Occluder with retractable waist

Abstract

The invention discloses an occluder for a structural heart defect, the occluder comprising: a tubular interwoven structure, the pitch of which varies along the axial length of the occluder; a proximal element; a distal element; and an intermediate element extending between the proximal element and the distal element. According to one aspect, when the occluder is in a relaxed state, a location of at least one transition section of the pitch from the first pitch to the second pitch is closer to an intermediate element of the occluder than an outer circumference of at least one of the proximal and distal elements.

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 device), TAVI (transcatheter aortic valve implantation) PLD, VSD (ventricular septal defect) occluders, LAA (left atrial appendage) occluders, atrial shunt devices such as AFR (atrial flow regulator), fistula devices and / or VP (vascular plug) devices. In particular, these devices are made of interwoven structures, preferably braided wire structures. Background Art

[0002] Occluders generally provide complete occlusion and allow for minimally invasive procedures for treating various structural heart or vascular diseases. Atrial shunt devices such as AFR allow for control of flow through the device upon implantation, see, e.g., WO2016 / 038115A1. Fistula devices can provide a passage between two body cavities. Vascular plugs can be used to occlude blood vessels. Interventional techniques for treating structural heart or vascular diseases using intravascular and / or cardiac occluders and devices have become routine.

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

[0004] The occluder with two discs can extend between the two sides of a cardiac structure such as a septal wall, a heart valve, a heart valve ring, or between two blood vessels such as the pulmonary artery and the aorta. The disc can be positioned on each side of the cardiac structure, preferably as a holding unit that holds the occluder in place when implanted. The waist can extend through the cardiac structure. This cardiac structure may have a large variability. In order to adapt to the huge variability of the length and shape of the anatomical structure, the occluder with a single disc is generally used to treat some diseases. For a single disc occluder, either the disc or the waist can be used as a blocking portion. However, the anatomical structure may distort the blocking waist, causing the blocking effect of the device to be lost. It may be challenging to securely place the occluder in the anatomical structure.

[0005] In cases where an occluder with two discs designed for a specific clinical / anatomical length is used that actually requires a waist of telescopic length to accommodate the anatomy, the discs may twist due to the rigidity of the waist. This may degrade the occlusion provided by the discs. Other structural heart diseases are treated with occluders of uniform diameter or with only a single disc.

[0006] In WO 2017 / 139702A1, a vascular occlusion device with petals of varying pitch is disclosed. In US 8313 505 B2, a single-pitch vascular occluder is disclosed. In WO 2014 / 150288 A2, a vascular treatment device that controls the braiding angle to control the porosity of the device is disclosed. In WO 2018 / 058033A1, a LAA occluder with a multilayer braid of different pitches is disclosed. In WO 2011 / 161136A1, a medical implant assembled from different braided segments is disclosed. In WO 97 / 42878A1, a closure device made of a tubular braid with a single pitch is disclosed. In EP 2 063 791A1 and the corresponding WO 2008 / 036156 A1, a cerebral vascular device is disclosed, wherein the braiding angle of the tubular braid not at the end portion of the device is controlled to limit the expansion of certain sections of the device. In WO2014 / 110589 A1, a closure device with a variable pitch is disclosed, but the disclosure does not mention the purpose and function of the variable pitch in the device. In WO 2017 / 214431 A2, a braided vascular occlusion member is disclosed, and the variable pitch of the braid is disclosed, but the disclosure does not mention the purpose and function of the variable pitch in the device. In WO03 / 065934A2, a braided modular stent is disclosed, wherein different braiding angles provide different radial strengths of the stent. In WO 2018 / 112203A1, a stent with a polymer electrospinning coating is disclosed. In US2015 / 238333A1, a vascular aneurysm stent device is disclosed.

[0007] Certain anatomies are not amenable to occlusion using any of the previously described occluders.

[0008] Furthermore, during the life duration of an implanted occluder, the length of the anatomical structure to be occluded by the waist may change. For example, the structure may expand in a structural heart disease. Furthermore, contraction may occur, such as during sinus rhythm of the heart or during fibrillation. For example, atrial appendages may contract or expand. The heart wall may thicken. Typically, known occluders are unable to cope with such changing anatomical conditions, resulting in tensioning of the surrounding implanted tissue, which may lead to rupture of the tissue, undesirable leakage at the implant site, or even device embolism with dire consequences for the patient.

[0009] Therefore, there is a need for an occluder having increased flexibility for treating anatomies having greater variability, such as length and / or shape. Summary of the invention

[0010] Therefore, embodiments of the present invention preferably seek to mitigate, alleviate or eliminate one or more deficiencies, disadvantages or problems in the art, such as those mentioned above, alone or in any combination, by providing an occluder in accordance with the appended patent claims.

[0011] The present invention is limited only by the appended claims, in particular by the scope of the appended independent claims. References throughout the specification to "embodiments" that are not within the scope of the appended claims represent only possible exemplary executions and are therefore not part of the present invention. In one aspect, the present disclosure includes an occluder having: a tubular interwoven structure having a pitch that varies along the axial length of the occluder, and wherein, when the occluder is in a relaxed state, the position of at least one transition section of the pitch is closer to the central axis or intermediate member of the occluder than the outer circumference of the proximal element and / or the distal element. The occluder includes a continuous tubular braided structure made of an integral base body of at least one wire and having a pitch that varies along the axial length of the base body and has at least one pitch transition section. The occluder is heat-set to have a shape that preferably includes a proximal retaining element, which has an outer circumference and a distal inner diameter at the first transition section in the relaxed state of the occluder. The shape preferably includes a distal retaining element having an outer circumference and a proximal inner diameter at the second transition section in the relaxed state of the occluder. The shape preferably includes an intermediate element extending between the first transition section of the proximal retaining element and the second transition section of the distal retaining element. When the occluder is in a relaxed state, at least one pitch transition section of the pitch from the first pitch to the second pitch is preferably located closer to the intermediate element or the central axis of the occluder than the outer circumference of at least one of the proximal element and the distal element. Preferably, when the occluder is in an axially extended state, at least one of the transition sections is located closer to the central axis, and the diameter of the intermediate element is reduced from the relaxed diameter of the intermediate element.

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

[0013] In another aspect of the present disclosure, a method for manufacturing an occluder is provided. The method includes: forming an integral base body from at least one wire, thereby providing a continuous tubular braided interwoven structure with a pitch, the pitch varying along the axial length of the base body of the occluder having at least one pitch transition section. The method includes: heat setting the base body into a shape preferably including a proximal retaining element, the proximal retaining element having an outer circumference and a distal inner diameter at a first transition section in a relaxed state of the occluder. The shape preferably includes a distal retaining element, the distal retaining element having an outer circumference and a proximal inner diameter at a second transition section in a relaxed state of the occluder. The shape preferably includes an intermediate element extending between the first transition section of the proximal retaining element and the second transition section of the distal retaining element. When the occluder is in a relaxed state, the position of at least one pitch transition section of the pitch from the first pitch to the second pitch is preferably closer to the intermediate element or the central axis of the occluder than the outer circumference of at least one of the proximal element and the distal element. Alternatively or in addition, the occluder is capable of extending from a relaxed state to an axially extended state that is longer in a longitudinal direction of the occluder than the relaxed state, and wherein, without twisting of the proximal retaining element or the distal retaining element, a ratio of load to extension measured in N / mm provided by the occluder when extended by at least 2 mm is less than approximately 0.75.

[0014] An embodiment of the present invention provides an occluder, which includes: at least one wire; a tubular interwoven structure, which is made of at least one wire and has a pitch, wherein the pitch varies along the axial length of the occluder; a proximal element, which has an outer circumference and an inner diameter in a relaxed state of the occluder; a distal element, which has an outer circumference and an inner diameter in a relaxed state of the occluder; and an intermediate element, which extends between the proximal element and the distal element.

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

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

[0017] In various embodiments, the first aspect and the second aspect may be mutually exclusive embodiments or combined into a single embodiment. Each of the first aspect and the second aspect may be combined with the following embodiments individually or together.

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

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

[0020] In an embodiment, at least one of the outer circumferences of the proximal element and the distal element is substantially constant as the inner diameter decreases when the occluder is stretched in the longitudinal direction.

[0021] In an embodiment, at least one of the proximal element and the distal element comprises only the first pitch.

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

[0023] In an embodiment, the occluder is extendable from a relaxed state to an axially extended state that is longer in a longitudinal direction of the occluder than the relaxed state.

[0024] In an embodiment, the ratio of load to extension measured in N / mm provided by the occluder when extended from at least 2 mm up to about 6 mm is less than 0.5 N / mm, preferably less than 0.75 N / mm, even more preferably less than 0.25 N / mm.

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

[0026] In an embodiment, the outer circumference of at least one of the proximal element and the distal element is substantially constant when the length of the occluder extends beyond 50% of the relaxed state up to about 150% of the relaxed state.

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

[0028] In an embodiment, the occluder is, 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, a LAA occluder, an atrial shunt device such as 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 to block anatomical structures with various shapes for which occlusion by surgery may be the only available option so far. In particular, the stretchability of the present invention provides an occluder that can adapt to the shapes of various anatomical structures and is therefore very flexible. For example, when used with a proximal element and / or a distal element whose diameter increases relative to the waist between the proximal element and the distal element, the occluder can provide occlusion by the proximal element and the distal element at the respective ends of the intermediate element. The occlusion can be enhanced by suitable coatings and / or fabric patches known to the technician.

[0030] The term "include / comprising" used in this application document is used to specify the existence of stated features, integers, steps or components, but does not exclude the existence or addition of one or more other features, integers, steps, components or a combination thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] These and other aspects, features and advantages that embodiments of the present invention can have will become apparent and elucidated from the following description of embodiments of the present invention with reference to the accompanying drawings, in which:

[0032] Figure 1a is a side view of an embodiment of a base body having an example of the basic shape of a tubular interwoven structure before heat setting to a relaxed plugging piece 1;

[0033] Figure 1b yes Figure 1a A side view of a base body of the device 1 with comparative indications of examples of which parts of the base body will be located in the occluder 1 when given the desired shape by a suitable heat setting process;

[0034] Figure 2a are a side view and a cross-sectional view at the center of an embodiment of the occluder in a longitudinal direction and viewed toward the proximal end and the distal end, respectively, when the occluder is in a relaxed state;

[0035] Figure 2b yes Figure 2a A stereoscopic image of the occluder in a relaxed state;

[0036] Figure 3a When the occluder is in the axial extension or elongation state Figure 2a A side view and a cross-sectional view of the center of the occluder along the longitudinal direction and viewed toward the proximal end and the distal end respectively;

[0037] Figure 3b yes Figure 2a A stereoscopic view of the occluder in an axially extended or elongated state;

[0038] Figure 4a are a side view and a cross-sectional view at the center of an embodiment of the occluder in a longitudinal direction and viewed toward the proximal end and the distal end, respectively, when the occluder is in a relaxed state;

[0039] Figure 4b yes Figure 4a A stereoscopic image of the occluder in a relaxed state;

[0040] Figure 5a When the occluder is in the axial extension or elongation state Figure 4a A side view and a cross-sectional view of the center of the occluder along the longitudinal direction and viewed toward the proximal end and the distal end, respectively; and

[0041] Figure 5b yes Figure 4a The occluder is in Figure 5a A perspective view of the axially extended or elongated state is shown. DETAILED DESCRIPTION

[0042] Specific embodiments of the present invention will now be described with reference to the accompanying drawings. However, the present invention can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; on the contrary, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey to those skilled in the art the scope of the invention defined by the appended claims. The terms used in the detailed description of the embodiments shown in the accompanying drawings are not intended to limit the present invention. In the accompanying drawings, the same reference numerals represent the same elements.

[0043] The present description of the present invention is given with reference to occluder 1, which is exemplified in the embodiment of a PDA occluder. Other occluders disclosed herein have similar shapes and functions, such as VSD, such as mVSD (muscular ventricular septum) occluders with the improvements disclosed herein, wherein conventional mVSD is discussed below for comparative measurements with occluders without the current improvements. However, it should be understood that the present invention is not strictly limited to the embodiments shown, but includes additional embodiments that form other types of occluders, such as PDA occluders, PLDs, TAVI-PLDs, VSD occluders, atrial septal defect (ASD) occluders, patent foramen ovale (PFO) occluders, LAA occluders, atrial shunt devices such as AFR (atrial flow regulator) that allows control of left / right heart blood flow through the atrial wall, fistula devices or vascular plug (VP) devices, fistula channels (at least partial flow blockage or flow guidance through the fistula) occluders.

[0044] The present invention will be described for the first and second aspects and embodiments of the present invention. The first and second aspects can form mutually exclusive embodiments. However, in some embodiments, the first and second aspects are combined into a single embodiment, which can be further limited by the detailed embodiments described herein. First, the common structure of the first and second aspects will be described.

[0045] like Figure 1a and Figure 1b As shown, the base body of the occluder 1 includes at least one wire 2, and the at least one wire 2 can be formed into a tubular interwoven structure 3 ( Figure 1a ). The base body is made of a single, integral and continuous interwoven structure 3, for example a single braid with two opposite ends. The interwoven structure 3 can also be made of a single wire. The wire 2 can also be called a strand. The wire can be made of metal. The wire can be made of a suitable polymer material. The strand can be made as a single core heavy wire, or can be composed of sub-elements forming a strand (multifilament), such as a braided multifilament strand similar to cable strand technology. The wire 2 can be formed of a shape memory material, such as a shape memory metal, for example Nitinol. In particular, the wire 2 can be formed of a shape memory material having superelastic properties.

[0046] The tubular interwoven structure 3 is generally interwoven by a braiding technique. Preferably, the tubular interwoven structure 3 is braided to provide a tubular interwoven structure 3 as a tubular braid. The tubular braid can be provided by known braiding techniques; however, a section with a variable pitch and / or elasticity is provided by the currently disclosed improvement. In US2007 / 0225760A1 of the same applicant as the present application, which is incorporated herein by reference as a whole for all purposes, a suitable example of a braiding technique for a bag-like base body with a single pitch is disclosed. A technician will know how to modify the teachings in US2007 / 0225760A1 to produce a base body according to the improvement disclosed in the present disclosure.

[0047] The wires of the tubular interwoven structure 3 are constructed with a pitch, which is the longitudinal distance required for the wires to make one rotation around the tubular interwoven structure 3. Figure 1a and Figure 1bAs shown, the pitch can vary along the axial length of the occluder 1. The pitch at the first section 3a can be greater than the pitch at the second section 3b. This provides a change in the extensibility (stretchability) or elasticity of the tubular interwoven structure 3 along the length of the tubular interwoven structure 3. Therefore, the first section, the second section (and another, for example, the third section) of the tubular interwoven structure 3 can have different extensibility (stretchability) by varying the pitch. For example, the first section can have a pitch that is less prone to extension (stretching) than the second section 3b. The third section (if present) can have a different pitch from the first section 3a or the second section 3b. In the example, the third section can have the same pitch as the first section 3a. Additional sections can be defined accordingly by changing the pitch in these sections relative to other sections in the base body of the tubular interwoven structure 3.

[0048] For example, the inclination of the wire (i.e., the angle defined between the turns of the wire and the axis of the interwoven structure) and the number of points of the tubular interwoven structure 3 (i.e., the number of wire crossings per unit length) can be adjusted according to the needs of a specific application. For example, the inclination of the wire can be about 90° to 130°, such as about 100°. In addition, as an example, when the occluder 1 is in a relaxed shape, the number of points in the second section 3b can be about 7 to 12 points / 5mm, such as about 9 points / 5mm. When the occluder is stretched by about 4mm to 6mm, the inclination of the wire can be about 50° to 90°, and / or the inclination in the second section 3b can be about 12 to 16 points / 5mm, such as about 14 points / 5mm. At the same time, the pitch and / or number of points of the first section 3a of the thermoformed occluder 1 can be constant in both the relaxed shape and the stretched shape. Alternatively or additionally, the wires in the first section 3a can be interwoven to form a petal-like shape. Thus, the number of points of the first section 3a may be substantially constant when the occluder is in the relaxed shape and in the stretched state, whereas the second section has a variable number of points in the relaxed shape relative to the stretched state.

[0049] Figure 1a The tubular interwoven structure 3 made of a braid of multiple wires is shown in its basic shape before heat treatment and shaping of the occluder 1 into its relaxed shape. Figure 1a and Figure 1b The base body interlaced structure 3 shows an embodiment comprising a first segment 3a and a second segment 3b, wherein the first segment 3a is distal to the second segment 3b. When the segments have different (variable) pitches, a pitch transition segment 9 exists between the segments.

[0050] In other embodiments, the base body interwoven structure 3 includes a third section ( Figure 1a or Figure 1b(not shown in the figure), the third section is formed at the proximal end of the second section 3b. The pitch of the third section may be different from the pitch of the second section 3b, for example, greater than the pitch of the second section 3b. In other embodiments, the pitch of the third section is smaller than the second section 3b.

[0051] Accordingly, other embodiments may have additional sections.

[0052] After the relaxed shape of the heat-set occluder 1, the heat-set occluder 1 will then have the same section defined by the base body along its longitudinal axis. The sections of the base body interlaced structure 3 may not correspond to the sections of the heat-set occluder 1:1. For example, the pitch transition section 9 is fixed along the base body and therefore also fixed along the heat-set occluder 1. However, the transition from the occluder element such as the end disc 6 to the adjacent occluder element such as the middle section 8 (also referred to as the "waist" of the occluder) at the transition section 9b as described in detail below can exist at a transition section or position 9a, 9b different from the pitch transition section 9 along the longitudinal axis of the heat-set occluder. The position of the transition sections 9a, 9b along the longitudinal axis and / or axial position of the occluder 1 can even be variable. For example, the variability of the position of the transition sections 9a, 9b can be determined by the tensile state of the occluder 1, see below.

[0053] Thus, an element of the occluder 1, such as a disc 4, 6, may have sections with two or more different pitch sections (such as 3a, 3b) along its extension. For example, the inner disc portion of a double-folded disc, such as the distal disc 6, may include a pitch transition section 9 between the sections of the base body, while the transition section 9b to the waist 8 is located more inwardly toward the central axis 10 of the occluder 1, such as Figures 2a to 5b shown.

[0054] Furthermore, the positions of the transition sections 9a, 9b are variable, see for example Figure 2a , Figure 2b and Figure 3a , Figure 3b as well as Figure 4a , Figure 4b and Figure 5a , Figure 5b comparison.

[0055] Thus, the length of the waist 8 may be variable partly due to the variable position of the transition sections 9a, 9b and partly due to the different pitches of the first section 3a and the second section 3b.

[0056] Furthermore, the extensibility (stretchability) or elasticity of the waist 8 may be selected to further promote waist stretching before deformation of the end portions / outer diameter of the disc occurs, see below.

[0057] In some embodiments, the pitch of the first segment 3a and the third segment is the same, which is configured to apply substantially equal forces to the second segment 3b when the occluder 1 is stretched or elongated, as will be described below. In other embodiments, the first segment 3a and the optional third segment can be formed by a petal-shaped wire, such as Figure 4b , Figure 5b This shape can also be used for Figure 2b , Figure 3b The embodiment shown.

[0058] Figure 1a The interwoven structure 3 forms a basic shape which can be heat treated in one or more steps to form the shape of the occluder in a relaxed or non-stretched state and to obtain the properties of the occluder, as will be further described below. The heat treatment of shape memory materials such as Nitinol is known per se and will not be described further here. Figure 1b The relative positions of the various parts of the occluder example can be observed in FIG.

[0059] In addition to the different pitch sections, the extensibility (stretchability) or elasticity of the tubular interwoven structure 3 can be further defined by the heat setting process, which can be done in sections with different parameters, as the skilled person will know how to implement. The extensibility (stretchability) or elasticity can therefore be defined as variable along the longitudinal axis of the heat set occluder 1. For example, the intermediate element 8 can have a higher extensibility (stretchability) than one or both end portions, such as the discs 4, 6.

[0060] After the heat treatment, the occluder is generally self-expandable. When collapsed, for example during delivery in a catheter sheath, the occluder will elastically return to the heat-set relaxed shape if not further restrained. The occluder can be fully or at least partially re-collapsed so that the occluder can self-expand again. Preferably, the strands are provided with a superelastic material, such as nitinol.

[0061] Figure 2a to Figure 2b The occluder is shown in a relaxed or non-stretched state. The occluder 1 may include a proximal element 4 having an outer circumference 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 circumference 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.

[0062] In particular, the distal element 6 can be a distal retaining element. In particular, the proximal element 4 can be a proximal retaining element. Retention refers to the ability to keep the occluder 1 in place when implanted. For example, the retaining element can be a retaining disc.

[0063] Each of the proximal element 4 and the distal element 6 may form a disk-shaped piece of the occluder 1 .

[0064] The occluder 1 may include a proximal element 4 and / or a distal element 6 , ie, a proximal disk-shaped member and / or a distal disk-shaped member.

[0065] The proximal element 4 / distal element 6 may, for example, be substantially circular, oval, substantially square, kidney-shaped (eg, for TAVIPLD), etc.

[0066] Furthermore, the proximal element / distal element may be cup-shaped, ie, the outer circumference of the proximal element / distal element may be curved in the direction of the proximal end and the distal end of the occluder 1 .

[0067] Furthermore, the proximal / distal elements may be dome-shaped (convex outer surface at the end surface).

[0068] In some embodiments, the proximal element 4 / distal element 6 is curved from the center of the proximal element 4 / distal element 6. In other embodiments, only a portion of the proximal element 4 / distal element 6 is curved.

[0069] Furthermore, the proximal / distal elements may additionally or alternatively be provided with recessed portions, for example to "hide" connecting elements such as welded or clamped ends of wires and prevent protrusion beyond the end surface, thereby providing improved endothelialization and / or reducing the risk of thrombus attachment to the occluder surface upon implantation.

[0070] The intermediate member 8 may form a waist of the occluder 1. The maximum outer diameter of the intermediate member 8 may be smaller than the maximum outer diameters of the proximal element 4 and the distal element 6.

[0071] In some embodiments, the intermediate element 8 includes a first pitch and a second pitch along the axial length of the intermediate element 8. In addition, the intermediate segment 8 can have a pitch that varies along the length of the intermediate segment 8, such as one or several segments having larger and smaller pitches along its length, such as in Figure 2b and Figure 3b This further enhances the elasticity of the middle section 8. In the example, the middle section 8 has much greater elasticity than the proximal element 4 and the distal element 6 in the longitudinal direction of the occluder.

[0072] According to the first aspect, when the occluder 1 is in a relaxed or non-stretched state, the position of at least one pitch transition section 9 from the first pitch to the second pitch is closer to the inner diameter D1a and / or the central axis 10 of the occluder than the outer circumference 5, 7 of at least one of the proximal element 4 and the distal element 6. In the example, the pitch transition section 9 is located on the inner disc-shaped portion (away from the end of the occluder and oriented toward the longitudinal middle part / center of the occluder) of the double-folded distal element in the form of a disc-shaped element. The distal element can have an outer diameter or an axial circumference. The position of the pitch transition section 9 is closer to the inner diameter D1a and / or the central axis 10 of the occluder than the outer circumference 5, 7. This contributes to the extensibility (stretchability) or elasticity of the intermediate member 8 that is higher than at least one of the proximal element 4 and the distal element 6.

[0073] According to a second aspect, the occluder 1 can be extended or stretched from a relaxed state to an axially extended state, which is longer in the longitudinal direction of the occluder than in the relaxed state. The occluder 1 can have a load-to-extension ratio measured in N / mm. The load-to-extension ratio can be measured as described below. When the occluder extends or stretches at least 2mm in the axial direction or in the longitudinal direction 10 of the occluder 1 along the center of the occluder 1, the load-to-extension ratio provided by the occluder 1 can be less than about 0.75N / mm. The load-to-extension ratio within the length elongation / occluder stretching range can be provided without significantly distorting the proximal element 4 and / or the distal element 4. When the retaining disc shape and / or its outer diameter / circumference are changed from the relaxed heat-set shape, the proximal element 4 and / or the distal element 4 are generally not twisted. Therefore, when the occluder 1 is implanted in a wide range, the distal element provides a holding capacity to stay in the implantation position. Thus, the ratio defines a higher extensibility (stretchability) or elasticity of the intermediate member 8 than the extensibility (stretchability) or elasticity of at least one of the proximal element 4 and the distal element 6, respectively. Thus, the occluder 1 is advantageously adaptable to anatomical changes, even during the (long-term) duration of implantation, while having a retained retainability (because the proximal element 4 and / or the distal element 6 do not deform). When further stretched beyond the limits of the range of the axially extended state, the shape of the occluder may be distorted (for example, when the occluder is collapsed into a delivery sheath for implantation, which is desirable).

[0074] Embodiments will be described below that may be combined with only the first aspect, with only the second aspect, or with the first and second aspects combined.

[0075] In some embodiments, the ratio of load to extension provided by the occluder 1 is less than 0.5N / mm, preferably less than 0.75N / mm. In some embodiments, the ratio of load to extension can even be less than 0.25N / mm. When the occluder 1 is extended or stretched by a predetermined length in its longitudinal direction, the ratio of load to extension can be provided. The predetermined length can be, for example, between at least 2mm and at most about 6mm. Before the above-mentioned distortion occurs, the occluder 1 is highly stretchable over a wide range compared to existing devices.

[0076] Figure 2a 1 and 2. There is a side view of the occluder 1 (center view), and a cross-sectional view taken through the middle portion 8 and looking towards the proximal element 4 (bottom view) and the distal element 6 (top view). Figure 3a 1 and 2. The occluder 1 is shown in a similar view taken in an extended state. Each of the proximal element 4 and the distal element 6 can be formed by a double layer of a double-layered interwoven structure 3, wherein the outer edges of the double layers form an outer diameter or circumference 5, 7, respectively. Thus, the transition section 9a of the proximal element 4 can be located on the distal side of the proximal element 4, such as Figure 2a Similarly, the transition section 9b of the distal element 6 can be located on the proximal side of the distal element 6, as shown in FIG. Figure 2a As shown in the top view.

[0077] As can be seen from the figure, when the occluder 1 is elongated within a large extension / stretching range, the transition sections 9a, 9b can have a variable axial position (distance from the longitudinal center axis 10) according to the elongated state of the occluder 1, while the outer diameter or circumference 5, 7 remains basically constant.

[0078] Generally, the occluder of the present disclosure avoids having a transition segment with reduced diameter. The occluder in some embodiments does not have a transition segment with reduced diameter, and in particular, these occluders do not have a transition segment between end elements such as the distal element 6 or the proximal element 4 and the intermediate element 8. The varying pitch and / or the soft section of the fabric make the various sections of the occluder have enhanced flexibility to each other. In particular, by arranging the relative positions of the transition segments 9a, 9b between the braided pitch transition segment and the occluder element, not only the stretchability is better than in the existing device, but also the pivoting or tilting motion of the elements of the occluder relative to each other is potentially improved. Therefore, the transition segment with reduced diameter can be omitted, and the transition segment with reduced diameter can be present in some embodiments.

[0079] In some embodiments, when the occluder 1 is in a relaxed state, at least one transition section 9 of the pitch is located between the outer circumference 5 , 7 and the inner diameter D1 a , D1 b of at least one of the proximal element 4 and the distal element 6 .

[0080] For example, at least one of the proximal element 4 and the distal element 6 may include at least a first pitch. The intermediate element 8 may include only a second pitch along the axial length of the intermediate element 8. Thus, in the example, the intermediate element 8 may be formed only by the second segment 3b of the tubular interwoven structure 3. Similarly, the proximal element 4 and / or the distal element 6 may be formed only by the first segment 3a / third segment of the interwoven structure 3.

[0081] Thus, the transition segment 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.

[0082] Figure 3a to Figure 3b The extended or elongated state of the occluder 1 is illustrated, in which the axial length of the occluder 1 is extended or elongated. In this state, the intermediate portion 8 of the occluder is extended / elongated. The occluder is longitudinally stretched. However, the axial length or thickness of the proximal element 4 and / or the distal element 6 in the longitudinal direction remains substantially constant without distortion. In addition, the inner diameter D3 of the intermediate element 8 decreases relative to the relaxed state in the elongated state of the occluder 1, while the outer circumference of the proximal element 4 and / or the distal element 6 remains substantially constant without distortion. When L2 > L1, D3 < D2, while D1 remains substantially unchanged. This is due to the different stiffnesses of the intermediate element 8 and the proximal element 4 and / or the distal element 6, resulting in different stretchabilities respectively.

[0083] As Figures 2a to 3b shown, at least one of the outer circumferences 5, 7 of the proximal element 4 and the distal element 6 remains substantially constant when the inner diameters D1a, D1b decrease due to the stretching or elongation of the occluder 1 along the longitudinal axis or central axis 10 of the occluder 1. This can be provided, for example, by providing varying pitches of the first segment 3a, the second segment 3b, and the optional third segment of the tubular interwoven structure 3.

[0084] In some embodiments, when the occluder extends from the relaxed state to the extended state along the axial length, the cross-sectional diameter of the intermediate element 8 decreases from the diameter D2 by less than 60%, preferably less than 40%, to the diameter D3 without the above-mentioned distortion.

[0085] Similarly, in some embodiments, the outer circumference or diameter 7 of at least one of the proximal element 4 and the distal element 6 remains substantially constant when the length of the occluder 1 extends from the non-extended or relaxed length L1 by more than 50% of the relaxed state, up to about 150% of the relaxed state, to the extended or elongated length L2.

[0086] In Figure 2a to Figure 2bIn the embodiment shown, the intermediate element 8 is at least partially straight or waist-shaped in shape, such as cylindrical or conical. However, in other embodiments, when the occluder 1 is in a relaxed state, the intermediate element 8 is bell-shaped or hourglass-shaped relative to the longitudinal axis or central axis 10 of the occluder 1. The shape of the intermediate portion 8, as well as the shape of the proximal element 4 and / or the distal element 6 can be formed by one or more molds during the heat treatment in one or more steps, and the same or different temperatures are used during the heat treatment of the shape memory material. Those skilled in the art will select the appropriate setting temperature and setting time and setting heat distribution of the desired device disclosed herein according to the actual material selected for the occluder 1, the selected pitch and its distribution along the base body, the distribution of the occluder elements along the longitudinal axis of the occluder, the desired softness or hardness of the fabric at the desired section of the occluder 1, etc. This contributes to the greater elasticity of the above-mentioned intermediate element 8 compared to the outer side directed toward the end of the occluder 1 of the proximal element 4 and the distal element 6, respectively. The intermediate element can therefore be heat set to have a fabric that is softer than the elements 4, 6. The intermediate element 8 may include a section having both a first pitch and a second pitch. Such an intermediate element may have a fabric that is softer than adjacent elements by heat treatment. Therefore, the intermediate element 8 may have two pitch sections whose woven fabric softness / elasticity / stretchability is different from the woven fabric softness / elasticity / stretchability of the adjacent elements 4, 6. The distal element 6 and / or the proximal element 4 may include a section having both a first pitch and a second pitch. The first pitch may be the same as the third pitch. After the heat treatment, the occluder 1 is removed from the molding element and substantially maintains the relaxed shape of the occluder 1 after deformation.

[0087] 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 weld, such as a laser weld. In the illustrated embodiment, the base body interlacing structure 3 is bag-shaped, i.e., the wire 2 starts at the proximal end, interlaced to the distal end, and then returns to the proximal end by interlacing. In other embodiments, the interlacing structure 3 is tubular and has an attachment element such as a clip, which ties the free end of the wire 2 at each end. The attachment element 11 for attaching the occluder 1 can be set at the central axis 10 of the occluder 1. The attachment element 11 for attaching the occluder 1 can also be set to deviate from the central axis 10, such as at the AFR. In WO09016265A2 of the same applicant as the present application, which is incorporated herein by reference as a whole for all purposes, a manufacturing method for tying the free ends of the wire 2 and fixing the ends together is disclosed. Thus, in such an embodiment, one end of the wire 2 is located at the distal end of the occluder, while the other end of the wire 2 is located at the proximal end of the occluder 1 (not shown).

[0088] Figure 4a to Figure 4b , Figure 5a to Figure 5b An embodiment is shown in which the outer circumference of the proximal element 14 and the distal element 16 has an alternative shape. The intermediate element 8 has a Figures 2a to 3b Furthermore, the proximal element 14 and the distal element 16 as well as the transition sections 9a, 9b to the intermediate element 8 can be as already described with reference to Figures 2a to 3b As shown, the proximal element 14 and the distal element 17 have a first diameter D1 and a second diameter D5. Thus, the configuration is similar to that described with respect to Figures 2a to 3b Elements described which have the same design are provided with the same reference numerals.

[0089] Figure 4a to Figure 4b , Figure 5a to Figure 5b The illustrated embodiment is, for example, a PVL occluder. In WO2013 / 041721A1 by the same applicant as the present application, which is incorporated herein by reference in its entirety for all purposes, a PVL occluder and a condition are disclosed. The disc and waist portion of the PVL device of WO2013 / 041721A1 can advantageously be provided with the improvements described herein. However, the disc 16 or the disc 14 has a concave curved portion and a convex curved outer circumference 5, 7 at opposite axial portions of the disc. This is particularly advantageous when the concave portion is juxtaposed or adjacent to an artificial heart valve during implantation. The relative convex curved circumference is anatomically advantageous in certain target areas to advantageously provide closure of paravalvular leaks while advantageously keeping the PVL occluder in place.

[0090] In other embodiments, the occluder has a single proximal element, such as a LAA occluder. The intermediate element may form a convex portion, such as a cylindrical body having end portions formed by the interlaced structure and having a diameter that does not exceed the diameter of the intermediate element. The intermediate element or the convex portion may be stretchable, such as with respect to Figures 2a to 3b As described. The hook can be attached to the distal element 6 (if present) and / or the intermediate element 8 and can engage an anatomical structure, such as the LAA. After the hook engages the vessel wall, the intermediate structure can be stretched and the proximal element positioned outside the anatomical structure. Due to the stretchability of the intermediate element / protrusion, the occluder is more flexible and conforms to the shape of the anatomical structure, wherein the performance of the occluder is enhanced.

[0091] For example, a LAA occluder is disclosed in WO2019197569 of the same applicant as the present application, which is incorporated herein by reference in its entirety for all purposes. The LAA device disclosed in WO2019197569 can advantageously be provided with an improved waist portion and a disc as described in the present disclosure.

[0092] In an embodiment, as an alternative or in addition to the above-mentioned hook, the LAA occluder can also have a distal anchoring element. Such a LAA occluder is disclosed in US8100938B1 of the same applicant as the present application, which is incorporated herein by reference in its entirety for all purposes. The LAA device disclosed in US8100938B1 can advantageously be provided with an improved waist portion and a disc-shaped member described in the present disclosure.

[0093] The AFR device allows controlled flow through the occluder when implanted, see, for example, WO2016 / 038115A1 of the same applicant as the present application, which is incorporated herein by reference as a whole for all purposes. The AFR device disclosed in WO2016 / 038115A1 can advantageously provide a waist portion and a disc having the improvements described in the present disclosure. The occluder 1 can have a through-channel as shown and described in WO2016 / 038115A1, such as the through-channel 106 in the drawings and description of WO2016 / 038115A1. The attachment element 11 for attaching the occluder 1 can also be arranged to deviate from the central axis 10, such as disclosed in WO2016 / 038115A1, and the base body 3 can be provided with a suitable through-channel when heat-set to provide the AFR according to the present disclosure. The double-layer disc is shown in FIG. 4c of WO2016 / 038115A1, for example, and is described in detail in the corresponding specification. These specific AFR elements are incorporated herein by reference. The first pitch section 3a may be part of an inner layer of one or both double folded discs. This provides an advantageous occluder 1 , here exemplified by an AFR device.

[0094] The load to stretch ratio may be determined using a tensile testing machine, such as Equipment No. 10017 provided by AMETEK Sensors, Test & Calibration and Brand Lloyd Instruments.

[0095] The testing process includes:

[0096] - Attach one end of the occluder 1 to a fixed reference and attach the other end of the occluder 1 to a tensile testing machine.

[0097] - Use a tensile tester to stretch the waist of the occluder to 3 N, with a tensile test speed of 600 mm / min. 3 N was selected as the maximum applied force to demonstrate the stretchability of the occluder under low force.

[0098] - Recording the extension or elongation of the occluder without distortion of the shape of the proximal and / or distal elements.

[0099] - Release the tension applied to the occluder and observe the reversibility of the stretching behavior, ie, the device can recover the original shape of the device without deformation after the release of the tension.

[0100] The following table illustrates test implementations A and B that fall within the above-mentioned D1, D2, D3, L1, and L2 ranges:

[0101] Test samples D1(mm) D2(mm) D3(mm) L1(mm) L2(mm) Implementation A 10 4 2 6 10 Implementation Method B 10 4 2 8 14

[0102] The test method was applied to the above defined and using size 4, part number 71VSD04 as reference. Tested embodiments A and B of the mVSD occluder. The 71VSD04 mVSD occluder is made of a base body with a single pitch. The overall shape of embodiments A and B corresponds to Figure 2b and Figure 3b The shape shown. Thus, embodiments A and B have proximal and distal elements shaped as discs, and an intermediate element in the form of an extendable waist. The disc shape is circular. The mVSD occluder has an overall similar shape, but has a more uniform and conventional stretchability, i.e., the elasticity of the intermediate element is similar to the stretchability of the proximal / distal elements, and is made of a single pitch braid. The diameter of the intermediate element or waist is 4 mm, the diameter of the proximal and distal elements (discs) is 10 mm, and the height of the waist or intermediate element is 7 mm.

[0103] The tensile behavior of the embodiments of the present invention relative to the mVSD device is shown in the following table:

[0104]

[0105]

[0106] The test specimens had the same raw materials and sterilization methods. Relative to the mVSD occluder, the pitch and heat setting of the braid varied between embodiments A and B. There are a variety of combinations of braid patterns and heat setting that can be used to achieve the above features, which fall within the disclosure as described above with respect to the embodiments of the invention.

[0107] As can be seen from the table above, embodiments of the present invention can be stretched or extended significantly longer than conventional devices. In particular, the test demonstrated that an occluder according to an embodiment of the present invention can be reversibly stretched or extended - that is, without distorting the original shape of the device, such as length or disc diameter, after stretching - to:

[0108] 100% to 150% when the applied load is 3N

[0109] 50% to 100% when the applied load is 1N

[0110] This should be compared to conventional occluders, such as the mVSD occluder, which are characterized by being able to reversibly stretch or elongate - without distorting the original shape of the device, such as length or disc diameter, after elongation - to:

[0111] 0% to 35% when the applied load is 3N

[0112] 0% to 30% when the applied load is 1N

[0113] It should also be understood that the features disclosed in the above description and / or in the attached drawings and / or the attached claims, both individually and in any combination thereof, are material for implementing the present invention in various forms. When used in the following claims, the terms "comprises", "comprising", "having" and their variations mean "including but not limited to".

[0114] The present invention has been described above with reference to specific embodiments. However, within the scope of the present invention, other embodiments than those described above are equally possible. Method steps different from those described above may be provided within the scope of the present invention. The different features and steps of the present invention may be combined in other ways than those described. The scope of the present invention is limited only by the appended patent claims.

Claims

1. An occluder (1), comprising: A continuous tubular braided structure made of an integral base body of at least one wire and having a pitch that varies along the axial length of the base body with at least one pitch transition section (9); the occluder is heat set to have a shape including: a proximal retaining element (4), which, in a relaxed state of the occluder (1), has an outer circumference at a first transition section (9a) and a distal inner diameter, a distal retaining element (6) having an outer circumference and a proximal inner diameter at a second transition section (9b) in the relaxed state of the occluder (1), and an intermediate element (8), said intermediate element (8) extending between said first transition section (9a) of said proximal retaining element (4) and said second transition section (9b) of said distal retaining element (6); wherein, - when the occluder is in the relaxed state, the position of the at least one pitch transition section (9) of the pitch from the first pitch to the second pitch is closer to the intermediate element or the central axis of the occluder than the outer circumference of at least one of the proximal retaining element (4) and the distal retaining element (6), wherein, - when the occluder (1) is in an axially extended state, the position of at least one of the first transition section (9a) and the second transition section (9b) can be changed from a first position to a second position closer to the central axis (10), and when the occluder (1) is in the axially extended state, the diameter of the intermediate element (8) is reduced from the relaxed diameter of the intermediate element (8), and wherein, - the outer circumference of the proximal retaining element (4) and the outer circumference of the distal retaining element (6) remain unchanged in the first position and the second position.

2. The occluder according to claim 1, wherein: When the occluder (1) is in the relaxed state, the at least one transition section (9) of the pitch is located between the outer circumference and the inner diameter of at least one of the proximal retaining element (4) and the distal retaining element (6).

3. The occluder according to claim 1 or 2, wherein: At least one of the proximal retaining element (4) and the distal retaining element (6) comprises at least the first pitch, and the intermediate element (8) comprises only the second pitch along the axial length of the intermediate element.

4. The occluder according to claim 1, wherein: At least one of the proximal retaining element and the distal retaining element comprises a common pitch having a different pitch than the intermediate element (8).

5. The occluder according to claim 1, wherein: The intermediate element (8) comprises a longitudinal section having the first pitch along the axial length of the intermediate element (8) and a longitudinal section having the second pitch along the axial length of the intermediate element (8).

6. The occluder according to claim 1 or 2, wherein: The occluder (1) is capable of extending from the relaxed state to an axially extended state that is longer in the longitudinal direction of the occluder (1) than in the relaxed state, and wherein, when extended by at least 2 mm, the ratio of the load measured in N / mm provided by the occluder (1) to the extension is less than 0.

75.

7. The occluder according to claim 6, wherein: The load to extension ratio measured in N / mm provided by the occluder (1) is less than 0.5 N / mm.

8. The occluder according to claim 6, wherein: The load to extension ratio measured in N / mm provided by the occluder (1) is less than 0.25 N / mm.

9. The occluder according to claim 6, wherein: The cross-sectional diameter of the intermediate element decreases by less than 60% when extending from the relaxed state to the extended state.

10. The occluder according to claim 6, wherein: The cross-sectional diameter of the intermediate element decreases by less than 40% when extending from the relaxed state to the extended state.

11. The occluder according to claim 1, wherein: When the length of the occluder (1) extends beyond 50% of the relaxed state to 150% of the relaxed state, the outer circumference of at least one of the proximal retaining element (4) and the distal retaining element (6) is substantially constant.

12. The occluder according to claim 1, wherein: When the occluder (1) is in the relaxed state, the intermediate element (8) is at least partially straight or waist-shaped in shape relative to the longitudinal axis of the occluder (1).

13. The occluder according to claim 1 or 2, wherein: 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 atrial shunt device, an atrial flow regulator (AFR) device, a fistula device or a vascular plug (VP) device.

14. An occluder (1), comprising: A continuous tubular braided structure made of an integral base body of at least one wire and having a pitch that varies along the axial length of the base body with at least one pitch transition section (9); the occluder is heat set to have a shape that includes: A proximal retaining element (4), wherein the proximal retaining element (4) has an outer circumference and a distal inner diameter at a first transition section (9a) in a relaxed state of the occluder (1); a distal retaining element (6), wherein the distal retaining element (6) has an outer circumference and a proximal inner diameter at the second transition section (9b) in the relaxed state of the occluder (1); an intermediate element (8), said intermediate element (8) extending between said first transition section (9a) of said proximal retaining element (4) and said second transition section (9b) of said distal retaining element (6), wherein: - the occluder (1) is extendable from the relaxed state to an axially extended state which is longer than the relaxed state in the longitudinal direction of the occluder, and wherein, without twisting of the proximal retaining element or the distal retaining element, when extended by at least 2 mm, the ratio of the load measured in N / mm provided by the occluder to the extension is less than 0.75, and wherein, - When the occluder (1) is in the axially extended state, at least one of the first transition section (9a) and the second transition section (9b) is located closer to the central axis (10) of the occluder (1), and the diameter of the intermediate element (8) is reduced from the relaxed diameter of the intermediate element (8).

15. According to the occluder according to claim 14, when the occluder is in the relaxed state, the position of at least one transition segment of the pitch from the first pitch to the second pitch is closer to the central axis of the occluder (1) or the intermediate element (8) than the outer circumference of at least one of the proximal retaining element (4) and the distal retaining element (6).

16. The occluder according to claim 15, wherein: When the occluder (1) is in the relaxed state, the at least one transition section (9) of the pitch is located between the outer circumference and the inner diameter of at least one of the proximal retaining element (4) and the distal retaining element (6).

17. The occluder according to claim 14, wherein: When extended from at least 2 mm up to about 6 mm, the ratio of load to extension, measured in N / mm, provided by the occluder (1) is less than 0.5 N / mm.

18. The occluder according to claim 14, wherein: When extended from at least 2 mm up to about 6 mm, the ratio of load to extension measured in N / mm provided by the occluder (1) is less than 0.75 N / mm.

19. The occluder according to claim 14, wherein: When extended from at least 2 mm up to about 6 mm, the ratio of load to extension measured in N / mm provided by the occluder (1) is less than 0.25 N / mm.

20. The occluder according to claim 14, wherein: The cross-sectional diameter of the intermediate element (8) decreases by less than 60% when extending from the relaxed state to the extended state.

21. The occluder according to claim 14, wherein: The cross-sectional diameter of the intermediate element (8) decreases by less than 40% when extending from the relaxed state to the extended state.

22. The occluder according to claim 14, wherein: 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 atrial shunt device, an atrial flow regulator (AFR) device, a fistula device or a vascular plug (VP) device.

23. The occluder according to any one of claims 14 to 22, wherein: The distal retaining element (6) and / or the intermediate element (8) comprise a hook.

24. A method of manufacturing an occluder according to any one of the preceding claims, the method comprising: forming a unitary base body from at least one wire, thereby providing a continuous tubular braided interwoven structure having a pitch that varies along the axial length of the base body of the occluder with at least one pitch transition section (9); and The base body is heat set to have a shape including: a proximal retaining element (4), which, in a relaxed state of the occluder (1), has an outer circumference at a first transition section (9a) and a distal inner diameter, a distal retaining element (6) having an outer circumference and a proximal inner diameter at a second transition section (9b) in the relaxed state of the occluder (1), and an intermediate element (8), said intermediate element (8) extending between said first transition section (9a) of said proximal retaining element (4) and said second transition section (9b) of said distal retaining element (6), wherein: When the occluder (1) is in the relaxed state, the position of the at least one pitch transition section (9) from the first pitch to the second pitch is closer to the middle element or the central axis of the occluder than the outer circumference of at least one of the proximal retaining element (4) and the distal retaining element (6), wherein: When the occluder (1) is in the axially extended state, the position of at least one of the first transition section (9a) and the second transition section (9b) can be changed from a first position to a second position closer to the central axis (10), and when the occluder (1) is in the axially extended position, the diameter of the intermediate element (8) decreases from its relaxed diameter, and wherein the outer circumference of the proximal retaining element (4) and the distal retaining element (6) remains unchanged in the first position and the second position.

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