1 may include an attachment element 11 for attaching the occluder 1 to a delivery device for catheter-based delivery. The attachment element 11 may be a joint, such as a laser welded joint. In the illustrated embodiment, the base body of the assembled structure 3 is pouch-shaped, i.e., the wires 2 start at the proximal end, are assembled to the distal end, and then return to the proximal end. In other embodiments, the assembled structure 3 is tubular with attachment elements, such as clamps, that bind the free ends of the wires 2 at each end. The attachment element 11 for attaching the occluder 1 may be provided on the central axis 10 of the occluder 1. The attachment element 11 for attaching the occluder 1 may also be provided off-center from the central axis 10, such as on the AFR. International Publication No. WO 09 / 016265 A2, which has the same applicant as the present application and is hereby incorporated by reference in its entirety for all purposes, discloses a manufacturing method in which the free ends of wire 2 are bundled and fixed at both ends. Thus, in such an embodiment, one end of wire 2 is positioned at the distal end of the occluder and the other end of wire 2 is positioned at the proximal end of occluder 1 (not shown).

[0078] Figures 4a-4b, 5a-5b illustrate an embodiment with alternative shapes of the outer circumferential surfaces of the proximal element 14 and the distal element 16. The intermediate element 8 has the same shape as described with reference to Figures 2a-3b. Furthermore, the proximal element 14, the distal element 16 and the transitions 9a, 9b to the intermediate element 8 may be designed as described with reference to Figures 2a-3b. The proximal element 14 and the distal element 17 have a first diameter D1 and a second diameter D5 as illustrated. Elements having the same configuration as described with reference to Figures 2a-3b therefore have the same reference numbers.

[0079] The embodiment illustrated in Figures 4a-4b, 5a-5b is, for example, a PVL occluder. The PVL occluder and thickened shape are disclosed in International Publication No. WO2013 / 041721, which is assigned to the same applicant as the present application and is incorporated herein by reference in its entirety for all purposes. The disks and waists of the PVL device of International Publication No. WO2013 / 041721 may be advantageously provided with the improvements described herein. However, disk 16 or disk 14 has a concave curved portion and a convex outer peripheral surface 5, 7 on opposing axial portions of the disk. This is particularly advantageous when the concave curved portion is apposed or adjacent to a prosthetic valve when implanted. The convex curved opposing outer peripheral surfaces are anatomically advantageous in certain target areas to advantageously hold the PVL occluder in place while providing advantageous occlusion of paravalvular leaks.

[0080] In yet another embodiment, the occluder has a single proximal element, such as for an LAA occluder. The intermediate element may be formed by the combined structures and form a lobe, such as a cylinder, having a diameter not exceeding that of the intermediate element. As described with respect to Figures 2a-3b, the intermediate element or lobe may be stretchable. The distal element 6 (if present) and / or the intermediate element 8 may have hooks attached thereto to engage an anatomical structure, such as the LAA. After the hooks engage the vessel wall, the intermediate structure may be stretched and the proximal element may be positioned outside the anatomical structure. The stretchability of the intermediate element and / or lobe allows the occluder to be more flexible and conform to the shape of the anatomical structure, improving the performance of the occluder.

[0081] LAA occluders are disclosed, for example, in commonly assigned International Publication No. WO2019197569, which is incorporated herein by reference in its entirety for all purposes. The LAA devices disclosed in WO2019197569 can advantageously be provided with a waist and disc, along with the improvements described in the present disclosure.

[0082] In embodiments, the LAA occluder may alternatively or additionally have a distal coupling element to the hook described above. Such an LAA occluder is disclosed, for example, in commonly assigned U.S. Patent No. 8,100,938, which is incorporated herein by reference in its entirety for all purposes. The LAA device disclosed in U.S. Patent No. 8,100,938 may advantageously provide a waist and disk, along with the improvements described in the present disclosure.

[0083] The AFR device allows for controlled flow across the occluder when implanted. See, for example, International Publication No. WO2016 / 038115, which is owned by the same applicant as the present application and is incorporated herein by reference in its entirety for all purposes. The AFR device disclosed in International Publication No. WO2016 / 038115 can advantageously provide a waisted portion and a disk, along with the improvements described in the present disclosure. The occluder 1 can have a through channel as shown and described in International Publication No. WO2016 / 038115, such as through channel 106 in the drawings and description of International Publication No. WO2016 / 038115. The attachment element 11 for attaching the occluder 1 can also be provided off-center from the central axis 10 as disclosed in International Publication No. WO2016 / 038115, and the base body 3 can be provided with appropriate channels upon heat setting to provide an AFR according to the present disclosure. A double layer disk is shown, for example, in FIG. 4c of WO2016 / 038115 and the corresponding detailed description. These particular AFR elements are incorporated herein by reference. The first pitch portion 3a may be part of the inner layer of one or both of the folded double layer disks. This provides an advantageous occluder 1 in one example of an AFR device herein.

[0084] The load to elongation ratio can be determined using a tensile tester such as a tensile tester using the AMETEK Sensor 1, Test & Clibration, Instrument Number 10017 and Brand Lloyd Instruments. The test procedure includes: - Attaching one end of the occluder 1 to a fixed control and the other end of the occluder 1 to a tensile tester. - Stretching the neck of the occluder to 3N using a tensile tester, the tensile test speed is 600mm / min. 3N is chosen as the maximum applicable force to demonstrate the stretchability of the occluder with less force. - recording the amount of stretch or elongation of the occluder without distorting the shape of the proximal and / or distal elements. - Releasing the tension applied to the occluder and observing the reversibility of the stretching behavior, i.e. the device returns to its original shape without deformation after the release of the tension.

[0085] The following table illustrates test embodiments A and B that fall within the ranges D1, D2, D3, L1, and L2 described above:

[0086] [Table 1]

[0087] The test method was applied to embodiments A and B, as defined above, using the Occlutech® mVSD occluder (size 4), item number 71VSD04, as a comparative control. The 71VSD04 mVSD occluder is made from a base body with one pitch. The overall shape of embodiments A and B corresponds to the shape illustrated in Figures 2b and 3b. Thus, embodiments A and B have proximal and distal elements formed as disks, and an intermediate element in the form of an extensible waist. The disk shape is circular. The mVSD occluder exhibits a similar overall shape, but with a more uniform and conventional elasticity. That is, the elasticity of the intermediate element is similar to that of the proximal and / or distal elements, and is made from a single pitch braid. The intermediate element or waist is 4 mm in diameter, the proximal and distal elements (discs) are 10 mm in diameter, and the waist or intermediate element is 7 mm high.

[0088] The stretch behavior of embodiments of the present invention for the mVSD device is illustrated in the table below.

[0089] [Table 2]

[0090] The test samples have the same raw materials and sterilization methods. The pitch of the braid and heat setting varies between embodiments A and B for the mVSD occluder. There are numerous combinations of braid patterns and heat setting that can be applied to achieve the above properties, all within the scope of the disclosure as described above with respect to the embodiments of the present invention.

[0091] As can be seen from the above table, embodiments of the present invention can be stretched or extended longer than conventional devices. In particular, this test demonstrates that occluders according to embodiments of the present invention can be stretched or extended in a restorable manner, i.e., without distorting the original shape of the device, such as length or disk diameter after extension.

[0092] When the applied load is 3N, it is 100% to 150% When the applied load is 1N, the rate is 50% to 100%

[0093] This should be contrasted with regular occluders, exemplified by the mVSD occluder, which are characterized by being reversibly stretched or extended without distorting the original shape of the device, such as length or disk diameter after extension.

[0094] When the applied load is 3N, the ratio is 0% to 35%. When the applied load is 1N, the ratio is 0% to 30%.

[0095] It is also to be appreciated that the features disclosed in the foregoing description, and / or in the foregoing drawings, and / or in any or any combination of the following claims may be material for realizing the invention in diverse forms thereof. When used in the following claims, the words "comprising", "include", "have" and their compounds mean "including but not limited to".

[0096] The present invention has been described above with respect to specific embodiments. However, other embodiments than those described are equally possible within the scope of the present invention. Various method steps other than those described above may be provided within the scope of the present invention. The various features and steps of the present invention may be combined in combinations other than those described. The scope of the present invention is limited only by the appended claims.

Claims

1. An occluder 1, comprising a continuous tubular braided structure made of at least one integral base body of wire and having a pitch varying along the axial length of the base body with at least one pitch transition 9 between portions of the occluder 1 having different pitches whose magnitudes vary from a first pitch to a second pitch, the occluder 1 comprising: a proximal retaining element 4 having an outer circumferential surface and a distal inner diameter at a first transition section 9a where, in a relaxed state of the occluder 1, the occluder element transitions to an adjacent occluder element; a distal retaining element 6 having an outer circumferential surface and a proximal inner diameter at a second transition portion 9b where, in the relaxed state of the occluder 1, another occluder element transitions to an adjacent occluder element; heat set to have a shape including an intermediate element 8 extending between a first transition portion 9a and a second transition portion 9b of the proximal retaining element 4 and the distal retaining element 6; Where: the at least one pitch transition 9 of the various pitches is located closer to the intermediate element 8 or to a central axis of the occluder 1 than to the outer circumferential surface of at least one of the proximal and distal retaining elements 4 and 6 when the occluder 1 is in the relaxed state; at least one of the first transition portion 9a and the second transition portion 9b is positioned closer to the central axis 10 than to the outer circumferential surface of at least one of the proximal retention element 4 and the distal retention element 6 when the occluder 1 is stretched from a relaxed state to an axially extended state, and the diameter of the intermediate element 8 is reduced from its relaxed diameter; - an occluder 1, characterized in that the outer diameter of the proximal retaining element 4 and the distal retaining element 6 is constant (unchanging) in the relaxed state and in the axially stretched state.

2. The occluder 1 according to claim 1, characterized in that the at least one pitch transition portion 9 is located between the outer circumferential surface and the inner diameter of at least one of the proximal retaining element 4 and the distal retaining element 6 when the occluder 1 is in the relaxed state.

3. An occluder 1 as described in claim 1 or 2, characterized in that at least one of the proximal retaining element 4 and the distal retaining element 6 includes at least the first pitch, and the intermediate element 8 includes the second pitch only along its axial length.

4. 3. An occluder (1) according to claim 1 or 2, characterized in that the proximal retaining element (4) and the distal retaining element (6) have the same pitch which is different from the pitch of the intermediate element (8).

5. 5. An occluder 1 as described in claim 1, 2 or 4, characterized in that the intermediate element 8 includes, along its axial length, a longitudinal portion having the first pitch and a longitudinal portion having the second pitch.

6. An occluder 1 as described in any one of claims 1 to 5, characterized in that the occluder 1 is stretchable from the relaxed state to an axially extended state which is longer in the longitudinal direction of the occluder 1 than the relaxed state, and the load to elongation ratio provided by the occluder 1, measured in N / mm, is less than 0.75 N / mm when stretched at least 2 mm in the longitudinal direction of the occluder 1.

7. 7. The occluder 1 of claim 6, wherein the load to elongation ratio provided by the occluder 1, measured in N / mm, is less than 0.75 N / mm when stretched at least 2 mm and up to about 6 mm in the longitudinal direction of the occluder 1.

8. 8. The occluder 1 according to claim 6 or 7, characterized in that when the occluder 1 is stretched from the relaxed state to a longer extended state in the longitudinal direction of the occluder 1, the cross-sectional diameter of the intermediate element is reduced by less than 60%.

9. An occluder 1 as described in any one of claims 1 to 8, characterized in that the outer circumferential surface of at least one of the proximal retaining element 4 and the distal retaining element 6 remains unchanged when the occluder 1 is stretched to a length of more than 50% of the length of the occluder 1 in a relaxed state and up to approximately 150% of the length of the occluder 1 in a relaxed state.

10. An occluder (1) according to any of the preceding claims, characterized in that the maximum outer diameter of the intermediate element (8) is smaller than the maximum outer diameter of the proximal and distal retaining elements (4,6).

11. 11. The occluder 1 according to any one of claims 1 to 10, characterized in that the occluder 1 is a patent ductus arteriosus (PDA) occluder, a paravalvular leak device (PLD), a transcatheter aortic valve implantation PLD (TAVI-PLD), a ventricular septal defect (VSD) occluder, an atrial septal defect (ASD) occluder, a patent foramen ovale (PFO) occluder, a left atrial appendage (LAA) occluder, an interatrial shunt device, an atrial flow regulator (AFR) device, a fistula device, or a vascular plug (VP) device.

12. An occluder 1, The occluder 1 comprises a continuous tubular braided structure made of an integral base body of at least one wire and having a pitch, the pitch varying along the axial length of the base body having at least one pitch transition 9; a proximal retention element 4 having an outer circumferential surface and a distal inner diameter at a first transition portion 9a in a relaxed state of the occluder 1; a distal retention element 6 having an outer circumferential surface and a proximal inner diameter at a second transition portion 9b in the relaxed state of the occluder 1; heat set to have a shape including an intermediate element 8 extending between a first transition portion 9a and a second transition portion 9b of the proximal retaining element 4 and the distal retaining element 6; Where: - the occluder 1 is stretchable from the relaxed state to an axially extended state that is longer in the longitudinal direction of the occluder 1 than the relaxed state, and the load to elongation ratio provided by the occluder 1, measured in N / mm, is less than 0.75 N / mm when stretched at least 2 mm in the longitudinal direction of the occluder 1 without distortion of the proximal retention element 4 or the distal retention element 6; - an occluder 1, characterized in that at least one of the first transition portion 9a and the second transition portion 9b is positioned closer to the central axis 10 of the occluder 1 than to the outer circumferential surface of at least one of the proximal retaining element 4 and the distal retaining element 6 when the occluder 1 is stretched from a relaxed state to an axially extended state, and the diameter of the intermediate element 8 decreases from its relaxed diameter.

13. The occluder 1 described in claim 12, characterized in that the at least one pitch transition 9 from a first pitch to a second pitch is located closer to the central axis of the occluder 1 or the intermediate element 8 than the outer circumferential surface of at least one of the proximal retaining element 4 and the distal retaining element 6 when the occluder 1 is in the relaxed state.

14. The occluder 1 according to claim 13, characterized in that the at least one pitch transition 9 is located between the outer circumferential surface and the inner diameter of at least one of the proximal retaining element 4 and the distal retaining element 6 when the occluder 1 is in the relaxed state.

15. An occluder 1 as described in any one of claims 12 to 14, characterized in that the load to elongation ratio provided by the occluder 1, measured in N / mm, is less than 0.75 N / mm when stretched at least 2 mm up to about 6 mm.

16. An occluder 1 according to any one of claims 12 to 15, characterised in that when the occluder 1 is stretched from the relaxed state to the stretched state, the cross-sectional diameter of the intermediate element 8 reduces by less than 60%.

17. An occluder 1 as described in any one of claims 12 to 16, characterized in that the diameter of the outer circumferential surface of at least one of the proximal retaining element 4 and the distal retaining element 6 is constant when the occluder 1 is stretched to a length of more than 50% of the length of the occluder 1 in a relaxed state and up to approximately 150% of the length of the occluder 1 in a relaxed state.

18. 18. The occluder 1 according to any one of claims 12 to 17, characterized in that the occluder 1 is a patent ductus arteriosus (PDA) occluder, a paravalvular leak device (PLD), a transcatheter aortic valve implantation PLD (TAVI-PLD), a ventricular septal defect (VSD) occluder, an atrial septal defect (ASD) occluder, a patent foramen ovale (PFO) occluder, a left atrial appendage (LAA) occluder, an interatrial shunt device, an atrial flow regulator (AFR) device, a fistula device, or a vascular plug (VP) device.

19. An occluder 1 according to any of the preceding claims, characterised in that the distal retaining element 6 and / or the proximal retaining element 4 are disc-shaped.

20. An occluder 1 as described in claim 19, characterized in that the disc is formed by a double layer and the pitch transition portion 9 is arranged in an inner layer of the disc.

21. An occluder 1 according to any of claims 12 to 18, characterised in that the distal retaining element 6 and / or the intermediate element 8 comprise a hook.

22. A method for manufacturing an occluder (1) according to any one of the preceding claims, said method comprising the steps of: forming an integral base body of at least one wire providing a continuous tubular braided interwoven structure having a pitch that varies along the axial length of the base body of the occluder 1 with at least one pitch transition 9 between portions of the occluder 1 having different pitches; a proximal retention element 4 having an outer circumferential surface and a distal inner diameter at a first transition portion 9a in a relaxed state of the occluder 1; a distal retention element 6 having an outer circumferential surface and a proximal inner diameter at a second transition portion 9b in the relaxed state of the occluder 1; an intermediate element 8 extending between the first transition portion 9a and the second transition portion 9b of the proximal retaining element 4 and the distal retaining element 6; and and heat setting the base body to have a shape including a diameter of the outer circumferential surface of the proximal retention element 4 and the distal retention element 6 that is constant in the relaxed state and in an axially elongated state in which the occluder 1 is longer in the longitudinal direction.

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