Vascular occlusion devices

Abstract

Regarding medical devices and intravascular medical procedures, more specifically, the present invention relates to devices and methods for occluding vascular disorders such as aneurysms. [Solution] The vascular occlusion device 10 includes a vascular occlusion structure 16 configured to be implanted in an aneurysm sac, which becomes a delivery configuration when confined within a delivery catheter 12 and a deployed configuration when released from the delivery catheter 12 into the aneurysm sac, and at least a portion of the vascular occlusion structure 16 is made of an AuPtW (gold-platinum-tungsten) alloy, the AuPtW alloy contains platinum in the range of 25% to 40% by weight, and the AuPtW alloy contains tungsten in the range of 0.01% to 10% by weight.

Description

Technical Field

[0001] The present disclosure generally relates to medical devices and endovascular medical procedures, and more particularly to devices and methods for occluding vascular disorders such as aneurysms.

Background Art

[0002] Vascular occlusion devices or implants are used for various reasons, such as the treatment of endovascular aneurysms. An aneurysm is an expansion of a blood vessel or other vessel, which can pose a risk to the patient's health due to rupture, clotting or dissection. For example, if an aneurysm in a patient's brain ruptures, it can cause a stroke, leading to brain damage or death. Brain aneurysms are detected in patients, for example, after a seizure or bleeding, and may be treated by applying a vascular occlusion device.

[0003] Generally used vascular occlusion devices include soft, helically wound coils formed by winding platinum (or platinum alloy) wire strands around a "primary" mandrel.

[0004] Subsequently, this coil is wound around a larger "secondary" mandrel and heat treated to impart a secondary shape. For example, U.S. Patent No. 4,994,069 issued to Ritchart et al. (which is hereby incorporated by reference in its entirety as if fully set forth herein) describes a vascular occlusion device that becomes a straight, helical primary shape when stretched for placement through the lumen of a delivery catheter and a folded, complex secondary shape when released from the delivery catheter and placed in the vascular system. A complex three-dimensional secondary shape can be imparted to the vascular occlusion device to more appropriately frame and fill an aneurysm, and the rigidity / flexibility of the vascular occlusion device can be changed.

[0005] To deliver a vascular occlusion device to a desired site within the vascular system, such as the aneurysm sac, it is commonly known that a small-profile delivery catheter or "microcatheter" is first positioned at that site using a guidewire. Generally, the distal end of the microcatheter is provided with a selected pre-formed bend, such as a 45-degree, 26-degree, "J"-shaped, "S"-shaped, or other bend shape, depending on the patient's specific anatomical structure, by the attending physician or manufacturer, so that when the guidewire is withdrawn, it remains in a specific position to release one or more vascular occlusion devices into the aneurysm sac. Subsequently, the delivery assembly or "pusher" assembly or "wire" is passed through the microcatheter until the vascular occlusion device, coupled to the distal end of the delivery assembly, extends from the distal end opening of the microcatheter into the aneurysm sac. Once inside the aneurysm sac, a portion of the vascular occlusion device can be deformed or bent to allow for more efficient and complete filling.

[0006] Subsequently, the vascular occlusion device is released or "separated" from the distal end of the delivery assembly, and the delivery assembly is retracted through the microcatheter. Depending on the patient's specific needs, one or more additional vascular occlusion devices can be pushed through the microcatheter and released into the same aneurysm sac.

[0007] Fluoroscopy is used to visualize the occlusion device during delivery into the aneurysm, while magnetic resonance imaging (MRI) can typically be used to visualize the treated area post-procedure (e.g., several weeks after initial treatment of the aneurysm) to confirm that the aneurysm sac is properly occluded. For this reason, the occlusion device can be constructed to allow for its radiopaqueness during aneurysm treatment while minimizing artifacts that interfere with visualization during post-procedure MRI (i.e., MRI-compatible). Furthermore, it is of paramount importance that such occlusion devices be "soft" (i.e., laterally flexible or adaptable) and thus non-traumatic in order to prevent rupture of the delicate tissue of the aneurysm.

[0008] Furthermore, it is crucial that such vascular occlusion devices remain within the aneurysm for an extended period. However, aneurysms with large openings, commonly known as "plaintorrhea aneurysms," are difficult to position and retain vascular occlusion devices within the aneurysm sac, and especially with small, relatively thin vascular occlusion coils, even with skillful placement, there is insufficient substantial secondary morphological strength to maintain their position within such aneurysm sacs. For this reason, stents or balloons may be placed in vessels adjacent to the neck of the aneurysm to ensure the vascular occlusion coil is securely retained within the aneurysm sac, thereby complicating the procedure. To address this problem, vascular occlusion devices composed of at least partially braided (or woven) structures have been developed. Such braided vascular occlusion devices provide a wide range and effective backbone throughout the neck of the aneurysm, thereby allowing them to be effectively retained within the plaintorrhea aneurysm without the need to deploy auxiliary aneurysm retention devices such as balloons or stents.

[0009] However, regardless of whether coiled or braided occlusive devices are used, the delivery system for occlusive devices is such that the devices are relatively short and have limited expandability, otherwise it would be difficult (if not impossible) to push them into / out of the microcatheter. Unfortunately, small (short) occlusive devices are not very advantageous because the delivery of such small occlusive devices to an aneurysm sac requires a longer and more complex procedure. For example, a 7mm diameter neuroaneurysm sac is typically filled with 5-7 individual spring coils, making the procedure longer and more complex than if the number of devices were reduced.

[0010] Theoretically, the length of the occlusive device can be increased, reducing the number of devices needed to treat an aneurysm. However, increasing the length of the occlusive device inevitably increases friction between such a device and the lumen of the delivery catheter. Therefore, to ensure reliable delivery of the occlusive device into the aneurysm, the column strength of such a device may be increased (e.g., by selecting a material with a high Young's modulus or by increasing the diameter of the wire on which the occlusive device is formed), and / or the diameter of the delivery catheter may be increased. However, as mentioned above, it is advantageous to keep the diameter of the delivery catheter as small as possible to allow access to the aneurysm from a very small vascular system, and for the occlusive device to be soft enough not to damage the delicate aneurysmal tissue.

[0011] While relatively long vascular occlusion devices possess column strength suitable for delivery through relatively small-diameter delivery catheters, materials that meet other competing design parameters, including softness, radiopaqueness, and MRI compatibility, are very limited.

[0012] For example, known materials with relatively high Young's modulus and relatively high radiopaqueness, such as platinum-tungsten (PtW) alloys from which vascular occlusion coils are typically manufactured, can be used to provide column strength suitable for relatively long vascular occlusion devices. However, the diameter of the wire from which such vascular occlusion devices are manufactured may be reduced to achieve a certain degree of flexibility while ensuring that the vascular occlusion device fits within a small-diameter delivery catheter. As a result, the radiopaqueness of the vascular occlusion device decreases, reducing the column strength, which may necessitate shortening the vascular occlusion device and / or requiring a larger-diameter delivery catheter.

[0013] As another example, known materials with relatively low Young's modulus and low radiopaqueness, such as nitinol, can be used to provide suitable softness for vascular occlusion devices. However, such vascular occlusion devices would lack the appropriate radiopaqueness and column strength to increase the length of the occlusion device. Furthermore, the heating process to set the nitinol into a predetermined shape can result in surface oxides, which may crack and release toxic nickel. Therefore, such oxides may need to be removed from the vascular occlusion device using a costly and time-consuming process.

[0014] As yet another example, using known materials with relatively intermediate Young's modulus and low radiopaqueness, such as titanium, if the optimal diameter is selected for the wire from which such a vascular occlusion device is manufactured, it may be possible to provide column strength suitable for relatively long and flexible vascular occlusion devices. However, such vascular occlusion devices would not exhibit sufficient radiopaqueness.

[0015] Therefore, there is a continuing demand for vascular occlusion devices that satisfy one or more of the design parameters described above. [Overview of the project]

[0016] The embodiments described herein relate to implantable medical devices such as embolization devices and blood flow filters that are at least partially made (i.e., constructed) from a gold-platinum-tungsten alloy.

[0017] In various embodiments, the implantable device is made from one or more elongated members made of a gold-platinum-tungsten alloy, such as in the form of a cut tube, a coiled wire, or a braided series of wires. The elongated members may include, but are not limited to, composite or non-composite wires having at least one layer, at least a core, or the entire cross-section made of a gold-platinum-tungsten alloy.

[0018] The vascular occlusion device includes a vascular occlusion structure configured to be implanted in an aneurysm sac, which is in a delivery configuration when confined within a delivery catheter and in a deployed configuration when released from the delivery catheter into the aneurysm sac, and at least a portion of the vascular occlusion structure is made of an AuPtW (gold-platinum-tungsten) alloy, the AuPtW alloy containing platinum in the range of 25% to 40% by weight and the AuPtW alloy containing tungsten in the range of 0.01% to 10% by weight.

[0019] Optionally, AuPtW alloys have a Young's modulus of less than 25 megapounds per square inch (Mpsi).

[0020] Optionally, the vascular occlusion structure includes a mesh made of AuPtW alloy.

[0021] Optionally, the mesh is a braid.

[0022] Optionally, the entire vascular occlusion structure includes a mesh.

[0023] Optionally, the vascular occlusion structure further comprises two spirally wound coils positioned at both ends of the mesh.

[0024] Optionally, each of the two spirally wound coils is made of AuPtW alloy.

[0025] Optionally, the mesh includes at least one wire, each wire having a minimum cross-sectional dimension in the range of 0.0005 inches to 0.004 inches.

[0026] Optionally, the mesh includes at least one twisted strand.

[0027] Optionally, the mesh may have a number of wires ranging from 8 to 96.

[0028] Optionally, the mesh has a number of wires in the range of 16 to 32 wires.

[0029] Optionally, the mesh has an unconstrained braiding angle in the range of 20 degrees to 60 degrees.

[0030] Optionally, the mesh has an extended geometric shape with a circular cross-section.

[0031] Optionally, the mesh has an extended geometric shape with a rectangular cross-section.

[0032] Optionally, the rectangular cross-section has a width in the range of 0.5 mm to 5.0 mm.

[0033] Optionally, the mesh has a bending stiffness of less than 150 mN / mm.

[0034] Optionally, the vascular occlusion structure includes a coil made of an AuPtW alloy.

[0035] Optionally, the coil is configured to take on a three-dimensional shape with multiple loops when deployed from a delivery catheter.

[0036] The vascular occlusion assembly includes a vascular occlusion device and a pusher member to which the vascular occlusion device is removably coupled.

[0037] The vascular occlusion treatment system includes the vascular occlusion assembly according to the claims and a delivery catheter in which the vascular occlusion assembly is disposed.

[0038] The vascular occlusion device includes a vascular occlusion structure configured to be implanted within an aneurysm sac, which has a delivery configuration when constrained within a delivery catheter and a deployed configuration when released from the delivery catheter into the aneurysm sac, and at least a portion of the vascular occlusion structure is made of an AuPtW (gold - platinum - tungsten) alloy.

[0039] Other and further aspects and features will become apparent from the following detailed description, with reference to the attached drawings. [Brief explanation of the drawing]

[0040] [Figure 1] Figure 1 is a side view of a vascular occlusion treatment system, and in particular shows vascular occlusion within the delivery catheter in the delivery configuration. [Figure 2] Figure 2 is a side view of the vascular occlusion treatment system shown in Figure 1, and in particular shows the vascular occlusion device deployed from the delivery catheter in an expanded configuration. [Figure 3] Figure 3 is a plan view of the vascular occlusion structure of the vascular occlusion treatment system shown in Figure 1, deployed within the aneurysm sac. [Figure 4] Figure 4 is a plan view of the mesh portion of the vascular occlusion structure of the vascular occlusion treatment system shown in Figure 1. [Figure 5] Figure 5A is a cross-sectional view of the wire used in the mesh portion of Figure 4. Figure 5B is a cross-sectional view of the wire used in the mesh portion of Figure 4. Figure 5C is a cross-sectional view of the wire used in the mesh portion of Figure 4. [Figure 6] Figure 6A is a cross-sectional view of the mesh portion of the vascular occlusion treatment system shown in Figure 1. Figure 6B is a cross-sectional view of the mesh portion of the vascular occlusion treatment system shown in Figure 1. [Figure 7] Figure 7 shows the AuW phase diagram. [Figure 8] Figures 8A and 8B show another embodiment of the vascular occlusion device. [Figure 9] Figure 9 is a side view of the vascular occlusion treatment system, and in particular shows the vascular occlusion within the delivery catheter in the delivery configuration. [Figure 10] Figure 10 is a side view of the vascular occlusion treatment system shown in Figure 9, and in particular shows the vascular occlusion device deployed from the delivery catheter in an expanded configuration. [Modes for carrying out the invention]

[0041] With respect to the terms defined below, unless otherwise given in the claims or elsewhere in this specification, those definitions shall apply.

[0042] All numerical values ​​herein, whether expressly or otherwise, are deemed to be qualified by the term “approximately.” The term “approximately” generally refers to a range of numerical values ​​that a person skilled in the art would consider equivalent to (i.e., having the same function or result as) the value mentioned. Often, the term “approximately” can include numerical values ​​rounded to the nearest significant figure.

[0043] A numerical range described by endpoints includes all numbers within that range (for example, 1-5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).

[0044] In this specification and the appended claims, the singular “a,” “an,” and “the” refer to multiple subjects unless the context explicitly indicates otherwise. In this specification and the appended claims, the term “or” is generally used to mean “and / or” unless the context explicitly indicates otherwise.

[0045] The following describes various features with reference to the drawings. The drawings are not necessarily drawn to scale, and the relative scale of selected elements may be exaggerated for clarity. Elements of similar structure or function are indicated by the same reference numerals throughout the drawings. It should also be understood that the drawings are intended to facilitate the description of features and are not intended to be an exhaustive description of the invention as described in the claims, or to limit its scope as defined by the attached claims and their equivalents.

[0046] Furthermore, each illustrated embodiment of the disclosed invention does not necessarily have to have all of the illustrated features, and features, aspects, or advantages described in relation to a particular embodiment are not necessarily limited to that embodiment and may be implemented in other embodiments even if not illustrated as such.

[0047] An embodiment of a vascular occlusion treatment system 10 constructed according to the present invention will be described with reference to Figures 1 and 2. The vascular occlusion treatment system 10 comprises a delivery catheter 12 and a vascular occlusion assembly 14 slidably disposed within the delivery catheter 12. The vascular occlusion assembly 14 comprises a vascular occlusion structure 16 and a pusher member 18 to which the vascular occlusion structure (or vascular occlusion device) 16 is detachably connected at a joint 20.

[0048] The delivery catheter 12 has a tubular structure and can take the form of, for example, a microcatheter. The delivery catheter 12 comprises an elongated sheath body 22 having a proximal portion 24 and a distal portion 26, and a lumen 28 (shown by a dashed line) extending through the sheath body 22 between the proximal portion 24 and the distal portion 26. The proximal portion 24 of the sheath body 22 remains outside the patient and accessible to the operator when the vascular occlusion treatment system 10 is in use, while the distal portion 26 of the sheath body 22 is of a size and size that can reach distant locations in the vascular system and is configured to deliver the vascular occlusion structure 16 to the aneurysm. The delivery catheter 12 may have at least one port 30 that fluidizes the lumen 28 of the delivery catheter 12 and is used to introduce fluid into the sheath body 22. The vascular occlusion assembly 14 is located within the lumen 28 of the delivery catheter 12, as can be clearly seen in Figure 1.

[0049] The delivery catheter 12 may include one or more regions along its length having different configurations and / or properties. For example, the distal portion 26 of the sheath body 22 may have a smaller outer diameter than the proximal portion 24 of the sheath body 22 in order to reduce the profile of the distal portion 26 and facilitate navigation in the winding vascular system. Furthermore, the distal portion 26 may be more flexible than the proximal portion 24. Generally, the proximal portion 24 may be formed from a more rigid material than the distal portion 26 of the sheath body 22, resulting in the proximal portion 24 having suitable pushability for advancing through the patient's vascular system (e.g., without the proximal portion 24 buckling or breaking), while the distal portion 26 may be formed from a more flexible material, allowing the distal portion 26 to maintain flexibility and advance more easily along the guidewire to access remote locations in winding regions of the vascular system. The sheath body 22 may be composed of a suitable polymer material such as polyethylene or stainless steel, a metal and / or alloy, or other suitable biocompatible material or a combination thereof. In some embodiments, the proximal portion 24 may include a reinforcing layer, such as a braided or coiled layer, to enhance the indentation of the sheath body 22. The sheath body 22 may include a transition region between the proximal portion 24 and the distal portion 26. In some cases, the distal portion 26 may also include a reinforcing layer.

[0050] Generally, the vascular occlusion structure 16 can be inserted into the patient (e.g., minimally invasively) by inserting the vascular occlusion treatment system 10 into the patient's vascular system to reach the aneurysm site. Therefore, the delivery catheter 12 is made as small as possible and has a very narrow inner diameter (i.e., lumen 28) (e.g., 0.015 inches to 0.025 inches, preferably 0.015 inches to 0.018 inches). The vascular occlusion treatment system 10 can be used in an "over-the-wire" configuration in which the delivery catheter 12 is introduced into the patient via a pre-introduced guidewire and the delivery catheter 12 extends along the entire length of the guidewire (not shown). Alternatively, the vascular occlusion treatment system 10 can be used in a "rapid exchange" configuration in which the guidewire extends from a guidewire port (not shown) through the distal portion of the vascular occlusion treatment system 10. In other alternative embodiments, the vascular occlusion treatment system 10 may be introduced into the patient after the guidewire has been withdrawn, leaving the distal portion of the sheath or access catheter at the target site, and the vascular occlusion treatment system 10 may be navigated through the patient's vascular system within the sheath or access catheter.

[0051] It should be noted that the delivery catheter 12 is not limited to having the dimensions described above, and in other embodiments, the delivery catheter 12 may have other dimensions. For example, in other embodiments, the lumen of the delivery catheter 12 may have an inner diameter of less than 0.020 inches, less than 0.018 inches, less than 0.016 inches, or less than 0.014 inches (such as 0.013 inches or less). In other embodiments, the lumen of the delivery catheter 12 may have an inner diameter greater than 0.020 inches, such as 0.04 inches, 0.06 inches, 0.08 inches, 0.1 inches, or 0.2 inches.

[0052] As shown in Figures 1 and 2, when the vascular occlusion structure 16 is housed inside the delivery catheter 12, the vascular occlusion structure 16 has a first cross-sectional dimension, and when the vascular occlusion structure 16 is delivered outside the delivery catheter 12, the vascular occlusion structure 16 has a second cross-sectional dimension that is larger than the first cross-sectional dimension. In particular, when the vascular occlusion structure 16 is inside the delivery catheter 12, the vascular occlusion structure 16 elastically collapses radially to form the first cross-sectional dimension. When the vascular occlusion structure 16 is outside the delivery catheter 12, the vascular occlusion structure 16 elastically returns radially outward to take its second cross-sectional dimension. In some embodiments, in addition to expanding radially from the longitudinal axis of the vascular occlusion structure 16, the vascular occlusion structure 16 may also have a three-dimensional configuration. As a non-limiting example, the vascular occlusion structure 16 can have multiple loops (e.g., open loops and / or closed loops), a helical configuration, a random configuration, and so on. In some embodiments, when the vascular occlusion structure 16 has a three-dimensional configuration with multiple loops, the loops can be located in their respective planes, and at least two of the planes can form a non-zero angle with respect to each other.

[0053] As shown in Figure 3, at the aneurysm site, the vascular occlusion structure 16 can be pushed distally through the aneurysm neck N into the aneurysm sac A via a pusher member 18 from a delivery catheter 12 located in the parent vessel V. After being pushed out from the delivery catheter 12, the vascular occlusion structure 16 can self-expand into a pre-configured state as described below. Once the vascular occlusion structure 16 is inserted into the aneurysm sac A, it can be detached from the pusher member 18. Multiple vascular occlusion devices 16 can be delivered to fill and occlude the aneurysm sac A. The vascular occlusion structure 16 can also be removed or withdrawn by pulling it proximal to the pusher member 18, folded, and returned to the delivery catheter 12.

[0054] The pusher member 18 may be a coil, wire, tendon, etc., having a column strength suitable for pushing the vascular occlusion structure 16 into the aneurysm sac. The joint 20 to which the pusher member 18 is coupled to the vascular occlusion structure 16 may take the form of an electrolytic segment for electrolytically detaching the vascular occlusion structure 16 from the pusher member 18, but other alternative detachment mechanisms may include mechanical, thermal, and hydraulic mechanisms for detaching the vascular occlusion structure 16 from the pusher member 18.

[0055] The pusher member 18 has a proximal portion 32 extending proximal to the proximal portion 24 of the delivery catheter 12, and a distal portion 34 to which the vascular occlusion device 16 is attached. The pusher member 18 may be made of a guidewire, a torqueable cable tube, or a hypotube. In any case, there are many materials available to enable the pusher member 18 to achieve the appropriate properties generally relevant to medical devices. Some examples may include metals, metal alloys, polymers, metal-polymer composites, or any other suitable material. For example, the pusher member 18 may include nickel-titanium alloys, stainless steel, or composites of nickel-titanium alloys and stainless steel. In some embodiments, at least a portion (e.g., a layer) or the whole of the pusher member 18 may be made of a nickel-titanium-platinum (NiTiPt) alloy. In some cases, the pusher member 18 may be made of the same material along its length, or in some embodiments, it may include portions or sections made of different materials. In some embodiments, the material used to construct the pusher member 18 is selected to give different flexibility and rigidity properties to different parts of the pusher member 18. For example, the proximal and distal portions 34 of the pusher member 18 may be formed of different materials, for example, materials having different elastic moduli, resulting in differences in flexibility. For example, the proximal portion 32 may be formed of stainless steel and the distal portion 34 may be formed of a nickel-titanium alloy. However, any suitable material or combination of materials can be used for the pusher member 18.

[0056] The vascular occlusion structure 16 is sized to be embedded in the aneurysm sac A and can take any geometric or cross-sectional shape. For example, in the illustrated embodiment, the vascular occlusion structure 16 takes the form of an elastic tubular member having a proximal end 36 and a distal end 38. In this case, the distal end 38 of the vascular occlusion structure 16 is typically free or open (allowing for maximum expansion), while the proximal end 36 of the vascular occlusion structure 16 is coupled / attached to a pusher member 18. Thus, the distal end 38 of the vascular occlusion structure 16 is free to float. In another example, the vascular occlusion structure 16 can take the form of a flat member that can be fixed at both the proximal and distal ends (allowing for minimal expansion). The vascular occlusion structure 16 has a compact delivery configuration when radially constrained within the delivery catheter 12 and is biased to expand radially outward into a deployable configuration when released from the delivery catheter 12 into the aneurysm sac. The cross-sectional dimensions of the vascular occlusion structure 16 in the extended deployment configuration may be, for example, greater than 1.5 times, preferably greater than 2 times, and most preferably greater than 3 times, the cross-sectional dimensions of the vascular occlusion structure 16 in its compact delivery configuration. The extended deployment configuration of the vascular occlusion structure 16 can be pre-configured and may be bent, curved, or three-dimensional (e.g., ball-shaped, loop-shaped, etc.) and may include secondary or tertiary structures.

[0057] In the embodiments shown in Figures 1 and 2, the entire vascular occlusion structure 16 includes a porous mesh 40 made of an AuPtW alloy, but as will be further detailed below, only a portion of the vascular occlusion structure 16 may include the mesh 40. In the illustrated embodiments, the mesh 40 is formed by braiding or weaving together wires 42 (for example, having 8 to 96 wires, more preferably 16 to 32 wires) (Figure 4). In alternative embodiments, the mesh 40 can be formed as a monolithic structure by etching or cutting a pattern from, for example, a tube or sheet of stent material, or by cutting or etching a sheet of material according to a design pattern and then winding the sheet or otherwise forming it into a tubular, branched, or other shape.

[0058] The mesh 40 may have an appropriate length (e.g., over 5 cm, 5 cm to 45 cm, 5 cm to 30 cm, etc.). The braid can be braided around a mandrel (e.g., a mandrel having a circular, elliptical, flat, or other shape depending on the final cross-sectional shape of the vascular occlusion structure 16 to be realized) using a braiding machine. Alternatively, the wire 42 may be braided into a flat braid, then shaped and heat-set around the mandrel to form a flat braid of a predetermined shape. After braiding, the mesh 40 can be heat-set (e.g., at 450 to 650 degrees Celsius for 1 to 60 minutes). The heat-set braid forms the linear "primary shape" of the mesh 40. Next, this heat-set braid can be wrapped around a second mandrel (e.g., a three-dimensional mandrel) and heat-set a second time to give it a three-dimensional "secondary shape" or "tertiary shape".

[0059] Each wire 42 may be a monofilament strand, as shown in Figures 5A and 5B, but in an alternative embodiment, each wire 42 may be a multifilament strand, as shown in Figure 5C. Each wire 42 may have any suitable cross-section with any suitable dimensions. For example, if the cross-section of each wire 42 is circular (as shown in Figure 5A), the diameter may be between 0.0005 inches and 0.0040 inches, and if the cross-section of each wire 42 is rectangular (as shown in Figure 5B), the thickness may be 0.0008 inches or more and the width may be 0.005 inches or less. In another embodiment, each wire 42 may be in the form of a twisted wire (as shown in Figure 5C) to increase the flexibility of the resulting vascular occlusion structure 16.

[0060] All wires 42 constituting the mesh 40 may be the same size and composition, but it should be understood that the wires 42 may have different sizes and compositions, as long as at least some of the wires 42 constituting the vascular occlusion structure 16 are made of AuPtW alloy. In some embodiments, the mesh 40 may be a braid, such as a ribbon braid. The braid may be made from wires of the same size or from wires of different sizes. In some embodiments, the braid may be made from wires having the same composition or from wires having different compositions. Preferably, the unconstrained braiding angle 44 of the mesh 40 (i.e., the angle between two intersecting wires 42) is 20 to 130 degrees, more preferably 20 to 60 degrees (Figure 4). Generally, the braiding angle 44 can be the angle between two intersecting wires 42 viewed in the longitudinal direction. Selecting a braiding angle 44 prevents the mesh 40 from collapsing, thereby increasing the ability to push the vascular occlusion structure 16 into the delivery catheter 12; otherwise, when pushed, the mesh 40 would bundle together within the delivery catheter 12, causing the vascular occlusion structure 16 to become lodged within the delivery catheter 12. Ultimately, the number of wires 42 in the mesh 40, the braiding angle 44, and / or the expanded configuration of the mesh 40 relative to its folded configuration can be selected to best suit the inner diameter of the delivery catheter 12 being used.

[0061] In some embodiments, the mesh 40 may be a braided structure having a tubular configuration. In other embodiments, the mesh 40 may have a non-tubular configuration. For example, in some embodiments, the mesh 40 may be a flat braid. The flat braid may be any braided structure having a cross section with a width W and a thickness T (measured perpendicular to the width), where the W / T ratio is equal to or greater than 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20. Also in some embodiments, the mesh 40 may be a ribbon braid. In one or more embodiments described herein, the braid may have a width of any of 0.020 inches (0.5 mm) to 0.197 inches (5 mm), preferably any of 0.030 inches (0.75 mm) to 0.079 inches (2.0 mm), more preferably any of 0.030 inches (0.75 mm) to 0.06 inches (1.5 mm). In further embodiments, the braid may have a width of 0.039 inches (1 mm) or more. For example, in one embodiment, the braid may have a width of about 1.25 mm (e.g., 1.25 mm ± 0.1 mm). In some embodiments, the braid may have a braid stiffness of less than 150 mN / mm. Furthermore, in some embodiments, the braid may be formed from multiple braid wires 42 of the same size and / or the same composition. In other embodiments, the braid may be formed from multiple braid wires 42 of different sizes and / or different compositions.

[0062] In some embodiments, when the braid is not constrained outside the catheter, the braid may have a first width, and when the braid is inside the catheter, the braid may elastically collapse and / or bend laterally (e.g., perpendicular to the longitudinal axis of the braid) to have a second width smaller than the first width. For example, the braid may be a flat braid that is elastically curled or rolled up to have a second width inside the catheter, and can elastically return to a relaxed configuration having a first width when unfolded outside the catheter.

[0063] In one embodiment shown in Figure 6A, the mesh 40 has an expanded geometric shape that is flat (e.g., ribbon) and can have a width in the range of, for example, 0.5 mm to 5.0 mm. In an alternative embodiment shown in Figure 6B, the mesh 40 can have an expanded geometric shape that is cylindrical (i.e., has a circular cross-section) and can have a diameter in the range of, for example, 0.5 mm to 5.0 mm. Thus, the mesh 40 may be a flat braid or a rounded braid. In some embodiments, regardless of whether the mesh 40 has a flat or rounded cross-section, the mesh 40 has column strength suitable for advancing into the delivery catheter 16 (e.g., the mesh 40 does not buckle, twist, bend, etc., in the lumen of the delivery catheter 16 as it advances).

[0064] Through prototyping and testing, the precise composition of the AuPtW alloy, the size and number of wires 42, the braiding angle used to construct the mesh 40 of the vascular occlusion structure 16, and the shape and size of the expanded vascular occlusion structure 16 can be optimized to achieve superior performance depending on the intended application.

[0065] For example, in some embodiments, a relatively soft, long, but radiopaque vascular occlusion device can be constructed by braiding N wires (e.g., a number ranging from 8 to 96, preferably 16 to 32, e.g., 24) into a flat braid having a width of 0.5 to 5 mm (preferably 1 to 2 mm, e.g., 1.25 mm) and a length of 12 cm or more, at any braiding angle (unrestricted) between 20 to 130 degrees (preferably 20 to 60 degrees), where each wire is composed of AuPtW, has a Young's modulus of less than 25 Mpsi, and has a wire diameter of any of 0.0005 inches to 0.004 inches (e.g., 0.001 inches). The vascular occlusion may be deliverable via a microcatheter (e.g., having an outer diameter of 0.026 inches and an inner diameter of 0.0165 inches). In some embodiments, the vascular occlusion device can be delivered with a frictional force of less than 0.06 pounds. Such vascular occlusion devices can have advantageous shape retention properties, specific bending stiffness (e.g., less than 150 mN / mm), and specific radiopaqueness, such as imaging at an X-ray energy of 82 kilovolts peak (KVp). Furthermore, in some embodiments, MRI images of novel AuPtW vascular occlusion coils (e.g., MRI at 3T) are advantageously free from the interfacial artifacts that may be present in existing vascular occlusion coils (e.g., vascular occlusion coils made from Pt / 8W).

[0066] Importantly, the inventors have found that a gold-platinum-tungsten (AuPtW) alloy, preferably comprising 25% to 40% by weight of platinum, 0.01% to 10% by weight of tungsten, and the remainder being Au (e.g., % of Au = 100% - % of Pt - %) of W, and having a Young's modulus of less than 25 × 10^6 pounds / square inch (25 Mpsi), can, given a suitable structure, exhibit a certain softness (e.g., have a bending stiffness of less than 150 mN / mm), have a certain length (e.g., longer than 5 cm), be compatible with small diameter delivery catheters (e.g., an inner diameter of 0.017 inches), have a certain radiopaqueness, have a certain MRI compatibility, and be easily manufactured (e.g., no surface oxide removal is required). In other embodiments, in addition to the AuPtW alloy, the vascular occlusion structure 16 may further contain iridium to improve its mechanical properties.

[0067] It should be noted that the vascular occlusion structure 16 is not limited to having the dimensions and features described herein, and the vascular occlusion structure 16 can have various dimensions and features in various embodiments. For example, in some embodiments, the vascular occlusion structure 16 may include a braided structure formed from braided wire 42. The braided wire 42 may have different shapes in different embodiments. For example, at least one of the braided wires 42 may have a circular, square, elliptical, or rectangular cross-section. In some embodiments, at least one of the braided wires 42 may have a cross-sectional dimension of any of 0.0001 inches (0.00254 mm) to 0.004 inches (0.1016 mm). In other embodiments, the braided wire 42 may have a cross-sectional dimension of less than 0.00085 inches (0.022 mm), preferably any of 0.0001 inches (0.00254 mm) to 0.0008 inches (0.020 mm), and more preferably any of 0.0003 inches (0.0076 mm) to 0.00075 inches (0.019 mm).

[0068] In some embodiments, when the braided wire 42 has a circular cross-section, the cross-sectional dimensions described herein are the diameter of the circular cross-section. In such cases, the diameter can be in the range of 0.0005 inches (0.0127 mm) to 0.004 inches (0.102 mm), preferably in the range of 0.0008 inches (0.0203 mm) to 0.004 inches (0.102 mm), and more preferably in the range of 0.001 inches (0.0254 mm) to 0.002 inches (0.051 mm). In other embodiments, the diameter of the circular cross-section of the braided wire 42 may be less than 0.00085 inches, preferably 0.0001 inches to 0.0008 inches, and more preferably 0.0003 inches to 0.00075 inches. In further embodiments, the braided wire 42 may have a diameter of any of 0.0001 inches (0.00254 mm) to 0.0015 inches (0.0381 mm), preferably any of 0.0005 inches (0.0127 mm) to 0.001 inches (0.0254 mm).

[0069] In some embodiments, the braided wire 42 may have an elongated cross-section (e.g., elliptical, rectangular, etc.) having a width W1 and a height (or thickness) H1. In some embodiments, the width W1 may be 0.005 inches or less, and the height H1 may be at least 0.0008 inches. In other embodiments, the braided wire 42 may have a width (W1) of 0.004 inches (0.102 mm) and a height (H1) of 0.002 inches (0.051 mm). In other embodiments, the braided wire 42 may have a maximum width of 0.002 inches (0.051 mm) and a minimum height of 0.0001 inches (0.00254 mm). In further embodiments, the braided wire 42 may have a cross-sectional dimension (width or thickness) of less than 0.00085 inches.

[0070] In some embodiments, the braided structure can be formed from one or more twisted strands. Furthermore, in some embodiments, the braided structure may have any number of wires, from 8 to 96, from 16 to 32, from 24 to 144, or from 24 to 72. In addition, in some embodiments, the braided structure can be formed from braided wires 42, which are ribbon wires.

[0071] It should be noted that using AuPtW alloy to construct vascular occlusion devices is counterintuitive, because AuPt alloy is not considered to be strengthenable by alloying with tungsten (W). Au and W are a difficult combination to alloy for several reasons. Firstly, tungsten has a much higher melting point (3422 degrees Celsius) than gold (1064 degrees Celsius), making it difficult to achieve a uniform solid solution and a uniform chemical composition. Secondly, according to the AuW phase diagram (Figure 7), Au and W appear to be immiscible, in that they cannot form a single phase or a uniform solid solution at low temperatures. Also, because tungsten is extremely hard and has a high modulus of elasticity, it is thought that alloying with tungsten may result in a brittle alloy. For these reasons, AuPtW alloy, especially in the form of wire, is not currently available commercially or academically. For the same reasons, AuPtW alloy is not used in the construction of implants such as vascular occlusion devices.

[0072] Nevertheless, the inventors discovered that by combining AuPt and PtW, an infinite solid solution can be formed in which platinum (Pt) acts as an interalloying element between gold (Au) and tungsten (W), thus enabling the formation of an AuPtW ternary alloy with a uniform solid solution. Furthermore, through meticulous analysis and prototyping, the inventors also discovered that by controlling the tungsten content to less than 10% by weight, the AuPtW alloy possesses a set of mechanical properties suitable for the manufacture of implants such as vascular occlusion devices. On the other hand, if the tungsten content in the AuPtW alloy exceeds 10% by weight, the resulting alloy is either too brittle to be drawn into wire for braiding or coil manufacturing, or too hard for the manufacture of implants.

[0073] In some embodiments, adding tungsten to an Au-Pt combination to create an alloy has the advantage of increasing the mechanical strength (ultimate tensile strength) to the range of 200-300 kpsi compared to 125-175 kpsi for AuPt alloys without tungsten. However, tungsten itself has a very high modulus of elasticity. For this reason, the tungsten content is controlled to less than 10% in order to achieve good mechanical strength while maintaining a modulus of elasticity level of less than 25 Mpsi, which is suitable for occlusion device applications.

[0074] In some embodiments, the vascular occlusion structure 16 made of AuPtW alloy has the same or greater softness, the same or greater radiopaqueness, and the same or greater braid length compared to a vascular occlusion structure made of AuPt alloy (which does not contain tungsten in the alloy).

[0075] Various techniques can be employed in various embodiments to produce AuPtW alloys. In one exemplary embodiment, solid PtW alloy and solid AuPt alloy can be obtained, and then the alloys can be melted to obtain PtW solution and AuPt solution. These solutions can then be mixed to form an AuPtW solution that achieves the designed composition (for example, 25-40 wt% Pt and 0.01-10 wt% W, with the remainder being Au, relative to the weight of the designed AuPtW composition). In some embodiments, in a fine-tuning step, additional Au solution, Pt solution, W solution, or any combination described above can be optionally added to the mixed solution to achieve the designed weight percentages of each component (Au, Pt, W).

[0076] In some embodiments, a solid alloy AuPt is obtained first. The AuPt alloy can be formed using a certain amount of Pt (e.g., 25-40% by weight relative to the weight of the designed AuPtW composition). The AuPt alloy is then heated to melt it and an AuPt solution can be obtained. Next, solid tungsten is obtained and melted to form a tungsten solution. Then, a certain amount of molten tungsten solution (e.g., less than 10% by weight relative to the weight of the designed AuPtW composition) is added to the AuPt solution to form an AuPtW solution. In some embodiments, in the fine-tuning step, additional Au solution, Pt solution, W solution, or any combination described above can be optionally added to the mixed solution to achieve the designed weight percentages of each component (Au, Pt, W).

[0077] In other embodiments, a solid alloy PtW is obtained first. The PtW alloy can be formed using a certain amount of Pt (e.g., 25-40% by weight relative to the weight of the designed AuPtW composition) and a certain amount of W (e.g., less than 10% by weight relative to the weight of the designed AuPtW composition). The PtW alloy is then heated to melt the alloy and obtain a PtW solution. Next, solid Au is obtained and melted to form an Au solution. Then, a certain amount of the molten Au solution is added to the PtW solution to form an AuPtW solution. In some embodiments, in the fine-tuning step, additional Au solution, Pt solution, W solution, or any combination described above can be optionally added to the mixed solution to achieve the designed weight percentages of each component (Au, Pt, W).

[0078] Furthermore, in some embodiments, the vascular occlusion device may have an AuPtW alloy in which at least 50%, 60%, 70%, 80%, 90%, 95%, 97%, 98%, 99%, 99.5%, 99.9%, etc., relative to the weight of the vascular occlusion device. Moreover, it should be understood that, as long as the percentage composition of tungsten (W) is 10% or less of the weight of the AuPtW alloy, the total percentage of gold (Au) and platinum (Pt) in the alloy may be equal to 100%-Pw (where Pw represents the percentage of W content in the AuPtW alloy) or less, in which other materials may be present.

[0079] In some embodiments, the AuPtW material may be further alloyed with one or more other materials. For example, in other embodiments, AuPtW can be alloyed with tantalum (Ta), iridium (Ir), rhenium (Re), rhodium (Rh), ruthenium (Ru), molybdenum (Mo), or any combination thereof to obtain a specific level of mechanical properties (e.g., to enhance the mechanical properties of the material). In further embodiments, the AuPtW material may be further alloyed with Zr, Hf, or any combination thereof to reduce magnetic susceptibility.

[0080] Furthermore, medical devices composed of the disclosed AuPtW alloy having a tungsten (W) percentage of 10% or less relative to the weight of the alloy may include one or more materials that impart specific properties to the device so that it can withstand the manufacturing processes in which it is made. These manufacturing processes include, for example, laser cutting, etching, crimping, annealing, stretching, pilling, electroplating, electropolishing, chemical polishing, cleaning, pickling, ion beam deposition or injection, sputter coating, and vacuum deposition.

[0081] It is advantageous to fabricate implantable medical devices using elongated components, such as braided wires, made from the AuPtW alloy described herein. The combination of platinum, gold, and tungsten in the AuPtW alloy provides an appropriate level of radiopaqueness, while gold also helps achieve a certain level of magnetic susceptibility, and tungsten helps obtain a set of mechanical properties. In some applications where a higher modulus of elasticity is advantageous, more W can be added to the AuPtW alloy (the W content should be kept below 10% to avoid brittleness). In such applications, the high Young's modulus of the AuPtW material (e.g., higher than AuPt without W) allows for the manufacture of implantable medical devices with high axial (column) stiffness and strength. As a result, implantable medical devices may be even smaller in size (e.g., cross-sectional dimensions) compared to conventionally known devices. An example of such an implantable medical device is a vascular occlusion device configured to be delivered to small vessels to occlude an aneurysm. Small vessels can be any vessel in the body, including distant vessels in the patient's brain. Furthermore, due to the high mechanical strength of the materials described herein, implantable medical devices can be smoothly delivered using small catheters without bending, buckling, or twisting. This remains true even when the size of the medical device is reduced. In addition, due to the high ultimate tensile strength (UTS) of the materials, the elongated components forming the implantable medical devices do not easily break or fracture during operation and processing. Moreover, because the Young's modulus of the materials is high in these applications, smaller elongated components can be used to manufacture implantable medical devices in order to achieve softer bending stiffness. As a result, implantable medical devices can have appropriate bending stiffness and exhibit better shape retention characteristics.

[0082] The properties of the gold-platinum-tungsten (AuPtW) alloy disclosed for manufacturing occlusion devices may include one or more exemplary properties such as column strength, tensile strength, tensile elongation, stress-strain properties, radial force, radiopaqueness, flexibility, bendability, thermal sensitivity, and biocompatibility. In particular, medical devices composed of AuPtW alloys with a tungsten (W) percentage of 10 wt% or less may have greater radiopaqueness, radial strength, hardness, yield strength and / or ultimate tensile strength, and / or further improved stress-strain properties, compression properties and / or expansion properties, bending properties and / or flexibility, overall strength and / or durability, longitudinal elongation properties, recoil properties, friction coefficient, thermal sensitivity, biostability and / or biocompatibility properties. For example, a medical device with a tungsten (W) percentage of 10% or less in the AuPtW alloy may be configured to have a Young's modulus of less than 25 Mpsi. Additionally or alternatively, medical devices in which the percentage of tungsten (W) in the AuPtW alloy is 10% or less are configured to have a magnetic susceptibility of less than 300 ppm, preferably less than 200 ppm, and more preferably less than 100 ppm, thereby reducing artifacts during magnetic resonance (MR) imaging.

[0083] It should be noted that the vascular occlusion structure 16 is not limited to having the configuration examples described, and the vascular occlusion structure 16 may have other configurations in other embodiments. For example, in other embodiments, the vascular occlusion structure 16 may have a coil configuration instead of having a mesh or braid. Figures 8A and 8B show an exemplary vascular occlusion structure in the form of an embolic coil 100 configured according to several embodiments. This coil 100 is formed of a helically wound wire 102 having a first end 104 and a second end 106. The wire 102 of the coil 100 (Figures 8A and 8B) is made of an AuPtW alloy with a tungsten (W) percentage of 10% by weight or less. The coil 100 includes stretch resistance members 108 fixedly attached to both the first end 104 and the second end 106. In alternative embodiments, the stretch resistance member 108 may be attached to one of the two ends, or not to either end. The coil 100 in Figure 8A is shown in its “primary” winding or shape, and the coil 100 in Figure 8B is shown in its “secondary” winding or shape. In some cases, the coil 100 may have a primary winding or shape when confined within the delivery catheter and a secondary winding or shape when deployed outside the delivery catheter. The secondary shape of the coil 100 in Figure 8B forms a spherical three-dimensional shape with non-overlapping loops 120. It should be understood that the secondary shape of the coil 100 can take any other suitable shape. The wire 102 of the coil 100 may also be formed of wire, stretch-filled tubing, thread, filament, etc. In some embodiments, as shown in Figures 8A and 8B, the diameter (D1) of the wire 102 is in the range of approximately 0.0005 inches (0.0127 mm) to approximately 0.005 inches (0.127 mm), the primary winding diameter (D2) of the coil 100 is in the range of approximately 0.003 inches (0.0762 mm) to approximately 0.030 inches (0.762 mm), and / or the secondary winding diameter (D3) is in the range of approximately 0.5 mm to approximately 50 mm.

[0084] As previously disclosed, coil 100, composed of the disclosed AuPtW alloy with a tungsten (W) percentage of 10% by weight or less, exhibits lower MR artifacts compared to current vascular occlusion devices due to its lower magnetic susceptibility.

[0085] As described above, in some embodiments, the entire vascular occlusion structure 16 may have a braided structure (e.g., mesh 40), and one or more (e.g., all) of the wires of the braided structure are made of AuPtW alloy. In other embodiments, the vascular occlusion structure 16 may have at least one braided element and at least one unbraided element. The unbraided element may be one or more coils. In some embodiments, the unbraided element may be made of AuPtW alloy. Furthermore, in some embodiments, the braided structure or braid may have one or more layers of braid (e.g., braid over braid). In other embodiments, the braided structure or braid may be arranged on a coil to form a braid overcoil structure.

[0086] For example, in other embodiments, the vascular occlusion structure 16 may include a mesh (or braid) and one or more coils. Figures 9 and 10 show another embodiment of a vascular occlusion treatment system 10' having a vascular occlusion structure with a mesh 40' and coils 39a, 39b. In particular, the vascular occlusion treatment system 10' is similar to the vascular occlusion treatment system 10, except that the vascular occlusion structure 16' includes a central mesh 40' and two helically wound coils 39a, 39b positioned at both ends of the central mesh 40'. The central mesh 40' can be constructed similarly to the mesh 40 described with respect to Figures 1 and 2. Preferably, the coil portions 39a, 39b are made of an AuPtW alloy. Notably, the coils 39a, 39b provide additional non-traumatic properties to the vascular occlusion structure 16'.

[0087] Coils 39a and 39b function as non-traumatic members to prevent the vascular occlusion structure 16' from puncturing or damaging tissues within the patient's body. In some embodiments, coils 39a / 39b may comprise coil wires having cross-sectional dimensions of any of 0.0001 inches (0.00254 mm) to 0.003 inches (0.075 mm), and coils 39a / 39b may have a primary winding diameter of any of 0.003 inches (0.076 mm) to 0.030 inches (0.762 mm). The coils 39a / 39b forming the non-traumatic members may have simple or complex shapes. In other embodiments, the vascular occlusion structure 16' may not include both coils 39a and 39b, but may include coil 39a or coil 39b.

[0088] Although the vascular occlusion structures 16 and 16' shown in Figures 1 and 2, and Figures 9 and 10, respectively, have been described as having a single layer of braid, it should be understood that the vascular occlusion structure may include multiple layers of braid (i.e., a braid-over-braid structure), or may include one layer of braid (e.g., an outer layer of braid) and a coil layer (e.g., an inner coil) (i.e., a braid-over-coil structure). In either case, one or more layers (e.g., all layers) of the vascular occlusion structure are preferably made of an AuPtW alloy.

[0089] In some embodiments, implantable medical devices made from AuPtW alloy, such as the vascular occlusion structure 16 described herein, may have lengths of 1.2 inches (3 cm) to 19.7 inches (50 cm), preferably 2 inches (5 cm) to 11.8 inches (30 cm). Also in one or more embodiments, an implantable medical device (e.g., a braid) having any of the lengths described herein is considered to have adequate column strength if, when inserted longitudinally into an elongated lumen, it can be extruded through the elongated lumen without buckling, twisting, or plastic deformation, where the elongated lumen has a maximum lumen width of 0.03 inches, preferably 0.016 inches, and more preferably 0.014 inches (e.g., 0.013 inches). The elongated lumen may be the lumen of a catheter or any elongated lumen, such as the lumen of a tube used to test the column strength of an implantable medical device.

[0090] It should be noted that the AuPtW alloys described herein are not to be limited to the manufacture of vascular occlusion devices, and AuPtW alloys can be used in the manufacture of other types of medical devices. For example, AuPtW alloys disclosed with a tungsten (W) percentage of 10% by weight or less can be used to form devices such as stents (e.g., slotted tubular stents and / or braided or woven stents), filters, thromboembolic trapping devices, flow diverters, intracapsular aneurysm implants, vascular delivery assemblies, catheters, reinforcing members, guidewires, delivery wires, and radiopaque markers.

[0091] Furthermore, in some embodiments, the implantable medical devices described herein are considered to have appropriate shape retention characteristics when an implantable medical device having a specific initial radius of curvature R1 is inserted into a catheter, and the implantable medical device has a radius of curvature R2 after being deployed from the catheter, and the deployed radius of curvature R2 of the implanted medical device is less than 5 times R1, preferably less than 4 times R1, more preferably less than 3 times R1, and even more preferably less than 2 times R1 (for example, less than 1.5 times R1 or less than 1.2 times R1).

[0092] As used herein, the term “braid” refers to any structure formed by a plurality of elongated members, which may or may not be braided to form the structure. In some embodiments, the braid may have a grid or mesh configuration having an open texture with spaced holes, which may form a uniform or random pattern. In other embodiments, the braid may have other configurations and may or may not have an open texture. In some embodiments, the elongated members may be joined to each other by mechanical forces, such as friction between the elongated members. As a non-limiting example, the frictional force that joins the elongated members to form the braid may be generated by twisting the elongated members, braiding the elongated members, overlapping the elongated members, etc. In other embodiments, the elongated members may be joined to each other by adhesive.

[0093] Please note that, as used herein, the term "approximately" refers to a variation of 10% or less unless otherwise specified. For example, "approximately 10%" or less in weight refers to a weight of 10% ± 1% or less of the total weight.

[0094] While specific embodiments have been shown and described herein, it will be understood by those skilled in the art that they are not intended to limit the disclosed invention. Furthermore, it will be apparent to those skilled in the art that various changes, substitutions, and modifications (e.g., dimensions of various parts, combinations of parts) can be made without departing from the scope of the disclosed invention as defined by the following claims and equivalents. Therefore, the specification and drawings should be considered illustrative, not restrictive. The various embodiments shown and described herein are intended to encompass alternatives, modifications, and equivalents of the disclosed invention that may fall within the appended claims.

Claims

1. A vascular occlusion device, The vascular occlusion structure includes a structure configured to be implanted in an aneurysm sac, wherein the vascular occlusion structure becomes a delivery configuration when confined within a delivery catheter and becomes a deployed configuration when released from the delivery catheter into the aneurysm sac, and at least a portion of the vascular occlusion structure is made of an AuPtW (gold-platinum-tungsten) alloy. AuPtW alloy contains platinum in the range of 25% to 40% by weight. A vascular occlusion device characterized by the AuPtW alloy containing tungsten in the range of 0.01% to 10% by weight.

2. In the vascular occlusion device according to claim 1, A vascular occlusion device characterized in that the AuPtW alloy has a Young's modulus of less than 25 MPa.

3. In the vascular occlusion device according to claim 1 or 2, A vascular occlusion device characterized in that the vascular occlusion structure includes a mesh made of AuPtW alloy.

4. In the vascular occlusion device according to claim 3, A vascular occlusion device characterized in that the mesh is braided.

5. In the vascular occlusion device according to claim 3 or 4, A vascular occlusion device characterized in that the entire vascular occlusion structure includes the mesh.

6. In the vascular occlusion device according to any one of claims 3 to 5, A vascular occlusion device characterized in that the vascular occlusion structure further comprises two spirally wound coils positioned at both ends of the mesh.

7. In the vascular occlusion device according to claim 6, A vascular occlusion device characterized in that each of the two helically wound coils is made of AuPtW alloy.

8. In a vascular occlusion device according to any one of claims 3 to 7, A vascular occlusion device characterized in that the mesh includes at least one wire, each wire having a minimum cross-sectional dimension in the range of 0.0005 inches to 0.004 inches.

9. In a vascular occlusion device according to any one of claims 3 to 8, A vascular occlusion device characterized in that the mesh includes at least one twisted strand.

10. In a vascular occlusion device according to any one of claims 3 to 9, A vascular occlusion device characterized in that the mesh has a number of wires ranging from 8 to 96.

11. In the vascular occlusion device according to claim 10, A vascular occlusion device characterized in that the mesh has a number of wires ranging from 16 to 32 wires.

12. In a vascular occlusion device according to any one of claims 3 to 11, A vascular occlusion device characterized in that, when the mesh is not constrained, the wires constituting the mesh intersect each other at braiding angles ranging from 20 to 60 degrees.

13. In a vascular occlusion device according to any one of claims 3 to 12, A vascular occlusion device characterized in that the mesh has an expanded geometric shape having a circular cross-section.

14. In a vascular occlusion device according to any one of claims 3 to 12, A vascular occlusion device characterized in that the mesh has an expanded geometric shape having a rectangular cross-section.

15. In the vascular occlusion device according to claim 14, A vascular occlusion device characterized in that the rectangular cross-section has a width in the range of 0.5 mm to 5.0 mm.

16. In the vascular occlusion device according to claim 14, A vascular occlusion device characterized in that the mesh has a bending rigidity of less than 150 mN / mm.

17. In the vascular occlusion device according to claim 1 or 2, A vascular occlusion device characterized in that the vascular occlusion structure includes a coil made of AuPtW alloy.

18. In the vascular occlusion device according to claim 17, A vascular occlusion device characterized in that the coil is configured to take on a three-dimensional shape having multiple loops when in an unconstrained configuration.

19. A vascular occlusion assembly, A vascular occlusion device according to claim 1, A vascular occlusion assembly characterized by comprising a pusher member to which the vascular occlusion device is detachably coupled.

20. A vascular occlusion treatment system, A vascular occlusion assembly according to claim 19, A vascular occlusion treatment system characterized by comprising a delivery catheter in which the vascular occlusion assembly is placed.

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