Medical devices with improved geometric properties

Abstract

Disclosed is a medical device having a helical shaped structure that can function as a stent, such as a flow diverter stent, for treating an aneurysm. The medical device can have a helical shaped structure that can function as an occlusion device, for example, for occluding an aneurysm. The medical device can include a shape-setting structure that selectively adjusts the shape of the medical device.

Description

Related Applications

[0001] This application is a non-provisional application claiming priority to U.S. Provisional Application No. 62 / 874,846, entitled “Spiral Flow Diverter,” filed July 16, 2019, the entire contents of which are incorporated herein by reference. [Background technology]

[0002] An aneurysm is a bulge along a blood vessel wall caused by a weakening of an area of ​​an artery, for example. If left untreated, an aneurysm can rupture over time, causing complications such as stroke. The rupture of a cerebral aneurysm can lead to a hemorrhagic stroke, which can be fatal to the patient or result in permanent neurological disability.

[0003] Aneurysms are traditionally treated using clipping or occlusion, in which an occlusion device such as a coil is implanted into the aneurysm to block blood flow to the aneurysm, cutting off the aneurysm's blood supply over time.

[0004] A recent technique in treating aneurysms utilizes flow diverter stents, which are braided tubular devices placed across the neck of the aneurysm. Flow diverter stents (also known as flow diverters) utilize a low porosity interface to restrict blood flow into the aneurysm, induce stasis within the aneurysm, cut off the blood supply to the aneurysm over time to reduce the likelihood of rupture, and promote endothelial growth over the stent to seal the aneurysm over time.

[0005] Conventional flow diverters utilize a constant tubular or cylindrical stent structure with a consistent low porosity profile throughout the entire length of the stent. However, this design can lead to complications. For example, due to the constant tubular shape, flow diverter stents are stiff, making deployment cumbersome in certain situations, such as when an aneurysm is positioned along a tortuous portion of the anatomy. Furthermore, conventional flow diverter stents cannot be repositioned after a certain point in the deployment process. Typically, the stent is mechanically coupled to the delivery pusher, and once this engagement with the stent is lost (e.g., when the stent is delivered and expanded), the stent is no longer connected to the delivery pusher and cannot be repositioned.

[0006] Conventional flow diverters have fixed sizes, and physicians must determine the size of the vessel before performing a procedure and utilize a flow diverter of a specific size that fits the specific target location. Complications may occur if the stent does not expand properly (e.g., due to pressure from the vessel wall or deployment across a tortuous bend) or if the stent is inaccurately sized, causing complications due to the flow diverting properties of the stent. For example, if the stent is too small, it may not be seated flush across the neck of the aneurysm, which prevents the flow diverting effect of the stent. If the stent is too large for the vessel, it may not be properly deployed from the delivery catheter or may not assume the correct shape after deployment.

[0007] There is a need for a flow diverter stent that addresses at least these issues.

[0008] In certain circumstances, occlusion rather than diverting blood flow is considered a better treatment option for treating aneurysms. Newer types of occlusion devices, known as intrasaccular devices, tend to focus on interrupting blood flow at the neck of the aneurysm to prevent blood flow to the aneurysm. Intrasaccular devices utilize structures such as meshes to occupy and occlude space within the aneurysm, preventing blood flow into the aneurysm while forming a barrier along the neck of the aneurysm. In many cases, these devices are highly adaptable to the size and dimensions of the aneurysm. However, it can be difficult to design an intrasaccular device that can provide good coverage of the aneurysm neck and sufficiently occlude the aneurysm to prevent blood flow to the aneurysm. This is because occlusion devices (including intrasaccular devices) generally have a fixed shape and structure.

[0009] There is a need for an occlusion device that addresses at least these issues.

[0010] Conventional medical devices (e.g., stents or occlusion devices) have a particular fixed size and are often heat set into an expanded state that the device adopts upon deployment from a delivery catheter. Thus, when the device is within the catheter, it has a fixed, smaller profile, delivery state, and when the device is outside the catheter, it has a fixed, heat set, expanded state. However, there is no way to adjust the size or shape of the device after deployment, when a particular target area could be better treated if the implant could assume a different shape.

[0011] There is a need for medical devices, such as stents or occlusion devices, that address at least these problems. Summary of the Invention

[0012] In some embodiments, a stent is described.

[0013] In one embodiment, a stent is described that is particularly useful as a flow diverter stent for use in treating aneurysms. In one embodiment, the stent utilizes a helical configuration. In one embodiment, the stent is comprised of one or more metal wires braided into a helical configuration. In one embodiment, the stent utilizes a multi-layer (e.g., bi-layer) helical configuration. In one embodiment, a multi-layer stent utilizes multiple wires, with some of the wires of one layer being offset relative to some of the wires of the other layers to enhance the flow interrupting effect of the stent.

[0014] In one embodiment, the stent utilizes a shape-setting structure to adjust the profile of the stent. In one embodiment, the shape-setting structure is one or more wires connected to the stent. In one embodiment, the shape-setting structure is one or more wires interbraided or woven with the stent. In one embodiment, the shape-setting structure is a scaffold type structure. In one embodiment, the shape-setting structure utilizes conductive elements (e.g., wires). In one embodiment, the shape-setting structure undergoes a heat treatment step to assume a particular shape when heated to a particular temperature. In one embodiment, the shape-setting structure is heated to a particular temperature to assume a particular shape in order to force the implant into a particular shape. In one embodiment, the stent has particular utility as a flow diverter stent for use in treating aneurysms.

[0015] In one embodiment, a method of treating a vascular condition with a stent is described. The method includes treating the vascular condition with the helical shaped stent by providing a stent having a helical shape and deploying the stent through and out of a delivery catheter such that the stent assumes its helical shape. In one embodiment, the stent is comprised of one or more metal wires braided into a helical shape. In one embodiment, the stent utilizes a multi-layer (e.g., bi-layer) helical shape. In one embodiment, a multi-layer stent utilizes multiple wires, with some of the wires of one layer being offset relative to some of the wires of the other layers to enhance the blood flow interrupting effect of the stent. In one embodiment, a method of treating an aneurysm is described. The method includes obstructing blood flow to an aneurysm with the helical shaped stent by providing a flow diverter stent having a helical shape and deploying the flow diverter stent through and out of a delivery catheter such that the flow diverter stent assumes its helical shape.

[0016] In one embodiment, a method of treating a vascular condition is described. The method includes providing a stent, deploying the stent through a delivery catheter such that at least a portion of the stent is in an expanded configuration, and actuating a shape-setting structure to place the stent in a different configuration (e.g., a helical shape). In one embodiment, the shape-setting structure is one or more wires connected to the stent. In one embodiment, the shape-setting structure is one or more wires interbraided or woven with the stent. In one embodiment, the shape-setting structure is a scaffold type structure. In one embodiment, the shape-setting structure utilizes conductive elements (e.g., wires). In one embodiment, the shape-setting structure undergoes a heat treatment step, which results in a particular shape when heated to a particular temperature. In one embodiment, the shape-setting structure is heated to a particular temperature to form a particular shape in order to force an implant into a particular shape. In one embodiment, the stent has particular utility as a flow diverter stent used to treat aneurysms. In one embodiment, a method of treating aneurysms is described. The method includes providing a flow diverter stent, deploying the flow diverter stent through a delivery catheter such that at least a portion of the stent is in an expanded shape, and actuating a shape-setting structure to configure the flow diverter stent in a different configuration (e.g., a helical shape).

[0017] In some embodiments, an occlusion device is described.

[0018] In one embodiment, an occlusion device is used to occlude an aneurysm. In one embodiment, the occlusion device utilizes a helical configuration. In one embodiment, the occlusion device is comprised of one or more metal wires braided into a helical configuration. In one embodiment, the occlusion device utilizes a multi-layer (e.g., bi-layer) helical configuration. In one embodiment, a multi-layer occlusion device utilizes multiple wires, with some of the wires in one layer offset relative to some of the wires in the other layers to increase blood flow resistance or interruption.

[0019] In one embodiment, a method of occluding an aneurysm is described. The method includes deploying an occlusion device through a delivery catheter, out of the delivery catheter, and into the aneurysm, whereby the occlusion device assumes its helical expanded configuration and occludes the aneurysm. In one embodiment, the occlusion device is comprised of one or more metal wires braided into a helical configuration. In one embodiment, the occlusion device utilizes a multi-layer (e.g., bi-layer) helical configuration. In one embodiment, the multi-layer occlusion device utilizes multiple wires, where some of the wires in one layer are offset relative to some of the wires in the other layers to increase blood flow resistance or interruption. In one embodiment, a method of occluding a treatment area is described. The method includes deploying an occlusion device through a delivery catheter, out of the delivery catheter, and into the treatment area, whereby the occlusion device assumes its helical expanded configuration and occludes the treatment area to treat a vascular condition.

[0020] In one embodiment, an occlusion device is described that utilizes a shape-setting structure to adjust the shape, configuration, or geometry of the device. In one embodiment, the shape-setting structure is one or more wires connected to the occlusion device. In one embodiment, the shape-setting structure is one or more wires that are braided or interwoven with the occlusion device. In one embodiment, the shape-setting structure is a scaffold type structure. In one embodiment, the shape-setting structure utilizes conductive elements (e.g., wires). In one embodiment, the shape-setting structure undergoes a heat treatment step, where it assumes a particular shape when heated to a particular temperature. In one embodiment, the shape-setting structure is heated to a particular temperature to assume a particular shape in order to force an implant (e.g., the occlusion device) into a particular shape. In one embodiment, the occlusion device has particular utility as an aneurysm occluder, such as an intrasaccular device.

[0021] In one embodiment, a method of occluding a treatment area is described. The method includes delivering an occlusion device through and out of a delivery catheter such that at least a portion of the occlusion device is outside of the delivery catheter, actuating a shape-setting structure, adjusting a shape, configuration, or configuration of the occlusion device, and occluding the treatment area with the occlusion device. In one embodiment, the shape-setting structure is one or more wires connected to the occlusion device. In one embodiment, the shape-setting structure is one or more wires that are braided or woven together with the occlusion device. In one embodiment, the shape-setting structure is a scaffold type structure. In one embodiment, the shape-setting structure utilizes conductive elements (e.g., wires). In one embodiment, the shape-setting structure undergoes a heat treatment step, which assumes a particular shape when heated to a particular temperature. In one embodiment, the shape-setting structure is heated to a particular temperature to assume a particular shape in order to force an implant (e.g., the occlusion device) into a particular shape. In one embodiment, the occlusion device has particular utility as an aneurysm occluder, such as an intrasaccular device. In one embodiment, a method of occluding an aneurysm is described. The method includes delivering an occlusion device through and out of the delivery catheter such that at least a portion of the occlusion device is outside the delivery catheter and within the aneurysm, actuating a shape-setting structure to adjust the shape, configuration, or geometry of the occlusion device, and occluding the aneurysm with the occlusion device.

[0022] In one embodiment, a method of manufacturing a medical device, including a flow diverter stent and / or an occlusion device, is described. The method, in one embodiment, includes forming a tubular structure by braiding one or more wires on a mandrel to form a tubular structure comprised of one or more layers. The tubular structure is then compressed to form a compressed multi-layer structure. The multi-layer structure is then helically wound around the tubular mandrel to create a multi-layer helical tubular shape. In one embodiment, one or more wires at a proximal end of the medical device are releasably connected to a delivery pusher for delivery of the medical device.

[0023] In one embodiment, the medical device utilizes a mechanical delivery pusher connected to a proximal end of the medical device. In one embodiment, the medical device is a helical shaped member. In one embodiment, the medical device is a stent, such as a flow diverter stent. In one embodiment, the medical device is an occlusion device. In one embodiment, the delivery system utilizes a connection interface between the delivery pusher and the medical device, the connection interface including a proximally disposed wire that includes a proximal portion of the medical device. In one embodiment, the delivery pusher includes a detachment system for detaching the delivery pusher from the medical device. In one embodiment, a thermal detachment system is utilized. In one embodiment, the detachment system includes a first system for detaching the medical device and a second system for actuating a shape-setting structure to adjust the shape, configuration, or configuration of the medical device.

[0024] In one embodiment, a method of detaching a medical device (e.g., a stent or occlusion device) is described that includes delivering the medical device to a treatment site (e.g., an aneurysm), deploying the medical device, and activating a detachment system to detach a delivery pusher from the medical device.

[0025] In one embodiment, a shape-setting system is described that includes a shape-setting structure. In one embodiment, the shape-setting system utilizes a shape-setting structure (in one embodiment, one or more conductive wires) and a heating system connected to the shape-setting structure to transmit electrical current and thereby heat the shape-setting structure. In one embodiment, heating the shape-setting structure adjusts its shape, contour, or configuration (e.g., either elongating it or expanding it or giving it a different shape), thereby adjusting or changing the shape, contour, or configuration of a medical device / implant connected to or integral with the shape-setting structure. In one embodiment, the shape-setting structure utilizes a structure (e.g., one or more wires) that is heat-set into a particular shape at a particular transition temperature, such that when the structure is subsequently exposed to this transition temperature, it assumes the heat-set shape. In one embodiment, the medical device is a stent, such as a flow diverter stent. In one embodiment, the medical device is an occlusion device.

[0026] In one embodiment, a method is described for using a shape-setting system or shape-setting structure to change the shape, contour, or configuration of a medical device or implant (e.g., a stent or occlusion device). The method includes the steps of heating the shape-setting structure by activating a heating system connected to the shape-setting structure to transmit electrical current, adjusting the shape, contour, or configuration, and adjusting the shape or contour or configuration of a medical device connected or integrated with the shape-setting structure. In one embodiment, a method for creating a shape-setting structure includes winding the shape-setting structure onto a mandrel into a particular shape and heat setting the shape at an appropriate transition temperature above body temperature to provide a transition temperature for the shape-setting structure.

[0027] In one embodiment, a medical device is described that can selectively function as either a stent or an occlusion device. In a first configuration, the device functions as a flow diverter stent that is placed across the neck of an aneurysm to divert blood flow from the aneurysm. In a second configuration, the device functions as an occlusion device that is placed within the aneurysm to occlude the aneurysm.

[0028] In one embodiment, a method is described that utilizes a medical device that can selectively function as either a stent or an occlusion device. The method includes deploying the medical device at a treatment site (e.g., an aneurysm), deploying a medical device from a delivery catheter to cause the medical device to assume a different shape, and treating the medical condition with the different shape. In one embodiment, the method further includes treating the target site with the medical device having the different shape by activating a shape-setting structure coupled to the medical device to cause the medical device to assume the different shape.

[0029] In one embodiment, a method of changing a shape of an implantable device is described, the method comprising the steps of providing a scaffold having a constrained state, an unconstrained state and a preset shape, providing a shape-changing device associated with the scaffold, and selectively activating the shape-changing device to change the scaffold from the unconstrained state to the preset shape.

[0030] In one embodiment, a medical implant is described that includes a tubular structure configured to have a rest shape and an operating shape, and a shape-setting mechanism associated with the tubular structure, the shape-setting mechanism operative to selectively change the tubular structure from the rest shape to the operating shape. [Brief description of the drawings]

[0031] The above-mentioned and other aspects, features and advantages enabled by the embodiments of the present invention will be apparent and become apparent from the following described embodiments of the present invention, taken in conjunction with the accompanying drawings.

[0032] [Figure 1] FIG. 1 illustrates a tubular structure used to create a multi-layered implant, according to one embodiment.

[0033] [Diagram 2] FIG. 2 illustrates the tubular structure of FIG. 1 disposed on a mandrel, according to one embodiment.

[0034] [Diagram 3] FIG. 1 illustrates a front profile of a tubular structure according to one embodiment.

[0035] [Figure 4] FIG. 1 illustrates a compressed front profile of a tubular structure according to one embodiment.

[0036] [Diagram 5] FIG. 13 illustrates a compressed front profile of a tubular structure according to another embodiment.

[0037] [Figure 6] FIG. 2 is a side view of a compressed tubular structure according to one embodiment.

[0038] [Figure 7] FIG. 1 illustrates a helical structure disposed on a mandrel according to one embodiment.

[0039] [Figure 8] FIG. 1 illustrates a side profile of a helix according to one embodiment.

[0040] [Figure 9] 1A-1D show a helical shaped stent for treating an aneurysm, according to one embodiment.

[0041] [Figure 10] FIG. 1 illustrates multiple layers of wire used in a spiral structure, according to one embodiment.

[0042] [Figure 11] FIG. 1 illustrates a delivery system used to deliver the spiral structure, according to one embodiment.

[0043] [Figure 12] FIG. 1 illustrates a delivery system used to deliver a spiral structure and including a breakaway joint, according to one embodiment.

[0044] [Figure 13] FIG. 13 illustrates a heating element used to release the helix, according to one embodiment.

[0045] [Figure 14] 1A-1C illustrate a helical shaped stent for treating an aneurysm and a helical shaped occlusion device for occluding an aneurysm, according to one embodiment.

[0046] [Figure 15] 1A-1C illustrate an occlusion device having a complex shape and including an inner member, according to one embodiment.

[0047] [Figure 16] 1 illustrates an elongate implant including shape-setting structures, according to one embodiment.

[0048] [Figure 17] FIG. 17 illustrates the implant of FIG. 16 having a helical shape, according to one embodiment.

[0049] [Figure 18] FIG. 1 illustrates an implant / pusher interface for an implant utilizing shape-setting structures, according to one embodiment.

[0050] [Figure 19] FIG. 19 illustrates the interface of FIG. 18 in a delivery catheter, according to one embodiment.

[0051] [Figure 20]FIG. 19 illustrates the interface of FIG. 18 when not in a delivery catheter, according to one embodiment.

[0052] [Figure 21] FIG. 1 illustrates a shape-setting structure having a coil-like shape partially along its length, according to one embodiment.

[0053] [Figure 22] FIG. 1 illustrates a shape-setting structure having a serpentine shape, according to one embodiment. Embodiment

[0054] Stents are used in the vascular system for a variety of reasons, such as acting as a scaffold to aid in the patency of blood vessels. One type of such stent, known as a flow diverter stent, is implanted in blood vessels adjacent to the neck of an aneurysm to help reduce or restrict blood flow into the aneurysm. If porosity is defined as the amount of open space within a stent (e.g., the inverse of the percentage of the area comprised by the stent material itself), a flow diverter stent has a relatively low porosity in order to restrict the amount of blood flow into the aneurysm.

[0055] Conventional stents, including flow diverter stents, have a tubular structure. However, this design is generally rigid and therefore may cause complications during deployment, for example, in smaller vessels (such as those of the neurovasculature) or along tortuous anatomical structures. The following embodiments describe stents that include flow diverter stents in general and are particularly useful for treating aneurysms in the neurovasculature.

[0056] FIG. 1 shows a tubular structure 100 used to create a helical shaped stent. The tubular structure 100 is composed of a mesh or braid of one or more wires that are braided together to form the shape. In one embodiment, a metallic shape memory wire (e.g., Nitinol, Stainless Steel, Cobalt-Chromium) is used. In one preferred embodiment, Nitinol is used. In one embodiment, a drawn filled tube (DFT) is used that utilizes a radiopaque (e.g., Platinum or Tantalum) core and an outer metal (such as Nitinol) armor; these DFT elements look and function similarly to wires.

[0057] In one embodiment, the tubular mesh or braid 100 includes an optional radiopaque wire 102 (e.g., tantalum or platinum) to aid in visualization. The radiopaque wire 102 is woven into other portions of the braid 100 such that the radiopaque wire 102 forms part of the braid or mesh. In one embodiment, the radiopaque wire 102 is wound simultaneously and similarly to the other wires of the braid. In one embodiment, the radiopaque wire 102 is wound in an over-under pattern (e.g., over a portion of a wire, under another portion of a wire, etc.) relative to the other wires of the braid such that the radiopaque wire 102 is woven as part of the mesh. In one embodiment, the radiopaque wire 102 is wound in a separate step after the other wires of the implant and is wound in an over-under pattern (e.g., over-under as described above) relative to the other wires of the mesh such that the radiopaque wire 102 is woven as part of the mesh.

[0058] In one embodiment, the radiopaque / visualization wire 102 is thicker than the other wires in the braid 100. This thicker wire is advantageous for visualization and for increasing the stiffness of the tubular braid 100 (since radiopaque materials are often stiffer than more flexible shape memory materials). In one example, the braid 100 is constructed from one or more wires with a diameter of about 0.01 mm to 0.08 mm, and the radiopaque wire 102 is about 0.05 mm to 0.15 mm. In one example, the braid 100 is constructed from one or more wires with a diameter of about 0.025 mm to 0.075 mm, and the radiopaque wire 102 is about 0.05 mm to 0.1 mm.

[0059] In one embodiment, the tubular mesh or braid 100 is single layer, and the tubular mesh shape is created by braiding one or more wires around a tubular mandrel, such as mandrel 104 shown in FIG. 2. A general cross-sectional profile of the tubular shape is shown in FIG. 3, which can be considered the front view of the tubular shape. In various embodiments, the orientation of the mandrel 104 can be either horizontal or vertical. A horizontal mandrel configuration is shown in FIG. 2. A vertical mandrel configuration flips the mandrel 90 degrees so that the windings are all vertical (e.g., against or with gravity). One advantage of the vertical mandrel configuration is that when winding top-down, gravity can be used as an additional force to aid the winding process.

[0060] Following the steps described above, the tubular mesh or braid 100 is configured into a helical shape. The tubular mesh 100 is first removed from the mandrel 104 and compressed to create a multi-layer (e.g., bi-layer) structure. This is illustrated in Figures 3-5. In Figure 3, a tubular shape is created having a top tubular portion 100a and a bottom tubular portion 100b. The tubular shape is then compressed (by a force F) to create the different cross-sections shown in either Figure 4 or Figure 5. In Figure 4, the tubular shape is compressed such that the top 100a and bottom 100b tubular portions are adjacent or nearly adjacent to create a compressed curved structure. In Figure 5, the tubular shape is compressed to create a flattened cross-sectional shape, which in some embodiments can be thought of as a flat or thin ribbon-type shape. FIG. 6 is a side view of the original tubular structure once it has been flattened or compressed into an elongated compressed shape 106, which can be thought of as the side profile of the tubular structure 100 of FIG. 1 after it has been flattened or compressed into a different shape 106.

[0061] Following the steps described above, the tubular mesh or braid 100 is configured into a helical shape. The tubular mesh 100 is first removed from the mandrel 104 and compressed to create a multi-layer (e.g., bi-layer) structure. This is illustrated in Figures 3-5, which depict a front view or a cross-sectional view (e.g., when the user faces the lumen of the tubular structure 100) of the tubular structure 100. In Figure 3, a tubular shape is created having a top tubular portion 100a and a bottom tubular portion 100b. The tubular shape is then compressed (by a force F) to create a different cross-section as shown in either Figure 4 or Figure 5. In Figure 4, the tubular shape is compressed such that the top 100a and bottom 100b tubular portions are adjacent or nearly adjacent to create a compressed curved structure. In Figure 5, the tubular shape is compressed to create a flattened cross-sectional shape, which in some embodiments can be thought of as a flat or thin ribbon-type shape. Figure 6 is a side view of the original tubular structure once flattened or compressed into an elongated compressed shape 106, which can be thought of as the side profile of the tubular structure 100 of Figure 1 after flattening or compression, assuming a different shape 106. The view of Figure 6 can also be thought of as a side view of the compressed tubular structure rotated 90 degrees, replacing the front views of the tubular structure of Figures 3-5.

[0062] The helix shape is created from a two-layer structure consisting of a first layer 100a disposed on top of a second layer 100b, as shown in Figures 4-6, so that the helix itself is two-layered. However, in other embodiments, more layers can be used (e.g., if a multi-layer tubular braid is created first, compression of the braid adds more of these layers). Thus, the helix itself is composed of at least two layers, but may be composed of more layers (e.g., 4, 6, 8, 10, or more).

[0063] FIG. 8 illustrates a multi-layered spiral configuration, where an individual or particular spiral component (e.g., one winding 108a of the spiral pattern 108) is comprised of two overlapping layers 100a, 100b. The layers 100a, 100b may be configured such that there is an open space or gap 112 between the layers (note that this is different than the gap 110 in FIG. 7, which illustrates the gap between adjacent windings of the spiral pattern 108). The open space or gap 112 may be controlled by utilizing bonding elements along specific locations that bond the two layers together, where the number of bonds between the layers and the bonding strength / tension will affect any open space / gap size. Alternatively, adhesive binding may be used, where some spacing is provided in the areas between the bond points to create areas of open space / gap.

[0064] Alternatively, layers 100a, 100b may be configured such that one layer is in direct contact with the other layer in a coplanar manner with no open spaces, which may be achieved, for example, by utilizing multiple closely spaced bonding elements along some of the windings of the spiral pattern, or by closely bonding layers 100a, 100b to one another using a continuous / substantially continuous adhesive portion.

[0065] A multi-layer helical pattern (each winding of the helical pattern is composed of two or more layers) has several important advantages when the helical pattern configuration is used as a stent, particularly as a flow diverter stent (also known as a flow diverter). This is illustrated in Figure 9, where a helical shaped flow diverter stent 118 is composed of multiple individual windings 118a, 118b, etc., each of which is itself an individual helical component. The flow diverter stent 118 is implanted within a blood vessel 116 adjacent an aneurysm 114 and is used to reduce blood flow into the aneurysm and promote clotting in the neck region of the aneurysm to occlude the aneurysm.

[0066] Because each winding 118a, 118b, etc., is constructed of multiple layers (e.g., at least two layers) as described herein, as discussed above, blood passing through the flow diverter stent 118 must pass through multiple layers of wires to enter the aneurysm, which creates a blood flow barrier and results in increased disruption or diversion of blood flow. Thus, each layer of wires in the windings of the helical stent 118 creates a flow diversion barrier for blood entering the aneurysm, with each subsequent layer creating an additional barrier. In one embodiment, the flow diversion effect is further enhanced when the wires of one layer are offset relative to the wires of the other layers. This configuration is shown in FIG. 10, where the wires 120 (larger grey lines) of one layer are offset relative to the wires 122 (smaller black lines) of the other layers. Although the wire / wire sizes are illustratively shown as different in FIG. 10, in one embodiment, the wires of the braid that comprises the helical shaped flow diverter stent are substantially similar. As can be seen from Figure 10, the offset configuration increases resistance to blood flow and increases flow shunting. The offset pattern can be constructed, for example, by bonding layers together (e.g., via mechanical bonding, welding, or adhesive) such that one layer is offset relative to the other layers.

[0067] In another embodiment, each layer is constructed such that one layer is not offset relative to the other layers, meaning that the wires of one layer are substantially aligned with the wires of the other layers, which may be accomplished, for example, by bonding the layers (e.g., via mechanical bonding, welding, or adhesive) such that the wires of one layer are aligned relative to the wires of the other layers.

[0068] In another embodiment, each layer is configured such that a portion of the braid is aligned with the wires of another layer and a portion of the braid is offset from the wires of another layer. To accomplish this, the bonding features and patterns in various regions of the braid can be configured in a particular manner, similar to that described above.

[0069] It should be noted that in a helical shaped flow diverter stent as shown in Figure 9, it is generally beneficial for each individual winding 118a of the helical pattern to be directly flush with or overlapping (meaning that a portion of a winding is located above or below an adjacent winding) each adjacent winding 118b. The purpose of this is to ensure that there are no gaps between the windings through which blood can pass, which would otherwise allow unhindered passage of blood into the aneurysm. In one embodiment, the directly adjacent or overlapping configuration can be set during winding of the pattern on the mandrel (e.g., the helical pattern is wound so that adjacent windings are flush with or overlap each other). In another embodiment, a small gap can be provided between adjacent windings, but because flow diverter stents are typically oversized for the vessel in which they are placed during the treatment procedure (typically because the flow diverter stent is placed to ensure close contact with the aneurysm neck), this oversizing ensures that adjacent windings are placed directly adjacent to one another or slightly overlapping, so that there are no open spaces between the windings of the stent when implanted.

[0070] 11, the stent 118 is connected to a delivery pusher 126 that is used to deliver the stent 118 via a catheter to a target treatment location. The stent 118 is in a flattened / compressed elongated shape while in the delivery catheter and then in an expanded helical shape while outside the delivery catheter.

[0071] It should be noted that in this disclosure, the terms "proximal" and "distal" are used. Proximal should be considered as the direction toward the surgeon performing the procedure, which is also the direction outside the vasculature and away from the patient. Distal should be considered as the direction toward the patient, which is the direction toward a region of the patient's vasculature or even within the patient's vasculature.

[0072] The pusher 126 has either a tubular or solid structure and is held at its proximal end by a user and used to push the connected stent 118 through the catheter to the treatment location. In one embodiment, the stent 118 is wound from one or more wires, first wound from proximal to distal (e.g., left to right in FIG. 11 ) and then wound from distal to proximal (e.g., right to left in FIG. 11 ). This causes each wire of the one or more wires of the braid to be braided such that each wire starts at a proximal location and ends at a proximal location. The one or more wires (e.g., eight wires shown in the example of FIG. 11 ) forming the stent 118 are then extended proximally and connected to the pusher 126. In this way, the stent 118 and the pusher 126 are connected via the extended connection interface 124. In one embodiment, the wires forming the extended connection interface 124 are covered by a tubular covering element or structure. 11 as being relatively long, interface 124 may be sized to any length, and by way of example, is relatively short to minimize the profile of any extension element extending from the proximal end of stent 118. In one embodiment, connection interface 124 is itself braided such that it may be thought of as a braided extension to other portions of stent 118.

[0073] 12 shows the connection interface 124 between the pusher 126 and the stent 118 in more detail. The wires forming the proximal end of the connection interface 124 are connected to a tubular marker element 128. In one example, the marker element 128 is radiopaque to aid in visualization of the distal end of the pusher 126 / proximal end of the stent 118. In one example, the proximal ends of the wires forming the connection interface 124 are welded or otherwise attached to the inner lumen of the tubular marker element 128 or to the outer surface of the marker element 128. In another configuration, the marker element 128 is a solid structure rather than tubular.

[0074] The detachment interface 130 is disposed proximal to the marker element 128. The detachment interface 130 is a severable joint (e.g., mechanically, electrolytically, or thermally) to detach the marker 128 and wire connection interface 124 from the remainder of the pusher 126. In one embodiment shown in FIG. 13, the detachment interface 130 includes an elongated tether 132 that extends between a distal portion of the inner lumen of the pusher 126 and the marker element 128, and a heater coil 134 connected to the pusher 126 and that is heated upon user action (e.g., via a proximal button) to heat and sever the tether 132.

[0075] In one example, the tether 132 is attached at one end within the internal lumen of the pusher 126 or to an external surface of the pusher 126 and at the other end to the internal lumen of the marker element 128. The cutting tether 132 detaches the marker 128 and the wire interface element 124 (connected to the marker 128) from the pusher 126 and the heater 134. The heater 134 is not detached and remains connected to the pusher 126. Each end of the heater 134 has a wire (not shown) connected to it, with a first wire connected to a first end of the heater 134 and a second wire of opposite polarity connected to a second end of the heater 134. These wires may extend through the lumen of the pusher 126 or outside the pusher 126, all the way to the proximal end of the pusher, where each wire connects to an associated contact. Each contact is oppositely polarized (one positive, one negative) so that the contact, wire, and heater form a circuit. The pusher is then connected to an external interface / detachment controller (e.g., a hand-held detachment element) to initiate the detachment sequence. The external controller has appropriate circuitry and a voltage source (e.g., a battery) and aligns with the proximally facing pusher contacts, polarizing them and causing current to flow through the pusher 126 (through the wire), heating the heater 134 and initiating detachment. Further details of the thermal detachment system can be found in U.S. Pat. No. 9,717,500, which is incorporated herein by reference in its entirety.

[0076] Alternative embodiments of the detachment interface 130 may utilize a meltable portion (such as a polymeric joint) heated by a heater to initiate thermal detachment. Other embodiments of the detachment interface 130 may utilize a mechanical connection, such as a screw, to initiate detachment, where the user simply rotates a threaded engagement element in a particular direction. Alternatively, an electrolytic system may be used, where a wire is used to polarize the corrodible detachment joint, with a return current provided by the patient's blood to complete the detachment circuit. An electrolytic detachment system is described in U.S. Pat. No. 5,122,136, which is incorporated herein by reference in its entirety. Any implant detachment technique commonly known to those skilled in the art may be used to detach the stent 118 from the pusher 126.

[0077] Although the stent 118 has been described primarily as a flow diverter stent, the stent can also function other functions, such as serving as a scaffolding element to prevent migration of other embolic material (e.g., embolic coils) from the aneurysm that occludes the aneurysm.

[0078] Thus far in this disclosure, we have discussed helical shaped elements that can be used as stents, for example flow diverter stents. As previously mentioned, helical shapes are significantly more flexible than rigid tubular shapes (the latter being traditional stent designs and shapes). This flexibility has great advantages in deployment into smaller vessels in the neurovasculature and across tortuous vasculature, where deployment is more difficult and requires good flexibility for the stent to take the shape of the vasculature. This flexibility also provides additional advantages that make such designs useful in other medical devices besides stents.

[0079] As another embodiment, the helical structure may be used as an embolization or occlusion element to occlude a target site. The helical shape has several important advantages in that it is more flexible, as previously explained. This flexibility is also beneficial in an occlusion device, as a flexible device can more easily be manipulated to assume the shape of a target area, such as an aneurysm. These characteristics are useful for occlusion and filling of aneurysms. Additionally, the enhanced filling or occlusion characteristics further enhance the interruption of blood flow at the neck of the aneurysm, thereby aiding in preventing blood flow to the aneurysm.

[0080] 14 illustrates one or more helically shaped occlusion structures 138, constructed in a manner similar to the helical structures previously described and specifically configured for occlusion purposes, being deployed within the aneurysm 114. Another helically shaped stent structure 118 (or alternatively a conventional tubular stent structure) is placed against the aneurysm as a scaffolding element to help retain the occlusion structure 138 within the aneurysm.

[0081] When used for occlusion purposes, the occlusion structure 138 can be specifically configured for occlusion purposes (e.g., via device sizing, mesh / braid density / pick count, and / or wire size for making the braid / mesh) as opposed to stenting purposes. Desirable occlusion characteristics include having a small profile and a highly flexible shape that can be encapsulated within an aneurysm, and the helical occlusion structure 138 can be configured with these conditions to function as an occlusion device. For example, the helical occlusion structure can be one or more of smaller, constructed of more wires (facilitating flexibility), constructed of smaller wires, and / or utilizing a configuration with larger gaps between windings as compared to the helical stent 118 structure.

[0082] In alternative embodiments, the occlusion structure 138 is formed into other (e.g., non-helical) shapes. For example, the occlusion structure can be formed into an elongated, linear, conformable mesh that has a high degree of flexibility to assume the shape of the target area (e.g., an aneurysm). In one embodiment, the linear occlusion structure includes a wire or elongated element that runs within an interior passageway of the occlusion structure and between opposing ends. In one embodiment, the interior wire or elongated element is tensioned to aid in deployment and to help the linear occlusion structure assume a curved shape (e.g., to enhance a space-filling shape) upon deployment.

[0083] Another embodiment, shown in FIG. 15, utilizes an occlusion structure 140 having a curved-linear or complex (e.g., three-dimensional) type shape. In one embodiment, the occlusion structure 140 is heat set into this complex shape. Alternatively, the occlusion structure 140 includes a tensioned internal wire or tether 142 that is heat set into the complex shape that the occlusion structure 140 subsequently assumes, such that the internal member 142 forces the occlusion structure 140 into the complex or curved-linear shape. The shape shown in FIG. 15 is one example of a curved-linear or complex shape, however, various shapes can be utilized to enhance the packing ability and occlusion effectiveness of the occlusion structure 140.

[0084] Each structure (stent structure 118 and occlusion structure 138 as shown in FIG. 14) is delivered by a separate catheter. A first catheter is deployed into the aneurysm. A second catheter is then placed into the parent vessel across the neck of the aneurysm, and the helical shaped stent 118 is deployed from the second catheter. One or more helical shaped occlusion structures 138 are then delivered into the aneurysm 114 from the first catheter (e.g., in many cases for occlusion, multiple structures are deployed sequentially until the aneurysm is sufficiently occluded), and once the procedure is complete, the first and second catheters are removed.

[0085] Medical devices, including stents and occlusion devices, must be appropriately sized for the target treatment location. This requires an initial imaging step of the treatment location to determine the appropriate size of the device to treat the target space, so that a facility or physician can order a specific size device to perform the procedure. However, problems can arise if the dimensional measurements of the target space are inaccurate, or if the device does not properly deploy and expand to the desired dimensions in the target space (e.g., due to mechanical issues with the device or vascular conditions, such as tortuous vessels, that make deployment or expansion difficult). Furthermore, medical devices are generally only configured to perform a single intended function and cannot be configured to change shape, e.g., to perform another intended function. In addition, while medical devices are most often heat set to assume a specific, set deployed shape, there is generally no way to encourage the device to assume a unique shape based on the specific size or shape of a particular vascular condition. The following embodiments address at least these issues by utilizing a shape-setting system that includes a shape-setting structure useful for reshaping the medical device.

[0086] 16 illustrates an implant 200 comprised of a braid or mesh of one or more wires. The implant 200 is in a first elongated configuration and is connected proximally to a pusher 226. The implant 200 includes a shape-setting structure that is used to change the shape, configuration, or geometry of the braided implant 200, as described below. The shape-setting structure is part of a larger shape-setting system. In one embodiment, the shape-setting structure (shown in FIG. 16) includes first and second conductive elements 206a, 206b that extend the length of the implant 200.

[0087] In one embodiment, the conductive elements 206a, 206b are conductive wires that are interbraided or woven with the wires of the mesh that comprises the implant 200. In terms of terminology, the conductive elements 206a, 206b can be considered as conductive wire elements, conductive core wire elements, conductive core wire portions, shape setting members, or shape setting structures that function as shape setting elements. In one example, the conductive elements 206a, 206b are interbraided or woven with the mesh throughout in a manner similar to the way the radiopaque wire 102 was interbraided with the mesh of FIG. 1 as previously described herein. In one example, the conductive elements 206a, 206b are interbraided or woven with the implant 200 in a separate step after the implant 200 is first braided with its constituent wires. In another example, the conductive elements 206a, 206b are wound or braided with the constituent wires of the implant braid such that the implant 200 is braided.

[0088] In another embodiment, the conductive elements 206a, 206b are connected directly to the braid on either the inner or outer surface of the braid 200 such that the conductive elements 206a, 206b directly contact one or more wires of the braid 200 but are not inter-braided or interwoven with the implant braid 200.

[0089] Shape memory implants (e.g., stents or occlusion devices utilizing shape memory materials) generally utilize a first and second shape or configuration, the first shape / configuration being the shape the implant assumes when constrained within a delivery catheter, this first shape being stretched and compressed and believed to be a stress-induced martensitic phase.

[0090] The second shape is imparted by a heat treatment step, meaning that the device is heat treated (e.g., after being wound onto a mandrel) at a particular temperature (e.g., about 20 degrees Celsius or 68 degrees Fahrenheit) to become the expanded shape that the device assumes when released from the delivery catheter. This shape is considered the superelastic shape and is considered the austenitic phase. The relatively low temperature ensures that the device will expand at ambient temperature and in the body, which is fairly warm at about 98.6 degrees Fahrenheit.

[0091] The shape-setting structure (e.g., the conductive wires 206a, 206b) causes the implant to assume a third shape upon heating of the shape-setting structure. The conductive wires 206a, 206b are wound around a mandrel into a particular configuration (e.g., the helical configuration shown in FIG. 17), and then the conductive wires 206a, 206b are heat treated in this configuration at a particular temperature above body temperature to assume this shape upon reaching the particular temperature. This temperature may be referred to as a transition temperature, and the conductive wires 206a, 206b assume their tertiary shape when heated to this transition temperature. In one example, the transition temperature is anywhere in the range from above body temperature (37 degrees Celsius / 98.6 degrees Fahrenheit) to 42 degrees Celsius / 108 degrees Fahrenheit. In some examples, values ​​of 38 degrees Celsius, 39 degrees Celsius, or 40 degrees Celsius may be used as the transition temperature. When used in a procedure, a heating element or system is used to heat the conductive wires 206a, 206b to a transition temperature to impart a third or tertiary shape. Because the remainder of the implant 200 is connected to the conductive wires 206a, 206b (e.g., either because the conductive wires are woven between or braided with each other or because the conductive wires are directly connected to the wires of the implant 200), as the conductive wires 206a, 206b change to the tertiary shape, the remainder of the implant 200 also assumes this tertiary shape.

[0092] Thus, the implant 200 and shape-setting structure (e.g., conductive wires 206a, 206b) have three shapes: a first elongated / compressed shape while in the delivery catheter, a second shape based on the ambient / blood temperature to which it is exposed upon release from the delivery catheter, and a third shape when the shape-setting structure / conductive wires 206a, 206b are heated after the implant 200 is in its second shape.

[0093] In one embodiment, the conductive elements 206a, 206b are configured to not exceed a particular temperature threshold (e.g., 42 degrees Celsius). Techniques for not exceeding a particular temperature (e.g., 42 degrees Celsius) include configuring the system to not exceed a particular current threshold, which may be associated with a particular temperature (e.g., 42 degrees Celsius) to not reach or exceed a certain temperature. Alternatively, an automatic shutoff feature may be triggered when a particular current or temperature threshold is detected.

[0094] In one embodiment, the braided implant 200 is configured similarly to the other multi-layer (two or more) layer braids described above and shown in FIGS. 7-9, where the braided implant initially has a linear elongated profile (e.g., when the helical shape of FIG. 7 or FIG. 9 is elongated / stretched) and when the conductive elements 206a, 206b reach a transition temperature and change shape to the helical configuration, they assume the helical multi-layer shape of FIG. 7 or FIG. 9, thereby encouraging the remainder of the implant braid 200 to also assume a helical shape.

[0095] In one embodiment, the conductive elements 206a, 206b are interbraided to the mesh implant in a manner similar to how the radiopaque wires 102 are interbraided or woven to the implant of Figure 1, as previously described herein. In one example, the conductive elements 206a, 206b are sized similarly to the other wires forming the mesh implant 200 (e.g., about 0.025mm to 0.075mm in diameter) or larger than the wires forming the mesh implant 200 (e.g., about 0.05mm to 0.15mm in diameter).

[0096] In one embodiment, the conductive elements 206a, 206b are constructed from a good shape memory material so that they can be heat set into the appropriate curved or spiral-type shape as a heated expansion shape. The conductive elements 206a, 206b must also be good conductors of electricity to facilitate the passage of electrical current and heat generation. In one embodiment, Nitinol is used, which is a good shape memory metal material. Alternatively, other materials such as stainless steel or cobalt chrome may be used. In one embodiment, a stretch-filled tube wire is used that utilizes a radiopaque metal core (e.g., platinum, platinum / tungsten alloy, gold, or tantalum) and a shape memory metal jacket (e.g., Nitinol, stainless steel, or cobalt chrome). To facilitate heat generation, the conductive elements 206a, 206b may further include high resistance regions (e.g., bands or coil / spiral shapes) along their length.

[0097] Several techniques can be used to maximize the thermal retention of the conductive elements 206a, 206b and prevent tissue damage due to thermal exposure. In one embodiment described above, a current or temperature threshold or automatic shutoff feature is used to maintain a constant current or temperature profile along the conductive elements 206a, 206b. In another embodiment, an insulating material (e.g., a polymer or a metal with low electrical conductivity) is used around the conductive elements 206a, 206b. In one embodiment, the insulating material is provided circumferentially around the conductive elements 206a, 206b, for example as a peripheral hollow tube. In one embodiment, the implant 200 itself is coated with an insulating material (e.g., a polymer).

[0098] As shown generally in FIG. 17, conductive elements 206a, 206b are connected to a proximal heating mechanism 202. In one embodiment, conductive elements 206a, 206b are comprised of a single wire that is wound in a first distal direction to the distal end of the implant (to form element 206a) and then back wound in a proximal direction to the proximal end of the implant (to form element 206b). In another embodiment, conductive elements 206a, 206b are two separate wires. The first wire 206a is wound proximally to distally and connected to conductive band 204. In one embodiment, conductive band 204 is wound in a first distal direction to the distal end of the implant (to form element 206a). In another embodiment, conductive elements 206a, 206b are two separate wires. The first wire 206a is wound proximally to distally and connected to conductive band 204. In one embodiment, conductive band 204 is wound in a second proximal direction to the proximal end of the implant (to form element 206b). 04 is radiopaque (e.g., platinum-iridium, which is radiopaque and has good conductive properties) and acts like a radiopaque marker by enhancing visualization of the distal end of the implant. A second wire 206b is wound from distal to proximal and connected to a conductive band 204. The conductive band 204 electrically connects the first and second wires 206a, 206b. In an alternative configuration, thin conductive tubes can be used instead of wires to form the conductive elements 206a, 206b.

[0099] 18 illustrates one embodiment of a heating mechanism 202 used to heat the conductive elements 206a, 206b. The distal end of the pusher 226 includes a first electrical contact 228 and a second electrical contact 230 that are oppositely polarized, e.g., the first contact 228 is positive and the second contact 230 is negative. However, this configuration can be reversed. The first and second contacts 228, 230 are polarized via wires 228a, 230a, with wire 228a connected to contact 228 and wire 230a connected to contact 230. Wires 228a, 230a are each connected to oppositely charged voltage sources (e.g., positive and negative terminals) at the proximal end of the system, and the wires carry associated electrical currents to each contact 228, 230.

[0100] In one embodiment, one or more of the contacts 228, 230 are tubular bands, and the tubular configuration allows a wire 230a to pass through the more proximally oriented contact 228 to connect to the distal contact 230. As shown in FIG. 18, each contact is enlarged relative to the distal portion of the pusher 226. The proximal ends of the conductive elements 206a, 206b are shown in FIG. 18, which shows how the proximal ends of the conductive elements 206a, 206b connect to a heater mechanism. At the proximal end of the conductive element 206a is a coil 208a, which is conductive and allows for electrical connection to the contact 228. At the proximal end of the second conductive element 206b is a coil 208b, which is conductive and allows for electrical connection to the contact 230. In one example, the coils 208 a , 208 b are radiopaque, such as tantalum, platinum, palladium, or gold, to enhance visualization of the proximal end or region of the braided implant 200 .

[0101] If conductive elements 206a, 206b are comprised of a single wire having a proximal-to-distal traverse portion (e.g., 206a) and a distal-to-proximal traverse portion (e.g., 206b), each end of the single wire is connected to (or in electrical communication with) a different contact, with one end connecting to contact 228 and the other end connecting to contact 230. If conductive elements 206a, 206b are comprised of two separate wires spanned by a distal conductive band, the proximal end of the first wire connects to contact 228 and the proximal end of the second wire connects to contact 230.

[0102] A proximal end of the first conductive element 206a is connected to a first contact 228 of one polarity (e.g., positive polarity) and a proximal end of the second conductive element 206b is connected to a second contact 230 of another polarity (e.g., negative polarity) so that, for example, current flows from the first conductive element 206a toward the distal end of the braided implant and back through the second conductive element 206b, completing a circuit. The current causes the braided implant to assume its subsequent (e.g., helical) shape by using a helical or curved shape memory by heating the first and second conductive elements 206a, 206b.

[0103] The user activates the heating mechanism via a handheld mechanism that includes a power / voltage source (e.g., pressing a button on a handheld controller connected to the proximal end of the pusher 226), causing an electric current to flow through the contacts and the connected conductive elements 206a, 206b, causing the implant 200 to assume a helical shape, configuration, or configuration.

[0104] The embodiment presented in Figure 18 does not necessarily require a detachment system to detach the implant 200 from the pusher 226 because the proximal marker coils 208a, 208b that form the proximal ends of the conductive elements 206a, 206b are in the recesses defined between the enlarged contacts 228, 230 when the braided implant 200 (or at least the proximal end of the implant 200) is in the delivery catheter. This is shown in more detail in Figure 19 with respect to the overlying delivery catheter 232. The marker coils 208a, 208b are horizontally constrained between the enlarged contacts 228, 230 and vertically constrained by the introducer sheath / catheter 232 above and the pusher portion below.

[0105] Once the entire implant 200 has been pushed distally or the catheter 232 has been retracted to fully expose the implant 200, the marker coils 208a, 208b are no longer constrained, releasing the implant as shown in FIG. 20. In one embodiment, the remaining wires forming the implant 200 are connected to a distal band element (not shown, located distal to the contact 230). The band element acts as a proximal collection point for the wires forming the implant 200 and can function similarly to the marker 128 of FIG. 12. This additional band element is part of the implant itself and therefore will release with the implant, but the contact 230 and everything proximal to the contact will not release with the implant 200 as they are part of or connected to the pusher 226.

[0106] In an alternative embodiment, instead of the catheter 232 providing a restraining force to prevent or enable detachment, a detachment system (e.g., electrolytic, mechanical, or thermoelectric system), as shown for example in Figure 13, is used, and the user can interact with a controller mechanism connected to the pushers 126, 226. The controller mechanism has two control interfaces (e.g., buttons), where activation of a first button heats the conductive elements 206a, 206b and causes the implant to assume a helical post-expanded shape, and activation of a second button activates the detachment system to detach the implant.

[0107] One significant advantage of using a shape-setting structure (e.g., conductive elements 206a, 206b) to assist the implant 200 in assuming its subsequent post-deployment shape is that the device does not need to be sized specifically for use in a vasculature environment (e.g., as a flow diverter stent or occlusion device). Even if the diameter of the helical shape is larger than the vessel in which the device is placed, the vessel wall provides a retaining force that limits the size of the shape the device can assume. Thus, in one example, a one-size-fits-all elongated structure can be used to treat vessels and vasculature conditions of various sizes, and after the shape-setting structure is heated / actuated, the elongated structure assumes a different shape (e.g., a helical shape, etc.).

[0108] The system and method of applying an electric current through the conductive elements 206a, 206b of the implant to cause it to assume a different shape can be used in a variety of different ways other than causing the implant to assume a helical shape. For example, the technique and system can be used to cause the implant to assume a wide variety of distinctly different shapes (e.g., not just a helical shape). The important feature is that the conductive elements 206a, 206b are wound into a particular shape and then thermally heat set at a particular transition temperature, which is the shape that the conductive elements 206a, 206b assume when heated to this particular transition temperature. The remaining portions of the implant are then connected to or interwoven with the conductive elements 206a, 206b, and therefore assume the shape of the conductive elements when this particular transition temperature is reached.

[0109] In one embodiment, the shape parameters are reversed so that the initial primary or delivery shape (e.g., the expanded shape the device initially assumes when delivered from a delivery catheter) is a helical or coiled shape, and then the subsequent or tertiary shape that the conductive elements 206a, 206b (and implant 200) assume as they are heated is a more elongated or linear shape.

[0110] In alternative embodiments, the conductive elements 206a, 206b can have alternative configurations other than the one or two elements illustrated in Figures 16-17. In Figure 18, the conductive elements 206a, 206b have two proximal end portions that allow for connection to the pusher 226 and electrical connection to the polarized contacts 228, 230. However, the conductive elements 206a, 206b can have a complex shape that reaches proximally to two proximal nodes or extensions. For example, instead of an elongated wire portion that travels from the proximal end of the implant to the distal end and back again, the elongated wire portion can travel in a serpentine manner (e.g., with several curves or complex shapes), an example of which is shown in Figure 22. One advantage of this configuration is that a larger area of ​​the implant braid 200 contacts the area of ​​the conductive elements 206a, 206b, increasing the shape manipulation effect on the implant braid 200 as the conductive elements are heated to a particular transition temperature and assume a particular shape profile. In another configuration, the conductive elements 206a, 206b can be of a similar structure to the implant braid 200 and utilize more of a scaffold shape that is placed above, below, or woven into the implant braid 200. One advantage of this configuration is that the majority of the implant braid 200 has adjacent conductive elements 206a, 206b, which increases the shape manipulation effect on the implant braid 200 when the conductive elements 206a, 206b are heated to a particular transition temperature and assume a tertiary shape. Although selective shapes are illustratively shown or described as examples, any number of shapes are contemplated without limitation, as any shape can be formed simply by utilizing a particular winding shape on the shape-setting members (e.g., conductive elements 206a, 206b). For example, FIG. 15 illustrates another complex shape that can be utilized as a tertiary shape that can be selectively actuated by actuation of a shape-setting member.

[0111] In one embodiment shown in FIG. 21, the conductive elements 206a, 206b include intermediate spring or coiled shapes 234a, 234b. One advantage of this shape is that the nested windings of these shapes increase the resistance of current flow through these sections, thereby increasing the associated temperature, allowing the conductive elements 206a, 206b to heat up without requiring as much current. Although the above configuration is shown as utilizing one consistent shape (meaning that the conductive elements 206a, 206b are a single element), the configuration could instead utilize a connecting band (e.g., band 204 in FIG. 16) and two separate wire elements in electrical communication through the connecting band.

[0112] The shape-setting features described herein can be used to selectively allow the implant to assume a particular shape or configuration when heated to a particular transition temperature point after deployment. In some embodiments, this mechanism can be used to allow the implant to selectively operate as an occlusion device or a stent device, where the device in a first stretched, deployed configuration can act as an occlusion mesh, but the user can optionally place the implant in a different helical configuration that acts as a flow diverter. In some embodiments, this mechanism can be utilized to allow the implant to selectively assume multiple shapes to treat a particular condition. For example, the user can treat an aneurysm with an elongated braid, or actuate a different subsequent shape configuration via transition temperature actuation to place the braid in another configuration (e.g., a helical shape), and then occlude the aneurysm with this alternative helical shape.

[0113] In one example, multiple implants 200 that can selectively assume a tertiary shape (e.g., a helical shape) at a treatment location can be used for multiple purposes. For example, a user can initially deploy a first implant across the neck of an aneurysm into an adjacent vessel as a stent that is actuated to a particular shape (e.g., a helical shape) through a shape-setting member. The user can then deploy a second implant into the aneurysm as an occlusion member, and the user can optionally actuate a shape-setting member to cause the implant to assume a particular shape (e.g., a helical shape) into another occlusion shape.

[0114] In an alternative embodiment, the heating system (via contacts 228, 230 configured to transmit electrical current through the shape setting members / conductive elements 206a, 206b) is configured with a user interface to allow a user to apply selective amounts of electrical current to control the extent to which the shape setting members / conductive elements 206a, 206b assume their respective tertiary shapes (e.g., helical shapes) and to control the extent to which the implant 200 assumes its tertiary shape (e.g., helical shape). In this manner, the user can control the extent to which the implant changes its shape. When the conductive elements 206a, 206b reach their respective shape memory transition temperatures, they begin to assume a particular shape (e.g., helical shape). In one embodiment, this is not necessarily an instantaneous transition, as continued exposure to electrical current at the transition point results in a related shape change over time. In one example, a user can manipulate a dial or button to initiate the shape transition process and then stop the transition via manipulation of the same dial or button once a desired shape (e.g., a partial helical shape instead of a full helical shape) is reached (e.g., move the dial up and then down or toggle the button once and then again to toggle it off). In this way, the user can control the particular final shape profile of the implant. For example, such control is desired in certain situations where the implant is too large compared to the vessel such that the helical shape partially conforms to the target treatment area, e.g., to act as a flow diverter. Alternatively, if the user desires to use the implant as an occlusion device, the user can control the final deployment shape of the occlusion device based on the particular configuration or shape of the target treatment area (e.g., aneurysm). In alternative embodiments, the thermal / current induced shape formation is more immediate, with non-exhaustive factors influencing time considerations including the size of the implant, how much contact the implant is with the shape-setting structure, the power associated with the heating system and how much current is passing through the shape-setting structure (e.g., conductive elements 206a, 206b), as well as the difference between body temperature and the shape memory transition temperature of the shape-setting structure.

[0115] The embodiments of Figures 16-22 generally utilize a three stage shape mechanism with a first stage stretched / compressed shape in the delivery catheter, a second stage expanded shape upon release from the delivery catheter and reaching a particular low ambient temperature, and then a third stage post-expanded shape upon the shape-setting member or structure being heated to a particular transition temperature. In some terminology, the shape that the implant assumes within the catheter can be considered a first or delivery shape, the shape that the implant assumes upon release from the catheter and initially expanding can be considered a secondary shape, and the shape that the implant assumes when the shape-setting structure is heated to a particular transition temperature (e.g., a helical shape) can be considered a tertiary shape. Alternatively, a stent can be considered to assume a first or primary expanded shape upon release from the delivery catheter, and then a secondary expanded shape when the shape-setting structure is heated to a particular transition temperature to place the implant in a different post-deployment shape (e.g., a helical shape).

[0116] With regard to terminology, implants according to embodiments described herein, when utilized with the shape-setting structures disclosed herein, can include three shapes or states (which may also be considered state-setting structures since they affect the shape and / or state of the implant). The implant is in a first compressed or elongated state when contained within a delivery catheter. The implant is in a second resting or expanded state, which, upon release from the delivery catheter, is exposed to ambient or blood temperature, which places the implant in its expanded delivery configuration. Finally, the implant is in a third or final state when the implant is heated after delivery (e.g., via heating of the shape or state-setting structure, as described above and in various embodiments herein), which may be considered a post-expanded state or final pre-set state. Because this third or final state is used in a surgery or procedure, the final pre-set state may be considered an operating state or operating shape.

[0117] Although this specification has primarily illustratively described the use of shape or state setting structures in conjunction with implants configured as stents or occlusion devices, the structures can in principle be used to change the shape or state of a variety of implants, and thus these embodiments are not limited in any way. Although the term stent is used frequently herein, the embodiments described herein can be used with a variety of vascular prosthetic devices, such as stents, stent grafts, and vascular scaffoldings.

[0118] Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as molecular weights, reaction conditions, and the like used in the specification and claims should be understood in all instances as modified by the term "about". Thus, unless otherwise indicated, the numerical parameters set forth in this specification and the appended claims are approximations that may vary depending on the desired properties sought to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should be construed, at the very least, in light of the number of reported significant digits and by applying ordinary rounding techniques. While the numerical ranges and parameters broadly defining the present invention are approximations, the numerical values ​​set forth in the specific examples are reported as precisely as possible. However, numerical values ​​inherently contain certain errors resulting from the standard deviation found in their respective testing measurements.

[0119] The terms "a," "an," "the," and similar references used in the context of describing the present invention (particularly in the context of the claims that follow) should be construed to encompass both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The recitation of ranges of values ​​described herein is merely intended to serve as a shorthand method of individually referring to each separate value falling within the range. Unless otherwise indicated herein, each separate value is incorporated herein as if it were individually recited herein. All methods described herein can be performed in any suitable order, unless otherwise indicated herein or clearly contradicted by context. The use of any and all examples or exemplary language (e.g., "etc.") provided herein is intended merely to better clarify the invention and does not impose limitations on the scope of the invention as otherwise claimed. No language in this specification should be construed as indicating any non-claimed element essential to the practice of the invention.

[0120] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member may be referred to and claimed individually or in any combination with other members of the group or other elements found herein. It is anticipated that one or more members of a group may be added to or deleted from a group for reasons of convenience and / or patentability. When such addition or deletion occurs, the specification is deemed to contain the modified group and the written description of all Markush groups used in the appended claims is satisfied.

[0121] Certain embodiments of the invention are described herein, including the best mode known to the inventors for carrying out the invention. Of course, variations of these described embodiments will become apparent to those skilled in the art upon reading the foregoing description. The inventors anticipate that such variations will be employed by those skilled in the art as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or clearly contradicted by context.

[0122] Additionally, throughout this specification, numerous references are made to patents and printed publications. Each of the above cited patents and printed publications is hereby incorporated by reference in its entirety.

[0123] Finally, it is to be understood that the embodiments of the invention disclosed herein are illustrative of the principles of the invention. Other variations that may be employed are within the scope of the invention. By way of example, and not of limitation, alternative configurations of the invention may be utilized in accordance with the teachings herein. Thus, the invention is not limited to that precisely as shown and described.

Claims

1. 1. A medical implant comprising: Pusher and a scaffold structure comprising one or more scaffold wires woven to form an elongated mesh; a shape-setting structure including a first conductive wire disposed along the elongated mesh; an electrical circuit having a first electrical contact and a second electrical contact included in the pusher, the electrical circuit providing electrical power through the first conductive wire to generate heat; a first coil at a proximal end of the shape-setting structure and in electrical contact with the first electrical contact; a second coil at a proximal end of the shape-setting structure and in electrical contact with the second electrical contact; The medical implant, wherein the first conductive wire has a transition temperature that changes a shape of the medical implant to an operative configuration.

2. 10. The medical implant of claim 1, wherein the shape-setting structure further comprises a second conductive wire, the first conductive wire and the second conductive wire being connected by a distal conductive band.

3. The medical implant of claim 1 , wherein the operating configuration is a helical shape.

4. The medical implant of claim 1 , wherein the operating configuration is a curved shape.

5. 2. The medical implant of claim 1, wherein the shape-setting structure further comprises a second conductive wire, the first conductive wire and the second conductive wire being directly connected to the elongated mesh on either an inner surface of the elongated mesh or an outer surface of the elongated mesh such that the first conductive wire and the second conductive wire are in direct contact with the elongated mesh without being interbraided or interwoven with the elongated mesh.

6. 10. The medical implant of claim 1, wherein the shape-setting structure further comprises a second conductive wire, the first conductive wire and the second conductive wire being interwoven with the elongated mesh.

7. The medical implant of claim 1 , wherein the elongated mesh is formed from a flat woven tube.

8. 10. The medical implant of claim 1, wherein the shape-setting structure further comprises a second conductive wire, the first conductive wire and the second conductive wire having an intermediate coiled shape.

9. 10. The medical implant of claim 1, wherein the shape-setting structure further comprises a second conductive wire, the first conductive wire and the second conductive wire comprising a stretch-filled tube.

10. 10. The medical implant of claim 1, wherein the shape-setting structure further comprises a second conductive wire, the first conductive wire and the second conductive wire comprising an outer layer of insulating material.

11. 10. The medical implant of claim 1, wherein the shape-setting structure further comprises a second conductive wire, a first coil positioned around a proximal portion of the first conductive wire, and a second coil positioned around a proximal portion of the second conductive wire.

12. 10. The medical implant of claim 1, wherein the pusher includes a recess between the first electrical contact and the second electrical contact, the first coil and the second coil being horizontally constrained within the recess.

13. The medical implant of claim 1 , wherein after said change in shape, said elongated mesh maintains said operating configuration below said transition temperature.

14. The medical implant of claim 1 , wherein after said shape change, said elongated mesh maintains said operating configuration at body temperature.

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