LAYERED BRAIDED ANEURYSM TREATMENT DEVICE WITH CORRUGATIONS
An implant including an open end and a pinched end can have a predetermined shape. When in the predetermined shape, the tubular braid can include a proximal inversion and two segments, and the braid can be composed of one or more wires. The first segment can extend from the open end of the tubular braid to the proximal inversion. The second segment can be at least partially surrounded by the open end and extend from the proximal inversion to the pinched end. The tubular braid can also include at least one corrugated fold. The one or more corrugated folds can be located within the first segment, second segment, or both. The corrugated folds can be configured to assist in anchoring the example device when in the implanted shape within an aneurysm in a similar manner to stent struts to help the tubular braid hold its shape.
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The present application is divisional of U.S. Pat. Application No. 16/865,116 filed May 1, 2020, which is a continuation-in-part of U.S. Pat. Application No. 16/748,877 filed Jan. 22, 2020, now U.S. Pat. No. 11,413,046, which is a continuation-in-part of U.S. Pat. Application No. 16/418,199 filed May 21, 2019, now U.S. Pat. No. 10,653,425.
U.S. Pat. Application No. 16/865,116 filed May 1, 2020, is also a continuation-in-part of U.S. Pat. Application No. 16/853,135 filed Apr. 20, 2020, now U.S. Pat. No. 11,497,504.
The contents of all of which are incorporated herein by reference in their entirety as if set forth herein.
FIELD OF INVENTIONThe present invention generally relates to medical instruments, and more particularly, to embolic implants for aneurysm therapy.
BACKGROUNDCranial aneurysms can be complicated and difficult to treat due to their proximity to critical brain tissues. Prior solutions have included endovascular treatment whereby an internal volume of the aneurysm sac is removed or excluded from arterial blood pressure and flow. Current alternatives to endovascular or other surgical approaches can include intravascularly delivered treatment devices that fill the sac of the aneurysm with embolic material or block the entrance or neck of the aneurysm. Both approaches attempt to prevent blood flow into the aneurysm. When filling an aneurysm sac, the embolic material clots the blood, creating a thrombotic mass within the aneurysm. When treating the aneurysm neck, blood flow into the entrance of the aneurysm is inhibited, inducing venous stasis in the aneurysm and facilitating a natural formation of a thrombotic mass within the aneurysm.
Current intravascularly delivered devices typically utilize multiple embolic coils to either fill the sac or treat the entrance of the aneurysm. Naturally formed thrombotic masses formed by treating the entrance with embolic coils can result in improved healing compared to aneurysm masses packed with embolic coils because naturally formed thrombotic masses can reduce the likelihood of distention from arterial walls and facilitate reintegration into the original parent vessel shape along the neck plane. However, embolic coils delivered to the neck of the aneurysm can potentially have the adverse effect of impeding the flow of blood in the adjoining blood vessel, particularly if the entrance is overpacked. Conversely, if the entrance is insufficiently packed, blood flow can persist into the aneurysm. Treating certain aneurysm morphology (e.g. wide neck, bifurcation, etc.) can require ancillary devices such a stents or balloons to support the coil mass and obtain the desired packing density. Once implanted, the coils cannot easily be retracted or repositioned. Furthermore, embolic coils do not always effectively treat aneurysms as aneurysms treated with multiple coils often recanalize or compact because of poor coiling, lack of coverage across the aneurysm neck, blood flow, or large aneurysm size.
Alternatives to embolic coils are being explored, for example a tubular braided implant is disclosed in US Pat. Publication No. 2018/0242979, incorporated herein by reference. Tubular braided implants have the potential to easily, accurately, and safely treat an aneurysm or other arterio-venous malformation in a parent vessel without blocking flow into perforator vessels communicating with the parent vessel. Compared to embolic coils, however, tubular braided implants are a newer technology, and there is therefore capacity for improved geometries, configurations, delivery systems, etc. for the tubular braided implants. For instance, delivery of tubular braided implants can require unique delivery systems to prevent the braid from inverting or abrading when pushed through a microcatheter, and some simple delivery systems that push embolic coils through microcatheters from their proximal end may not be effective to deliver tubular braids.
There is therefore a need for improved methods, devices, and systems for implants for aneurysm treatment.
SUMMARYIt is an object of the present invention to provide systems, devices, and methods to meet the above-stated needs. Generally, it is an object of the present invention to provide a braided implant that can secure within an aneurysm sac and occlude a majority of the aneurysm’s neck. The implant can include a tubular braid that can be set into a predetermined shape, compressed for delivery through a microcatheter, and implanted in at least one implanted position that is based on the predetermined shape and the geometry of the aneurysm in which the braid is implanted. The tubular braid can include a single layer of braided material, or two or more layers of braided material constricted together at a pinched end. The tubular braid can also include one or more corrugated folds. The wire of the braid along the corrugated folds can be flatter relative to the wire in other portions of the braid.
In some examples presented herein, when compressed, the implant can be sufficiently short to mitigate friction forces produced when the implant is delivered unsheathed through the microcatheter allowing for a more simplistic delivery system compared to some other known braided embolic implant delivery systems.
In some examples presented herein, when the implant is implanted, a majority of the aneurysm sac can be free from embolic material to facilitate the formation of a thrombotic mass that is primarily naturally formed. Percentage of volume of the aneurysm sac filled with embolic material can be controlled by adding more layers of braided material that are constricted together at the pinched end. Additional layers of braided material can also serve to provide a denser barrier to occlude blood flow into the aneurysm neck.
In some examples presented herein, the tubular braid can be implanted in two distinct implanted shapes, depending on the size of the aneurysm, allowing for treatment of a wider range of aneurysm sizes compared to some other known braided embolic implants.
In some examples presented herein, when implanted, the tubular braid can have a compaction resistant column extending across a majority of the height of the aneurysm and positioned centrally within the aneurysm sac.
An example implant can include two layers (layer A and layer B) of tubular braid constricted together at a pinched end. The two layers can each have a predetermined shape in which each of the two layers respectively has a first and second inversion and a first, second, and third segment. The third segment extends from the pinched end to the second inversion. The second segment extends from the second inversion to the first inversion and at least partially surrounds the third segment. The first segment extends from the first inversion and at least partially surrounds the second segment.
For each of the two layers, the first segment can only partially surround the second segment.
One of the two braid layers can lack any radiopaque wire. The other of the two braid layers can include a radiopaque wire.
The two layers of tubular braid can be stable in a first implanted shape based on the predetermined shape when constrained by a first substantially spherical cavity. The two layers of tubular braid can be stable in a second implanted shape based on the predetermined shape when constrained by a second substantially spherical cavity. In each of the first implanted shape and the second implanted shape, each of the two layers can include an outer layer corresponding to the first segment of the predetermined shape and a proximal inversion corresponding to the first inversion of the predetermined shape.
In the first implanted shape, the outer layer of layer A can be positioned to contact a cavity wall of the first substantially spherical cavity, the outer layer of layer B apposes the outer layer of layer A, and the proximal inversion of each of the two layers can be positioned to be placed approximate an entrance to the first substantially spherical cavity. In the first implanted shape, each of the two layers of tubular braid can include a sack corresponding to the second segment of the predetermined shape. The sack of layer B can be positioned to appose a portion of a cavity wall of the first substantially spherical cavity and the sack of layer A can be contained within the sack of layer B.
In the second implanted shape, the outer layer of layer A can be positioned to contact a cavity wall of the second substantially spherical cavity, the outer layer of layer B can be positioned to appose the outer layer of layer A, and the proximal inversion of each of the two layers can be positioned to be placed approximate an entrance to the second substantially spherical cavity. In the second implanted shape, each of the two layers of tubular braid can include a middle layer and inner layer corresponding to the second segment of the predetermined shape and a fold separating the middle and inner layer such that the inner layer of layer B apposes the inner layer of layer A which apposes the middle layer of layer A which apposes the middle layer of layer B which apposes the outer layer of layer B.
In the predetermined shape, each of the two layers of tubular braid can include a bend positioned in the second segment. In the second implanted shape, for each of the two layers, the fold separating the middle layer and the inner layer corresponds to the bend in the second segment of the predetermined shape.
In the first implanted shape, the pinched end can be suspended within the sacks of layer A and layer B. In the second implanted shape, the pinched end can be encircled by the proximal inversions of layer A and layer B.
In the first implanted shape, the two layers can form an open end that encircles the sack. In the second implanted shape, the open end can encircle the fold.
The implant can be configured to treat a first aneurysm can include a first diameter measuring about 4 mm and a first height measuring about 6 mm, a second aneurysm can include a second diameter measuring about 5 mm and a second height measuring about 8 mm, and a third aneurysm can include a third diameter measuring about 6 mm and a third height measuring about 6 mm.
The implant can be configured to treat a plurality of aneurysms within a continuum of aneurysm sizes, the continuum bounded by and including diameters between about 4 mm and about 5 mm and heights between about 6 mm and about 8 mm.
As an alternative to having two implanted shapes, the two layers of tubular braid can be stable in an implanted shape based on the predetermined shape when constrained by a substantially spherical cavity. In the implanted shape, layer A can include an outer layer apposed to a cavity wall of the substantially spherical cavity, layer B can include and outer layer apposed to the outer layer of layer A, layer B can include an inner sack apposed to the outer layer of layer B, and layer A can include an inner sack positioned within the inner sack of layer B. Further, for each of the two layers, a proximal inversion corresponding to the first inversion can be positioned approximate an entrance to the substantially spherical cavity, and a distal inversion corresponding to the second inversion can be positioned approximate a distal portion of the cavity wall. Further, each of the two layers can include a post corresponding to the third segment such that the posts extend centrally within the respective inner sacks and along a majority of a length between the distal inversion and the proximal inversion. The post of layer B can be positioned within the post of layer A.
An example method for treating an aneurysm can include one or more of the following steps implemented in a variety of orders and can include additional steps as understood by a person of ordinary skill in the art according to the teachings of the present disclosure. A distal end of a catheter can be positioned approximate an aneurysm neck of an aneurysm. A pinched end of an implant comprising two layers (a layer A and a layer B) of tubular braid can be pushed distally through at least a portion of the catheter. An outer layer of layer A can appose to the aneurysm wall. An outer layer of layer B can appose to the outer layer of layer A. A sack can be formed of layer B, such that the sack is at least partially surrounded by the outer layers of layer A and layer B. A sack can be formed of layer A such that the sack is at least partially surrounded by the outer layers of layer A and layer B and is contained within the sack of layer B. The implant can be positioned within the aneurysm solely via manipulation of the pinched end and via positioning of the distal end of the catheter.
Each of the two layers can be extended to respectively form a single layer tubular shape such that layer A is surrounded by layer B. The two layers can be collapsed to have an outer circumference that is smaller than the outer circumference of a completely collapsed single layer tubular braid having a wire count equal to the sum of the wire count of the two layers and a wire circumference about equal to the average wire circumference of the wires in the two layers.
The outer layer A can press to the aneurysm wall with a radial force that is greater than a radial force applied by a single layer braid to an aneurysm wall of a second aneurysm having a substantially identical size to the aneurysm, the two layers having a total wire count that is about equal to the wire count of the single layer braid, an average wire circumference about equal to the average wire circumference of the single layer braid, and a predetermined shape formed by a substantially identical process as the single layer braid.
The implant can be implanted such that, compared to a similarly implanted single layer braid, across the aneurysm neck the two layers of braid have a smaller inlet channel, a decreased porosity, and/or an increased metal coverage. In this step, the two layers have a total wire count that is about equal to the wire count of the single layer braid, an average wire circumference about equal to the average wire circumference of the single layer braid, and a predetermined shape formed by a substantially identical process as the single layer braid. Also, in this step, the single layer braid is implanted in an aneurysm having a substantially identical size as the aneurysm in which the two-layer implant is implanted.
The sacks of each of the two layers can be collapsed to form an inner layer and a middle layer separated by a fold in each of the two layers such that that the inner layer of layer B apposes the inner layer of layer A which apposes the middle layer of layer A which apposes the middle layer of layer B which apposes the outer layer of layer B. The pinched end can be positioned approximate the aneurysm neck. The pinched end can be disengaged while the pinched end is positioned approximate the aneurysm neck and the sacks of each of the two layers are collapsed. Alternatively, the pinched end can be disengaged while two layers each retain their respective sacks.
When the sacks of each of the two layers are collapsible to form the inner layer and the middle layer, the method can further include determining the implant is suitable for treating a first aneurysm comprising a first diameter measuring about 4 mm and a first height measuring about 6 mm, a second aneurysm comprising a second diameter measuring about 5 mm and a second height measuring about 8 mm, and a third aneurysm comprising a third diameter measuring about 6 mm and a third height measuring about 6 mm. Additionally, or alternatively, the method can further include determining the implant is suitable for treating a continuum of aneurysm sizes, the continuum bounded by and including diameters between about 4 mm and about 5 mm and heights between about 6 mm and about 8 mm.
As an alternative to collapsing the sacks of each of the two layers, a tubular segment of layer A can be extended within the sack of layer A and the sack of layer B to terminate at the pinched end. A tubular segment of layer B can be extended within the tubular segment of layer A to terminate at the pinched end. The pinched end can be positioned approximate the aneurysm neck. The pinched end can be disengaged while the pinched end is positioned approximate the aneurysm neck and the tubular segments extend within the respective sacks.
An example method for forming an implant can include one or more of the following steps implemented in a variety of orders and can include additional steps as understood by a person of ordinary skill in the art according to the teachings of the present disclosure. Two layers of tubular braid (a layer A and a layer B) constricted at a pinched end can be shaped to a predetermined shape. Forming the predetermined shape can include inverting each of the two layers of tubular braid to form a respective distal inversion and inverting each of the two layers of tubular braid to form a respective proximal inversion, each respective distal inversion separating an inner segment and a middle segment of each of the two layers, the inner segment of each of the two layers extending from the respective distal inversion to the pinched end and at least partially surrounded by the middle segment, each respective proximal inversion separating the middle segment from an outer segment of each of the two layers, and each respective middle segment extending from the first inversion to the second inversion and at least partially surrounded by the outer segment.
The implant can be determined to be suitable for treating a first aneurysm comprising a first diameter measuring about 4 mm and a first height measuring about 6 mm, a second aneurysm comprising a second diameter measuring about 5 mm and a second height measuring about 8 mm, and a third aneurysm comprising a third diameter measuring about 6 mm and a third height measuring about 6 mm.
The implant can be determined to be suitable for treating a continuum of aneurysm sizes, the continuum bounded by and including diameters between about 4 mm and about 5 mm and heights between about 6 mm and about 8 mm.
An example implant can include a tubular braid having an open end and a pinched end. The tubular braid can have a predetermined shape that has two inversions that divide the braid into three segments. In the predetermined shape, the braid can have an outer segment that extends between the open end and a first of the two inversions, a middle segment that extends between the two inversions and is encircled by the open end, and an inner segment that extends between the second of the two inversions and the pinched end of the tubular braid and is surrounded by the middle segment.
When in the predetermined shape, the tubular braid can have a height measured between the two inversions and a substantially radially symmetrical shape having an outermost diameter. The ratio of outermost diameter to height can be between about 2:1 and about 1:3 or, more specifically, between about 2:1 and about 1:1. In the predetermined shape the middle segment can have maximum diameter that is equal to the diameter of the open end. When compressed, the tubular braid can be extended longitudinally to a single layer of braid having a length measured from the open end to the pinched end. The ratio of the outermost diameter in the predetermined shape to length in the compressed, delivery shape can be between about 0.2 and about 0.3.
The length of the tubular braid in the delivery shape can be between about 10 mm an about 40 mm, depending on the size of the aneurysm being treated.
A collection of implants, each having a uniquely shaped tubular braid can be created to provide a catalogue of implants for treating aneurysms ranging in diameter and height. Each implant in the collection can be suitable for treating aneurysms with a sub-range of diameters and a sub range of heights.
The tubular braid can have two distinct implanted shapes based on the predetermined shape and constrained by the geometry of an aneurysm in which the tubular braid is implanted. In other words, the implant can be implanted in either a larger aneurysm or a smaller aneurysm, the smaller aneurysm having a height measuring less than the height of the larger aneurysm, and the tubular braid can take one of the two implanted shapes when implanted in the larger aneurysm and the tubular braid can take on the other of the implanted shapes when implanted in the smaller aneurysm. In either implanted shape, the first, outer segment of the predetermined shape can be positioned to form an outer layer that juxtaposes / apposes an aneurysm wall and the inversion adjacent to the outer segment in the predetermined shape can be positioned to form a proximal inversion at an aneurysm neck. When implanted in the larger aneurysm, the second, middle segment of the predetermined shape can form a sack that apposes a portion of the aneurysm wall and apposes the outer layer of the braid, the pinched end can be suspended within the sack of the braid, and the open end can encircle the sack. When implanted in the smaller aneurysm, the middle segment of the predetermined shape can be folded to form a middle layer that apposes the outer layer and an inner layer that apposes the middle layer, the open end can be positioned near the fold dividing the middle and inner layers, and the pinched end can be positioned near the proximal inversion and aneurysm neck. The tubular braid in the predetermined shape can have a bend in the middle, second segment, and when tubular braid is in the smaller aneurysm implanted shape, the middle segment can fold at the bend to separate the middle layer from the inner layer.
An example implant having the tubular braid having two distinct implanted shapes can treat aneurysms within a range of sizes including an aneurysm having a diameter of 4 mm and a height of 6 mm, an aneurysm having a diameter of 5 mm and a height of 8 mm, and an aneurysm having a diameter of 6 mm and a height of 6 mm. Additionally, or alternatively, the implant can be suitable for treating aneurysms within a continuum of aneurysm sizes, the continuum bounded by and including aneurysm diameters between 4 mm and 5 mm and heights between 6 mm and 8 mm. The implant capable of treating aneurysms having the aforementioned sizes, when compressed for delivery through a microcatheter can have a length measuring between about 22 mm and about 25 mm.
As an alternative to having two distinct implanted shapes, the implant can have an implanted shape that includes a compaction resistant post extending within an inner sack of the braid and extending between a proximal inversion near an aneurysm neck and a distal inversion near a distal portion of an aneurysm wall. In the implanted shape, the tubular braid can have an outer layer that corresponds to the outer segment in the predetermined shape, the inner sack in the implanted shape can correspond to the middle segment in the predetermined shape, the compaction resistant post can correspond to the inner, third segment in the predetermined shape, and the distal and proximal inversions can correspond to the two inversions in the predetermined shape. The compaction resistant post can serve to inhibit the implant from impacting when implanted in the aneurysm.
An example method of treating an aneurysm can include one or more of the following steps presented in no particular order, and the method can include additional steps not included here. A tubular braid having an open end and a pinched end can be selected and shaped to a predetermined shape. The predetermined shape can be formed by inverting the braid to form a distal inversion, moving the open end over some or all of the braid to form a proximal inversion, shaping a first segment that extends between the open end and the proximal inversion, shaping a second segment that extends between the two inversions, positioning the open end to encircle the second segment, shaping a third segment that extends between the distal inversion and the pinched end of the braid, and positioning the second segment to surround the third segment. Forming the predetermined shape can further include shaping the open end and second segment so that the open end has a diameter greater than or equal to the maximum diameter of the second segment.
The tubular braid can be formed in the predetermined shape such that the tubular braid is implantable in two distinct implanted shapes and in either of two aneurysms having differing heights such that the braid takes on one implanted shape in the taller aneurysm and the second, different implanted shape in the shorter aneurysm. The example method can further include reshaping the tubular braid into one of the two distinct implanted shapes. When the tubular braid is reshaped for the taller aneurysm, the first segment can be reshaped to form an outer braid layer that apposes an aneurysm wall of the taller aneurysm, the proximal inversion can be positioned at the neck of the taller aneurysm, and the second segment can be reshaped to form a sack that nests within the outer layer and also apposes the aneurysm wall of the taller aneurysm. When the tubular braid is reshaped for the shorter aneurysm, the first segment can be reshaped to form an outer braid layer that apposes an aneurysm wall of the shorter aneurysm, the proximal inversion can be positioned at the neck of the shorter aneurysm, and the second segment can be folded to form a middle braid layer that apposes the outer layer and an inner braid layer that apposes the middle layer.
Forming the predetermined shape can further include forming a bend in the second segment, and when the tubular braid is reshaped for the shorter aneurysm, the second segment can be folded at the bend to form the fold that separates the middle braid layer and the inner braid layer.
When the tubular braid is reshaped for the taller aneurysm, the pinched end can be suspended within the sack. When the tubular braid is reshaped for the smaller aneurysm, the pinched end can be positioned near the proximal inversion.
When the tubular braid is reshaped for the taller aneurysm, the open end can encircle the sack. When the tubular braid is reshaped for the shorter aneurysm, the open end can be positioned near the fold separating the middle braid layer and the inner braid layer.
The method can further include shaping the tubular braid into a delivery shape to be delivered through a microcatheter. The tubular braid can have a length in the delivery shape that is measured between the open end and the pinched end. When the tubular braid is shaped to the predetermined shape, it can be shaped to have an outermost diameter. The length of the tubular braid in the delivery shape can measure between 3.5 and 5 times that of the outermost diameter of the tubular braid in the predetermined shape.
In the predetermined shape, the outermost diameter can be shaped to be between 2 and ⅓ times the height of the tubular braid.
When the tubular braid is shaped to the predetermined shape, the tubular braid can be shaped to be suitable to be implanted in an aneurysm having a diameter of 4 mm and a height of 6 mm, an aneurysm having a diameter of 5 mm and a height of 8 mm, and an aneurysm having a diameter of 6 mm and a height of 6 mm. Additionally, or alternatively, when the tubular braid is shaped to the predetermined shape, the tubular braid can be shaped to be suitable for treating a continuum of aneurysm sizes including aneurysms having diameters between 4 mm and 5 mm and heights between 6 mm and 8 mm. The tubular braid that is suitable for treating aneurysms sized as above can be extended to a single layer delivery shape having a length measuring between about 22 mm and about 25 mm, the delivery shape sized to be delivered through a microcatheter.
The method can further include positioning the proximal inversion on a proximal side of a plane defining a boundary between an aneurysm and blood vessel branches. The first segment can be reshaped to appose an aneurysm wall and the second segment can be reshaped to provide an outwardly radial force in the plane. The force can be sufficient to appose the first segment to the aneurysm neck. The force can also be sufficient to resist compaction of the implant within the aneurysm.
The method can further include collapsing the implant to fit within a microcatheter and pushing the pinched end of the unsheathed tubular braid through a majority of the length of the microcatheter to an aneurysm within a patient.
An example tubular implant including an open end and a pinched end can have a predetermined shape. When in the predetermined shape, the tubular braid can include a proximal inversion and two segments, and the braid can be composed of one or more wires. The first segment can extend from the open end of the tubular braid to the proximal inversion. The second segment can be at least partially surrounded by the open end and extend from the proximal inversion to the pinched end. The tubular braid can also include at least one corrugated fold. The one or more corrugated folds can be located within the first segment, second segment, or both. The corrugated folds can be configured to assist in anchoring the example device when in the implanted shape within an aneurysm in a similar manner to stent struts to help the tubular braid hold its shape.
In an example, the tubular braid can be formed into the predetermined shape by inverting the braid inwardly to separate the second segment from the first segment. The tubular braid can include memory shape material that can be heat set to a predetermined shape. This heat-set material can be utilized to form corrugations in the first or second segments, or both. Further, the wires of the tubular braid making up the corrugated folds of the first segment can be compressed or flattened along a vertical axis. Flattening the wires of the corrugated folds can make these portions of the tubular braid more rigid, thereby assisting in maintaining the shape of the tubular braid and anchoring it within an aneurysm. Flattening wires within the braid can make those wires bendable in two opposite directions rather than in all directions, which makes the flattened or compressed wires more resistant to bending than other non-flattened wires in the braid. When the tubular braid is in the predetermined shape, at least one corrugated fold in the second segment can appose the first segment, can appose a corrugated fold in the first segment, or both, thereby exerting an outwardly radial force on the first segment.
When in the implanted shape, the braid can have an outer layer corresponding to the first segment of the predetermined shape, a proximal inversion corresponding the proximal inversion of the predetermined shape, and an inner layer corresponding to the second segment of the predetermined shape. The tubular braid can have at least one corrugated fold in the inner layer, outer layer, or both corresponding to the corrugated folds in the predetermined shape. In the implanted shape, at least one corrugated fold in the inner layer can appose at least a portion of the outer layer, can appose a corrugated fold in the outer layer, or both, thereby exerting an outwardly radial force on the outer layer to anchor the implant within the aneurysm. The corrugated folds of the outer layer can also provide an outwardly radial force sufficient to appose the outer layer to the aneurysm wall and anchor the implant within the aneurysm. The corrugated folds in the outer layer can be flattened to increase the rigidity of the corrugations and assist with anchoring the tubular braid within the aneurysm.
An example method for forming an implant to treat an aneurysm can include positioning a distal end of a catheter approximate an aneurysm neck, pushing a pinched end of a tubular braid composed of one or more wires and having an open end distally through at least a portion of the catheter, positioning the open end within an aneurysm sac, and deploying the tubular braid to an implanted shape within the aneurysm based upon a predetermined shape. The implant in the implanted shape can include an inner layer, outer layer, and proximal inversion. The outer layer, inner layer, or both can include at least one corrugated fold. At least one corrugated fold within the inner layer can provide an outwardly radial force against the outer layer, against a corrugated fold in the outer layer, or both, the force sufficient to appose the outer layer to the aneurysm wall. In a similar manner, the corrugated folds of the outer layer can provide an outwardly radial force sufficient to appose the outer layer the aneurysm wall.
The one or more wires in at least one corrugated fold of the tubular braid can be compressed along a vertical axis such that the diameter of the wires of the corrugated fold along the axis is lesser than the diameter of the uncompressed portions of the tubular braid. This compression can increase the rigidity of the at least one corrugated fold relative to the rest of the braid. The cross-sectional shape of a flattened portion of wire can be different from the cross-sectional shape of a non-flattened portion.
The above and further aspects of this invention are further discussed with reference to the following description in conjunction with the accompanying drawings, in which like numerals indicate like structural elements and features in various figures. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating principles of the invention. The figures depict one or more implementations of the inventive devices, by way of example only, not by way of limitation.
Examples presented herein generally include a braided implant that can secure within an aneurysm sac and occlude a majority of the aneurysm’s neck. The implant can include a tubular braid that can be set into a predetermined shape, compressed for delivery through a microcatheter, and implanted in at least one implanted position that is based on the predetermined shape and the geometry of the aneurysm in which the braid is implanted. When compressed, the implant can be sufficiently short to mitigate friction forces produced when the implant is delivered unsheathed through the microcatheter allowing for a more simplistic delivery system compared to some other known braided embolic implant delivery systems.
Referring to
The tubular braid 110 can be formed into the predetermined shape by first inverting the braid outwardly to separate the inner segment 146 from the middle segment 144 with an inversion 124, then the middle segment 144 can be shaped over a form to produce the substantially “S” shaped profile illustrated, and finally, the braid 110 can be inverted outwardly again to separate the middle segment 144 from the outer segment 142 with another inversion 122. If necessary, the braid can be trimmed at the open end 114. The open end 114 can be positioned to encircle the middle segment 144. The open end 114 can positioned within the middle third section of the braid’s height as illustrated.
It can be advantageous to minimize a neck opening 126 defined by the lower extension of the “S” shape of the middle segment 144 to maximize occlusion of an aneurysm neck when the implant 100 is implanted. The middle segment 144 can have one or more bends 132, 134. The bends 132, 134 can be positioned facilitate the movement of the braid 110 into the second implanted shape illustrated in
The tubular braid 110 can include memory shape material that can be heat set to a predetermined shape, can be deformed for delivery through a catheter, and can self-expand to an implanted shape that is based on the predetermined shape and confined by the anatomy of the aneurysm in which it is implanted.
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The outer layer 142b in the second implanted shape can correspond to the outer layer 142 in the predetermined shape, the proximal inversion 122b in the second implanted shape can correspond to the inversion 122 adjacent to the outer layer 142 in the predetermined shape, the middle layer 144b and inner layer 146b in the second implanted shape can correspond to the middle segment 144 in the predetermined shape, the distal inversion 124b in the second implanted shape can correspond to a bend 134 in the middle segment 144 in the predetermined shape, and a portion of the braid 110 near the detachment feature 150 forming the inner layer 146b in the second implanted shape can correspond to the inner segment 146 in the predetermined shape.
During delivery through the microcatheter 600, the detachment feature 150 can be attached to a delivery system at a proximal end of the implant 100, the pinched end 112 can be positioned near the proximal end of the implant 100, and the open end 114 can define the distal end of the implant 100. Collapsing the braid 110 to a single layer tube can result in a braid 110 that has a sufficiently small diameter and a sufficiently short length L to mitigate effects of friction force on the braid 110 when it is delivered through the microcatheter, allowing the braid 110 to be delivered unsheathed in some applications.
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The ratio of the outermost diameter of the braid 110 in the predetermined shape illustrated in
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The braid can be pulled proximally as illustrated in
Implants having a predetermined shape and dimensions as illustrated and described in relation to
A collection of implants, each having a uniquely shaped tubular braid can be created to provide a catalogue of implants for treating aneurysms ranging in diameter and height. The catalogue can include implants suitable for treating aneurysms ranging from 3 mm to 15 mm in diameter and ranging from 3 mm to 15 mm in height, or in another example, ranging from 3 to 11 mm in diameter and 3 to 7 mm in height. As will be apricated and understood by a person of ordinary skill in the art, some aneurysm dimensions are extremely rare, and the catalog need not include implants for treating aneurysms having a large height: diameter ratio or a large diameter: height ratio.
Each implant in the collection can be suitable for treating aneurysms with a sub range of diameters and a sub-range of heights. An example catalogue can include a listing of implants for treating aneurysms of one or more of, but not limited to, the following size sub ranges (diameter range in mm, height range in mm): (3-5, 3-5), (6-8, 4-5), and (9-11, 5-7).
In some examples, each size sub range can be treated by a single implant having a tubular braid uniquely sized and shaped to be suitable for treating aneurysms within that sub range. In some examples, the sub ranges in the catalogue can be represented by implants each having a tubular braid with a delivery length (length when the braid is collapsed for delivery through a microcatheter) that is about 10 mm, about 40 mm, and/or including a length in between.
As will be appreciated and understood by a person of ordinary skill in the art, aneurysm height and diameter are measured with some margin of error. To that end, the size sub range included in the catalogue for a given implant can represent a portion of aneurysm sizes that can be treated with the implant and the implant can treat aneurysms outside of the listed sub range. For instance, an implant listed for treating aneurysms having heights between height a and height b and diameter range between diameter x and diameter y can be suitable for treating aneurysms slightly taller than the maximum listed height b if the diameter of the aneurysm is near the lower limit of the range (about diameter x), the implant can be suitable for treating diameters slightly larger than diameter y if the height of the aneurysm is near the lower limit of the height range (about height a).
As illustrated in
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Comparing the predetermined shape of the braid 210 illustrated in
The tubular braid 210 illustrated in
An implant 200 having a braid 210 having a predetermined shape as illustrated in
The braid 210 can be elongated to a single layer tubular braid in a delivery shape that is sized to traverse a microcatheter. The length of the braid 210 in the delivery shape can be measured from the open end 214 to the pinched end 212. A braid 210 having a predetermined shape as illustrated in
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Comparing the predetermined shape of the braid 310 illustrated in
The tubular braid 310 illustrated in
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Comparing the predetermined shape of the braid 410 illustrated in
The tubular braid 410 illustrated in
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Any of the implants 100, 200, 300, 400 illustrated and described herein can include one or more additional braid layers that move substantially parallel to the tubular braid 110, 210, 310, 410. The multiple layers can be stacked coaxially with each other and heat treated as a single unit into a predetermined shape. In some applications, multiple layers may be able to provide additional coverage at the aneurysm neck and additional support and conformability within the aneurysm. Each one layer of the braid can be selected with different properties with different wire counts and thickness, braid angle and diameter and wire material to potentially increase metal coverage, reduce profile (microcatheter size), facilitate deployment and reduce neck inlet channel size while providing visibility under angiogram.
The two layers 510, 560 can press together to potentially perform like a stronger single layer braid which, in some applications can facilitate implant deployment in an angled aneurysm. When deployed in aneurysm, the outer segments of each of the two layers expand outwardly against the aneurysm wall to stabilize the braid against the aneurysm wall. Comparing an implant having a singular braid layer to an implant having two or more braid layers, the two implants having a similarly sized and shaped predetermined shape, the singular braid layer may require repositioning of the distal end of the catheter to facilitate inversion near the aneurysm neck while the implant having two or more braid layers may be inverted near the aneurysm neck by distal movement of the pinched end without requiring repositioning of the distal end of the catheter. The added wire counts can also increase the conformability and support at the aneurysm dome.
The two layers can also potentially increase chronic outward force to support the inner braid against the outer braid and resist compaction. As illustrated in
In the predetermined shape illustrated in
In the first implanted shape illustrated in
In the first implanted shape illustrated in
The implant 500 can be delivered and implanted following steps similar to those illustrated in
By virtue of having two implanted shapes, similar to the implant 100 illustrated in
Including two or more braid layers can potentially decrease the inner neck channel size for devices made of Nitinol-platinum wire woven braid. In other words, for a substantially identical process of achieving a predetermined shape, the neck channel opening 526, 726 of an implant 500, 700 having two layers 510, 710, 560, 760 can be smaller than the neck channel opening 126 of an implant 100 having a single braid layer 110. Similarly, when implanted, the neck channel opening 526a illustrated in
Depending on the specific needs and braid properties, in an implant including two or more braid layers, an all nitinol braid can be used in combination with a nitinol-platinum braid such that the nitinol-platinum braid facilitates visualization of the braided portion of the braid and the all nitinol braid facilitates movement of the braid layers to the predetermined shape. The all nitinol braid can either be used as the inside or outside braid to reduce the inner channel size when fabricated with nitinol-platinum braid.
Referring to
The implant 700 can be delivered through a catheter 600 similar to as illustrated in
The braid layers 810, 860 are constricted at a pinched end 812 at which a detachment feature 850 can be affixed to the braid layers 810, 860. As illustrated, in the predetermined shape, each of the braid layers 810, 860 can have a respective open end 814, 864, first segment 842, 882, first inversion 822, 872, second segment 844, 884, first bend 832, 892, second bend 834, 894, second inversion 824, 874, and third segment 846, 886 similar to as described in relation to the implant 100 illustrated in
The two layers 810, 860 of tubular braid can be stabilized in an implanted shape based on the predetermined shape illustrated in
The implant 800 can be delivered and implanted similar to as described in relation to the first implanted shape of the implant 500 illustrated in
Although not illustrated, the implants 300, 400 illustrated in
The implant 900 can include a connection and detachment feature 150 attached to the braid 910 at the pinched end 912. The pinched end 912 can include a marker band and/or soldered point with visibility, and/or the connection feature 150 can include radiopaque material. The tubular braid 910 can be formed in a predetermined shape (
Referring to
When in a predetermined shape, the tubular braid 910 can be substantially radially symmetrical about a central vertical axis. The tubular braid can be formed into a predetermined shape by inverting the braid inwardly to separate the second segment 944 from the first segment 942. The tubular braid 910 can include memory shape material that can be heat set to the predetermined shape. This heat-set material can be utilized to form one or more corrugations 950, 960 in the first and/or second segments 942, 944.
As illustrated in
The tubular braid 910 can be deformed for delivery through a catheter and can self-expand to an implanted shape (e.g.,
The tubular braid 910 in the implanted shape can be radially or vertically compressed or extended compared to the predetermined shape. Compressing the tubular braid 910 can cause the folds in the inner layer 950a to provide a force against the first segment 942a and/or a corrugated fold in the first segment 960a. This compression can also cause the corrugated folds 960a in the first segment 942a to apply a radial force against the aneurysm wall 14.
When the tubular braid 910 is in the implanted shape within an aneurysm 10, at least one corrugated fold in the inner layer 950a can appose at least a portion of the outer layer 942a, thereby exerting an outwardly radial force on the outer layer 942a to anchor the implant 900 within the aneurysm 10. The wire of the tubular braid 910 comprising the corrugated folds 950a in the inner layer 942a can be flattened as described in
In
A method for forming an implant 900 to treat an aneurysm can include positioning a distal end of a catheter approximate a neck 16 of an aneurysm 10, pushing a pinched end 912 of a tubular braid 910 having one or more wires and an open end 914 distally through at least a portion of the catheter, positioning the open end 914 within a sac 12 of the aneurysm 10; and deploying the tubular braid 910 to an implanted shape within the aneurysm based upon a predetermined shape. The implant 900 can be deployed to an implanted shape within the aneurysm based upon a predetermined shape by inverting the tubular braid 910 to form a proximal inversion 922a by moving the open end 914 over at least a portion of the braid 910, shaping an outer layer 942a of the tubular braid 910 extending between the open end 914 and the proximal inversion 922a, and shaping an inner layer of the tubular braid 944a extending between the proximal inversion 922a and the pinched end 912, wherein at least one corrugated fold 950a is located within the inner layer 944a.
The method can further include positioning the implant within the aneurysm sac solely via manipulation of the pinched end and via positioning of the distal end of the catheter. The outer layer can also include at least one corrugated fold 960a within the outer layer 942a. When implanted, at least one corrugated fold 950a within the inner layer 944a can provide an outwardly radial force against the outer layer 942a, against a corrugated fold in the outer layer 960a in a plane defining a boundary between the aneurysm 10 and a blood vessel 22, or both. The force can be sufficient to appose the outer layer 942a to walls 14 of the aneurysm 10. In a similar manner, the corrugated folds 960a of the outer layer 942a can provide an outwardly radial force in a plane defining a boundary between the aneurysm 10 and a blood vessel 22, the force sufficient to appose the outer layer 942a to walls 14 of the aneurysm 10.
The wire of the tubular braid 910 comprising the at least one corrugated folds can be compressed along a vertical axis such that the diameter of the corrugated fold along the axis is lesser than the diameter of the uncompressed portions of the tubular braid 910. This compression can increase the rigidity of the at least one corrugated fold relative to the rest of the braid.
Although not illustrated, the implants 100, 200, 300, 400, 500, 600, 700, 800 illustrated in prior figures can alternatively include a combination of round and flattened wires according to the principles illustrated and described in relation to
The tubular braid 110, 210, 310, 410, 510, 560, 710, 760, 810, 860, 910 of the example implants 100, 200, 300, 400, 500, 700, 800, 900 can include memory shape material that can be heat set to a predetermined shape, can be deformed for delivery through a catheter, and can self-expand to an implanted shape that is based on the predetermined shape and confined by the anatomy of the aneurysm in which it is implanted. Tubular braid can further include platinum wire strands, markers, or other radiopaque features.
The example implants 100, 200, 300, 400, 500, 700, 800, 900 described herein can rely on a radial outward force to anchor the implant within the sac of an aneurysm. To this end, the braid(s) 110, 210, 310, 410, 510, 560, 710, 760, 810, 860, 910 can be shaped to a predetermined shape having a diameter (diameter of outermost braid, radially, for implants having multiple braid layers) that is greater than its height (between distal most layer and proximal most layer for implants having multiple braid layers) so that the braid is radially constricted when implanted in an aneurysm. The ratio of diameter to height of the braid(s) 110, 210, 310, 410, 510, 560, 710, 760, 810, 860, 910 in a respective predetermined shape can be within the range of 2:1 to 1:3 to treat aneurysms of many known sizes and shapes.
As used herein, the terms “about” or “approximately” for any numerical values or ranges indicate a suitable dimensional tolerance that allows the part or collection of components to function for its intended purpose as described herein. More specifically, “about” or “approximately” may refer to the range of values ±20% of the recited value, e.g. “about 90%” may refer to the range of values from 71% to 99%.
The descriptions contained herein are examples of embodiments of the invention and are not intended in any way to limit the scope of the invention. As described herein, the invention contemplates many variations and modifications of the implant, including alternative materials, alternative geometries, alternative detachment features, alternative delivery systems, alternative means for forming a braid into a predetermined shape, alternative treatment methods, alternative number of braid layers, etc. These modifications apparent to those having ordinary skill in the art to which this invention relates are intended to be within the scope of the claims which follow.
Claims
1. A method comprising:
- positioning a distal end of a catheter approximate a neck of an aneurysm;
- pushing a pinched end of a tubular braid distally through at least a portion of the catheter, the tubular braid comprising an open end and one or more wires;
- positioning the open end within a sac of the aneurysm; and
- deploying the tubular braid to an implanted shape within the aneurysm based upon a predetermined shape as follows: inverting the tubular braid to form a proximal inversion by moving the open end over at least a portion of the braid; shaping an outer layer of the tubular braid extending between the open end and the proximal inversion; and shaping an inner layer of the tubular braid extending between the proximal inversion and the pinched end, wherein the inner layer comprises at least one corrugated fold.
2. The method of claim 1, wherein a cross-sectional shape of the one or more wires forming the at least one corrugated fold is different from a cross-sectional shape of the one or more wires forming the remainder of the inner layer.
3. The method of claim 1, wherein the one or more wires in the at least one corrugated fold of the inner layer are compressed along an axis such that a diameter of the one or more wires in the corrugated fold along the axis is lesser than a diameter of uncompressed portions of the tubular braid.
4. The method of claim 1, further comprising apposing at least a portion of the outer layer with at least one corrugated fold formed within the inner layer.
5. The method of claim 1, wherein the outer layer comprises at least one corrugated fold.
6. The method of claim 5, further comprising apposing one or more walls of the aneurysm with at least one corrugated fold formed in the outer layer.
7. The method of claim 5, further comprising apposing at least a portion of the outer layer with at least one corrugated fold formed within the inner layer.
8. The method of claim 5, further comprising apposing at least one corrugated fold within the outer layer with at least one corrugated fold within the inner layer.
9. The method of claim 8, wherein the one or more wires in the at least one corrugated fold of the outer layer are compressed along an axis such that a diameter of the wire in the corrugated fold along the axis is lesser than a diameter of uncompressed portions of the tubular braid.
10. The method of claim 9, wherein compressing the wires comprising the at least one corrugated fold of the outer layer along an axis increases the rigidity of the at least one corrugated fold relative to the rest of the braid.
11. The method of claim 5, wherein the outer layer is positioned to contact a wall of the aneurysm, and the proximal inversion is positioned to be approximate a neck of the aneurysm.
12. The method of claim 5, wherein the at least one corrugated fold of the outer layer provides an outwardly radial force in a plane defining a boundary between the aneurysm and a blood vessel, the force sufficient to appose the outer layer to walls of the aneurysm.
Type: Application
Filed: Feb 17, 2023
Publication Date: Jun 29, 2023
Applicant: DePuy Synthes Products, Inc. (Raynham, MA)
Inventors: Pedro PEDROSO (Raynham, MA), Lacey GOROCHOW (Miami, FL)
Application Number: 18/111,036