Abstract
The invention relates to a medical implant (1) that is adapted to repair or close defect (D), in particular an opening in a ventricular, atrial, or septal wall (W). The medical implant (1) may, in particular, be a patch. It comprises an adhesive composition (6). It further comprises two states, wherein in the first state, the medical implant (1) can be deployed to an implant site while the adhesive composition (6) is inactive. It can be brought into a second state by an activation mechanism. The adhesive composition (6), in the second state, is curable by a curing mechanism.
Claims
1.-74. (canceled)
75. A medical implant comprising an adhesive composition, the medical implant comprises two states, wherein the medical implant in its first state can be deployed to an implant site while the adhesive composition is inactive, and brought into the second state, by an activation mechanism, the adhesive composition, in said second state, is curable by a curing mechanism.
76. The medical implant according to claim 75, comprising a radiopaque element.
77. The medical implant according to claim 76, comprising a support structure.
78. The medical implant according to claim 76, wherein the radio-opaque element is arranged within or formed by the adhesive composition.
79. The medical implant according to claim 76, wherein the radio-opaque element comprises at least one of barium sulfate and iodine.
80. The medical implant according to claim 75, wherein the medical implant has a generally flat shape with a first and a second surface, wherein the first and the second surfaces have substantially opposite orientations, and wherein at least one property of the first surface is different from a corresponding property of the second surface.
81. The medical implant according to claim 80, wherein the first surface is adapted to enhance cell ingrowth.
82. The medical implant according to claim 80, wherein the second surface is adapted to provide adhesion to biological tissue.
83. The medical implant according to claim 75, wherein at least one surface of the implant, comprises a velour-like surface.
84. The medical implant according to claim 75, wherein the adhesive composition is arranged on the medical implant in a pattern.
85. The medical implant according to claim 75, wherein the adhesive composition comprises GelMA.
86. The medical implant according to claim 85, wherein the GelMA is of animal origin selected from Fish GelMA or porcine GelMA.
87. The medical implant according to claim 85, wherein the GelMA is formed by a mixture of at least two GelMAs of animal origin.
88. The medical implant according to claim 85, wherein the adhesive composition further comprises a photoinitiator.
89. The medical implant according to claim 85, wherein the GelMA is cross-linkable by X-ray radiation.
90. The medical implant according to claim 75, comprising at least retaining element for retaining a suture at an outer circumference of the implant, and a suture that is arranged within said loop.
91. The medical implant according to claim 75, wherein the adhesive composition comprises a dried adhesive composition.
92. A medical implant according to claim 91, wherein the dried adhesive composition is activatable by exposure to a liquid.
93. A method for deploying a medical implant that comprises an adhesive, comprising the steps deploying the medical implant to a first site in a first state, bringing the medical implant into a second state by means of an activation mechanism, where the adhesive is cured by means of a curing mechanism.
94. The method according to claim 93, comprising the step of increasing the temperature to bring the medical implant into the second state.
95. The method according to claim 94, wherein the temperature increase is at least partially provided by an external heat source.
96. The method according to claim 93, wherein the temperature increase is at least partially provided by a patient's body heat.
97. The method according to claim 93, wherein the temperature increase is at least partially provided by electromagnetic radiation.
98. The method according to claim 93, comprising the step of applying a pressure increase to bring the implant into the second state.
99. The method according to claim 98, wherein the pressure increase is at least partially caused by osmotic pressure.
100. The method according to claim 93, comprising the step of exposing the implant to humidity to bring it into the second state.
101. The method according to claim 93, comprising the step of spontaneous mixing of two components in the second state, which causes curing of the adhesive.
102. The method according to claim 93, comprising the step of exposing the implant to electromagnetic radiation in the second state, which causes curing of the adhesive.
103. The method according to claim 93, comprising the step of disposing a liquid to bring the medical implant into the second state.
104. The medical implant according to claim 75, comprising a biodegradable material that is adapted to lose its mechanical strength in a human body within six to 36 months.
105. The medical implant according to any claim 75, comprising a spine structure.
106. A method of producing a medical implant, wherein an adhesive composition is at least partially liquid and is arranged on at least one surface of the medical implant, further comprising a step of drying the adhesive composition.
107. A method of producing a medical implant, comprising the steps of arranging at least one extension element at an outer circumference of the medical implant, configure the at least one extension element to form a retaining element, bonding an end of the extension element such as to fix the extension element it a configuration comprising a retaining element.
Description
[0171] In the following, the invention is described in detail with reference to the following figures, showing:
[0172] FIG. 1a-1b: an embodiment of a medical implant.
[0173] FIG. 2: an embodiment of a medical implant implanted into a patient.
[0174] FIG. 3: an embodiment of a delivery device with a medical implant.
[0175] FIG. 4: an embodiment of a delivery device after release of a medical implant.
[0176] FIG. 5a-5c: an embodiment of a medical implant and schematically a release mechanism.
[0177] FIG. 6: an embodiment of a medical implant.
[0178] FIG. 7: an embodiment of a medical implant with a delivery device.
[0179] FIG. 8: an embodiment of a delivery device.
[0180] FIG. 9a-9d: different embodiments of a medical implant.
[0181] FIG. 10a-10b: an embodiment of a medical implant.
[0182] FIG. 11a-11b: an embodiment of a medical implant.
[0183] FIG. 12: an embodiment of a medical implant and schematically a release mechanism.
[0184] FIG. 13: an embodiment of a medical implant and schematically a release mechanism.
[0185] FIG. 14: an embodiment of a medical implant and schematically a release mechanism.
[0186] FIG. 15a-15c: schematically different embodiments of adhesive delivery.
[0187] FIG. 16a-16b: an embodiment of a medical implant.
[0188] FIG. 17: an embodiment of a medical implant implanted into a patient.
[0189] FIG. 18a-18b: a patch with capsules containing a filler material.
[0190] FIG. 19a-19b: patches with different first and second surfaces in a side view.
[0191] FIG. 20a-20b: patches with a patterned adhesive layer in a top view.
[0192] FIG. 21a-21c: patches with different embodiments of radio-opaque markers.
[0193] FIG. 22: a patch with a discrete marker.
[0194] FIG. 23a-23b: a patch with a dried adhesive before and after activation.
[0195] FIG. 24a-24b: two embodiments of a handle of a delivery device with a gauge.
[0196] FIG. 25: a patch with an adhesive having a three-dimensional pattern.
[0197] FIG. 26a-26d: schematically a method of patterning an adhesive layer on a patch.
[0198] FIG. 27a-27d: schematically a method of producing a patch with a retaining element.
[0199] FIG. 28a-28b: schematically an embodiment of a backbone for a medical implant.
[0200] FIG. 29: a medical implant with a retaining element being attached to a retention element and
[0201] FIG. 30 schematically an implant attached to a tissue wall.
[0202] FIGS. 1a and 1b show an embodiment of a medical implant 1 according to the invention. The implant comprises a fabric patch 5 with a tear line 3. The fabric is a woven fabric of biocompatible fibers made of polyglycolic acid and is coated with a bioadhesive. Additionally or alternatively, the fibers may be made of another polymer such as PET.
[0203] FIG. 1a shows the medical implant 1 in a side view. Very well visible in the perspective is the silicone layer 2 that is only arranged on one side of the implant 1. This prevents adhesion between the medical implant and the tissue of the patient in the area that does not remain in the patient. Also visible in this perspective is the thickness T of the implant, which is 150 μm.
[0204] FIG. 1b shows a front view of the medical implant 1. The fabric is mechanically flexible and can adapt to the anatomy of the patient and the surface structure of the tissue at the implant site. The tear line 3 comprises a plurality of laser-cut parts along the circumference of the patch 5 that together form a circular pre-determined breaking line. The tear line is adapted to break upon radial stretch of the patch 5 and does not have any free fibers after tearing. Between the outer edge OC of the medical implant 1 and the tear line 3 is a layer silicone 2 as a non-adhesive material. The patch 5 further comprises a cross-shaped cut 4 in the in its center that is adapted such that a delivery device (not shown) can partially extend through it. The patch is adapted to degrade in the human body within six months. The woven structure facilitates tissue growth such that by the time the implant is degraded, it has been replaced with tissue. The implant has a diameter of 25 mm including the rim on the outer edge OC, and the patch has a diameter of 20 mm after tearing along the tear line 3.
[0205] FIG. 2 shows a medical implant 1 in the form of a patch 5 at an implant site. The implant site is a defect D in an atrial wall W of a patient's heart. Here, the medical implant 1 is shown during the implantation process. A delivery device C comprising a positioning device P partially extends through the patch 5 and cut in its center (not visible). The patch is coated with an adhesive composition 6, in this case GelMA. Alternatively, glutaraldehyde may be employed. This provides an effective attachment of the patch 5 to the atrial wall W.
[0206] FIG. 3 shows a similar medical implant 1 as shown in FIG. 2. Here, the implant is shown during the implantation process, but before detachment from the delivery device (not shown) comprising a balloon B. The medical implant comprises a patch 5 made of a knitted fabric that is attached to a balloon B by means of adhesive rims 7 one the balloon-side of the medical implant 1 and in between the outer edge OC of the medical implant 1 and its tear line. On the other side, the implant 1 is coated with an adhesive composition 6 within the area surround by the tear line 3. In between the tear line 3 and the outer edge OC, on the opposite site of the adhesive rims 7, is a PTFE coating that prevents wetting of the adhesive and thus adhesion. In the illustration shown here, the balloon B is partially inflated.
[0207] As shown in FIG. 4, further inflation applies a force F on the patch (not shown for clarity) and the tear lines 3 due to the extension, in a direction orthogonal to the longitudinal axis L of the delivery device, of the outer rims 8 of the medical implant that are attached to the balloon B through the adhesive rims 7. Thus, further inflation ruptures the tear line 3 and releases the patch 5. Here, the delivery device C is shown and is adapted to expose the patch to electromagnetic irradiation E.
[0208] FIGS. 5a-5c show schematically a medical implant 1 and a release mechanism for a medical implant 1. Here, the medical implant comprises a patch of spun fibers of polylactic acid. However, the person skilled in the art will of course understand that the release mechanism could be combined with any patch material or even any sort of medical implant. The implant 1 comprises beads 9 made of a polymeric material. Here, the beads are made of a biodegradable polymeric material that is adapted to degrade in the human body within typically two weeks. Of course, they could also be adapted to degrade faster or slower. They are attached to the edge OC of the medical implant 1.
[0209] FIG. 5a shows the medical implant 1 from the side. It is particularly well visible in this illustration that the beads 9 have a diameter that is larger than the thickness of the medical implant. Here, the beads 9 have a slightly elongated shape, but it would be possible to arrange spherical beads as well.
[0210] In FIG. 5b, the medical implant 1 is shown from a top perspective. It is well visible that the beads are considerably smaller than the medical implant. Typically, they have a diameter of 300 μm, but could also be up to 1 mm in diameter. Here, the implant 1 comprises four beads that are spaced equally around the circumference of the medical implant 1. It would of course be conceivable to arrange a higher or lower number of beads on the medical implant, and/or to space them unequally.
[0211] FIG. 5c shows schematically how an implant 1 as shown in FIGS. 5a and 5b can be released. The delivery device comprises at least one tube 10, typically one tube 10 per bead 9 attached to the medical implant 1. In said tube 10 a wire 11 with a lower holder 12a and an upper holder 12b. The holders 12a, 12b are adapted such that a bead 9 that is located between them in the tube 10 cannot pass the holders along the longitudinal direction of the tube. Thus, for implantation, the bead 9 is arranged in the tube 10 in between the upper holder 12b and the lower holder 12a. This enables the release mechanism shown in the illustration wherein the wire 11 is actuated such that the upper holder 12b is released from the tube 10. This clears the way for the bead 9 to also leave the tube 10, thus releasing the implant 1.
[0212] FIG. 6 shows another embodiment of a medical implant 1 and schematically a release mechanism. Here, the medical implant 1 comprises a patch 5 made of a biodegradable fabric. The fabric comprises fibers that are coated with an adhesive composition (not shown). The implant 1 comprises four extensions 13 that extend away from the implant 1. Each extension 13 is separated from the implant 1 by a tear line. Here, the extensions are made of the same material as the patch 5. This is particularly simple, but of course it would be possible to include other materials as well. The tear lines are arranged such that upon tearing of the tear lines, the patch 5 is substantially spherical and has a diameter of 20 mm.
[0213] FIG. 7 shows another embodiment of a medical implant 1. Here, a balloon B is attached to a delivery device (C). The balloon is made of implant-grade material, here from polyurethane. The balloon is coated with an adhesive composition 6 on a distal side. It further comprises a tear line 3 that is substantially circular and arranged in a plane that is substantially perpendicular to the longitudinal axis L of the delivery device C. Here, the tear line is formed as thinner wall part of the balloon B that creates a pre-determined breaking point. However, it is still sealed to allow for inflation of the balloon B. Inflation of the balloon B creates a mechanical stress in the balloon wall in a tangential direction. Due to the pre-determined breaking point, the balloon rupture along the tear line 3. The patch formed by the rupture adheres to the tissue by means of the adhesive composition 6. Thus, the medical implant was part of the balloon B during delivery.
[0214] FIG. 8 shows another embodiment of a delivery device C. Here, the delivery device C comprises a balloon B as described in other embodiments that can serve to deliver the medical implant 1. Of course, any medical implant 1 described herein can be combined with such a delivery device shown here. Here, the medical implant consists of a fabric patch with adhesive fibers. The delivery device comprises a second balloon 14 that forms an outer layer around the balloon B and the medical implant 1. It thus protects the patch and the adhesive from being in contact with tissue. Here, the outer balloon 14 comprises an opening 30 arranged approximately at the center of the medical implant 1. This provides an advantageous way to implant the medical implant 1, but is optional. This allows for a preliminary attachment to the tissue. For deployment, the outer balloon is retracted in a direction away from the implant 1 along the longitudinal axis L of the delivery device. This exposes the implant 1 to tissue and enables the adhesive composition to attach to the tissue.
[0215] FIGS. 9a-9d show different embodiments of fabric patches that are cut out from a fabric scaffold. Thus, the extensions 13 shown here consist of the same material as the patch 5. Throughout the FIGS. 9a-9d, only one reference sign is shown for certain identical features for clarity. The extensions 13 shown in these embodiments have a typical length of 15 mm and a width of 3.5 mm. Of course these values can be adapted to reach a particular mechanical strength or to adapt the patch to a particular delivery device.
[0216] FIG. 9a shows a patch with eight extensions 13 made from PET fabric 15. The extensions 13 are separated from the patch 5 by tear line 3 each. PET is a non-absorbable material. The shown embodiment is thus particularly advantageous if the replacement of the implant with tissue is not possible or undesired, for example due to insufficient stability of the newly formed tissue.
[0217] FIG. 9b shows an embodiment of a patch 5 with only two extensions 13. The fabric 15 consists of knitted poly(L-lactic acid) (PLLA). PLLA absorbs in in the human body within two years. Thus, the shown embodiment is particularly advantageous if cell-ingrowth is slow or support by the patch 5 for one to two years is desired.
[0218] FIG. 9c shows an embodiment of a patch 5 that is cut from a fabric 15 made of electrospun polycaprolactone (PCL). It comprises six extensions 13, each separated from the patch 5 by a tear line 3. PCL is particularly advantageous for electrospinning and thus provides an easy way to manufacture the fabric 15. It degrades in the human body within about six months and is thus the material of choice if relatively fast degradation is required or desired.
[0219] FIG. 9d shows another embodiment of a patch that made of the same electrospun PCL fabric 15 as shown in FIG. 9c. The patch 5 has a circular shape and a continuous circularly shaped tear line 3 around its circumference that forms an outer rim 8.
[0220] FIGS. 10a and 10b show another embodiment of a medical implant 1 in a cross-sectional view (FIG. 10a) and in a top view (FIG. 10b). For clarity, only one reference sign is shown for identical features. The medical implant 1 comprises an electrospun patch wherein the fibers are functionalized and have directionality. The implant 1 comprises a reservoir 16 that can be filled with an adhesive composition. A region 18 of the patch 5 can be functionalized such as to have a lower permeability. Here, this prevents an adhesive disposed in the reservoir 16 from permeating through the patch and be released this side of the medical implant. Instead, the shown embodiment comprises microchannels 17 integrated by selective laser welding. These microchannels 17 are in fluid connection with the outer surface of the medical implant 1 and the reservoir 17. The adhesive can thus be released in a directional manner by means of the microchannels.
[0221] FIGS. 11a and 11b show an embodiment of a spine structure 31. FIG. 11a shows a spine structure 31 by itself. The shown spine structure is made of a polymer, similar or different from the patch. It comprises three elongated structures 19, 20. This is typically the most advantageous arrangement in that it provides sufficient mechanical stability to the implant. However, it would also be possible to adapt a spine structure with several additional elongated structures, or with only one or two of them, if necessary. The elongated structures comprise an inner part 20 and tear arms 19 that a separated by a predetermined breaking point 33. The elasticity of the tear arms is generally lower than that of the inner part. The inner part 20 is designed to be arranged in an area close to a medical implant 1 and remain in the patient upon implantation. Thus, the length of one arm of the inner part 20 is approximately half a diameter of the implant, typically around 10 mm. Of course, the size of the spine structure 31 as a whole and of the inner part 20 can be adapted to a specific implant and thus be larger or smaller. The inner part gives the implant mechanical stability during delivery and implantation, and also provides additional support after implantation. The spine structure 31 further comprises a round-shaped hole 32 in the middle of structure 31. This enables a delivery device and/or positioning device (both not shown) to extend through the spine structure 31 and be retracted through it again. Furthermore, the less elastic tear arms 19 are can be attached to a delivery device. Breaking at the predetermined breaking point allows for the release of the implant 1. A spine structure 31 as shown here provides a particularly advantageous way of decoupling the force needed to release the patch from the mechanical properties of the medical implant 1.
[0222] FIG. 11b shows a spine structure with the same features as shown in FIG. 11a but in combination with a medical implant 1.
[0223] FIG. 12 shows a delivery device C for a medical implant 1 and schematically a release mechanism. The delivery device C comprises an inflatable or expandable structure, such as a balloon B and outer struts 21 to hold and release the medical implant 1. Here, the medical implant comprises suture with notches 22 that are held by the outer struts 21. The mechanism of holding and releasing the notches substantially corresponds the ball release schematically shown FIG. 5c, wherein the notches 22 have the technical effect of the balls shown in FIG. 5c. The balloon B can thus be used to exert a pressure on the medical implant, but is not necessary to release the implant 1 from the delivery device C.
[0224] FIG. 13 shows a similar delivery device C as shown in FIG. 12. However, the outer struts 21 here are connected to the medical implant 1 through sutures 23. The sutures are fixedly connected to the outer struts 21 that do not comprise a mechanism to release the sutures 23. Instead, the balloon B, when inflated, pushes the outer struts 21 away from the medical implant, thus rupturing the connection and releasing the implant 1.
[0225] FIG. 14 shows schematically a delivery device C with a medical implant 1 similar to the one shown in FIG. 6. The implant 1 comprises elongated flaps 3 that are connected to the implant 1 through tear lines 3. The shown embodiment of the implant 1 has four such flaps 13, but could also be adapted to have smaller or larger number of flaps. The delivery device comprises a balloon B. Upon inflation, the balloon exerts a force on the tear lines 3, causing them to rupture and release the implant. The flaps 13 can then be retracted together with the delivery device C, while the medical implant 1 remains in the patient. Although not shown here, the embodiment illustrated is well suited to be combined with spine structure as shown in FIGS. 11a and 11b.
[0226] FIGS. 15a-15c show schematically different embodiments of patches 5 comprising an adhesive composition.
[0227] FIG. 15a shows a patch 5 comprising two different types of cavities 24a, 24b. The cavities 24a, 24b are spherical and have a diameter of approximately 1 mm. The patch has a diameter of 20 mm and consists of poly(lactic acid-co-glycolic acid). Other absorbable materials such as PLA-GA, PLGA, PCL, PU could also be used. Alternatively, non-absorbable materials such as PET, PE, and/or PP may be used. The cavities 24a, 24b contain two different components, a resin and a hardener, of an adhesive composition. The resin and the hardener are physically separated from one another and become curable upon mixing. Thus, the adhesive composition is not curable in the shown state where the two components are separated. However, cavities 24a, 24b in the shown embodiment are adapted to burst upon application of a mechanical pressure, for example exerted by an inflatable balloon. The burst of the cavities causes the release of both components of the adhesive composition, rendering it curable. Typical adhesives might be GelMA (Metacrylated Gelatin), CollMA (methacrylated Collagen) or MeTro (methacrylated Tropoelastin).
[0228] FIG. 15b shows a patch that comprises a foam 25. The pores 35 of the foam are surrounded by walls 34 made of a hydrogel. The hydrogel is adapted to degrade in the human body within 24 months. The pores 35 are filled with an adhesive composition. The patch is adapted to release the adhesive composition from the pores 35 upon a mechanical deformation. The adhesive composition here is curable by exposure to electromagnetic radiation. It will be understood by the person skilled in the art that any adhesive composition could be combined with the shown patch, in particular any curing mechanism. The pores 35 are adapted in their size to facilitate cell in-growth such that after release of the adhesive composition, the empty pores can serve as a scaffold for tissue growth. The biodegradation of the patch 5 is adapted such that the patch degrades after the formation of new tissue.
[0229] FIG. 15c shows yet another embodiment of a patch 5. The shown patch is made of electrospun fibers 26 of polycaprolactone. The fibers have a diameter of approximately 3 μm and a length of several 100 μm. The fibers are coated with methacrylated gelatin as an adhesive composition. This patch can thus easily be attached to tissue and is particularly easy to fabricate by electrospinning. It will of course be understood by the person skilled in the art that the fibers could also consist of an adhesive composition instead of being coated by it. Similarly, although polycaprolactone is particularly advantageous for electrospinning, the fibers could be made of another material.
[0230] FIGS. 16a-16b show an embodiment of medical implant 1 in a lateral cross-section. The implant 1 comprises an inflation reservoir 27, a patch 5 and a separate layer 28 comprising reservoirs 16 for containing an adhesive. The shown embodiment is similar to the medical implant shown in FIGS. 10a and 10b.
[0231] FIG. 16a shows the medical implant 1 in a first state. The inflation reservoir is empty. The reservoirs 16 for comprising an adhesive are filled with adhesive. Typically the adhesive can be a poly(acrylic) acid which uses an acrylate/methacrylate/amuse crosslinker.
[0232] The patch 5 is made of electrospun fibers of Dacron and is not biodegradable. However, it would of course be possible to adapt the patch 5 to be biodegradable as well. The layer 28 comprising the reservoirs 16 for the adhesive is of solid Dacron.
[0233] FIG. 16b shows the medical implant 1 in a second state wherein the inflation reservoir 27 is inflated. The inflation of the inflation reservoir 27 applies a mechanical pressure to the reservoirs 16 containing the adhesive which is subsequently squeezed out, forming a layer of adhesive 6 on one side of the implant 1. Here, the patch 5 is adapted to not be penetrable by the adhesive composition, thus leading to a selective release of the adhesive composition on the other side of the implant. The inflation reservoir is adapted to be removed after inflation. However, it would also be conceivable to form it from an implant grade material that remains in the patient.
[0234] FIG. 17 shows another embodiment of the medical implant according to the invention in an implanted state closing a defect D in a heart wall W. The implant 1 comprises a support structure 29 that extends around a circumference of the defect D. The support structure is made of a shape memory polymer that provides self-expanding at the implant site. Upon expansion, it is engaged in the defect D. Two patches 5 are attached to the support structure 29. The patches in the shown embodiment comprise electrospun Dacron fibers coated with a methacrylated collagen that swells upon exposure to humidity in the body. However, any patches as described herein can be used, of course.
[0235] It will of course be understood by the person skilled in the art that the embodiments described herein are examples are not restrictive to the scope of the invention. In particular, the different features described herein may be freely combined with other features and/or used without certain features.
[0236] FIGS. 18a and 18b show an embodiment of a patch 5 comprising capsules 36 with a filler material 37 in the capsule wall 38.
[0237] FIG. 18a shows the patch in a first state. The capsules 36 are spherically shaped and have a diameter of approximately 0.5-2 mm and are evenly distributed in the patch 5. An adhesive composition 6 comprising methacryloyl-substituted tropoelastin is contained in the inside of the capsules 36. Here, the capsules 36 are adapted to break open due to an osmotic pressure. For example, exposure to blood or another liquid causes swelling of the capsules 36. The resulting pressure increase then causes bursting of the capsules 36.
[0238] FIG. 18b shows the patch 5 in a second state after rupture of the capsules 36. The adhesive composition 6 is evenly distributed over the surface of the patch 5. The filler material 37 remains in the adhesive composition 6 and provides additional mechanical strengths to the adhesive layer.
[0239] FIG. 19a shows a patch 1 in a side view. The patch 1 has a first surface 101′ and a second surface 102. The first surface 101′ is configured as a velour-like surface having shorts strands of fabric 101″ extending away from the first surface 101′. The second surface 102 comprises an adhesive layer. The medical implant 1 is made of a polyurethane, and the velour-like surface 101′ comprises polyurethane fibers. In the shown configuration, the velour-like surface 101′ enhances cell ingrowth and thus tissue overgrowth, while the second surface 102 provides adhesion to tissue.
[0240] FIG. 19b shows a similar embodiment as shown in FIG. 19a. The medical implant 1 comprises a first surface 103′ and a second surface 103″. The first surface 103′ has a lower permeability for an adhesive composition (not shown) than the first surface 103′. In the present case, this is achieved by a thicker layer of porous material. The implant comprises the adhesive composition and can release it by means of a sponge-like mechanism when mechanical pressure is applied. The adhesive composition preferentially permeates the second surface 103″ and thus, the second surface 103″ provides more adhesion as compared to the first surface 103′, when activated.
[0241] FIG. 20a shows a patch 1 with an adhesive layer 104 that has a patterned structure. The pattern is configured as five sectors of a circular shape that forms the patch 1. Consequently, there are four intermediate sectors 105 that do not comprise an adhesive layer. The adhesive layer 104 was printed via inkjet printing and is based on a mixture of porcine and fish GelMA. Alternatively, extrusion printing may also be employed. Presently, the pattern is two-dimensional. The adhesive layer is thus substantially flat and the sectors 104,105 of the patch 1 differ in whether or not they have an adhesive layer, but not in the thickness of said adhesive layer.
[0242] FIG. 20b shows a medical implant similar to the one shown in FIG. 20a. The patch 1 comprises an inkjet-printed pattern of adhesive 104. The adhesive pattern is two-dimensional and is arranged substantially at the circumference of the patch 1. The adhesive pattern comprises several curved lines.
[0243] It will be understood that any particular pattern of adhesive may be arranged on a patch, in particular if the adhesive is inkjet printed. Alternatively, extrusion printing may also be employed.
[0244] FIG. 21a shows an embodiment of a patch 1 with a radio-opaque element 106. The radio-opaque element 106 consists of four beads comprising barium sulphate arranged at a circumferential area of the patch 1 and spread substantially equally along in the direction of the circumference of the patch 1.
[0245] FIG. 21b shows an alternative embodiment of a patch 1 having a radio-opaque element 107. The radio-opaque element 107 consists of a cross-shaped metallic spine structure.
[0246] FIG. 21c shows an alternative embodiment of a radio-opaque element 108,109 on a patch 1. A spine structure 108 made of a polyurethane comprises small capsules 109 filled with iodine. The iodine provides radio opacity.
[0247] FIG. 22 shows a patch 1 with a discrete marker 110. The discrete marker 110 is configured as a spring-like element. The discrete element 110 consists of titanium and is thus also radio-opaque and echo-opaque. However, it would be possible to alternatively configure the discrete marker 110 to not be radio-opaque and/or echo-opaque. The discrete marker is deformable by pressure and thus provides information on the pressure acting on the patch 1 at its location. Presently, the pressure can be read by measuring the extension of the marker 110 along a longitudinal axis (perpendicular to the surface of the patch 1), for example via radiography.
[0248] FIG. 23a shows a medical implant 1 with a dried adhesive 111′. The dried adhesive comprises fibers 112 of porcine GelMA spun from an aqueous solution and then dried. Any gelatin may also be employed as in addition or as an alternative to porcine GelMA.
[0249] FIG. 23b shows the medical implant 1 of FIG. 23a after exposure to an aqueous liquid. The adhesive composition 111″ is swollen from water incorporation and the fibers 112″ are thus larger in diameter as compared to the dried fibers 111′,112′. In the swollen state, the fibers 112″ exhibit an adhesive force to human tissue.
[0250] FIG. 24a shows a handle 113 for a delivery device. The handle 113 comprises a digital gauge 114′ that is adapted to show a numerical value representing an adhesive force between an implant as shown herein and human tissue (not shown) to which it is attacked. The gauge 114′ is attached to the implant at a distal end and measures the adhesive force.
[0251] FIG. 24b shows an alternative embodiment of a handle 113. An analog gauge 114″ provides a qualitative measure (for example high, medium, low) of an adhesive force between an implant as shown herein and human tissue (not shown) to which it is attached.
[0252] It will be understood that a digital gauge may also be used to show a qualitative measure and/or an analog gauge may be used to show a numerical value.
[0253] FIG. 25 shows an embodiment of a medical implant 1 with a three-dimensionally patterned adhesive 115. The adhesive is formed as pyramids 116 evenly spaced over one surface of the implant. The medical implant is configured as a patch made of pericardium. The adhesive 115 consists of pyramids 116 of fish GelMA.
[0254] FIGS. 26a-26d schematically show a method of patterning an adhesive composition on a medical implant 1.
[0255] FIG. 26a shows a medical implant 1 made of polyurethane with a smooth, homogeneous layer 117′ of adhesive. The adhesive is based on bovine GelMA.
[0256] FIG. 26b shows a stamp-like element 118. The stamp-like element has a shape representing a negative of the desired adhesive pattern on the medical implant 1. The stamp-like element 118 is made of a metallic material with a PTFE coating. Thus, the stamp-like element 118 does not adhere to the adhesive layer 117′ and can be removed easily from the adhesive bearing surface.
[0257] FIG. 26c shows the stamp-like element 118 being pressed on the adhesive layer 117′ of the medical implant 1. The stamp-like element 118 pushes the adhesive laterally away.
[0258] FIG. 26d shows the medical implant 1 after removal of the stamp-like element. The adhesive layer 117″ has a pattern that substantially corresponds to a negative shape of the stamp-like element. The medical implant 1 hence comprises areas 119 that are not covered by an adhesive layer. The aggregate of the area 119 substantially corresponds to the shape of the stamp-like element.
[0259] Any of the implants and adhesives disclosed herein are suitable to be patterned with the method shown in FIGS. 26a-26d. It would also be possible to pattern a three-dimensional pattern using the method of FIGS. 26a-26b.
[0260] FIGS. 27a-27d schematically show a method to produce a medical implant 1 comprising a retaining element for holding suture(s).
[0261] FIG. 27a shows a first step of the method. The medical implant 1 is arranged with three radially extending flaps 120. In the present case, the extending flaps 120 are made of polyurethane and separately attached to a patch 121 made of pericardium. One of the three extending flaps 120 comprises an indentation 122 that functions as a pre-determined breaking point to reduce the necessary force to break the extending flap and/or to control where breaking occurs. It would alternatively be possible to have any number of extending flaps 120 with or without indentation.
[0262] FIG. 27b shows the medical implant 1 of FIG. 27a, wherein the extending flaps have been folded towards the center of the medical implant 1. After folding, the medical implant 1 has a substantially round shape. Around an area of the fold 123 a passage is formed (not visible, see FIG. 27c).
[0263] FIG. 27c shows a cross-section of the medical implant 1 of FIG. 27b along the plane M. In the area of the fold 123, a passage 124 is formed that can be used, for example, to hold a suture (not shown).
[0264] FIG. 27d shows schematically an embodiment of a medical implant 1 as shown in FIGS. 27a-27c. The implant 1 is held at the fold 123 in the passage 124 by sutures 125. Pulling of the sutures 125 releases the implant 1 by tearing the extending flaps 120 at the area of the fold 123.
[0265] FIG. 28a shows an embodiment of a spine structure 31 made of a polyurethane. The spine structure 31 in generally suitable to be combined with any of the disclosed medical implants. The spine structure 31 comprises three arms 126. Each arm has a thickness of 2 mm and further comprises an indentation 127, where the arm 126 has a reduced thickness of 1 mm. The indentation 127 is placed at a distance of 10 mm from the center 128 of the spine structure 31. Thus, when arranged on a medical implant, the indentation is typically located at the circumference of the implant. The spine structure is also configured to extend beyond the circumference of an implant in this case, and is therefore particularly suited to produce an implant as shown in FIGS. 27a-27c.
[0266] FIG. 28b shows a cross-section of a spine structure similar to the one shown in FIG. 28a. The arm 126 is folded around the indentation 127. In the shown embodiment, the spine structure 31 is attached to a medical implant 1 configured as a fabric patch.
[0267] The arm 126 was bonded onto the fabric of the implant 1 by heat bonding wherein the polyurethane was partially molten and diffused into the fabric, thus providing adhesion. The folded arm 126 forms a passage 124 through which a suture is passed. The folded arm 126 thus forms a retaining element and is held by a suture 125. The suture is adapted in its mechanical strength (i.e. thickness and material choice) such that pulling of the suture may tear the arm 126 of the spine structure 31 at the indentation 127. The implant further comprises a radio-opaque element 106, configured as a platinum particle, held on the implant 1 by the folded arm 126. As an alternative to platinum, iridium is also suited as a material for a radio-opaque marker. Additionally or alternatively, the spine structure 31 could be made from a polymer filled with radiopaque agents, such as BaSO4.
[0268] FIG. 29 shows an implant 1 according to the invention. The implant 1 is similar to the one shown in FIG. 27d. The implant comprises extending arms 120 cut from the same base sheet material as the body of the implant 1. The arms 120 were folded onto the patch 1, thus leaving a small passage 124 at a circumferential area of the patch 1 to allow a suture 125 to pass through. The sutures 125 can be mounted to a delivery system via retention elements 129. Any delivery system as shown in FIGS. 12-14 is suitable to be combined with the retention elements 129. Pulling the sutures backwards causes the sutures 129 to cut through the polymeric sheet and thus releases the implant 1. The required force for the cut can be controlled/adjusted by cutting small indentations into the arm 120, as shown in FIG. 27a. The implant further comprises a hole in a center region 128 that enables additional holding with a delivery instrument, for example for easier centering of the implant 1 at an implantation site.
[0269] FIG. 30 shows schematically an implant 1 attached to a tissue wall W such as to close a defect D. The implant 1 is attached to the tissue wall W by means of two rivets 130. The rivets consist of a biodegradable material and degrade in a human body within a year. Thus, the rivets 130 provide temporary attachment while until, for example, a sufficient adhesive force has formed and/or tissue has formed on the implant 1.
