Occlusion Device And Method For Its Manufacture

Abstract

The present invention relates to an occlusion device (1) consisting of a braiding (2) of thin wires or threads (4) which is given a suitable form in a molding and heat treatment procedure. The occlusion device (1) has a proximal retention area (6) and a distal retention area (8), whereby the ends of the wires or threads (4) converge into a holder (5) in distal retention area (8). A cylindrical crosspiece (10) is furthermore disposed between the proximal and distal retention areas (6, 8). With the objective of providing an occlusion device which positions as flat as possible against the septum at the proximal side of a septal defect in the inserted state, the invention provides for the proximal retention area (6) of the braiding (2) to exhibit a completely closed proximal wall (112) disposed with a continuous surface at the proximal end of the occlusion device (1) which forms the proximal end (12) of said occlusion device (1).

Claims

1. A braiding machine producing a spherical braid structure, the braiding machine comprising: a braiding head unit comprising in combination: a braiding head, a braiding crown for spherical braiding, a plurality of form elements, the braiding head having a first end located proximal to the braiding crown and an opposite second end, the first end being curved or rounded peripherally in a direction from the first end to the second end, wherein the braiding head unit is placed axially in a center of an orbit of impellers of the circular braiding machine, and each of said impellers arranged to hold an end of a wire extending from a position between the braiding crown and across the braiding head of the braiding head unit.

2. The braiding machine of claim 1, wherein the braiding head is axially disposed in a direction perpendicular to a plane defined by the orbit, the first end of the braiding head being circumferentially arched or curved in a direction perpendicular to said plane.

3. The braiding machine according to claim 1, wherein the braiding head is placed so that the wires are directed at a shallow angle downwards towards clasps of the braiding machine when the circular braiding machine is used.

4. The braiding machine according to claim 1, wherein the braiding head unit is secured to a support beam that is arranged above the braiding head unit.

5. The braiding machine according to claim 1, wherein the first end of the braiding head is connected to the braiding crown via the form elements.

6. The braiding machine according to claim 1, wherein the first end has a partly spherical shape.

7. The braiding machine according to claim 1, wherein the braiding head has a larger diameter at the first end than the second end, and wherein the braiding head is shaped so as to taper from the first end to the second end.

8. The braiding machine according to claim 1, wherein the braiding head has a generally conical shape with the base of the conical shape formed by the first end and the apex of the cone shape by the second end.

9. The braiding machine according to claim 1, wherein the braiding head has a depression between the first end and the second end which runs in the longitudinal direction of the braiding head.

10. The braiding machine according to claim 1, wherein the form elements comprise a plurality of elongate elements which connect the braiding crown to the braiding head, thereby forming a gap between the braiding crown and the braiding head, so that when in use, wires of the ball braid between the braiding crown and the braiding head and stretch past the form elements.

11. The braiding machine according to claim 10, wherein the braiding crown has a circular shape at an end connected to the braiding head, said plurality of elongate elements being disposed about the periphery of said circular shape.

12. The braiding machine according to claim 10, wherein the elongate members are connected to a perimeter of the first end of the braiding head, the first end being curved or rounded radially outside the perimeter.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0046] These and other aspects, features and advantages of which embodiments of the invention are capable of will be apparent and elucidated from the following description of embodiments of the present invention, reference being made to the accompanying drawings, in which

[0047] FIG. 1 is a perspective view of a preferred first embodiment of an occlusion device according to the present invention in expanded state in which only the outlined contour of the occlusion device is depicted;

[0048] FIG. 2 is a perspective detail view of the distal retention area of the first embodiment of the FIG. 1 occlusion device in the expanded state;

[0049] FIG. 3 is a side view of the inventive occlusion device shown in FIG. 2 in the expanded state;

[0050] FIG. 4 is a three-dimensional view of a round braiding machine to illustrate the inventive manufacturing method for the occlusion device;

[0051] FIG. 5 is a top plan view onto the round braiding machine depicted in FIG. 4 to illustrate the inventive manufacturing method for a ball-shaped, bulb-shaped or teardrop-shaped base braiding structure in accordance with FIGS. 9a-9c, which can serve as a base structure for the occlusion device according to the present invention;

[0052] FIG. 6 is a detail view of the braiding head of the round braiding machine depicted in FIG. 4;

[0053] FIG. 7 is an example of a braiding produced with the braiding head shown in FIG. 6, which can serve as the base structure for the occlusion device according to the present invention;

[0054] FIG. 8a is a side view of a special braiding head for manufacturing a ball-shaped, bulb-shaped or teardrop-shaped base braiding structure in accordance with FIGS. 9a-9c, which can serve as the base structure for the occlusion device according to the present invention;

[0055] FIG. 8b is a sectional view of the braiding head according to FIG. 8a;

[0056] FIG. 8c is a stereoscopic representation of the special braiding head used to produce a spherical braiding;

[0057] FIG. 9a is a perspective representation of a base body for a spherical braiding constituting the initial body for the inventive occlusion device, whereby the base body is configured in a form as close to a ball as possible;

[0058] FIG. 9b is a perspective representation of a base body for a spherical braiding suited for producing the occlusion device according to the present invention and whereby the base body is configured to the greatest extent possible in the form of a bulb-shaped body;

[0059] FIG. 9c is a perspective representation of a base body for a spherical braiding, whereby the base body is suited for producing the occlusion device according to the present invention and whereby the base body is configured in a teardrop-shaped form;

[0060] FIG. 10a is a spherical braiding as a base body for different occlusion devices in accordance with the present invention which is produced with a special braiding method and which exhibits a distal holder;

[0061] FIG. 10b is a sectional side view of the right side of an inventive PFO-type occlusion device, whereby the occlusion device is made from a spherical braiding in accordance with FIG. 9a;

[0062] FIG. 10c is a sectional side view of the right side of an inventive ASD-type occlusion device, whereby the occlusion device is made from a spherical braiding in accordance with FIG. 9a;

[0063] FIG. 11 is a sectional side view of the right side of an inventive PFO-type occlusion device, whereby the occlusion device is made from a ball-shaped, bulb-shaped or teardrop-shaped base braiding structure in accordance with FIGS. 9a-9c and comprises a distal holder;

[0064] FIG. 12 is a sectional side view of the right side of an inventive VSD-type occlusion device, whereby the occlusion device is made from a ball-shaped, bulb-shaped or teardrop-shaped base braiding structure in accordance with FIGS. 9a-9c and comprises a distal holder;

[0065] FIG. 13 is a sectional side view of the right side of an inventive ASD-type occlusion device according to the invention, whereby the occlusion device is made from a ball-shaped, bulb-shaped or teardrop-shaped base braiding structure in accordance with FIGS. 9a-9c and comprises a distal holder;

[0066] FIG. 14 is a sectional side view of the right side of an inventive PDA-type occlusion device, whereby the occlusion device is made from a ball-shaped, bulb-shaped or teardrop-shaped base braiding structure in accordance with FIGS. 9a-9c and comprises a distal holder;

[0067] FIG. 15a is a tubular braiding known from the prior art, for example in accordance with U.S. Pat. No. 5,725,552, constituting the starting structure or base for manufacturing a known occlusion device, whereby the respective ends of the tubular braiding need to be held in a holder;

[0068] FIG. 15b is a sectional side view of the right side of a PFO-type occlusion device known from the prior art, for example in accordance with U.S. Pat. No. 5,725,552, whereby the occlusion device is made from a tubular braiding in accordance with FIG. 15a;

[0069] FIG. 15c is a sectional side view of the right side of an ASD-type occlusion device known from the prior art, for example in accordance with U.S. Pat. No. 5,725,552, whereby the occlusion device is made from a tubular braiding in accordance with FIG. 15a;

[0070] FIG. 16a is a tulip-shaped or bell-shaped braiding having a distal holder as known from the prior art, for example from WO 2005/020822 A1;

[0071] FIG. 16b is a sectional side view of the right side of a PFO-type occlusion device known from the prior art, for example in accordance with WO 2005/020822 A1, whereby the occlusion device is made from a tubular braiding in accordance with FIG. 16a; and

[0072] FIG. 16c is a sectional side view of the right side of an ASD-type occlusion device known from the prior art, for example in accordance with WO 2005/020822 A1, whereby the occlusion device is made from a tubular braiding in accordance with FIG. 16a.

DESCRIPTION OF EMBODIMENTS

[0073] FIG. 1 shows a perspective view of a preferred first embodiment of the occlusion device 1 according to the invention in the expanded state, whereby only the outlined contour of occlusion device 1 is depicted in FIG. 1. FIG. 2 shows a perspective detail view of the distal retention area 8 of the first embodiment of the occlusion device 1 shown in the expanded state in FIG. 1. FIG. 3 shows a side view of the inventive occlusion device 1 shown in expanded state in FIG. 2.

[0074] The occlusion device 1 essentially consists of a braiding 2 of thin wires or threads 4, preferable made from nitinol or another shape-memory material or material having memory effect. The braiding 2 exhibits sufficient flexibility such that the occlusion device 1 can be tapered to the diameter of a (not explicitly shown) catheter used in an intravascular surgical procedure. Because of the material's memory effect, the occlusion device 1 tapered as such has a shape-memory function such that the device 1 self-expands after exiting the catheter and reassumes the predefined form which corresponds to its use. This normally ensues after the occlusive device 1 initially disposed in the catheter has been positioned at the location to be treated.

[0075] As especially shown in FIGS. 2 and 3, the occlusion device 1 exhibits a proximal retention area 6, a distal retention area 8 and a cylindrical crosspiece 10 arranged between said proximal and distal retention areas 6, 8 in the expanded state. The two retention areas 6, 8 serve to occlude a defect or shunt in a septum. This ensues by areas 6, 8 positioning against the two sides of the shunt to be occluded while the crosspiece 10 passes through the shunt. The occlusion device 1 according to the invention therefore represents an occluding system which can be introduced into a patient's body and positioned at its intended location in a minimally-invasive procedure; i.e., using a catheter and guide wires, for example.

[0076] The design to the inventive occlusion device 1 is thereby based on the principle of having the occlusion device 1 taper to the dimensions of the catheter. After being discharged from the catheter, the retention areas 6, 8 then unfold by themselves, thereby positioning themselves on both sides of the septum. The inventive design moreover reflects the occlusion device 1 being a self-positioning and self-centering system. The crosspiece 10 thereby has the length of the atrial diaphragm, the septum respectively, in order to ensure secure placement of retention areas 6, 8 at the septum wall.

[0077] Unlike conventional occlusion systems known from the prior art in which a self-expanding umbrella serves as proximal retention area 6, the proximal retention area 6 of the present invention has a flat covering in the form of a proximal wall 112 closed to the proximal end 12 such that no material of the implanted occlusion device 1 whatsoever can extend past the septum wall in the proximal area of the patient's organ. The closed contouring to the proximal end 12 of proximal retention area 6 further ensures that the rim of proximal retention area 6 will always lie flush with the septum wall. This occurs over a relatively wide area independent of the diameter to the defect or the thickness of the atrial diaphragm, the septum respectively, and thereby allows complete endothelialization to occur relatively quickly after the occlusion device 1 has been implanted and precludes any possible defense mechanism reactions from the patient's body since the blood is effectively prevented from coming into contact with the material of implant 1.

[0078] Because of the self-expanding property to implant 1 based on the memory effect of the material used, the occlusion device 1 according to the invention exhibits a self-centering function in the shunt or the septal defect. The occlusion device 1 can furthermore be retracted at any time up to the uncoupling of the guide wires of the insertion instrument.

[0079] The occlusion device 1 according to the invention can of course furthermore comprise fabric inserts, which are not explicitly shown in the present drawings, the principle behind which is known from the prior art. Such fabric inserts consist mostly of Dacron material. Chemically speaking, Dacron is a polyethylene terephthalate polyester, obtained by polycondensating ethylene glycol and terephthalic aciddimethyl ester. It is hereby conceivable to incorporate the fabric inserts within the interior of crosspiece 10 or at the proximal end 12 of retention area 6 in order to be able to fully occlude the defect or the shunt in the septum wall. The fabric inserts can be incorporated by bracing same within occlusion device 1, for example. The implant 1 inserted into the body will then be completely enveloped by the body's own tissue within a few weeks or months.

[0080] The braiding 2 which serves as the base structure for the occlusion device 1 according to the invention exhibits sufficient rigidity to clamp the fabric insert and have it remain in position.

[0081] The braiding 2 converges into a holder 5 at the distal end 3 of distal retention area 8. This is thereby realized by producing an internal thread in holder 5 which then serves to engage with a guide wire of a not shown insertion instrument when the occlusion device 1 is being guided to the appropriate position relative the location of the defect in the septum, for example in an intravascular surgical procedure. After the occlusion device 1 has been positioned in the shunt or defect, the engagement between the guide wire of the insertion instrument and distal end 3 is then disengaged. It is, of course, also conceivable to make use of a differently-configured mechanism in place of an internal thread in holder 5 at distal end 3.

[0082] As already indicated, FIG. 1 shows a perspective view of the preferred first embodiment of the occlusion device 1 according to the invention in expanded state while FIG. 2 shows a perspective partial view of the distal retention area 8 of the occlusion device 1 shown in FIG. 1. For simplification purposes, FIG. 1 only shows the outline of occlusion device 1. For even further simplification, a detailed depiction of the braiding 2 serving as the base structure is dispensed with and the form of occlusion device 1 is shown as that of a closed surface. This occlusion device 1 exhibits a much flatter proximal retention area 6 compared to the first embodiment. Depending upon actual intended application, the proximal retention area 6 is configured in a more or less distinctly flattened shape so as to ultimately form the proximal wall 112 in the expanded state. Yet also conceivable would be for the proximal wall 112 to exhibit a completely flattened spherical shape or an almost plate-shaped profile.

[0083] FIG. 4 shows a three-dimensional view of a round braiding machine 7 in order to illustrate the method of manufacturing the occlusion device 1 according to the present invention. FIG. 5 is a top plan view of the round braiding machine 7 depicted in FIG. 4 in order to illustrate the inventive manufacturing method for a ball-shaped, bulb-shaped or teardrop shaped initial braiding structure 2 according to FIGS. 9a-9c, which can serve as the starting structure for the occlusion device 1 according to the invention. FIG. 6 further shows a braiding head 11 for the round braiding machine 7 of FIG. 4 in greater detail, while FIG. 7 shows a braiding 2 made for example with the braiding head 11 shown in FIG. 6, which can serve as the base structure for the occlusion device 1 according to the invention. FIG. 8a is furthermore a side view of a special braiding head 11 for manufacturing a ball shaped, bulb-shaped or teardrop-shaped initial braiding 2 according to FIGS. 9a-9c, which likewise can serve as the base structure for the inventive occlusion device 1. The braiding head 11 according to FIG. 8a is further shown in sectional view in FIG. 8b, while FIG. 8c depicts a stereoscopic representation of the special braiding head 11 for manufacturing a spherical braiding of this type.

[0084] In contrast to the known braiding methods where all the threads or wires 4 are gathered into one bundle at the leading end of the braiding 2 and stretched to an extractor device, in the method according to the invention, the material supply is stretched from every second spool 9 to a braiding head 11 and from there to each next respective spool 13 or a multiple of the dividing gap. The spools 13 not having a material supply only have an auxiliary thread extending at least to braiding head 11. The end of the material supply is connected to the end of the auxiliary thread as close as possible to the auxiliary thread spool by means of bolt 14.

[0085] The braiding head 11, depicted in detail in the latter cited figures, is of crown-shaped configuration and is provided with form elements 15 which allow the threads or wires 4 to be hooked. Form elements 15 can be lowered in order to hook/unhook braiding 2. Braiding head 11 is axially positioned at the center of the orbit of impellers 16 such that the threads or wires 4 are aligned at a flat downward angle to bobbins 17 of the braiding machine 7.

[0086] After all the wires 4 required for the braiding 2 have been joined and tightened, braiding commences in conventionally known manner in that impellers 16 rotate around the center while bobbins 17 shift from impeller to impeller, their orbits thereby crossing. The infeed for braiding 2 is realized by means of a cam plate 18 based on the revolutions of impellers 16. The length to the braiding which can be produced with this method is proportional to the circumference and pitch of braiding 2 as well as to the length of the end of the wire or thread connected to the auxiliary thread. Subsequent braiding, the free ends are bundled or gathered, lopped off from the material supply and uncoupled from the auxiliary thread. The ball-shaped or bag-like hollow braiding 2 thus produced is closed at its leading end and bundled at its trailing end. The wire bundle is gathered such that an internal thread can be produced therein for engaging with the guide wire of a insertion instrument.

[0087] In the subsequent material-dependent molding and heat treatment process, the braiding 2 is brought into the form desired for occlusion device 1. The initial structure is suitable for manufacturing an occlusion device 1 for the treatment of a patent foramen ovale (PFO), ventricular septal defect (VSD), atrial septal defect (ASD) or persistent ductus arteriosus (PDA).

[0088] It is noted at this point that FIG. 10b, for example, shows a side sectional view of the right side of an inventive PFO-type occlusion device 1, whereby this PFO-occlusion device 1 is made from a spherical braiding 2 as described above. FIG. 10c moreover shows a side sectional view of the right side of an inventive ASD-type occlusion device 1, whereby this ASD-occlusion device 1 as well is made from a spherical braiding 2, the manufacture of which is described above. FIG. 11 furthermore shows another side view of an inventive PFO-type of occlusion device 1.

[0089] It is furthermore pointed out that FIG. 12 discloses a side sectional view of the right side of an inventive VSD-type occlusion device 1, whereby this VSD-occlusion device 1 is made from a ball-shaped, bulb-shaped or teardrop-shaped initial braiding 2 as described above. Finally, reference is made to FIGS. 13 and 14 which respectively depict sectional views of the right sides of occlusion devices 1 of the ASD and PDA types. The inventive occlusion devices shown in FIGS. 13 and 14 are in turn made from a ball-shaped, bulb-shaped or teardrop-shaped initial braiding structure in accordance with FIGS. 9a-9c, whereby said initial braiding is produced as described above.

[0090] From the perspective of holder 5 and depending upon configuration, an expanded diameter (i.e. distal retention area 8) is formed, followed by crosspiece 10, to which another expanded closed diameter (i.e. proximal retention area 6, proximal wall 112 respectively) is joined. Since circumstances dictate that braiding 2 serving as the base for the occlusion device 1 cannot as such always fully occlude a defect, fabric inserts can be introduced into crosspiece 10 and in the expanding diametersdistal and/or proximal retention areas 6, 8. These fabric inserts, preferably of Dacron, then close the gaps remaining in braiding 2 when occlusion device 1 is in its inserted state. Said fabric inserts can be secured for example by being stretched over the proximal opening like a cloth.

[0091] Reference is herewith again made to FIG. 6 which depicts the braiding head 11 of the round braiding machine 7 from FIG. 4 in greater detail, while FIG. 7 shows an example of a braiding 2 produced with the braiding head 11 shown in FIG. 6, which can serve as the starting structure for the occlusion device 1 according to the invention. Clearly to be seen here is that the braiding 2 serving as the base structure for occlusion device 1 is configured in the form of a tubular or bag-shaped braiding 2 closed to it top which only needs to be provided with one holder 5 at its end 3, while the threads or wires 4 on the opposite side 12 are, for example, intertwined from the center outward.

[0092] The closed braiding 2 can be shaped as a ball (cf. FIG. 9a), a bulb (cf. FIG. 9b) or also a teardrop (cf. FIG. 9c), whereby only one holder 5 having an internal thread for snugly connecting with an insertion catheter is provided at distal end 3.

[0093] The core but also highly specific occlusion device 1 can be manufactured from the ball shaped (FIG. 9a), bulb-shaped (FIG. 9b) or teardrop-shaped (FIG. 9c) initial braiding structure 2, as will be described below, whereby this inventive occlusion device 1 can be given substantially improved functional properties such as in particular the extreme flattened form to the proximal wall 112 and without any additional seams in proximal retention area 6, proximal wall 112 respectively.

[0094] Specifically, this is an occluder 1 for treating an atrial septal defect (ASD), which is a hole in the heart's atrial septum. FIG. 13 shows an example of such an ASD-occluder 1.

[0095] Occluder 1 can moreover be produced to treat a patent foramen ovale (PFO); i.e. for treating oval openings/apertures in the heart's atrial septum. FIG. 11 shows this type of inventive PFO-occluder.

[0096] It is moreover conceivable in accordance with the invention, to manufacture an occluder to treat persistent ductus arteriosus (PDA), meaning to treat an open channel between the aorta and the pulmonary artery. FIG. 14 depicts this type of PDA-occluder 1.

[0097] It is also pointed out in conclusion that, according to the invention, an occluder 1 for treating a ventricular septal defect (VSD) is also conceivable; i.e. for treating a hole in the heart's ventricular wall. FIG. 12 shows an example of such a VSD-occluder.

[0098] Attention is drawn to the fact that realizing the invention is not limited to the embodiments specified by the figures, but is instead feasible in a plurality of variants.