DE102010019365A1 - Bioabsorbable occlusion device, which is introduced by a catheter in a folded condition in a patient's body, where the device in an area of its surrounding envelope comes to a constriction, useful to treat e.g. atrial septal defects - Google Patents

Abstract

Bioabsorbable occlusion device (1), which is introduced by a catheter in a folded condition in a patient's body, where the occlusion device in an area of its surrounding envelope comes to a constriction, which on one side causes the anchoring, as the proximal and distal retention areas (18, 19) are not affected by this constriction and alternatively, the defect is closed so that at the conclusion of the implantation process a variable final shape is formed, which no longer coincides with the permanent initial form of the occlusion device, is claimed. Bioabsorbable occlusion device (1), which is introduced by a catheter in a folded condition in a patient's body, and it adapts to the defect site of the geometry of the boundary zone, where the occlusion device in an area of its surrounding envelope comes to a constriction, which on one side causes the anchoring, as the proximal and distal retention areas (18, 19) are not affected by this constriction and alternatively, the defect is closed so that at the conclusion of the implantation process a variable final shape is formed, which no longer coincides with the permanent initial form of the occlusion device, is claimed. ACTIVITY : Cardiant. MECHANISM OF ACTION : None given.

Description

The invention relates to a biodegradable, intravascular closure device for the priority treatment of holes in the region of the membranous septum (atrial septum) between the two atria of the heart (atria), the so-called atrium-septal defect (ASD) or atrial septal defect, wherein the closure device (Occlusioninstrument or occluder) in its outer contour conforms to the course of the ASD. With this closure device, other heart defects such as the patent foramen ovale (PFO), an oval opening / slit in the atrial septum of the heart, which normally closes by gluing the setting edges after birth, are treatable. Such occlusion devices are suitable for placement at the otherwise difficult to reach defect sites in the human heart by minimally invasive treatment methods via the use of a catheter or a sheath.

Background of the invention

From the morphology forth, various atrial septal defects are indexable. So we know atrial septal defects under the introduced short name ASD.

Regarding the incidence of such defects, ASD is the most common congenital heart defect found in adults at 30%; in children it accounts for 6% of congenital heart defects diagnosed. For further classification, the ostium-secundum defect can be assigned to 70% of ASD cases. The defect is located in the fossa ovalis and affects women more often than men (3: 1). The sinus venosus defect affects 10% of ASD cases and is located in the upper part of the atrial septum. And finally, the ostium-primum defect, this ASD lies in the lower part of the atrial septum. He is most often diagnosed in childhood.

Another common defect in the right and left anterior ventricles is the persistent foramen ovale (PFO). The PFO is a gate-shaped opening between the left atrial septum primum and the right atrial septum secundum in the area of the fossa ovalis. In the fetal circulation, the PFO serves as a physiological connection for the blood flow from the right to the left atrium. After birth with interruption of the placental circulation, a left atrial pressure increase usually results in the functional closure of the PFO by pressing the septum primum to the septum secundum; both grow together later, but in about 30% of the cases remains a PFO.

The location and size of such ASD and PFO defects necessitate a variety of different and size-graded occlusion devices.

State of the art

One of the first developers of such occlusion instruments to occlude PFO and ASD is Kurt Amplatz from the USA. The patent discloses this US 6,123,715 a method for forming a medical device and other medical devices for such applications, which can be produced by means of this method. In principle, such an occlusion device consists in the basic form of a braided tube, wherein first the two ends are each fixed with a clamp and then brought into a stable final shape, with two double discs (proximal and distal) facing each other and by a strongly tapered central part are connected. This tapered center element is located exactly in the middle of the defect site of the PFO and ASD defect. The device is finally fixed by the limiting and covering double discs (proximal and distal), which finally lead to the closure of the PFO and ASD. After insertion of the occlusion implant, endothelialization immediately begins on the surface of the occlusion device, ultimately leading to complete occlusion of the PFO / ASD.

After the self-centering Amplatzer system with a double umbrella made of flexible superelastic mesh of Nitinol wire bundles, an alloy of titanium and nickel, there are a number of other devices that are usually a treatment option for open foramen ovals.

• a) Cardia-Star-PFO-Occluder der Firma Cardia mit jeweils 6 Nitinolarmen und Polyvinylalkohol als Patch-Trägermaterial.
• b) Cardio SEAL-PFO-Occluder von NMT Medical Inc. mit flexiblen, septal gerichteten Nitinolarmen zur Erhöhung des koaxialen Anpressungsdruckes sowie Dacron-Trägermaterial (siehe dazu WO 2005/074814A2 ).
• c) Helex-Gore-PFO-Occluder, bestehend aus einem Nitinol-Drahtrahmen sowie aus speziellen Polytetrafluoroethylen(PTFE)-Patchmaterial, das durch Rückzugsmanöver zu einem links- und rechtsatrialen Schirmchen koaxial zum Septum konfiguriert wird.
• d) Premere-PFO-Occluder von St. Jude Medical; über eine Zugvorrichtung wird ein distal befindliches Kreuzsystem gepresst auf eine im rechten Vorhof befindliche Platte.
• e) Solysafe-PFO-Occluder, mit zwei gegenüber liegenden Polyesterscheiben, welche über ein Zugsystem aus Draht, hergestellt aus Phynox (auf Kobaltbasis) und fixiert durch Drahthalter aus PEEK (Etheretherketone Polymer) zusammengezogen werden.
• f) Occlutech-Figulla-PFO-Occluder, in ähnlicher Ausführung wie der Amplatzer-PFO-Occluder, allerdings distal ohne Klemme, das erfordert im Gegensatz zum Amplatzer-Occluder, hergestellt aus einem schlauchförmigen Drahtgewebe, eine andere Ausgangsform und zwar kam hier erstmalig ein Kugelgeflecht mit nur einer proximalen Klemme zur Anwendung.

Thus, from the current application of transvenous PFO closure systems with predominantly Nitinolgerüst known:

• a) Cardia Star PFO occluder from Cardia, each containing 6 nitinol moles and polyvinyl alcohol as patch carrier material.
• b) Cardio SEAL-PFO Occluder from NMT Medical Inc. with flexible, septum-directed nitinol arrays to increase the coaxial contact pressure and Dacron support material (see WO 2005 / 074814A2 ).
• c) Helex Gore PFO occluder consisting of a Nitinol wire frame and special polytetrafluoroethylene (PTFE) patch material configured by withdrawal maneuvers to a left and right atrial screen coaxial with the septum.
• d) Premere PFO Occluder of St. Jude Medical; Via a pulling device, a distally located cross system is pressed onto a plate located in the right atrium.
• e) Solysafe-PFO-Occluder, with two opposite polyester discs, which are pulled together by a pull system made of wire, made of Phynox (based on cobalt) and fixed by wire holder made of PEEK (etheretherketone polymer).
• f) Occlutech-Figulla-PFO-Occluder, similar in design to the Amplatzer-PFO-Occluder, but distally without clamp, which requires in contrast to the Amplatzer Occluder, made of a tubular wire mesh, a different starting shape and indeed came here for the first time Ball braid with only one proximal clamp for use.

ASD occluders are, for example, off WO 2007 / 110195A1 and EP 1 965 706 A1 known.

Initial approaches to partial biodegradation of occlusion instruments can be found in a PFO device of NMT, the Starflex Occluder; this differs from the Cardio SEAL-PFO occluder (see above) in that the patch liner has been replaced with a collagen coating that is biodegradable.

Out DE 10 2005 053 958 A1 is a self-expanding medical occlusion device for treating defects in the heart of a patient, particularly for occluding abnormal tissue openings such as PFO / ASD, the device being entirely made of a polymer composition that is biodegradable. Ultimately, however, these occlusion instruments are of a constructive and functional design, like the metal occluders presented in the prior art:
The occluders have a predetermined shape (permanent shape). During insertion of the occlusion device into the body of a patient by means of a suitable catheter, a second pre-definable shaping (temporary shape) results and in the implanted state of the occlusion device this tries to reach the first predetermined shape (permanent shape) again.

This principle of achieving the prescribed permanent shape after implantation by means of a catheter works very well with the metallic braid occluders, but very difficult with the polymer-polymer occluders. The reasons for this lie exclusively in the different or specific properties of such metal or plastic occluders. Suitable polymer compounds can be stretched elastically up to 500% and more (up to 1000%) with respect to their initial length. The restoring forces to return to the initial state, however, are very low. Vascular resistances in the area of the defect site are thus difficult to overcome. Stainless steels have an elastic deformability of approx. 0.1%. The metallic braid occluders commonly used in medical technology also consist of nitinol; the elastic properties allow changes in length of about 8%, which is 80 times higher than steel. In relation to the comparison of elastic behavior of Nitinol to steel, we therefore speak of superelasticity of nitinol. The metal occluders are due to their relatively large restoring forces very well able to return after implantation in the predetermined shape (permanent shape). The major disadvantage of such metal occluders, in turn, is that they are no longer explantable after successful implantation and subsequent endothelialization.

DE 10 2009 036 817.5 respectively. US 61 / 273,919 disclose a biodegradable occlusion device that is self-expanding and, in particular, expandable by other auxiliary devices. The disadvantage here is that in some cases the auxiliary devices have to be removed in a second cardiological treatment method by means of a catheter after the endothelialization phase has ended. Incidentally, the apply to DE 10 2005 053 958 A1 Explanations on the elastic behavior of polymer materials and their effects on a permanent final form or the ability to return to the default starting shape after implantation.

task

The object of the invention is to provide a biodegradable Occluder that is able without auxiliary devices to safely close an atrial septal defect (atrium-septal defect) of the human heart, wherein the ASDs may be small, large, single or multiple , The heart may otherwise be normal or have other additional malformations.

In the present invention, an intravascular device (occlusion device) made of biodegradable materials is used, which in particular takes into account the special requirements of the material properties, so that such an atrium-septal defect can be safely closed. The preferred embodiments of occlusion devices in the present invention are capable of extremely changing their shape and shape. Thus, these occlusion instruments adapt their outer shape so that their transport or a minimally invasive introduction into a patient via a catheter is possible. In contrast to the metal braid occluders listed in the prior art and biodegradable occluders shown there, which function on the same principle to achieve their permanent initial shape as far as possible after implantation in the expanded state, this basic principle is not important here. In the embodiments according to the invention, the part of the occlusion device which comes into contact with the defect site in the vessel adapts precisely to these spatial conditions. That is, the embodiments according to the invention no longer have a permanent final shape, which corresponds to the original shape of the occlusion device. Rather, it is the case that the permanent final shape of the occlusion devices according to the invention and their permanent initial shape are excluded. All occlusion devices according to the invention have a permanent initial shape (before the implantation process) and a variable final shape (after the implantation process) which do not match due to their function. The variable final form is exclusively defined or characterized by the characterization or shape of the defect, which applies to both PFO and ASDs.

The biodegradable materials used in the preferred exemplary embodiments according to the invention can be used as film or braiding bodies in various variants. The film bodies get their desired shape in a prefabricated mold. Such an occlusion device made of a film body can be folded or inserted into the lumen of the catheter. This occluder is scooped distally through the catheter and unfolds on the treatment side as follows:
After placement of the device exactly in the defect area, the Occluder constricts in the area of the defect site, facilitated by the smaller wall thickness of the film body of the occluder in this area. The much larger material thicknesses of the film body at the proximal and distal ends of the Occluder cause these Occluderteile can reach in their final form exactly the predetermined initial shape again; so it comes in unfolded state in these areas back to its original form. The result is a body that tends to narrow down in the area of such a defect (such as a hole in the atrial septum). Since the distal and proximal ends of the Occluder are not affected by this constriction, and not only because they are not directly in the hole, but directly above and below and further because they are more in the free space of the left and right atria In fact, distal and proximal occlusion of the defect occurs, eventually leading to permanent anchoring and occlusion of the ASD.

Likewise, it is contemplated to employ preferred embodiments based on braids in the present invention. In this case, the film body of the occlusion device is replaced by a suitable braid body. Analogously to the film body, there are in the same way mold areas or elements in the braid body, which have similar properties due to changes in the braiding density (eg lower braiding density) or different braiding processes, as achieved by different material thicknesses.

embodiment

In the following, preferred embodiments of the occlusion device according to the invention and the exemplary explanation of manufacturing method of the occlusion device according to the invention are explained in more detail with reference to the drawings. The features mentioned in the claims and in the description may each be essential to the invention individually or in any desired combination. Show it:

1 an overview of formations of atrial septal defects (atrial septal defects) in five different variants as plan views (a-e);

2 a perspective view of an embodiment of the invention in three views (a-c);

3 a model of a closure device for displaying the functional principle as a sectional view in three views (a-c);

4 Production of a film body according to the invention in three steps by the stretching process as a sectional view in three views (a-c);

5 Production of a film body according to the invention in two steps by the stretching process as a sectional view in two views (a, b);

6 Moldings and film base for an inventive embodiment in side view;

7 further form elements and film base body for an inventive embodiment in side view;

8th at the proximal and distal ends with molded elements reinforced foil body after 6 in a half-sided sectional view;

9 at the proximal and distal ends with molded elements reinforced foil body after 7 in a half-sided sectional view;

10 a stretched film body with flow openings and network in a half-sided sectional view;

11 a stretched film body with flow openings and another network variant in a half-sided sectional view;

12 a film base body with flow channels as a sectional view (a) and a plurality of spatial representations (b-d) with a half-sided sectional view (e);

13 a film base body with flow slots as a sectional view (a) and a plurality of spatial representations (b-d) with a half-sided sectional view (e);

14 a perspective view of an embodiment of the invention ASD Occluders in side view (a), sectional views (b, c);

15 Representation of the detail too 14 with the coupling element at the proximal end of the occlusion device;

16 another embodiment of the invention the detail 14 with the coupling element at the distal end of the occlusion device and the through-hole forming element at the proximal end;

17 presentation of the 15 with insertion wire and catheter;

18 presentation of the 16 with insertion wire and catheter;

19 Representation of an embodiment of the invention ASD Occluders in a sectional view, with coupled catheter (a) and decoupled catheter (b) for an occlusion with additional push button device;

20 Presentation of details to 19 with coupled catheter (a) and disconnected catheter (b);

21 an inventive variant of an ASD occluder with an equipped with flow channels Occlusionsinstrument, which was additionally combined with a network construction including push-button mechanism, representation of the items;

22 Representation of an ASD occluder according to the invention with an inner tube bushing with slots to support a stable end position of the Occlusionsinstruments in side view (a) and sectional views (b, c);

23 Detail too 22 with already uncoupled insertion wire;

24 Representation of the individual components, slotted foil body, distal X-ray marking, tube bushing with slots and coupling element closed 22 ;

25 an embodiment according to the invention of a PFO occluder with a slit foil main body in three-dimensional views (a, c) and in a side view (b);

26 an inventive embodiment of a PFO Occluders with stretched film base body, slotted in front view (a), sectional view (b) and as a sectional view in the implanted state (c);

27 an embodiment according to the invention of an ASD II Occluder (Cribriform Occluder) with a slit foil main body in a spatial representation (a), a perforated atrial septum (b) and as a sectional view in the implanted state (c);

28 an embodiment of an occlusion device according to the invention based on a 3D braid body in a spatial view (a) and in a test device, partial section (b) for simulating the real conditions after implantation in the atrial septum;

29 an embodiment according to the invention of an occlusion device based on 2D lichen in combination with active technique as a braid body in a spatial view (a) and in a test device, partial section (b) for simulating real conditions after completion of the implantation in the atrial septum;

30 a partial view of 28 (a) in the area of the variable final shape between the proximal and distal retention area;

31 a partial view of 29 (a) in the area of the mesh body (variable end shape) between the proximal and distal retention area;

32 a partial view of 29 (b) in the region of the mesh body laterally with a cutout between the proximal and distal retention area in the region of the variable final shape;

33 Representation of a detail of 32 to illustrate the knitting process and showing a single stitch (a) and three connected stitches (b);

34 an inventive embodiment of an ASD Occluders based on a 3D braid body in (a) in three different sizes and in (b) as a 2D braid body combined with the Wirkflechtverfahren in graduated sizes;

35 an inventive embodiment of a PFO Occluders based on 3D braid body in different sizes and

36 an inventive embodiment of an ASD II-Occluders (Cribriform Occluder) in (a) in graduated sizes as a 3D braid body and in (b) as a 2D braid body combined with the Wirkflechtverfahren in different execution sizes.

In the in the 1 to 36 the occlusion device according to the invention (Occlusionsinstrument or occluder) is shown in various views, also in various application variants as ASD and PFO Occluder and ASD II Occluder (cribriform), also the morphology of ASD and PFO and in principle sketches individual components and process steps.

1 shows some essential forms of such holes in the membranous septum (atrial septal defect / ASD). With the help of X-ray technology, it can be problematic to accurately determine the defect sizes; this also applies to the ballooning, if it is z. B. is ASD's, which as in 1 (b) or in 1 (c) elliptical or elliptical and curved. In the case of the prior art occluders, it is problematic to close such ASDs correctly. In the case of the occlusion device according to the invention, the shape-like expression of such ASDs plays only a minor role, which will be explained below, thus resulting in a significant advantage of the closure devices according to the invention.

In 2 and 3 a first embodiment of a closure device according to the invention is shown. It is essentially a hollow cylindrical body. It is made in a mold, as is usual with a balloon. The peculiarities are that as in the cut 3 (a) is shown, the upper, circular top surface (distal retention area 19 ) and the lower circular top surface (proximal retention area 18 ) exhibit a greater material thickness than the thinner sheath around the longitudinal axis (range of the variable final shape 22 ). With regard to the end purpose of this closure device is made of very elastic material, which should be biodegradable to it.

Exactly these requirements are fulfilled for the production of the occlusion instruments according to the invention known biodegradable and superelastic polymers.

Elastic polymers are more or less cross-linked polymers which upon deformation give a reversible change in length of from 50% to more than 500%, the polymers completely resuming their initial form. For superelastic polymers, the reversible change in length can be 1000% or more. The elastic polymers can be subdivided into covalently crosslinked elastomers and thermoplastic elastomers.

In the case of the covalently crosslinked elastomers, which are also called soft rubber, there are few, ie widely meshed, network polymers which are produced industrially by covalent crosslinking of corresponding rubbers. The rubbers are uncrosslinked and largely amorphous linear polymers which are composed of flexible basic building blocks and whose glass transition temperature (T _g ) is therefore below the service temperature. Technically important rubbers are natural rubber, diene rubbers, such as styrene-butadiene rubber, each composed of flexible hydrocarbon chains, poly (chloroprene), or silicone rubber, which consists of very flexible polysiloxane chains and leads to elastomers with low-temperature elasticity. By crosslinking these rubbers, which is also called vulcanization, elastomers are formed. Since the underlying rubber polymers are very resistant to hydrolysis, they can not be used to produce biodegradable elastomers.

However, biodegradable, covalent elastomers can be prepared relatively simply on the basis of polyphosphazene rubbers (PNF), which by means of various reactions (for a review cf. HR Allcock, Chemistry of Materials 6 (1994) 1476-91 ), such. B. by peroxide or irradiation with γ-rays, can be crosslinked. The polyphosphazenes (-N = PR ₂ -) are inorganic polymers which are accessible by ring-opening polymerization of hexachlorocyclotriphosphazene and subsequent nucleophilic substitution (cf. JE Mark, HR Allcock, R. West, Inorganic Polymers, Prentice Hall, Englewood Cliffs 1992, 61-140 :

Depending on the substituents R, PNF rubbers are obtained which have a T _g significantly below room temperature, eg. B. T _g = -76 ° C in the case of R = OCH ₃ , show. It is advantageous that the properties of the polyphosphazenes, such as. B. the elasticity (R = O-alkyl, O-aryl), the degradability (R = NHCH (R ') COOC ₂ H ₅ ) or the hydrophilicity (R = NHCH ₃ ) can be easily adjusted by varying the substituents. For the medical use of polyphosphazenes, it is particularly important that polyphosphazenes be hydrolytically degraded in the body to non-toxic components (phosphates and ammonium salts), which are then excreted. Therefore, many polyphosphazenes are for biomedical applications, z. B. as bioinert polymers, hydrogels, membranes or as water-soluble bioactive polymers (see, above-mentioned monograph of Mark et al. ).

In the case of thermoplastic elastomers, there are no covalently crosslinked but purely physically crosslinked polymer networks. The networks consist of so-called "hard" domains, which are embedded in a "soft" matrix. In this case, the term "hard" domains means the regions in the thermoplastic elastomer which are characterized by a significantly higher glass transition temperature compared to the service temperature. At temperatures below the service temperature, these "hard" domains are the crosslinks between which the flexible chains can be reversibly deformed. At higher temperatures, these crosslinking areas are melted and the polymer is then like a thermoplastic, for. B. by extrusion, injection molding, molding or blown film. Technically important thermoplastic elastomers are styrene-diene triblock copolymers or olefin thermoplastic elastomers. Both classes of materials are composed of hydrocarbon chains and therefore not biodegradable.

On the other hand, biodegradable thermoplastic elastomers z. B. on the basis of polyether or polyester segment copolymers easy to build. The crystalline thermoplastic (hard) domains are incorporated in an amorphous elastomeric matrix. The flexible segments can be easily constructed from aliphatic polyether or polyester sequences, the rigid (hard) from aromatic polyester or urethane moieties. In this context, especially segmented polyurethane copolymers show good biocompatibility. In this case, the hard segment-forming phase by a reaction of diisocyanates, especially methylene bis (4-phenyl isocyanate) or hexamethylene diisocyanate, with short-chain diols, especially 1,4-butanediol, accessible and is the flexible phase of oligomeric polyester diols such. Example of OH-terminated poly (ε-caprolactone) or poly (ethylene adipate). With this, polymer networks can be produced which exhibit reversible strains in the range of 50 to 400%. In addition, a good and controlled biodegradability, in particular starting from oligomeric polyester diols based on degradable polyesters such as polylactic acid) PLA, poly (glycolic acid) PGA, poly (3-hydroxybutyric acid) PBA, poly (4-hydroxyvaleric acid) PVA or poly (ε- caprolactone) PCL or corresponding copolymers can be achieved.

Superelastic polymers with reversible strains of approx. 800 to 1550% could be prepared on the basis of novel multi-drop copolymers with periodically arranged tri-, tetra- and hexafunctional linkage points (cf. Y. Zu et al. Macromolecules 39 (2006) 4428-36 ). The synthesis was carried out by anionic polymerization by coupling of difunctional polyisprene anions and polystyrene arms with tri-, tetra- and hexafunctional chlorosilanes. Such Multipfropfcopolymere largely contain only hydrocarbon segments and are therefore not hydroplytic or enzymatically degradable in the human organism.

In order to achieve a sufficient contraction of the occlusion device according to the invention in the case of external force, in the area of the sheath, in 3 (a) . 30 and in the area of the proximal retention area, in 2 (c) . 18 , corresponding flow openings 30 incorporated.

The occlusion device works in the simplest form already with the in 3 illustrated construction; In addition to the flow openings, 30 , which in particular have the function in the contraction phase of the Occluders, to divert backflowing blood into the right atrium, we find at the distal end 17 , on the internal side an X-ray marker and at the proximal end 16 a coupling element 21 for a screw wire (insertion wire) or a fastener 20 leading to the proximal end 16 may be formed as a ball to be coupled in turn with a special insertion wire. Both the coupling element 21 and the fastener 20 should be visible in X-ray and thus realize a second X-ray marking and also be biodegradable. For example, biodegradable magnesium alloys are suitable for these occluder constituents, since it may also be necessary, for example, for the coupling element 21 to make an internal thread mechanically to realize the connection with the insertion wire.

Magnesium (Mg) is a chemical element important for the physiological organ functions of humans. The body of an adult contains about 21-28 g Mg, of which half is in the bone. Only about 1% of Mg in the human body is in the plasma. The recommended daily intake of Mg in the diet is around 310-420 mg in adults. In healthy adults, about 50-120 mg Mg is excreted daily from the urine.

It is known that Mg was first introduced by Lambotte ( A. Lambotte, Bull. Mem. Soc. Nat. Chir. 28 (1932) 1325-34 ) used as implant material. A Mg alloy with a low aluminum content then used Verbrugge ( J. Verbrugge La Presse Med. 42 (1934) 460-5 ). Today, numerous biodegradable Mg alloys are known as surgical implant material (see Review: CK Seal et a. IOP Conf. Series: Mat. Sci. Eng 4 (2009) 1-4 ) or patented. The advantages of the Mg alloys are above all the low density, the bone modulus of elasticity (about 45 GPa) and the very good biocompatibility. Commercial Mg alloys investigated as implant material (cf. EN Switzer, Dissertation 2005 University of Veterinary Medicine Hannover ) are AZ31, an alloy of 94% by mass of Mg, 3% by mass of aluminum (Al) and 1% by mass of zinc (Zn); AZ91, an alloy containing 90% by mass of Mg, 9% by mass of Al and 1% by mass of Zn; WE43, an alloy containing 93% by mass of Mg, 4% by mass of yttrium and 3% by mass of rare earths and LAE442, an alloy containing 90% by mass of Mg, 4% by mass of lithium, 4% by mass of Al and 2% by mass. % Rare earth.

The corrosive decomposition of Mg takes place with liberation of hydrogen. Since the inclusion of the body is limited to hydrogen gas or to avoid hydrogen gas bubbles must be controlled under physiological conditions, the corrosion of Mg and thus the release of hydrogen, which by the addition of certain alloying elements, such as. B. Al, Zn or elements of rare earths, and what z. B. already in the GB-PS 12337035 or the U.S. Patent 3,687,135 has been described. So z. B. in implants based on such Mg alloys such as AZ31 or LAE442 in animal studies no formation of hydrogen gas bubbles can be found. The use of Mg alloys for vascular or cardiovascular applications has been described e.g. By Heublein et al. examined ( B. Heublein et al. Heart 89 (2003) 651-6 ). So z. For example, for a 4 mg stent based on AE21 in pig, complete degradation was found after 3 months. Depending on the area of application (stent 3-6 months, orthopedic implant: 1 to 1.5 years), the different rate of degradation can be adjusted by varying the composition and amount of the Mg alloy. Suitable biodegradable Mg alloys are u. a also in the U.S. Patent 6,287,332 ; 6,854,172 ; 6,767,506 or in U.S. Patent Application Publication Nos. 20040098108; 20060058263; 200600552825 or 20090081313 described. In addition, in the WO / 2008/092436 bioresorbable metal stents, e.g. B. based on a Mg alloy, with controlled absorption by an enclosure with a special polymer, eg. B. claimed a biodegradable polymer.

• • Aluminium < 0.01 Gew.%,
• • Kupfer < 0.03 Gew.%,
• • Nickel < 0.005 Gew.%,
• • Silber < 0.01 Gew.%,
• • Quecksilber < 0.03 Gew.%,
• • Cadmium < 0.03 Gew.%,
• • Beryllium < 0.03 Gew.%,
• • Chrom < 0.03 Gew.%
• • Seltenerdmetalle 2.0 bis 5.0 Gew.%, dabei Neodym 1.5 bis 3.0 Gew.%,
• • Yttrium 3.5 bis 4.5 Gew.%,
• • Zirkonium 0.3 bis 1.0 Gew.%,
• • Rest 0 bis 0.5 Gew.%,

wobei Magnesium den auf 100 Gew.% verbleibenden Gewichtsanteil an der Legierung einnimmt. Die Legierung zeigt sehr günstige mechanische und physiologische Eigenschaften und ein günstiges Degradationsverhalten in vivo. Sie kann einfach verarbeitet werden und zeigt in ersten Studien einen positiven physiologischen Effekt auf das umgebene Gewebe in Mensch und Tier, wenn die Legierung in Endoprothesen, insbesondere Stents, verwendet wird. Die Sammelbezeichnung „Seltenerdmetall” steht für die Elemente Scandium (Ordnungszahl 21), Lanthan (57) sowie die 14 auf das Lanthan folgenden Elemente Cer (58), Praseodym (59), Neodym (60), Promethium (61), Samarium (62), Europium (63), Gadolinium (64), Terbium (65), Dysprosium (66), Holmium (67), Erbium (68), Thulium (69), Ytterbium (70) und Lutetium (71), die als Lanthanoide bezeichnet werden. Der Anteil der Seltenerdmetalle an der Magnesiumlegierung umfasst somit auch den Anteil des Neodyms. Letzterer Anteil ist ebenfalls auf das Gesamtgewicht der Legierung bezogen und muss im angegebenen Bereich liegen. Liegt der Anteil an Neodym in der Legierung z. B. bei 2.0 Gew.% und der Anteil an Seltenerdmetallen bei 2.5 Gew.%, so werden zwangsläufig Seltenerdmetalle außer Neodym einen Gewichtsanteil an der Legierung von 0.5 Gew.% aufweisen. Die in den aufgezählten Publikationen oder Patenten beschriebenen bioabbaubare Mg-Legierungen lassen sich auch für die Herstellung der erfindungsgemäßen Occlusionsinstrumente einsetzen.Of particular importance is to keep the proportion of aluminum as small as possible in such magnesium alloys. Aluminum in particular has a pronounced negative influence on the physiological behavior, as material studies have shown. DE 10 2004 043 232 A1 describes such a magnesium alloy:

• Aluminum <0.01% by weight,
• Copper <0.03 wt.%,
• Nickel <0.005% by weight,
• Silver <0.01% by weight,
• Mercury <0.03% by weight,
• Cadmium <0.03% by weight,
• Beryllium <0.03% by weight,
• Chromium <0.03% by weight
• Rare earth metals 2.0 to 5.0% by weight, while neodymium 1.5 to 3.0% by weight,
• Yttrium 3.5 to 4.5% by weight,
• Zirconium 0.3 to 1.0% by weight,
• • balance 0 to 0.5% by weight,

wherein magnesium occupies the weight percentage of the alloy remaining at 100% by weight. The alloy shows very favorable mechanical and physiological properties and a favorable degradation behavior in vivo. It is easy to process and in early studies shows a positive physiological effect on the surrounding tissue in humans and animals when the alloy is used in endoprostheses, especially stents. The collective term "rare earth metal" stands for the elements scandium (atomic number 21), lanthanum (57) and the 14 lanthanum elements cerium (58), praseodymium (59), neodymium (60), promethium (61), samarium (62 ), Europium (63), gadolinium (64), terbium (65), dysprosium (66), holmium (67), erbium (68), thulium (69), ytterbium (70) and lutetium (71), which are known as lanthanides be designated. The proportion of rare earth metals in the magnesium alloy thus also includes the proportion of neodymium. The latter proportion is also based on the total weight of the alloy and must be within the specified range. If the proportion of neodymium in the alloy is z. B. at 2.0 wt.% And the proportion of rare earth metals at 2.5 wt.%, So inevitably rare earth metals except neodymium have a weight fraction of the alloy of 0.5 wt.% Have. The biodegradable Mg alloys described in the listed publications or patents can also be used for the production of the occlusion devices according to the invention.

In 3 (b) the situation is clarified, as in the defect site 2 the external forces on the occlusion device 1 act. The borders of the hole in the atrial septum (septum) 2 act on the occlusion device according to the invention 1 in such a way that it constrictions in the shell between the retention areas 18 . 19 Occluder comes and thus to a firm anchorage in the field of variable final shape 22 , Since the strength of the septum is known, the envelope of the occluder located in the region of the defect site must be correspondingly dimensioned so that ultimately the anchoring of the implant proceeds optimally. In 3 (c) is an idealized optimally anchored occluder shown. This occlusion device shown here can later be constructively used for the application ASD 12 and PFO 13 vary, as will be shown and described below.

In the 2 and 3 becomes the occlusion device 1 shown in a first preferred embodiment. The basic function mechanism is as follows:
The medical devices 1 have a permanent starting shape after 2 and 3 (a) , The devices 1 be in folded condition by a catheter 38 introduced into the body of the patient. They unfold on the distal 19 and proximal side 18 as in 3 (b, c) and in this subregion of the device ideally resume their output shapes. The one in defect 2 located part of the medical devices 1 adapts to the local conditions 1 accurate to shape; The reasons for this lie in the superelastic properties of the bioresorbable polymer materials used and in the balanced structural design of these occluders, with a corresponding thinness in the area of the defect site 2 of the atrial septum 11 , Thus, the medical devices have 1 after implantation a variable, the defect site adapted final shape.

Thus, the medical devices presented here differ fundamentally from the Nitinol Occlusionsinstrumenten listed in the prior art including the previously known bioresorbable plastic occluder, which operate on the principle after implantation, due to their elasticity, to accept the original, predetermined initial shape again ,

Another preferred embodiment of a closure device 1 arises from that after 4 and 5 as starting form a balloon-shaped film base body 34 which is used in the region of the variable final shape 22 is stretched under thermal influence, this hot air is directed directed shortly below the melting point of the polymer compound. An advantage of such a stretched film body 34 is that you achieve very low material thicknesses and also are the transitions to the outer retention areas 18 . 19 very short. Such an embodiment according to the invention is optimally designed to be an occlusion instrument 1 to manufacture which for the treatment of PFO's 3 suitable is. For exact dimensional implementation of the stretching process, it makes sense, as in 4 shown to realize the method in several intermediate stages; a first stretching process is followed by a second stretching; another multiple stretching is possible. For cost reasons, the number of stretching stages is to be kept as low as possible.

Another preferred embodiment of a closure device 1 is in the embodiments 6 - 9 to find. The basis is a film base body 34 which already indicates the dimensionally correct thickness in the area of the variable final shape 22 , On the proximal and distal retention areas 18 . 19 become suitably formed mold elements 28 . 27 applied under thermal action, which lead in these areas to stabilize the final shape, as in 6 and 7 for two Exemplary embodiments shown. In the half-side sectional views 8th For 6 and 9 For 7 It can be clearly seen that similar material cross-sections as in the first closure devices according to the invention 1 in 3 . 5 result.

Another preferred embodiment of a closure device 1 is in two embodiments in 10 and 11 seen. An already prefabricated film base body 34 . 35 according to the already presented embodiments of the closure devices 1 is additionally with a thread network 31 coated and with increasing braiding density in the direction of the proximal and distal ends 16 . 17 the closure devices. Preferred applications are the treatment of atrial septal defects 2 ,

Another embodiment of a closure device according to the invention in two embodiments show the 12 and 13 , Here you can see the film base 34 , which are in the range of the variable final form 22 are increasingly recessed, which can be shaped elements, as in 12 with elliptical basic shape 32 or as in 13 with slits 33 , In these variants eliminates the flow openings 30 ,

In 14 one sees another preferred embodiment of a closure device 1 , The preferred application is an occlusion device 1 for the treatment of atrial septal defects, so-called ASD occluders 12 , In principle, the film base body 34 be prefabricated according to all previous preferred embodiments of the closure devices 1 , In the present preferred embodiment, the cylindrical basic shape is modified into a truncated cone, wherein the diameter of the distal retention area 19 greater than that of the proximal retention area 18 ,

In 15 - 18 one sees the detailed design of the coupling mechanism in two embodiments 21 and 21 . 37 as a detailed representation of 14 , In 15 one sees a variant in which the coupling element 21 at the proximal end 16 located and in 17 in combination with catheter 38 and insertion wire 39 , The coupling element 21 is made of a biodegradable magnesium alloy, as previously described. The X-ray marking also made of a magnesium alloy 23 is located on the inside at the distal end 19 of the occluder. In 16 you can see a clutch solution in which the clutch 21 in the distal end region 17 . 19 and in the proximal end region 16 . 18 of the occlusion device as a shaped element with passage 37 is attached. In 18 You can see a representation of the coupling mechanism in combination with catheter 38 and insertion or screwing wire 39 ,

As already explained above and in 1 There are a variety of different atrial septal defects, which may vary considerably in shape and size; this starts with ASD's from hole diameter 1 to 40 mm.

In 19 and 20 is another preferred embodiment of a closure device 1 characterized in that the two retention areas 18 . 19 inside with a push button element 40 can be connected, resulting in a more stable fixation in the defect site. In 20 one sees in a detailed representation an additional cable pull mechanism 41 to the connection of the push-button element 40 with the clutch 21 manufacture. It is from the proximal end 16 A slight pushing movement with one in the catheter 38 located insertion wire 39 which in turn is in the clutch 21 docked, executed. Opposite this is with the same force by means of cable mechanism 41 the push button element 40 in the direction of the clutch 21 guided until it comes to a mechanical connection. The endless rope of the cable mechanism 41 can be at the proximal end of the catheter 38 be cut off, then finally remove it from the patient.

Another preferred embodiment 1 can be seen in 21 and is characterized by its structure, a film base body 34 to identify which additionally with a network construction 31 and with a push button element 40 and clutch 21 Is provided. The components are shown loosely.

In 22 to 24 one sees another embodiment of a closure device according to the invention 1 , With the same intention as with the push button system 40 . 21 is located as a distance fixation between the proximal and distal retention area 18 . 19 a slotted hose socket 42 , made of the same material as the foil body 15 that is biodegradable polymers. In 23 one sees in the detailed view that the hose bushing 42 at the distal end 17 firmly anchored. At the proximal end 16 is the hose socket 42 in the coupling element 21 hooked. Before inserting the hose bushing with slots 42 in the film body 15 is previously an X-ray mark 23 in the hose socket 42 attached. In 24 looks a compilation of the individual components of such Occlusionsinstruments. As part of the implantation process is the slotted tube bushing 42 Able to stretch or stretch as far as the stretched length of the particular occlusion device requires. In the end position of the slotted hose bush 42 This additionally fixes the occlusion device in the defect site.

In 25 to 26 One sees another preferred embodiment of the closure device according to the invention, wherein the outer diameter of the proximal retention area 16 is greater than the diameter of the distal retention area 17 ; the basic shape is therefore also that of a truncated cone, as in 14 shown. Such an occlusion device is a preferred embodiment variant for a PFO occluder 13 ,

Another preferred embodiment of the medical closure device 1 is in 27 characterized in that the features mentioned in the description can be applied individually or in any combination, namely to the already explained and here application-related occlusion as ASD II Occluder 14 in which the cover discs of the proximal and distal retention area 18 . 19 identify approximately the same outer diameter. The design of the ASD II Occluder, also known as the Cribriform Occluder, allows for multiple contiguous ASD defects, as in 27 (b) shown to be covered simultaneously with a closure device.

Another preferred occlusion device 1 to 28 - 36 does not consist of a foil body 15 but from a braid body 43 ; Further advantages, features and details of the invention will become apparent from the following description in which embodiments are described in detail with reference to the drawings. The features mentioned in the exemplary embodiments and in the description can each be used individually or in any desired combination.

In 28 is a preferred embodiment of the medical closure device 1 characterized in that the braid body 43 made with the 3-D braiding process. The 3-D braiding process differs from the rotationally symmetrical braiding in that the braided bobbins are not placed in a circle on a platform, but like on a chessboard. The clappers can realize numerically controlled movements. This leads to the fact that the braid density of the braid is permanently changed as needed. In 28 (b) is the medical closure device 1 in a tester 44 ; in the field of variable final shape 22 you can see that the braid density 49 . 50 decreases from the edge. This means that through the targeted change of braiding density occluder 1 are manufacturable, which can achieve identical properties, as in the medical closure devices 1 from film bodies 15 were achieved, see also detail 36 in 30 ,

In 29 is a preferred embodiment of the medical closure device 1 characterized in that the braid body 43 is partially made with the 2-D braiding process, namely the circular covers at the proximal and distal ends 16 . 17 up to the edge or the transition of the circumferential envelope between the retention areas 18 . 19 , In the 2-D braiding process, the braided bobbins are in the same plane as the braid, analogous to the spokes on a bicycle, which are aligned from the rim towards the center. The circumferential envelope of the occlusion device, ie the area of the variable final shape 22 , is carried out with another braiding method, the machine working. The active technique is a braiding process in which simultaneously several braid threads 48 be intertwined with each other. In the execution of the knitting technique with a thread one speaks of knitting. The basic principle of knitting is in 33 to see in the 33 (a) with a stitch and in 33 (b) with three consecutive stitches. In 32 to see the operation of a knitted form element; this is the detailed representation of the preferred exemplary embodiment of the medical closure device 1 , what a 29 (a) is shown. Such an occlusion device, which was manufactured as described with the 2-D braiding method combined with the active technique, can also be inserted in the folded state through a catheter into the body of a patient and unfolds as in 29 (b) The knitted occluder cover can be easily constricted, resulting in a secure fixation of the implanted occluder.

Further preferred embodiments of the medical closure device, which with a braid body 43 After the 3-D braiding or 2-D braiding combined with the active technique are produced, can be supplemented with the form elements X-ray marking 23 , the insertion technique 21 . 37 to 15 - 18 , Push button technique 40 . 46 . 21 to 19 . 20 (with and without cable mechanism 41 ) and the additionally inside hose bushing with slots 42 to 22 . 23 ,

In further preferred embodiments of the medical closure device can be seen in 34 various embodiments of an ASD occluder 12 to 34 (a) in 3-D braiding technique and in 34 (b) in 2-D braiding technique in combination with active technique; in 35 various embodiments of a PFO occluder 13 in 3-D braiding technique and in 36 various embodiments of an ASD II occluder 14 in 36 (a) in 3-D braiding technique and in 36 (b) in 2-D braiding technique in conjunction with impact technology.

LIST OF REFERENCE NUMBERS

1

Occlusion element or occluder (closure device)

2

Atrium septal defect / ASD (atrial septal defect)

3

Persistent foramen ovale / PFO

4

front view

5

sideview

6

Top view

7

bottom view

8th

sectional view

9

Half-sided sectional view

10

Spatial representation

11

Interatrial septum (atrial septum)

12

ASD occluder

13P

FO-occluder

14

ASD II occluder cribriform

15

film body

16

Proximal end

17

Distal end

18

Proximal retention area

19

Distal retention area

20

fastener

21

coupling member

22

Range of the variable final shape

23

radiopaque marker

24

Right Atrium Area (Right Atrium)

25

Left atrium area

26

Through Hole

27

Form element, distal

28

Form element, proximal

29

balloon

30

Flow openings

31

network construction

32

Flow channels

33

Flow slots

34

Film base body

35

Foil base, stretched

36

detail

37

Form element with through hole

38

catheter

39

insertion wire

40

Push-button element

41

cable mechanism

42

Hose socket with slots

43

braid body

44

Tester

45

longitudinal axis

46

Sleeve for push button element 40

47

weave

48

thread

49

High braid density (fine mesh)

50

Low braid area (coarse mesh)

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 6123715 [0006]
• WO 2005/074814 A2 [0008]
• WO 2007/110195 A1 [0009]
• EP 1965706 A1 [0009]
• DE 102005053958 A1 [0011, 0013]
• DE 102009036817 [0013]
• US 61/273919 [0013]
• GB 12337035 [0070]
• US 3687135 [0070]
• US 6287332 [0070]
• US 6854172 [0070]
• US Pat. No. 6767506 [0070]
• WO 2008/092436 [0070]
• DE 102004043232 A1 [0071]

Cited non-patent literature

• HR Allcock, Chemistry of Materials 6 (1994) 1476-91 [0061]
• JE Mark, HR Allcock, R. West, Inorganic Polymers, Prentice Hall, Englewood Cliffs 1992, 61-140 [0061]
• Mark et al. [0062]
• Y. Zu et al. Macromolecules 39 (2006) 4428-36 [0065]
• A. Lambotte, Bull. Mem. Soc. Nat. Chir. 28 (1932) 1325-34 [0069]
• J. Verbrugge La Presse Med. 42 (1934) 460-5 [0069]
• CK Seal et a. IOP Conf. Series: Mat. Sci. Eng 4 (2009) 1-4 [0069]
• EN Switzer, Dissertation 2005 University of Veterinary Medicine Hannover [0069]
• B. Heublein et al. Heart 89 (2003) 651-6 [0070]

Claims (21)

Bioabsorbable occlusion device 1 for occlusion of atrial septal defects introduced by means of a suitable catheter in a folded state into the body of a patient and conforming to the geometry of the marginal zone at the defect site, whereby in the case of the occlusion instrument it is in the region of its circumferential envelope 22 constriction occurs, which on the one hand causes anchoring, since the proximal and distal retention areas 18 . 19 are not affected by this constriction and on the other hand close the defect so that forms a variable final shape at the conclusion of the implantation process, which no longer with the permanent output form of Occlusionsinstruments 1 matches. The bioabsorbable occlusion device of claim 1, substantially characterized by a hollow cylindrical body 34 , which is manufactured in a tool mold with the specific shape, in the region of its circumferential shell 22 be designed to be thinner wall than the circular and final upper cover surface in the adjacent left atrium 25 and lower cover area in the adjacent right atrium 24 and to ensure sufficient contraction with incorporated flow openings 30 in the area of the variable final shape of the shell 22 and in the area of the proximal retention area 18 , A bioabsorbable occlusion device according to claims 1 and 2, characterized in that for the production of the occlusion devices according to the invention 1 biodegradable and superelastic polymers based on polyphosphazene rubbers attributable to biodegradable covalent elastomers. Bioabsorbable occlusion device according to claim 1 and 2, characterized in that for the production of Occlusionsinstrumente invention biodegradable and superelastic polymers based on polyether or polyester-segment copolymers are used, which are attributable to the biodegradable thermoplastic elastomers. A bioabsorbable occlusion device as claimed in any of claims 1 to 4 with an x-ray marker 23 at the distal end 17 of the occluder lying inside and at the proximal end 16 a radiopaque fastener 20 , which may be formed as a ball, in turn to be coupled with a special insertion wire with pliers. A bioabsorbable occlusion device as claimed in any of claims 1 to 4 with an x-ray marker 23 at the distal end 17 of the occluder lying inside and at the proximal end 16 a radiopaque coupling element 21 for a screw wire (insertion wire) 39 , A bioabsorbable occlusion device according to claims 1 to 6 with a fastener element visible in X-ray light 20 and coupling element 21 these components are made from biodegradable magnesium alloys with very low levels to zero of aluminum, copper, nickel, silver, mercury, cadmium, beryllium, chromium and minor amounts of rare earth metals, yttrium, zirconium and a major proportion of magnesium. A bioabsorbable occlusion device according to claim 1, 3 to 7, wherein as a starting form a film base body 34 which is used in the region of the variable final shape 22 is stretched under thermal influence, in order to achieve very thin material thicknesses and in which to secure a sufficient contraction flow openings 30 in the area of the variable final shape of the shell 22 and in the area of the proximal retention area 18 were introduced. The bioabsorbable occlusion device of claims 1 to 7, wherein a film body 34 with corresponding wall thickness for the area of the variable final shape 22 was equipped and additionally covering and stiffening form elements 27 . 28 which are applied under thermal influence and in the distal and proximal retention areas 18 . 19 lead to the stabilization of the final form. A bioabsorbable occlusion device according to claims 1 to 9 with a suture network 31 namely equipped with increasing braiding density in the direction of the proximal and distal ends 16 . 17 the closure devices. A bioabsorbable occlusion device according to claims 1 to 8 having a foil body 34 , which are in the range of the variable final form 22 are increasingly recessed, namely with form elements with elliptical basic shape 32 , with slits 33 or similar recesses, wherein the flow openings 30 omitted. The bioabsorbable occlusion device according to claims 1 to 11, having the preferred application for the treatment of atrial septal defects, so-called ASD occluders, in which the basic shape of the film body 15 was changed to a truncated cone, wherein the diameter of the distal retention area 19 is visibly larger than that of the proximal retention area 18 , The bioabsorbable occlusion device of claims 1 to 12, wherein the coupling 21 in the distal axial end region 17 . 19 is attached, wherein in the proximal end region 16 . 18 of the occlusion device a form element with passage 37 is attached. The bioabsorbable occlusion device according to claims 1 to 12, comprising an additional push-button closure device, wherein the two retention areas 18 . 19 inside with a push button element 40 located at the distal end 17 and at the same time serves as an X-ray marking, via one on the coupling element 21 attached sleeve 46 be connected with this. The bioabsorbable occlusion device according to claim 14, wherein a cable pull mechanism is used to implement the push button closure device 41 the push button element 40 in the direction of the clutch 21 leads, until it comes to a mechanical connection, wherein the pulling movement of the cable mechanism is opposite to the pushing movement of the catheter 38 located insertion wire 39 , The bioabsorbable occlusion device of claims 1 to 12, wherein for spacing fixation between the proximal and distal retention regions 18 . 19 a slotted hose socket 42 made of the same material as the film body 15 , ie from biodegradable polymers, which are used at the distal end 17 is firmly anchored and the proximal end in the coupling element 21 was hooked and finally additionally with an X-ray marker 23 in the distal area of the slotted tube bush 42 Is provided. The bioabsorbable occlusion device according to claims 1 to 11 and 13 to 16 with the preferred application for the treatment of persistent foramen ovals, so-called PFO occluders, in which the basic shape of the foil body 15 was changed to a truncated cone, wherein the diameter of the distal retention area 19 Visible smaller than that of the proximal retention area 18 , The bioabsorbable occlusion device according to claims 12 to 16 for further preferred application of the treatment of atrial septal defects as so-called ASD occluders. The bioabsorbable occlusion device according to claims 1 to 11 and 13 to 16, with the preferred treatment of multiple atrial septal defects in an atrial septum using only the cylindrical basic shape of the medical closure device. The bioabsorbable occlusion device of claims 1 to 19, wherein the film body 15 through an analogous braid body 43 which is manufactured according to the 3-D braiding method and in which the braid density is used as a measure of an additional extension or shortening of the braid body, wherein in the section of the variable final shape 22 the surrounding envelope of the occlusion device areas with lower braid density 49 are found as in the proximal and distal retention areas 18 . 19 with a high mesh density 50 , The bioabsorbable occlusion device of claims 1 to 19, wherein the film body 15 through an equivalent braid body 43 is replaced, which is partially manufactured by the 2-D braiding method and that precisely the circular covers at the proximal and distal ends 16 . 17 up to the edge or transition of the circumferential envelope between the retention areas 18 . 19 ; this circumferential envelope in the area of the variable final shape 22 is made with the braiding process and is very easy to constrict, resulting in a secure fixation of the implanted occluder.

Images