Implantable embolization device

Abstract

In some examples, the present disclosure provides an embolization device comprising a plurality of segments having a three-dimensional non-helical structure when deployed at a vascular site. The plurality of segments includes a first segment and one or more second segments that are smaller than the first segment. The first segment can have a deployed configuration configured to anchor the device at a vascular site (e.g., a blood vessel) of a patient, while each of the one or more second segments can be formed by a loop configured to pack and occlude the vascular site. In some cases, the embolization device further includes a third segment having a deployed configuration in which a plurality of helical windings or loops are configured to anchor the embolization device at the vascular site.

Description

[0001] This application claims priority to U.S. Application 16 / 539,575, filed August 13, 2019, entitled “Implantable Embolization Device”. Technical Field

[0002] This technology relates to implantable medical devices constructed for embolizing vascular sites. Background Technology

[0003] Implantable embolization devices can be used to embolize (e.g., occlude) vascular sites. Possible clinical applications include controlling bleeding caused by hemorrhage, reducing blood flow to tumors, and treating a variety of conditions, including lesions of the brain, heart, and peripheral vascular system. In other examples, implantable embolization devices can be used to treat aneurysms, vascular malformations, arteriovenous fistulas, pelvic congestion syndrome, and varicocele. Implantable embolization devices can be configured to fill vascular sites in a patient's body, thereby reducing blood flow, promoting coagulation, and ultimately occluding the vascular site. Summary of the Invention

[0004] In some aspects, this disclosure describes an exemplary embolization device comprising multiple segments having a three-dimensional non-helical structure when deployed at a vascular site or other hollow anatomy in a patient. The multiple segments include a first segment and one or more second segments configured to deploy into a smaller volume than the first segment. For example, the multiple segments may include a first segment and two or more second segments following the first segment. In some cases, different types of segments are configured to provide different features and / or capabilities. For example, in some examples, the first segment may have a deployment structure configured to anchor the device in the patient's vascular system. For example, the first segment may define a ring configured to form a stent within a hollow anatomy (e.g., a vascular lumen) to hold the device in place. In some cases, the second segments define a ring smaller than the ring of the first segment and are therefore capable of fitting within and filling the stent defined by the first segment to occlude the hollow anatomy.

[0005] Some exemplary embolization devices include a third segment with an expanded configuration, different from the first and second segments. For example, an embolization device may include a third segment, for example, used at the tip, having multiple helical windings or loops configured to anchor the embolization device at a target site with a relatively high fluid (e.g., blood) flow rate anatomy.

[0006] In some aspects, this disclosure also describes components for embolizing vascular sites. Methods for delivering and deploying exemplary embolization devices, as well as methods for forming exemplary embolization devices, are also discussed.

[0007] Clause 1: In some examples, a medical device includes a device body comprising a first segment and at least one second segment, wherein in an unfolded configuration of the structure: the first segment defines a plurality of first loops forming a three-dimensional non-helical structure configured to anchor the device body to a patient's vascular system; each second segment defines a plurality of secondary loops forming a three-dimensional non-helical structure; and the maximum cross-sectional dimension of each second segment is smaller than the maximum cross-sectional dimension of the first segment.

[0008] Clause 2: In some examples of the medical devices described in Clause 1, the device body includes a plurality of second segments.

[0009] Clause 3: In some examples of medical devices described under Clause 1 or Clause 2, the device body includes a coil comprising multiple windings.

[0010] Clause 4: In some examples of the medical device pursuant to any one of Clauses 1-3, the maximum cross-sectional dimension of the first segment is about 10% to about 50% of the maximum cross-sectional dimension of each second segment.

[0011] Clause 5: In some examples of the medical device pursuant to any one of Clauses 1-4, the device body is constructed for a nominal vascular size, wherein the maximum cross-sectional dimension of the first segment is about 1.1 to about 2.0 times the nominal vascular size, and wherein the nominal vascular size is about 1.0 to about 1.1 times the maximum cross-sectional dimension of each second segment.

[0012] Clause 6: In some examples of the medical device pursuant to any one of Clauses 1-5, the three-dimensional non-helical structure of the first segment and the three-dimensional non-helical structure of each of the one or more second segments are approximately polyhedra.

[0013] Clause 7: In some examples of the medical device pursuant to any one of Clauses 1-6, the device body further includes a third segment connected to the first segment, wherein, in the deployed configuration, the third segment defines a plurality of third loops forming a helical structure configured to anchor the device body to the patient's vascular system.

[0014] Clause 8: In some examples of the medical devices described in accordance with Clause 7, the helical structure has a conical configuration.

[0015] Clause 9: In some examples of the medical devices described in accordance with Clause 8, the diameter of the tapered configuration increases toward the first segment.

[0016] Clause 10: In some examples, a component includes: a catheter defining an inner lumen; and a medical device according to claim 1, the medical device being positioned within the inner lumen in a delivery configuration, wherein the medical device is configured to expand from the delivery configuration to an unfolding configuration in response to unfolding from the inner lumen of the catheter.

[0017] Clause 11: In some examples of the components described in Clause 10, in the delivery configuration of the medical device, the device body comprises a substantially linear configuration within an inner lumen.

[0018] Clause 12: In some examples of the components described in accordance with Clause 10 or Clause 11, each of the one or more second segments follows the first segment.

[0019] Clause 13: In some examples, a method includes introducing a catheter into a patient's vascular system; delivering a medical device through the catheter to a site within the patient's vascular system, the medical device including a device body comprising a first segment and one or more second segments; and deploying the medical device at the site, wherein in the deployed configuration of the device body: the first segment defines a plurality of first loops forming a three-dimensional non-helical structure configured to anchor the device body in the patient's vascular system, each second segment defines a plurality of secondary loops forming a three-dimensional non-helical structure, and the maximum cross-sectional dimension of each second segment is smaller than the maximum cross-sectional dimension of the first segment.

[0020] Clause 14: In some examples of the method described in accordance with Clause 13, the medical device includes a plurality of second segments.

[0021] Clause 15: In some examples of the methods described under Clause 13 or Clause 14, the device body includes a coil that includes multiple windings.

[0022] Clause 16: In some examples of the method according to any one of Clauses 13-15, the maximum cross-sectional dimension of the first segment is about 10% to about 100% of the maximum cross-sectional dimension of each second segment.

[0023] Clause 17: In some examples of the method according to any one of Clauses 13-16, the device body further includes a third segment connected to the first segment on a side of the first segment opposite to one or more second segments, wherein, in the unfolded configuration, the third segment defines a plurality of third loops forming a helical structure configured to anchor the device body to the patient's vascular system.

[0024] Clause 18: In some examples of the method described in accordance with Clause 17, the spiral structure has a conical configuration in which the diameter increases toward the first segment.

[0025] Clause 19: In some examples of the method according to any one of Clauses 13-18, deploying the medical device at the site includes deploying the medical device such that the first segment is proximal to one or more second segments.

[0026] Clause 20: In some examples of the method according to any one of Clauses 13-19, deploying the medical device at the site includes deploying the medical device such that the first segment is distal to one or more second segments.

[0027] Clause 21: In some examples, the medical device includes a device body comprising a coil comprising a first segment, two or more second segments connected to one end of the first segment, and a third segment connected to the other end of the first segment. In a primary configuration of the device body, the coil has a longitudinally extending configuration, and in an expanded configuration of the device body, the first segment defines a plurality of first loops forming a three-dimensional non-helical structure configured to anchor the device body in the patient's vascular system, each second segment defines a plurality of secondary loops forming a three-dimensional non-helical structure, the maximum cross-sectional dimension of each second segment being smaller than the maximum cross-sectional dimension of the first segment, and the third segment defines a plurality of third loops forming a helical structure configured to anchor the device body in the patient's vascular system.

[0028] Clause 22: In some examples of the medical device described in accordance with Clause 21, the maximum cross-sectional dimension of the first segment is about 10% to about 100% of the maximum cross-sectional dimension of each second segment.

[0029] Clause 23: In some examples of the medical device described in accordance with Clause 21 or Clause 22, the body of the device is constructed for a corresponding nominal vascular size, wherein the maximum cross-sectional dimension of the first segment is about 1.1 to about 2.0 times the nominal vascular size, and wherein the nominal vascular size is about 1.0 to about 1.1 times the maximum cross-sectional dimension of each second segment.

[0030] Clause 24: In some examples of the medical device pursuant to any one of Clauses 21-23, the three-dimensional non-helical structure of the first segment and the three-dimensional non-helical structure of each of the second segments are approximately polyhedra.

[0031] Clause 25: In some examples of medical devices pursuant to any one of Clauses 21-24, each of these second segments follows the first segment.

[0032] Clause 26: In some examples of the medical device pursuant to any one of Clauses 21-25, the spiral structure of the third segment has a conical configuration.

[0033] Clause 27: In some examples, a method of forming a medical device includes attaching a first end of an elongated structure to a mandrel; forming a first segment of a device body, wherein forming the first segment includes winding the elongated structure around the mandrel to form a plurality of first loops, the plurality of first loops forming a corresponding three-dimensional non-helical structure; and forming a plurality of second segments of the device body, wherein forming the plurality of second segments includes, for each second segment, winding the elongated structure around the mandrel to form a plurality of secondary loops, the plurality of secondary loops forming a corresponding three-dimensional non-helical structure, wherein the maximum cross-sectional dimension of each of the second segments is smaller than the maximum cross-sectional dimension of the first segment.

[0034] Clause 28: In some examples of the method described in accordance with Clause 27, the elongated structure includes a coil comprising a plurality of windings, and wherein winding the elongated structure around a mandrel includes winding the coil around the mandrel.

[0035] Clause 29: In some examples of the methods described under Clause 27 or Clause 28, winding the elongated structure includes a rotating mandrel.

[0036] Clause 30: In some examples of the method pursuant to any one of Clauses 27-29, the method further includes a heated mandrel and an elongated structure wound around the mandrel.

[0037] Clause 31: In some examples of the method described in accordance with Clause 30, the method further includes removing the elongated structure from the mandrel.

[0038] Clause 32: In some examples of the method according to any one of Clauses 27-31, the method further includes forming a third section of the device body, wherein forming the third section includes winding an elongated structure around a mandrel to form a plurality of third rings forming a conical helical structure.

[0039] Clause 33: In some examples of the method according to any one of Clauses 27-32, the maximum cross-sectional dimension of each second segment is the outer diameter of each corresponding second segment, and the maximum cross-sectional dimension of the first segment is the outer diameter of the first segment.

[0040] Details of one or more aspects of this disclosure are set forth in the accompanying drawings and description below. Other features, objects, and advantages of the technology described in this disclosure will be apparent from the specification, drawings, and claims. Attached Figure Description

[0041] Figure 1 This is a side view showing an exemplary embolization device.

[0042] Figure 2 It shows that it includes the means to... Figure 1A schematic diagram of an exemplary component of a catheter system for delivering an exemplary embolization device to a blood vessel site.

[0043] Figure 3 It shows the expansion at the vascular site. Figure 1 A schematic diagram of the embolization device.

[0044] Figure 4 This is a flowchart illustrating an exemplary method for deploying an exemplary embolization device.

[0045] Figure 5 This is a flowchart illustrating an exemplary method for forming an exemplary embolization device. Detailed Implementation

[0046] This disclosure describes an implantable embolization device configured to embolize a site within a patient's vascular system or for use in another hollow anatomical structure of the patient. For example, the embolization device may be configured to fill a vascular site (e.g., a blood vessel) within the patient, thereby reducing blood flow at that site. The embolization device may be used, for example, to occlude a blood vessel (e.g., a peripheral vasculature) and sacrifice the vessel. The embolization device may also be referred to as an embolization coil, an occlusion coil, and / or a vascular occlusion coil. While this document primarily relates to blood vessels, the exemplary embolization devices described herein may be used in other hollow anatomical structures or other vascular sites, such as, but not limited to, the splenic artery, hepatic artery, iliac artery, gastroduodenal artery, peripheral aneurysm, ovarian vein, or spermatic vein.

[0047] The embolization devices described herein each have an elongated primary structure, such as, for example, a linear or coiled wire. The primary structure may also be referred to herein as a primary shape, primary configuration, or delivery configuration. Once deployed at the vascular site, the embolization device takes on a secondary configuration or shape, also referred to herein as a deployment configuration or deployment shape. In the deployment configuration, the device comprises at least two distinct segments, each defining a three-dimensional (“3D”) non-helical structure. The 3D non-helical structure defines a relatively complex 3D shape, such as rings of various orientations relative to each other, having the same or different sizes, and not limited to simple helices. The orientation of the rings in the complex 3D non-helical structure can be, for example, polyhedral, such as tetrahedral, hexahedral, octahedral, etc. When compared to an embolization device without multiple 3D non-helical structures, the combination of multiple 3D non-helical structures can provide additional features or beneficial effects. For example, an embolization device with multiple 3D non-helical structures may include some of these structures configured to anchor the device at the vascular site, and others configured to fill and more completely block the site.

[0048] Catheter delivery systems are commonly used to place implantable embolic devices at a vascular site within a patient. Delivery systems may sometimes include, for example, a microcatheter configured for delivery via a guidewire to the target vascular site, and a positioning element (e.g., a pusher, optionally having a disengagement mechanism connected to the coil) that pushes one or more coils out of the lumen of the microcatheter to the vascular site. Once positioned, the coil is disengaged from the delivery system. The coil may be configured to occlude (e.g., fill or otherwise occupy space through which blood flow passes) the vascular site, thereby reducing blood flow, promoting clotting, and ultimately occluding the blood vessel. Different types of coils may be implanted, including, for example, frame or anchored coils and occlusion coils.

[0049] In many cases, embolic devices may take on different shapes depending on their surroundings. In some cases, different shapes may include a primary shape as the embolic device is delivered through a narrow section of the catheter, and a secondary shape once deployed at the site of the vascular system. For example, the embolic device may have a longitudinally extending shape as it is advanced through the catheter. Upon exiting the catheter, the device may take on a secondary shape within the vascular system (e.g., defining a larger cross-sectional dimension than the primary shape). For example, the embolic device may exhibit a secondary shape designed to more completely fill the cross-section of the vascular site.

[0050] In some examples, the first segment of the embolization device and one or more second segments of the device each have an unfolded configuration that defines a 3D non-helical structure formed by multiple loops of the device's elongated primary structure. The unfolded configuration of the first segment is configured to anchor the embolization device in the patient's vascular system, while the unfolded configuration of one or more second segments is configured to occlude the lumen of a blood vessel. The loops forming the first segment may, in some cases, be referred to as anchoring loops and may be slightly larger than the nominal blood vessel size for which the embolization device is designed. The first segment also helps to anchor the embolization device within more flexible blood vessels, such as some veins, which can expand to a relatively large size. The first segment may additionally help compensate for size errors in clinicians who underestimate the size of the target vascular system.

[0051] The maximum cross-sectional dimension (e.g., diameter or width) of the unfolded configuration of the second segment may be smaller than the maximum cross-sectional dimension of the unfolded configuration of the first segment. For example, the 3D non-helical structure of the second segment may be formed of a ring, sometimes referred to as a packing ring, which is designed to more easily fill the space created by the anchoring 3D structure at the embolization site. For example, the second segment may unfold at least partially (e.g., partially or completely) within the first segment. Each second segment is configured to unfold into a smaller volume than the first segment. The unfolded volume of the first or second segment may be a function of the corresponding maximum cross-sectional dimension.

[0052] In some examples, the embolization device described herein may include a third segment different from the first and second segments. The third segment has an unfolded configuration comprising a plurality of loops of an elongated primary structure, which may be, for example, a wire or a longitudinally extending coil (the coil itself is defined by the elongated structure, thus formed, for example, by winding around a central axis to define a plurality of turns). The plurality of loops in the third segment may be inherently helical. In some examples, the maximum cross-sectional dimension of one or more helical loops may be slightly larger than the nominal vascular size for which the device is designed. In some examples, the diameter of one or more helical loops may be approximately the same as the maximum cross-sectional dimension of the unfolded configuration of the first segment. Thus, the unfolded configuration of the third segment can be configured to provide additional anchoring of the embolization device within the patient's vascular system. In some examples, the maximum cross-sectional dimension of one or more helical loops in the helical loops of the third segment may be smaller than the nominal vascular size for which the device is designed. Thus, the unfolded configuration of the third segment can be configured to help ensure that these loops of the coil are in an unfolded configuration rather than an elongated configuration upon exiting the delivery system. In some examples, some or all of the rings in the third segment may have a tapered configuration, wherein the diameter of the rings increases from one end to the other.

[0053] The third segment of the device may be closest to the first segment, and the first segment is opposite to the second segment. Therefore, the order of these segments may extend from the third segment at the front end to the first segment and then to the second segment at the rear end. The front end may be, for example, a distal end in some examples, or a proximal end in other examples, and the rear end may be, for example, a proximal end in some examples, and a distal end in other examples.

[0054] When performing certain vascular embolization medical procedures, two objectives are to locate the embolic device without displacement and to rapidly and completely occlude the vascular lumen. The blood flow rate in the vessels (which can be very high, for example, in some arteries) can make locating the embolic device and occluding the vessel very challenging, especially when compared to embolizing spaces with lower flow drag, such as, for example, aneurysms. The exemplary embolization device described herein has an unfolded configuration with multiple 3D non-helical structures that can be configured to address these challenges by providing a first segment that anchors the embolic device in the vessel and one or more second segments configured to occlude a stent defined by the first segment. Releasing the anchoring and occlusion functions of the embolization in this manner can contribute to more effective results.

[0055] The embolization devices described herein can also be used for aneurysm occlusion. In these examples, a first segment may be configured to provide a juxtaposition against the aneurysm wall and one or more second segments may be configured to occlude the aneurysm sac.

[0056] As described herein, the exemplary embolization device has a primary structure, which may also be referred to as a primary shape, primary configuration, or delivery configuration. The exemplary embolization device also has a secondary configuration when deployed at a vascular site, which may also be referred to as a secondary structure or shape, or deployment configuration, shape, or structure. Furthermore, the exemplary embolization device is described as comprising one or more first segments, one or more second segments (e.g., two or more second segments), and in some examples, a third segment. As described herein, each of these segments of the exemplary device has its own primary configuration and secondary (e.g., deployment) configuration. These structures may alternatively be described as corresponding segments of the overall primary and deployment configurations of the device. Thus, a 3D non-helical structure may be described herein as part of the deployment configuration of a first segment of the exemplary embolization device, and may alternatively be referred to as a first segment of the deployment configuration of the exemplary embolization device. For convenience, such structures may also be referred to herein as first, second, and third deployment configurations or structures, each referring to a corresponding segment of the overall deployment configuration of the device.

[0057] Figure 1 This is a side view of an exemplary implantable embolization device 10 configured to embolize a site in a patient's vascular system. Figure 1 An embolization device 10 in a secondary (or expanded) configuration is shown, which includes multiple 3D non-helical structures, which in some cases may also be referred to as complex shapes, configurations or structures. Figure 1 The secondary configuration shown represents the configuration in which device 10 is in its relaxed state when no external force is applied to it. In some cases, the material forming device 10 may not be self-supporting, allowing device 10 to flatten under its own weight.

[0058] The embolization device 10 includes a device body 12, which is shaped to generate Figure 1 The illustrated unfolded configuration. In some examples, the device body 12 may be a wire or other filamentous material. In some examples, the device body 12 may be a section of coiled material. For example, the device body 12 may be a section of coil formed by a number of windings or turns of wire or other suitable material. In some examples, the device body 12 may also incorporate other previously disclosed elements such as detachable elements and tensile strength elements to assist in the function of the detachable coil.

[0059] refer to Figure 2 The embolization device 10 also has a primary configuration (also known as a delivery configuration), such as... Figure 1 Shapes or structures not shown in the diagram. For example... Figure 2As shown, the device body 12 of the embolization device 10 has a primary shape configured to fit within the lumen 42 of the catheter 44 for delivery of the device 10 to the target vascular system site 46. In this case, the primary shape can be, for example, a longitudinal or elongated extension of the device body 12. Figure 2 As partially shown in the examples, the device body 12 is a coil extending from the tail end 13 to the front end 15. In some examples, the coil has a primary configuration that is substantially linear within the inner lumen 42 of the catheter 44. As the device 10 unfolds from the inner lumen 42 at the vascular site 46, the device body 12 exits the catheter 44 and presents its second configuration (e.g., Figure 1 and Figure 3 (As shown). When formed from coils, the device body 12 may be referred to as the “primary coil” to distinguish the structure and configuration of the device body 12 from the other “secondary” loops and the bending of the coil itself in the secondary configuration of the embolization device described herein.

[0060] Back Figure 1 The embolization device 10 includes a first segment 14 and one or more second segments 16. Although Figure 1 The diagram shows three second segments 16, but in other examples, the embolization device 10 may include any suitable number of second segments 16, such as one, two or more than three second segments 16 following the first segment 14.

[0061] exist Figure 1 In the unfolded configuration, each of the first segment 14 and the second segment 16 includes a plurality of rings 18 of the device body 12, which form a separate 3D non-helical structure for each of the segments 14, 16. The rings 18 forming the first segment 14 may be described herein as first rings, while the rings 19 forming each of the second segments 16 may be described as secondary rings. In some examples, the 3D non-helical structure of the first segment 14 is configured to anchor the device 10 to the patient's vascular system, and the 3D non-helical structure of the second segment 16 is configured to occlude or embolize vascular sites (e.g., vascular lumen or aneurysm sac). Thus, in some cases, the rings forming the unfolded structure of the first segment 14 may be referred to as "anchoring" rings and the rings forming the unfolded structure of the second segment 16 may be referred to as "occlusion" or "filling" rings. For example, the unfolded first segment 14 may define a support, and the one or more second segments 16 may be configured to fit within and fill the support, such that the one or more second segments 16 are inserted into the first segment 14. Relative to Figure 1 , Figure 3 An example of this configuration is shown and described.

[0062] The first segment 14 has a maximum cross-sectional dimension 20, and each second segment 16 has a maximum cross-sectional dimension 22. The maximum cross-sectional dimension 22 of each second segment 16 is smaller than the maximum cross-sectional dimension 20 of the first segment 14. As a result, each second segment 16 is configured to unfold into a smaller volume than the first segment 14. The maximum cross-sectional dimensions of the embolization device, the first segment, the second segment, and the third segment described herein refer to the dimensions of the overall structure (e.g., from edge to edge along a plane), and not the cross-sectional dimensions of the wires, coils, or other elongated structures used to form the respective structures.

[0063] Using a second segment 16 with a smaller maximum cross-sectional dimension (e.g., a smaller unfolded volume) than the first segment 14 facilitates occlusion of vascular system sites (e.g., aneurysm sacs or parent vessels). In some examples, the first segment 14 forms a stent within the vascular lumen or aneurysm sac when anchored to the vessel wall at that site. The smaller maximum cross-sectional dimension 22 of each second segment 16 can facilitate the formation of a ring of the second segment 16 to occlude the stent provided by the first segment 14. In some examples, the maximum cross-sectional dimension 20 of the first segment 14 is approximately 10% to approximately 100% of the maximum cross-sectional dimension 22 of each second segment 16, such as approximately 10% to 50%. When used to modify numerical values, the term "about" as used herein may refer to a specific value or a value close to the range allowed by manufacturing tolerances. For example, "about 10%" means "10% or close to 10% within the range allowed by manufacturing tolerances."

[0064] In some cases, as discussed below, the maximum cross-sectional size 20 of the first segment 14 is selected based on the size of the blood vessel intended for use with the device 10, and the maximum cross-sectional size 22 of each second segment 16 is selected based on the determined maximum cross-sectional size 20 of the first segment 14. For example, when the device 10 is deployed at a patient's vascular site, the maximum cross-sectional size 22 of each second segment 16 may be selected to be located within the larger size of the maximum cross-sectional size 20 of the first segment 14.

[0065] In some examples, the embolization device may be constructed or designed for use with a specific size of blood vessel. Therefore, in some cases, clinicians may assess the size of the vessel to be embolized and then select a specific embolization device 10 constructed for that specific size from a plurality of embolization devices as described herein, wherein the size of the device varies according to a range of nominal vessel sizes. In some examples, the embolization device 10 may be constructed for a specific nominal vessel size. In such examples, the maximum cross-sectional dimension 20 may be slightly larger than the nominal vessel size. For example, the maximum cross-sectional dimension 20 may be about 1.1 to about 2 times the nominal vessel size (exactly 1.1 to 2 or within 10%), such as about 1.1 to about 1.4 times the nominal vessel size, or about 1.1 to about 1.3 times the nominal vessel size. A maximum cross-sectional dimension 20 that is too large, for example, about 2 times the nominal vessel size in some examples, may adversely affect the ability of the device 10 to form a loop within the vascular system when the device 10 is deployed.

[0066] In some examples, for each second segment 16, the maximum cross-sectional dimension of the second segment 16 may be substantially the same (e.g., identical but with manufacturing tolerances), or the dimension may vary between one second segment 16 and another. In examples where the maximum cross-sectional dimension 22 differs due to, for example, design and / or tolerances, each maximum cross-sectional dimension 22 is still smaller than the maximum cross-sectional dimension 20 of the first segment 14. In some examples, the embolization device 10 is constructed for a nominal vascular size and the maximum cross-sectional dimension 22 is equal to or slightly smaller than the nominal vascular size. For example, the maximum cross-sectional dimension 22 may be about 85% to about 100% of the nominal vascular size, or the nominal vascular size may be about 1.0 to about 1.1 times the maximum cross-sectional dimension 22 (e.g., precisely 1.0 to 1.1 or within 10%).

[0067] As described herein, exemplary implantable embolization devices have secondary or unfolded configurations comprising multiple 3D non-helical structures. Figure 1 As shown, the embolization device 10 includes a first segment 14 having a 3D non-helical structure and three second segments 16, each having a 3D non-helical structure. In some cases, the 3D non-helical structure may also be referred to as a complex shape or configuration because the structure is formed by one or more loops located in various planes, which differs from, for example, simple structures such as helical coils. In some examples, the first segment 14 and / or the second segment 16 may comprise a 3D non-helical structure that approximates a polyhedron, wherein each loop of the structure approximates one face of the polyhedron. Figure 1 In the examples, each 3D non-spiral structure is formed by six rings of the six facets of an approximate cube. In some examples, the 3D non-spiral structure can be a cube, tetrahedron, octahedron, or any entity constructed with edges of regular polygonal shape.

[0068] In some examples, including some of those described herein, the 3D non-helical structure can be considered to approximate a sphere to a greater or lesser extent. In this case, the maximum cross-sectional dimension of each second segment is the outer diameter of the second segment. Furthermore, the maximum cross-sectional dimension of the first segment is the outer diameter of the first segment. For example, Figure 1 The 3D non-helical structure of the embolization device 10 shown can be considered approximately spherical, such that the maximum cross-sectional dimension 20 can be considered the outer diameter or outer diameter 20 of the first segment 14. In a similar manner, the maximum cross-sectional dimension 22 can be considered the outer diameter 22 of the second segment 16.

[0069] The exemplary embolization devices described herein include multiple segments having a three-dimensional non-helical structure when deployed at a vascular site. The multiple segments may include at least one (e.g., one or more) first segment 14 and at least one (e.g., one or more) second segment 16 smaller than the first segment. Some exemplary embolization devices may include two or more second segments connected to adjacent first segments. Figure 1 As shown, the deployed configuration of the exemplary device 10 includes three adjacent second segments 16 connected to a first segment 14. Some exemplary embolization devices may include more or fewer than three adjacent second segments 16.

[0070] In some examples, the embolization device 10 also includes a third segment 30 configured to anchor the embolization device 10 in the patient's vascular system. For example, the third segment 30 may be configured to anchor the embolization device 10 together with a first deployment structure of the first segment 14. Figure 1 In the unfolded configuration shown, the third segment 30 includes multiple rings, which are also referred to herein as multiple third rings. Figure 1 In some examples, the third segment 30 is connected to the first segment 14 and is located on the side of the first segment 14 opposite to the second segment 16. In some examples, the third ring forming the third segment 30 is configured as a helical structure, such as a coiled structure, to anchor the device 10 in the patient's vascular system. In some examples, the helical structure has a tapered configuration, the diameter of which increases from the anterior ring 32 toward the tail ring 34 connected to the first segment 14, such as... Figure 1 As shown. Alternatively, the diameter of the helical structure of the third segment 30 may increase from the tail ring 34 toward the front ring 32. In examples where the third segment 30 has a conical helical configuration, the third segment 30 may define a conical spiral, for example, a three-dimensional spiral extending along the outer surface of an imaginary cone. In some examples, the spiral may taper gradually in the guiding direction (away from the second segment 16), such as... Figure 1As shown, or in other examples, it may taper gradually in the proximal direction. In some examples, the smallest loop of the coil is smaller than the intended vascular treatment range of the device, ensuring that this segment of the coil presents an expanded configuration rather than an elongated configuration when leaving the delivery system and unfolding into the vascular system.

[0071] The loops of the third segment 30 may not be closed loops, wherein the loops of the coil are coplanar, and the loops of the coil contact adjacent loops in a “resting” state (where no compressive force is applied to the third segment 30 from the catheter, blood vessel, etc.). Spacing the loops apart in the longitudinal direction (e.g., proximal to distal or distal to proximal) provides space for the loops to bend relative to each other, and allows larger loops to reduce their cross-sectional size by longitudinal expansion when anchored in a relatively small-diameter blood vessel. In some examples, in their resting secondary configuration, where no outward force is applied to the device 10 from the blood vessel wall or catheter, the loops 32, 34 (and other loops, if present) may be separated from each other. Furthermore, in examples where the loops 32, 34 (and other loops, if present) have different maximum (or largest) cross-sectional dimensions (e.g., diameters) from each other, each loop of the third segment 30 may differ from the adjacent loop in its maximum cross-sectional dimension by a predetermined amount. For example, if the third segment 30 is defined by an elongated structure with a diameter of 0.25 mm, then the diameter of each ring can be 0.50 mm larger than the adjacent distal (or proximal in some examples) ring. Other ring sizes may also be used in other examples.

[0072] In examples where the third segment 30 is closer to the front end of the device 10 than the first segment 14 (e.g., the most distal portion of the embolization device 10 or the most proximal portion of the embolization device in other examples), the third segment 30 may unfold from the catheter 44 before the first segment 14 and the second segment 16. For example, the first loop 32 of the third segment 30 may engage with the vessel wall, and then subsequent loops of the third segment 30 may be deformed into a helix against the vessel wall, potentially altering the shape of the third segment 30, for example, from a conical coil to a helix with a more uniform loop size. The helical structure of the third segment 30 allows the third segment 30 to be deployed from the catheter 44 ( Figure 2 The distal end 56 of the third segment 30 engages with the vessel wall and is anchored at the target vessel site. For example, the third segment 30 may be configured to engage with the vessel wall in a relatively straight (e.g., cylindrical) vessel segment.

[0073] While the first segment 14 is also configured to engage the vessel wall to anchor the embolization device 10 within the vascular system, the configuration of the third segment 30 (e.g., a helical structure) allows the third segment 30 to deploy more effectively than the first segment 14. This third segment, despite having a similar overall deployed outer diameter, has smaller individual loops, allowing the embolization device 10 to be more effectively anchored within the vessel as it deploys from the catheter 44. This more effective anchoring of the embolization device 10 allows it to begin embolization at or relatively close to the distal end 56 of the catheter 44, rather than sliding along the vessel wall without engaging it. The structure of the embolization device 10, allowing it to begin embolization at or relatively close to the distal end 56 of the catheter 44 (or other deployed positions of the catheter), provides clinicians with more precise control over the implantation location of the embolization device 10 within the patient's vascular system, potentially leading to better treatment outcomes (e.g., sacrificing a vessel via the device 10).

[0074] In some examples, the third ring forming the helical structure of the third segment 30 can further aid in anchoring the device 10 because the third ring can be configured to exert a greater radial force against the vessel wall compared to the first segment 14 and / or the second segment 16. For example, the helical ring can facilitate penetration of open spaces within the vessel. Furthermore, in examples where the third segment 30 includes a conical ring, the various ring sizes defined by the third segment 30 allow the third segment 30 to expand (when it unfolds from the catheter) to accommodate various vessel sizes (in cross-section). In these examples, the embolization device 10 can be configured to accommodate clinicians' size preferences (e.g., some clinicians may prefer a larger or smaller distal ring based on their personal experience implanting embolization devices in patients), and the uncertainty of vessel size when selecting a particular size of embolization device 10 for implantation in a patient. In some cases, embolization device manufacturers may offer embolization devices in 1-millimeter increments corresponding to different vessel sizes (cross-sections), such as 4mm vessels, 5mm vessels, etc. Compared to devices configured for a specific blood vessel size, embolization devices 10 configured to accommodate a range of blood vessel sizes allow clinicians to better select devices 10 that can provide positive outcomes for patients by requiring less precise determination of the patient's blood vessel size.

[0075] In some examples, the first 180 degrees of the smallest ring (e.g., ring 32) defined by the third segment 30 may be selected to define a cross-sectional size that is the same as or smaller (e.g., within 10%) the cross-sectional size (e.g., diameter) of the smallest vessel that a clinician can treat with the embolization device 10. Furthermore, in addition to or instead of the parameters described above, in some examples, the cross-sectional size of the largest ring (e.g., ring 34) defined by the third segment 30 may be selected to have a cross-sectional size that is larger (e.g., 10% to 50% larger, such as 25% to 30% larger) than the largest vessel that a clinician can treat with the embolization device 10. By increasing the size of the largest ring, the third segment 30 can provide sufficient radial outward force to engage with the vessel wall and help anchor the device 10 to the vessel wall.

[0076] In some examples, such as those where the third segment 30 defines a conical spiral, the third segment 30 can also help center the embolization device 10 within the vessel wall, which can enable the embolization device 10 to achieve a higher packing density in some cases. By providing greater kinetic energy absorption for blood flow, a higher packing density can more effectively impede blood flow through the vessel for a given time.

[0077] The third segment 30 may be formed of any suitable material. In some examples, the third segment 30 is formed of a material (e.g., chemical composition) different from that of the first segment 14 and / or the second segment 16. In other examples, the third segment 30 is formed of the same material as the first segment 14 and / or the second segment 16. For example, the third segment 30 may be integrally formed with the first segment 14 and the second segment 16, and may be formed of the same material as the first segment 14 and the second segment 16. In any of these examples, the third segment 30 may be formed of a metallic alloy, such as platinum-tungsten (e.g., approximately 98% Pt and approximately 2% tungsten), platinum, iridium, or other suitable biocompatible materials. Furthermore, in some examples, the third segment 30 may be at least partially formed of a material that enables the third segment 30 to engage with the vessel wall (e.g., by friction engagement or the use of an adhesive material) for a relatively short period of time, which is less than the intended implantation time of the embolization device 10.

[0078] For example, at least a portion of the outer surface of the third segment 30 may be formed at least partially of a biodegradable and biocompatible hydrophilic material, such as, but not limited to, poly(lactic-co-glycolic acid) (PGLA), wherein the biodegradable and biocompatible hydrophilic material is configured to dry (dehydrate) due to sterilization by the embolization device 10. For example, the third segment 30 may be formed of metal or fibers wound or coated with PGLA or other biodegradable and biocompatible materials. PGLA or other biodegradable and biocompatible materials may, for example, be formed as fibers wound together with other fibers forming the structure of the third segment 30. The state in which the biodegradable and biocompatible material of the third segment 30 is dehydrated may also be referred to as the dehydrated state of the third segment 30.

[0079] In its dehydrated state, the third segment 30 can be configured to adhere to and engage with the vessel wall better (e.g., by static friction) than in its undried (i.e., hydrated) state. This may be due to, for example, surface features that are more prevalent in its dehydrated state compared to its hydrated state. After the embolization device 10 is implanted into the vessel, the water in the blood can hydrate the material of the third segment 30, for example, until the material reaches equilibrium with its environment. The third segment 30 can be softer in its hydrated state than in its dehydrated state, and can soften and engage less with the vessel wall, for example, due to changes in surface features that are less prevalent in the hydrated state. However, because the embolization device 10 can be fully deployed at this time, the first segment 14 can further facilitate anchoring the device 10 in the vessel. In this way, the material of the third segment 30 can be used to further facilitate more accurate deployment of the embolization device 10 by anchoring the device 10 near the distal end 56 of the catheter 44, so that the device 10 can be embolized at or relatively close to the catheter tip.

[0080] In other examples, the embolization device 10 includes a first segment 14 and one or more second segments 16, but does not include a third segment 30.

[0081] Figure 2 This is a schematic diagram illustrating an exemplary component 40, which includes an embolization device 10 positioned within the inner lumen 42 of a catheter 44. Figure 2 This is a schematic cross-sectional view of conduit 44, where the cross-section is taken along the longitudinal axis 50 of conduit 44. The longitudinal axis 50 may be the central longitudinal axis of one or more components of conduit 44, such as the elongated body 52 of conduit 44. The elongated body 52 of conduit 44 extends from a proximal end 54 to a distal end 56. In some examples, conduit 44 may include a strain-relieving member 60. In such examples, the proximal end 54 of the elongated body 52 may be partially covered by the strain-relieving member 60, such that the proximal end 54 of the elongated body 52 is comparable to... Figure 2 It is shown as closer.

[0082] The elongated body 52 has an outer wall 62 defining a lumen 42. In some examples, in addition to the lumen 42, the elongated body 52 may also define one or more additional lumens (not shown). Such additional lumens can be used to aspirate fluids and / or deliver drugs or medical agents into blood vessels. In some examples, the catheter 44 may also include a hub 64 located at a proximal end 54 of the elongated body 52. ​​In such examples, the lumen 42 may extend longitudinally through the elongated body 52 to reach the hub 64. The hub 64 may include at least one of a first port 66 or a second port 68, one or both of which are in fluid communication with the lumen 42.

[0083] The catheter 44 is configured to navigate through the patient’s vascular system to deliver the embolization device 10 to a target site 46 within the patient’s vascular system. Figure 2 An example is shown in which site 46 is within a patient's blood vessel 48. Some exemplary components may also include a positioning device 45, which may also be referred to as a locator 45 or a pushing member. The locator 45 is configured to advance the embolization device 10 through the lumen 42 of the catheter 44 to deploy the device 10 at site 46. In some examples, the positioning device 45 may also be actively attached to the embolization device 10 and then detached from it once the device 10 has been deployed at site 46. A variety of positioning devices or locators may be used to deliver the exemplary embolization devices described herein, including those described in U.S. Patent 8,328,860 entitled "IMPLANT INCLUDING ACOIL AND A STRETCH-RESISTANT MEMBER," the disclosure of which is incorporated herein by reference in its entirety.

[0084] Such as about Figure 1 The exemplary embolization device discussed has a primary configuration designed to fit within the lumen of a catheter. For example... Figure 2 As shown, in some examples, the device body 12 is formed by a coil extending from the tail end 13 to the front end 15. The coil has a substantially linear configuration within the inner lumen 42 of the catheter 44 because the device 10 is configured to advance through the inner lumen 42 during deployment at the target site 46 within the blood vessel 48. The coil exits the inner lumen 42 of the catheter 44 and begins to exhibit a secondary configuration as the device 10 is deployed to the target site 46. Figure 2 An embolization device 10 in a first or primary configuration is shown, except that the tip 15 of the device 10 has begun to present a secondary configuration outside the inner lumen 42 of the catheter 44. The exemplary embolization device 10 includes a first segment 14, a plurality of second segments 16, and a third segment 30, as also described above. Figure 1 As described. For clarity, in Figure 2 The figure uses a single instance of reference numeral 16 to represent multiple second segments 16.

[0085] In some examples, the sections of the exemplary embolization device are arranged in different ways. Figures 1-3 In this example, the exemplary embolization device 10 includes a first segment 14 and three second segments 16 following the first segment 14. In some cases, the second segments 16 are connected to and may also be adjacent to the first segment 14. The exemplary embolization device 10 also includes a third segment 30 located further forward than the first segment 14. In some examples, the third segment 30 is connected to and adjacent to the first segment 14, such as... Figures 1-3 As shown.

[0086] As shown in the figure, the exemplary embolization device 10 may include three second segments 16 connected to a first segment 14, which in turn connects to a third segment 30. It should be understood that the number of these segments may vary depending on, for example, a specific target site, delivery method, etc. For instance, in some examples, more than three or fewer than three second segments may be used. In some examples, the first, second, and third segments may not be directly connected or adjacent, but may instead have elongated structures with some open length between the segments.

[0087] Figure 3 This is a schematic diagram showing the embolization device 10 in an expanded configuration at the target site 46 within the blood vessel 48. Figure 3 A catheter 44 is also shown, which deploys one or more second segments 16 into a stent defined by the first segment 14. In other examples, the embolization device 10 may be deployed at other vascular sites, such as within an aneurysm sac.

[0088] The first segment 14 includes a 3D non-helical structure configured to engage with the vessel wall 80, thereby anchoring the device 10 within the vessel 48. The anchoring structure provided by the first segment 14 can be tamped together with one or more second segments 16 of the embolization device 10. For example, as Figure 3 As shown, a first segment 14, unfolding within a blood vessel 48, may define a stent (e.g., a framework including a space), and at least a portion of one or more second segments 16 may be inserted into and fill the stent defined by the first segment 14 (e.g., into the space defined between the loops or other structures of the unfolded first segment 14). For example, a smaller loop defined by the second segment 16 may unfold within the stent defined by the first segment 14. Figure 3 As shown, catheter 44 can be positioned relative to the deployed first segment 14 such that one or more subsequently deployed second segments 16 are delivered into the stent defined by the first segment 14.

[0089] Constructing the first segment 14 to anchor within the blood vessel 48 or at another vascular site may result in the first segment 14 being insufficient to fill the vascular site and reduce blood flow at that site. The relatively small unfolded volume of each of the one or more second segments 16 allows the one or more second segments 16 to fit within and fill the stent defined by the first segment 14 to help occlude the blood vessel 48. Therefore, by including one or more second segments 16 in the embolization device, the embolization device 10 can exhibit effective anchoring and effective occlusion at the vascular site.

[0090] Such as about Figure 1 and Figure 2 As described, in some examples, the embolization device 10 includes a third segment 30 connected to the first segment 14 on the side of the first segment 14 opposite to one or more adjacent second segments 16. Figure 3 In the unfolded configuration, the third segment 30 includes a plurality of spiral loops with gradually decreasing diameters, the diameter increasing from the end loop 32 (e.g., the anterior loop) to the starting loop 34 (e.g., the tail loop), the starting loop being connected to and adjacent to the first segment 14. The third segment 30 is configured to anchor the device body 12 to the patient's vascular system, for example, by engaging with the wall 80 of the blood vessel 48 at the vascular site 46.

[0091] Figure 4 This is a flowchart illustrating an exemplary method of deploying an exemplary embolization device, such as the exemplary embolization device described herein. The method includes introducing catheter 44 into the patient's vascular system (132) and advancing catheter 44 to a target site 46 within the patient's vascular system. Figure 3 (134). Once the distal end 56 of the catheter 44 is in the desired position relative to the target site 46, the clinician can advance the embolization device 10 through the lumen 42 of the catheter 44 (136) and deploy the embolization device 10 at the target site 46 (138). For example, the clinician can use a positioner 45 or another device to position the device body 12 at the tail end 13 ( Figure 2 Apply thrust to deploy the main body 12 of the device from the inner lumen 42 and deploy the embolization device 10 at the target location 46.

[0092] When the embolization device 10 is deployed at the desired vascular treatment site 46, the device body 12 of the embolization device 10 takes on an deployed configuration, for example, as... Figure 3 As shown. In some examples, the unfolded configuration includes a first segment 14 defining a plurality of first rings forming a 3D non-helical structure configured to anchor the device body 12 at the treatment site, and one or more second segments 16 each defining a plurality of secondary rings forming a 3D non-helical structure. Furthermore, in some cases, the maximum cross-sectional dimension of each second segment 16 is smaller than the maximum cross-sectional dimension of the first segment 14.

[0093] Embolization device 10 and other embolization devices described herein, including first segment 14 and one or more second segments 16, can be formed using any suitable technique, such as by using a mandrel that includes different rods extending therefrom to define different portions of embolization device 10.

[0094] Figure 5 It shows the formation of embolic devices such as Figure 1 A flowchart illustrating an exemplary method of the exemplary embolization device 10. Although Figure 5 This is described with reference to embolization device 10, but in other examples, Figure 5 The method shown can be used to form other embolic devices including a first segment and one or more second segments, as described herein. In some examples, the method includes attaching the end of an elongated structure (e.g., a wire or coil) to a mandrel (142). For example, in some cases, the elongated structure can be attached to the mandrel by inserting one end of the elongated structure into an initiation hole defined by the mandrel. In some cases, the elongated structure may be stretched and tightly wound around a portion of the mandrel to secure the end of the elongated structure relative to the mandrel.

[0095] In some examples, the elongated structure can be a linearly configured metal wire or a metal wire forming a primary coil, such as in... Figure 2 The examples shown are exemplary. Exemplary embolization devices, such as those described herein, can be formed from any suitable biocompatible material. In some examples, the elongated structure can be formed from metals or metal alloys, including platinum, platinum alloys, palladium, nitinol, stainless steel, and / or any other metallic material characterized by suitable biocompatibility.

[0096] like Figure 5 As shown, the exemplary method also includes winding an elongated structure around a mandrel to define a first segment 14 (144) of the embolization device 10. For example, the elongated structure may be wound around the mandrel to form a plurality of first loops that form a 3D non-helical structure in an unfolded configuration of the first segment 14. The method also includes winding the elongated structure around the mandrel, for example, one or more second winding cores extending from the main axis of the mandrel, to define one or more second segments 16 (146) of the embolization device 10. For example, the elongated structure may be wound around the mandrel to form a plurality of secondary loops that form a corresponding 3D non-helical structure in an unfolded configuration of the second segment 16.

[0097] After the elongated structure is wound around the mandrel, the mandrel and the elongated structure can be heated (148), and the resulting structure can be removed from the mandrel (150).

[0098] In some examples, Figure 5The method shown also includes forming a third section of the embolization device 10, for example by winding an elongated structure around a mandrel 90 to define a plurality of third rings as part of a conical helical structure.

[0099] In some examples, embolization devices such as those described herein may include elongated structures, such as a primary coil comprising wires of different sizes. For example, in some cases, the primary coil may be formed from two wires of different diameters or from a single wire in segments of different diameters. In some examples, the front segment of the primary coil may be formed from wire with a diameter greater than that of the wire forming the tail segment of the primary coil. In some examples, the front segment of the primary coil may be formed from wire with a diameter smaller than that of the wire forming the tail segment of the primary coil.

[0100] According to some examples, the embolization device described herein may include one or more fibers. For example, the device may include multiple fibers, at least one bundle of fibers, or multiple fiber bundles. In some examples, the fibers may be wrapped, tied, or knotted to multiple locations on the embolization device. In some examples, the fibers or fiber bundles may be arranged such that they cannot be tied or knotted to the device, thereby avoiding potential obstructive bundles that could hinder device deployment. In some examples, one or more fibers may be non-absorbable. Exemplary materials that may be used include, but are not limited to, nylon, polyethylene, and / or polypropylene. In some examples, one or more fibers may be bioabsorbable. Exemplary bioabsorbable materials that may be used include, but are not limited to, polyglycolic acid (PGA), polylactic acid (PLA), PGLA, and / or polydioxanone (PDO).

[0101] It should be understood that the various aspects disclosed herein can be combined in combinations different from those specifically presented in the specification and drawings. It should also be understood that, by way of example, the actions or events of any process or method described herein may be performed in a different order, and may be added, combined, or excluded entirely (e.g., all described actions and events may not be necessary for performing the technology). Furthermore, although some aspects of this disclosure are described for clarity as being performed by a single module or unit, it should be understood that the technology of this disclosure can be performed by a combination of units or modules associated with, for example, a medical device.

Claims

1. A medical device comprising: a device body comprising a first segment, a plurality of second segments, and a third segment connected to the first segment on an opposite side of the first segment relative to the plurality of second segments, wherein the device body defines a longitudinal axis extending in a direction from the third segment to the plurality of second segments, wherein the device body comprises a coil comprising a plurality of windings, and wherein in a deployed configuration of the device body: the first segment defines a plurality of first segment loops forming a three- dimensional non-helical structure configured to anchor the device body in a vasculature of a patient, each of the plurality of second segments defines a plurality of second segment loops forming a three-dimensional non-helical structure, some of the plurality of second segments are spaced apart from one another along the longitudinal axis such that at least one second segment follows another second segment, a maximum cross-sectional dimension of each of the plurality of second segments is less than a maximum cross-sectional dimension of the first segment, and the third segment forms a structure of a different size and shape than the three- dimensional non-helical structure formed by the first and second segments and defines a third segment loop that is larger than at least one of the plurality of first segment loops, wherein the third segment defines a helical structure.

2. The medical device of claim 1, wherein the plurality of second segments comprises at least three second segments.

3. The medical device of claim 1, wherein the maximum cross-sectional dimension of the first segment is 10% to 50% greater than the maximum cross-sectional dimension of each second segment.

4. The medical device of claim 1, wherein the device body is configured for a nominal vessel size, wherein the maximum cross-sectional dimension of the first segment is 1.1 to 2.0 times the nominal vessel size, and wherein the nominal vessel size is 1.0 to 1.1 times the maximum cross-sectional dimension of each second segment.

5. The medical device of claim 1, wherein in the deployed configuration, the third segment defines a plurality of loops forming the helical structure configured to anchor the device body in the vasculature of the patient, the plurality of loops comprising the third segment loop.

6. The medical device of claim 5, wherein the helical structure has a conical configuration.

7. The medical device of claim 6, wherein a diameter of the conical configuration increases toward the first segment.

8. The medical device of claim 1, wherein the third segment is formed of a material having a chemical composition different from a chemical composition of a material forming at least one of the first segment or the plurality of second segments.

9. The medical device of claim 1, wherein the third segment is configured to exert a greater radial force against a vessel wall than at least one of the first segment or the plurality of second segments.

10. The medical device of claim 1, wherein the three-dimensional non- helical structure of the first segment and the three-dimensional non-helical structure of each of the plurality of second segments is approximately polyhedral.

11. A medical assembly comprising: a catheter defining an inner lumen; and the medical device of claim 1 positioned within the inner lumen in a delivery configuration, wherein the medical device is configured to expand from the delivery configuration to the deployed configuration in response to deployment from the inner lumen of the catheter.

12. The medical assembly of claim 11, wherein in the delivery configuration of the medical device, the device body comprises a substantially linear configuration within the inner lumen.

13. The medical assembly of claim 11, wherein each of the plurality of second segments follows the first segment.

14. A medical device comprising: a device body comprising a coil including a first segment, two or more second segments connected to one end of the first segment, and a third segment connected to another end of the first segment, wherein in a primary configuration of the device body, the coil has a longitudinally extending configuration, and wherein in a deployed configuration of the device body: the first segment defines a plurality of first segment loops forming a three- dimensional non-helical structure configured to anchor the device body in a vasculature of a patient, each second segment defines a plurality of second segment loops forming a three- dimensional non-helical structure, a maximum cross-sectional dimension of each second segment is less than a maximum cross-sectional dimension of the first segment, and the third segment defines a plurality of third loops forming a helical structure configured to anchor the device body in the vasculature of the patient, wherein the third segment is configured to exert a greater radial force against a vessel wall than at least one of the first segment or the plurality of second segments, wherein the three-dimensional non-helical structure of the first segment and the three-dimensional non-helical structure of each second segment is approximately polyhedral.

15. The medical device of claim 14, wherein the maximum cross-sectional dimension of the first segment is 10% to 100% greater than the maximum cross-sectional dimension of each second segment.

16. The medical device of claim 14, wherein the device body is configured for a corresponding nominal vessel size, wherein the maximum cross-sectional dimension of the first segment is 1.1 to 2.0 times the nominal vessel size, and wherein the nominal vessel size is 1.0 to 1.1 times the maximum cross-sectional dimension of each second segment.

17. The medical device of claim 14, wherein each of the second segments follows the first segment.

18. The medical device of claim 14, wherein the helical structure of the third segment has a conical configuration.

19. The medical device of claim 14, wherein at least one ring of the plurality of third rings is larger than at least one first segment ring of the plurality of first segment rings.

20. A medical device comprising: a device body comprising a first segment, at least one second segment, and a helical third segment directly connected to a first segment on an opposite side of the first segment relative to the at least one second segment, wherein in a deployed configuration of the device body: the first segment defines a plurality of first segment rings forming a three- dimensional non-helical structure configured to anchor the device body in a vasculature of a patient, each second segment defines a plurality of second segment rings forming a three- dimensional non-helical structure, a maximum cross-sectional dimension of each second segment is smaller than a maximum cross-sectional dimension of the first segment, and the helical third segment defines a plurality of third segment rings forming a helical structure configured to anchor the device body in a vasculature of a patient, at least one third segment ring of the plurality of third segment rings is larger than at least one first segment ring of the plurality of first segment rings.

Images