VASCULAR OCCLUSION DEVICES COMPRISING OPEN STRUCTURAL COMPONENTS AND SEALED MEMBRANES

A vascular occlusion device includes a structural component comprising an axis and a membrane that contacts the structural component and is constructed of a polymeric material. The membrane includes a first end and a second end. At least one of the first end and the second end extends axially beyond the structural component along the axis and includes a sintered seal. The sintered seal may seal off a cavity delineated by the membrane to occlude blood flow that is incident on the sintered seal.

TECHNICAL FIELD

The present specification generally relates to vascular occlusion devices.

BACKGROUND

Vascular occlusion or embolization devices are intravascular implants that are intended to occlude blood flow in percutaneous interventions. For example, a vascular occlusion device may be positioned to control hemorrhaging due to aneurysms, certain tumors, and arteriovenous malformations. Vascular occlusion devices may also be positioned to block blood vessels providing flow to certain types of tumors. Existing embolization devices may rely on a complex network of components (e.g., a fiber mesh and occluding membrane) to occlude a vessel. Such devices have unnecessarily complex fabrication processes and, as a result, are costly to produce.

SUMMARY

Embodiments of the present disclosure are directed to improvements over the above limitations by providing vascular occlusion devices that occlude vessels via sintered seals of polymeric material. By relying on sintered seals as opposed to a complex network of fibers like in existing occlusion devices, the vascular occlusion devices may be produced using more efficient production processes.

In one embodiment, a vascular occlusion device includes a structural component comprising an axis and a membrane that contacts the structural component and is constructed of a polymeric material. The membrane includes a first end and a second end. At least one of the first end and the second end extends axially beyond the structural component along the axis and includes a sintered seal that closes an end of the structural component.

In another embodiment, a vascular occlusion device includes a structural component and an expanded polytetrafluoroethylene (ePTFE) membrane surrounding the structural component. The ePTFE membrane includes a substantially cylindrical-shaped tube having a wall thickness and a sintered end comprising melted and re-solidified ePTFE. A distance separates sintered end and an end of the structural component.

In yet another embodiment, a method of forming a vascular occlusion device, the method includes positioning a structural component in an expanded polytetrafluoroethylene (ePTFE) membrane such that an end of the ePTFE membrane extends beyond an end of the structural component. The method also includes sintering the end of the ePTFE membrane to seal off a cavity delineated by the ePTFE membrane.

In yet another embodiment, a method of occluding a vessel includes guiding a vascular occlusion device to an occlusion position within a catheter and removing the catheter. The vascular occlusion device includes a structural component comprising an axis; and a membrane that contacts the structural component and is constructed of a polymeric material. The membrane includes a first end and a second end. At least one of the first end and the second end extends axially beyond the structural component along the axis and includes a sintered seal. The method also includes expanding the structural component such that the occlusion device contacts a vessel wall and occludes the vessel via the sintered seal.

DETAILED DESCRIPTION

Embodiments of the present disclosure are directed to vascular occlusion devices including structural components that support membranes including one or more sintered seals to occlude blood flow within a vessel. In embodiments, the structural component may include an open structure (e.g., include one or more open ends) that circumferentially defines a lumen extending along an axis. The membrane may include at least one end that extends axially beyond the structural component (e.g., in a direction of the axis). Different portions of the at least one end of the membrane may be sintered to one another to form a sintered seal that closes off (e.g., prevents blood flow from reaching) the lumen of the structural component. The combined structure of the membrane and structural component may occlude an entire section of the vessel to achieve embolization of the vessel. By sintering the membrane to close the lumen of the structural component, the vascular occlusion devices of the present disclosure may achieve occlusion with structural components that are less expensive and time consuming to fabricate than those used in currently existing vascular embolization devices.

FIG.1Aschematically depicts a vascular occlusion device100according to an example embodiment.FIG.1Aschematically depicts the vascular occlusion device100in an expanded state. The expanded state may represent the size and configuration of the vascular occlusion device100in an as-deployed condition within a blood vessel. It should be understood that the vascular occlusion device100may include a different size and/or shape in an un-expanded state (e.g., when not deployed within a blood vessel). The vascular occlusion device100includes a structural component102and a membrane104that contacts the structural component102. In embodiments, the structural component102is an open structure including a structural frame that circumferentially surrounds an axis A. The structural component102includes a first end106and a second end108. In embodiments at least one of the first end106and the second end108may be open ended. For example, in the embodiment depicted inFIG.1A, the structural component102includes a first open end120(e.g., at a distal end thereof) and a second open end122(e.g., at a proximal end thereof). In embodiments, the structural component102is free of components (e.g., fibers, mesh structures, members) that extend radially inward towards the axis from the open structure surrounding the axis A. The structural component102may be constructed of a biocompatible material such as nitinol. In embodiments, the structural component102is a coil structure patterned from a tube of a biocompatible material, for example. The structural component102may have a variety of different forms (e.g., a helical coil, an alternating helical coil, a tubular mesh structure, a substantially cylindrical frame comprising a plurality of axial and circumferential components) depending on the implementation. For example, in some embodiments, the structural component102may be a self-, balloon-, or otherwise-expandable stent or similar structure. It should also be appreciated that the structural component102may have a variety of sizes (e.g., both axially and radially).

The membrane104includes a first end portion110and a second end portion112. In embodiments, at least one of the first end portion110and the second end portion112extends axially beyond the first end106and/or the second end108of the structural component102. For example, in the embodiment depicted inFIG.1A, both the first end portion110and the second end portion112extend axially beyond the first end106and the second end108of the structural component102, respectively. As described herein, the non-overlapping ends of the structural component102and the membrane104may facilitate the vascular occlusion device100occluding flow within a vessel despite the open structure of the structural component102, or despite the structural component102lacking components extending perpendicular to flow in some embodiments.

In embodiments, the membrane104is constructed of a suitable polymeric material. In embodiments, the membrane104includes a woven polymer fabric or textile. In embodiments, the membrane104is constructed of expanded polytetrafluoroethylene (ePTFE), polyolefin, or polyester. Constructing the membrane104of ePTFE may facilitate anchoring the vascular occlusion device100within a blood vessel. For example, the membrane104may include pores that facilitate blood coagulation thereon to aid in adhering the vascular occlusion device100to vessel walls. In embodiments, the membrane104is a substantially cylindrical tube-like structure that is structurally supported by the structural component102to circumferentially surround the axis A. While membrane104depicted inFIG.1Ais disposed outside (e.g., covering) the structural component102, it should be understood that embodiments are also envisioned where the membrane104is disposed radially inward of the structural component (e.g., such that the structural component102or a cover layer disposed thereon contacts a vessel wall). In embodiments, the membrane104includes an axial length (e.g., in the direction of the axis A depicted inFIG.1A) that is greater than that of the structural component102such that ends thereof are axially offset from the first end106and the second end108of the structural component102. It should be understood that the axial length and radial dimensions of the membrane104may vary depending on the implementation and that membranes having wide variety of sizes and/or shapes are contemplated and within the scope of the present disclosure.

With reference toFIGS.1A and1B, the membrane104is depicted to include a first sintered seal114(e.g., at a first or distal end thereof) and a second sintered seal116(e.g., at a second or proximal end thereof). In embodiments, the first end portion110and the second end portion112comprise open ends of a tube-shaped body of the membrane104that are sintered shut at the first and second sintered seals114and116. For example, the first sintered seal114and the second sintered seal116may be melted joints of the polymeric material out of which the membrane104is constructed. The melted joints may aid in strengthening the first and second end portions110and112, as segments of the material of the membrane104may contact one another on either side thereof, thereby increasing the thickness of the membrane104at the melted joints. In embodiments, the first and second sintered seals114and116are axially offset from the first and second ends106and108of the structural component102(e.g., by gaps or separation distances), respectively. Such gaps may aid in forming the first and second sintered seals114and118(e.g., via application of heat from a suitable heat source) without heating the structural component102to a significant extent. Heating of the structural component102may alter the thermal treatments thereof and alter the shape of the structural component102(e.g., when the structural component102is formed from a shape memory material such as a shape memory polymer or a shape memory alloy such as nitinol).

As depicted inFIG.1B, the melted joint of the first sintered seal116may extend an entirety of a distance between two opposing portions of the membrane104. In embodiments, the second sintered seal116(seeFIG.1A) has a similar construction to that depicted inFIG.1Bsuch that, via the first sintered seal114and the second sintered seal116, a cavity124is completely closed off from an environment external to the vascular occlusion device100. In embodiments, the cavity124may be filled with a suitable gas to facilitate the vascular occlusion device100maintaining its shape when encountering blood flow.

With reference toFIG.1B, in embodiments, a length of the first sintered seal114may correspond to a diameter of a vessel such that blood flow in the vessel is occluded by the vascular occlusion device100. As such, the vascular occlusion device100may occlude the vessel via at least one of the first sintered seal114and the second sintered seal116. The material of the membrane104closes off the first open end120and the second open end122of the structural component102to block blood flow therethrough. The material of the membrane104extends between opposing portions of the structural component102(e.g., at opposite ends of a diameter extending through the axis A) to prevent blood from flowing through the first open end120and the second open end122. By relying on the material of the membrane104to occlude blood flow, the vascular occlusion device100does not rely on the structural component102to form an occlusion structure that blocks flow proximate to the axis A. Instead, the structural component102provides structural support to the membrane104around a periphery of the vascular occlusion device100and the material of the membrane104extends radially inward from the structural component102to prevent flow therethrough. In the embodiment depicted inFIGS.1A-1B, for example, the first end portion110of the membrane104is not in contact with the structural component102and extends radially inward from the structural component102to occlude blood flow. Such a structure aids in reducing the complexity of the structure of the structural component102as compared to those contained in existing vascular occlusion devices, thereby simplifying production processes. The open structure of the structural component102may also aid in collapsing the vascular occlusion device100into an unexpanded state to facilitate delivery of the vascular occlusion device100into a vessel (e.g., via a catheter) and placement at a desired position.

While the embodiment depicted inFIGS.1A and1Bincludes the first and second end portions110and112having similar structures (e.g., both including sintered seals), it should be understood that alternative embodiments are contemplated and within the scope of the present disclosure. For example, embodiments are envisioned where the vascular occlusion device100only includes a one of the first end portion110and the second end portion112and only includes a single sintered seal. In such embodiments, the membrane104may include an open end (e.g., on an end opposite to the direction of the blood flow that the vascular occlusion device100is used to occlude) to provide access to the cavity124from the open end. Such an open end may aid in deployment of the vascular occlusion device100by allowing components of a catheter assembly to be inserted into the vascular occlusion device100during deployment.

Alternative structures for the first end portion110and/or the second end portion112are also contemplated and within the scope of the present disclosure. In the depicted embodiment, for example, the first end portion110is a symmetrical structure about the first sintered seal114, with two equally-sized portions of the membrane104being pressed inwards and joined together at the first sintered seal114. Embodiments are envisioned where the first and second end portions110and112are asymmetrical (e.g., where portions of the membrane104of differing lengths are pressed inward to form the first and second sintered seals114and116). Moreover, embodiments are also envisioned where the first sintered seal114and/or the second sintered seal116are non-linear in shape. For example, in embodiments, the first sintered seal114may form a point, with the first end portion110including a conical shape. In embodiments, the first end portion110may have a geometry that differs from the second end portion112(e.g., the first sintered seal114may have a linear shape as depicted inFIG.1B, while the second sintered seal116may be a point).

Alternative locations for the first sintered seal114and the second sintered seal116are also envisioned. For example, in embodiments, the first sintered seal114may lie along an outer peripheral surface of the vascular occlusion device100(e.g., along the membrane104outside of the first end portion110). For example, a portion of the first end portion110may be folded over the first open end120of the structural component102and the first sintered seal114may be formed at an interface between the folded portion and the tube-like body of the membrane104. In such embodiments, the first end portion110may extend perpendicular to the axis A and the first sintered seal114may not directly contact the blood flow in the vessel.

In the embodiment depicted inFIGS.1A and1B, the membrane104is formed from a single integrated body. For example, in embodiments, the membrane104, the first end portion110, and the second end portion112are formed from an ePTFE tube. Embodiments where the membrane104is constructed from a plurality of separate components are also contemplated and within the scope of the present disclosure. For example, in embodiments, the first and second end portions110and112may include separate pieces of polymeric material that are welded to the membrane104. In such embodiments, the first and second sintered seals114and116may include shapes corresponding to a circumferential shape of the membrane104and structural component102. For example, the first and second sintered seals114and116may be substantially circular-shaped and extend around a circumference of the membrane104at ends thereof to cover the first and second open ends120and122. The first and second end portions110and112may also be constructed of a different material than the remainder of the membrane104. In an example, the first and second end portions110and112are constructed of an elastic polymeric material such as urethane and the remainder of the membrane104is constructed from ePTFE, though other combinations are contemplated and possible. Embodiments are also envisioned where the portion of the membrane104circumferentially surrounding the axis A (e.g., contacting or extending parallel to a wall of a vessel) is constructed of a plurality of different components (e.g., a plurality of different ePTFE tubes may be sintered or otherwise coupled to one another in an overlapping fashion to form the membrane104).

With reference toFIG.1A, in embodiments, the vascular occlusion device100includes one or more anchors118extending radially outward from the structural component102. In embodiments, the one or more anchors118are integral with the structural component102(e.g., formed from the same piece of material) and outward from the remainder of the structure component102. For example, the one or more anchors118may extend radially outward from the membrane104. In the embodiment depicted inFIG.1A, the one or more anchors118includes a first anchor extending from the first end106of the structural component102and a second anchor extending from the second end108of the structural component102. In embodiments, the one or more anchors118may extend through different portions of the membrane104disposed proximate to the first end106and the second end108, respectively. As the structural component102expands to the configuration depicted inFIG.1A(e.g., via the shape memory effect when the structural component102is formed of nitinol) when deployed in a vessel, the one or more anchors118may extend into walls of the vessel and prevent the vascular occlusion device100from migrating from a desired location. Embodiments are also envisioned where the one or more anchors are formed separately from the structural component102and attached thereto via a suitable connection method (e.g., via welding, brazing, or the like).

FIG.1Cschematically depicts a cross-sectional view of the vascular occlusion device100through the line I-I ofFIG.1A. In embodiments, the vascular occlusion device100comprises an inner liner126disposed radially inward of the structural component102. In embodiments, an exterior surface128of the inner liner126contacts an interior surface130of the structural component102. The inner liner126may be a substantially cylindrical-shaped tube having a wall thickness. In embodiment, the inner liner126includes a structure that is similar to that of the membrane104described herein. For example, in embodiments, the inner liner126may include an ePTFE tube. That is, the inner liner126and the membrane104may be constructed of the same material. In embodiments, the inner liner126and the membrane104may be formed of different materials.

In embodiments, the structural component102is disposed in an annular space between the inner liner126and the membrane104. The inner liner126may include an axial length corresponding to an axial distance between the first and second ends106and108of the structural component102. In some embodiments, the inner liner126includes an open-ended structure (e.g., lacks structures corresponding to the first and second end portions110and112described herein with respect toFIGS.1A and1B). In some embodiments, the inner liner126comprises end portions that are closed via sintered seals similar to the first and second end portions110and112of the membrane104. It should be appreciated that the inner liner126is optional and embodiments are envisioned that do not include the inner liner126.

In some embodiments, the first and second end portions110and112of the membrane104described herein with respect toFIGS.1A and1Bare components of the inner liner126. In such embodiments, the vascular occlusion device100may lack the membrane104.

The relative radial positioning of the structural component102and the polymer-based material (e.g., either of the membrane104or the inner line126) that is sintered to occlude a vessel may vary depending on the implementation. Any vascular occlusion device where a segment of polymer-based material is adhered to another segment of polymer-based material to occlude a vessel is within the scope of the present disclosure. As used herein, the term “sintered seal” is used to describe instances where portions of polymeric material are joined together using a suitable adhesion technique. Sintered seals may be produced by welding, heating, pressure, or any combination thereof. Moreover, the terms “sintered seal” or “sintered end,” as used herein, may encompass embodiments where portions of polymer material are attached to one another via another suitable technique (e.g., a biocompatible adhesive).

FIG.2Aschematically depicts a vascular occlusion device200disposed in a vessel in an unexpanded state. The vascular occlusion device200depicted inFIG.2may be similar in structure to the vascular occlusion device100described herein with respect toFIGS.1A-1C, with the exception that the vascular occlusion device200does not include the one or more anchors118. Accordingly, like reference numerals are used inFIG.2Ato indicate the incorporation of such like components. As depicted inFIG.2A, when initially disposed inside the vessel, the structural component102may be radially contracted such that the vascular occlusion device200has a diameter than is less than that of the vessel, when in the unexpanded state. The vascular occlusion device200may be delivered into the vessel via a catheter206. For example, the vascular occlusion device200may be advanced to a desired position via a lumen208of the catheter206and released from the catheter206via a suitable delivery mechanism. In embodiments, the membrane104comprises an inner liner and outer ePTFE liner that is sintered around the structural component102such that the ePTFE liners expand in conjunction with the structural component102once placed in the vessel. That is, and as noted above, the structural component102may be an expandable structure (e.g., a self-expandable, stent or coil) formed from shape-memory materially that automatically expands to the expended state once deployed, such as in response to body temperature. Though in other embodiments, it is contemplated that the structural component102may be expandable via some expansion actuator such as a balloon, for example. As a result, the first and second end portions110and112may expand in conjunction with the structural component102to occlude the vessel via the first and second sintered seals114and116. In embodiments, the membrane104includes an axial length that is greater than the structural component102when the structural component is in the unexpanded state, thus causing the first and second end portions110and112to vary in shape by expanding by an amount that is dependent on axial position relative to the ends of the structural component102once the vascular occlusion device200is deployed in the vessel.

FIG.2Bdepicts the vascular occlusion device200in an expanded state. As depicted inFIG.2B, when the vascular occlusion device200is in the expanded state, the structural component102may apply a force (e.g., a radial force) to walls202of the vessel. For example, in embodiments, the structural component102may compress the membrane104against the walls202such that an outer peripheral surface of the membrane104corresponds in shape to surfaces of the walls202. As a result, the first and second end portions110and112(e.g., via first and second sintered seals114and116) occlude the vessel by filling an entirety of the space extending between the walls202.

In some embodiments, the structural component102may directly contact the walls202. In such embodiments, and as described above, the membrane104may be disposed radially inward of the structural component102(e.g., in a position corresponding to the inner liner126depicted inFIG.1C). Blood flow in the vessel may contact the structural component102(e.g., proximate to the first and second ends106and108, seeFIG.1A), but the vascular occlusion device200may occlude blood flow via pressure applied to the walls202via the structural component102. For example, in embodiments, the structural component102may be configured to expand to a radial dimension larger than that of the vessel (e.g., such that different circumferential portions thereof are separated by a distance greater than a distance separating the walls202) if left unimpeded. As a result, expansion of the structural component102may result in the structural component102applying a pressure to the walls202and creating a seal that blocks blood flow. In embodiments, coagulated blood may accumulate on an external surface of the membrane104and result in a seal being formed at the interface between the vascular occlusion device200and the walls202. The first end portion110and the second end portion112, by preventing blood from flowing radially inward of the structural component102, result in the total blockage of blood flow within the vessel.

FIG.3schematically depicts another vascular occlusion device300according to another example embodiment. The vascular occlusion device300includes a structural component302and a membrane310. In embodiments, the membrane310is substantially similar to the membrane104of the vascular occlusion device100described herein with respect toFIGS.1A-1Cand may include any of the structures described herein with respect to the membrane104. For example, the membrane310may include a substantially cylindrical-shaped tube of a suitable polymeric material such as ePTFE. The membrane310is also depicted to include an end portion312and a sintered seal314(e.g., a sintered end) that may be similar in structure to the first end portion110and first sintered seal114described herein with respect toFIGS.1A-1C.

The structural component302may be substantially similar to the structural component102of the vascular occlusion device100described herein with respect toFIGS.1A and1C(e.g., including an open structural frame such as a nitinol coil or other suitable structure). The structural component302is depicted to include a first end304and a second end308displaced from the first end304along an axis A of the vascular occlusion device300. The structural component302may include an open end (e.g., free of material) proximate to the first end304. The structural component302differs from the structural component102described herein with respect toFIGS.1A-1Cin that the second end308extends into an end portion312of the membrane310. In embodiments, the second end308may include a portion of a wire from which the structural component302is formed, for example that is bent into a desired shape. The second end308may contact a sintered seal314formed in the end portion312of the membrane310. The second end308may provide structural support to the end portion312at the sintered seal314and aid in reducing stress on the material of the membrane310.

In embodiments, the second end308may be structured in a way that corresponds to an interior surface of the end portion312to provide structural support thereto at positions that are displaced from the sintered seal314. For example, the second end308and the end portion312may be compressed and formed in the same processing step (e.g., from tubes of different respective materials) such that the second end308substantially corresponds in shape to the end portion312. The structural component302may include a coil portion providing structural support to a body of the membrane310and a non-coil portion at the second end308. The non-coil portion may extend directly from an end of the coil portion and be patterned differently (e.g., the non-coil portion at the second end308may include a tubular segment having a compressed end to substantially correspond in shape to the end portion312). In embodiments, the structural component302may vary in structure from the end portion312at the second end308to selectively support a particular location of the end portion312(e.g., at the sintered seal314, radially displaced from the sintered seal).

In the vascular occlusion device300, the sintered seal314may not be separated from the structural component302. There may be at least one point of contact between the structural component and the end portion312of the membrane310used to occlude the vessel. The at least one point of contact may increase the durability of the vascular occlusion device300. While the second end308of the structural component302is depicted to contact the end portion312inFIG.3, it should be understood that alternative portions of the structural component302may contact the end portion312in alternative embodiments. For example, in embodiments, the structural component302includes a support structure (not depicted) extending from a coil portion of the structural component302(e.g., offset from the second end308) to contact the end portion312. Such a support structure may have any suitable shape to support the end portion312in any desired manner.

Referring still toFIG.3, the membrane310of the vascular occlusion device300is depicted to include an open end316. The open end316may be devoid of the material of the membrane310and provide access to the interior of the vascular occlusion device300. Such access may allow insertion of components therein to aid in deployment of the vascular occlusion device300. In the depicted embodiment, the end portion312may be used to occlude blood flow and the vascular occlusion device300may be positioned in a vessel such that blood flow initially contacts the end portion312. Embodiments are also envisioned where the membrane310includes an additional end portion (e.g., covering the open end316depicted inFIG.3). The structural component302may contact such an additional end portion via a structure extending from the first end304.

FIG.4schematically depicts another example vascular occlusion device400. The vascular occlusion device400includes a structural component402and a membrane412. In embodiments, the membrane412includes a first end portion416and a second end portion418. The membrane412may be similar in structure to the membrane104described herein with respect toFIGS.1A-1Cand include first and second sintered seals420and422for enclosing an interior volume and occluding blood flow.

In the depicted embodiment ofFIG.4, the structural component402may be a stent graft structure. For example, in embodiments, the structural component404comprises a plurality of support structures404that are interconnected with one another to circumferentially surround an axis A of the vascular occlusion device400. The plurality of support structures404, for example, may include a mesh of a suitable structural support material such as stainless steel or a suitable alloy. The structural component402may be any suitable structure. For example, the structural component402may be an expandable (e.g., balloon expandable such as where only one end of the of the membrane412is closed, self-expandable, such as via a stent or coil formed of a shape memory material, or expandable via any suitable expansion mechanism.

Because the material of the membrane412occludes flow of the vessel via one or more of the first sintered seal420and the second sintered seal422, a variety of open frame-like structures may be used as the structural component402. The design of the vascular occlusion device400thus provides flexibility to re-purpose various existing open structures as structural supports for vascular occlusion devices. Any suitable structure that can be expanded in shape to conform to a shape a vessel may be used for a structural component of the vascular occlusion devices herein because the vascular occlusion devices described herein do not rely on an structural components extending non-parallel to the occluded blood flow to provide an occluding structure.

FIG.5depicts a flow diagram of a method500of fabricating a vascular occlusion device, according to an example embodiment of the present disclosure. For example, the method500may be performed to fabricate any of the vascular occlusion devices (e.g., the vascular occlusion devices100,200,300and400described herein with respect toFIGS.1A-4) described herein. To aid in the description of the method500, references will be made to the vascular occlusion device100described herein with respect toFIGS.1A-1C. It is noted that a greater or fewer number of steps may be included, in any order, without departing from the scope of the present disclosure.

At step502, the method500includes providing an inner liner. For example, as described herein with respect toFIG.1C, the inner liner126of the vascular occlusion device100may include a tube of a suitable polymeric material. In embodiments, the inner liner126is formed of ePTFE. Such an inner liner126may be fabricated by initially fabricating a PTFE tube (e.g., via a suitable extrusion process). The PTFE tube may be heated and stretched to convert the PTFE tube into an ePTFE tube that serves as the inner liner126. The ePTFE tube may be provided with any suitable radial dimension and length depending on a desired size of the vascular occlusion device100. It should be appreciated that embodiments are envisioned where the method500does not include the step502. At step504, the method500includes providing a structural component circumferentially surrounding the inner liner. For example, in embodiments, the inner liner126may be provided over a mandrel, and a nitinol wire may be wound around the mandrel in a desired pattern to form the structural component102. In embodiments, the combination of the inner liner126and the nitinol wire may be subjected to a heat set process to set the coil to a desired expanded state at an elevated temperature. In embodiments, the structural component102is formed and/or heat set prior to being placed into contact with the inner liner126.

At step506, the method500may include providing an outer liner circumferentially surrounding at least a portion of the structural component. For example, in embodiments, the membrane104comprises a tape of suitable polymeric material (e.g., ePTFE) that is wrapped around the structural component102. In embodiments, the membrane104is a separately extruded ePTFE tube into which the inner liner126and structural component102are inserted. The structural component102may be positioned within the membrane104such that at least one end of the membrane104(e.g., corresponding to the first end portion110and/or the second end portion112) extends axially beyond the structural component102. In embodiments, after provision of the outer liner, the entire assembly may be placed in a sintering furnace such that the inner and outer liners are sintered together with the structural component being encapsulated within polymeric material. At step508, the method includes sintering at least one end of one or more of the inner liner and the outer liner to form a sintered seal. For example, in the vascular occlusion device100, both the first end portion110and the second end portion112of the membrane104are subjected to a secondary joining process where portions of the membrane104are pressed together and heated via an energy source (e.g., an ultrasonic energy beam, a laser, a torch, a thermocompression bonding apparatus) to form the first and second sintered seals114and116. Axial separation between the structural component102and the first and second end portions110and112may beneficially avoid heat being applied to the structural component102, which may affect the thermal behavior thereof. Pressure may be applied in any distribution to the inner our outer liners to provide sintered seals having any desired shape or form.

Referring now toFIG.6, a method600of occluding a vessel via deployment of a vascular occlusion device therein is shown, according to an example embodiment of the present disclosure. It is noted that a greater or fewer number of steps may be included, in any order, without departing from the scope of the present disclosure. In an example, the method600may be performed to position the vascular occlusion device200described herein with respect toFIGS.2A-2Bat a target location within a vessel to occlude blood flow within the vessel. Accordingly, reference will be made to various components of the vascular occlusion device200ofFIGS.1A-1Cto aid in the description of the method600.

At step602, an occlusion device in an unexpanded state is provided. For example, the structural component102of the vascular occlusion device200may include a shape memory component (e.g., a nitinol coil) that is in an unexpanded state below body temperature (e.g., at room temperature). As a result, a radial dimension of the vascular occlusion device100may be diminished, as depicted inFIG.2A, when beneath body temperature. In embodiments, the structural component102is an elastic structure that is compressed into the unexpanded state (e.g., via insertion into a catheter assembly). In embodiments, the structural component102is in the unexpanded state by default at room temperature and is expanded within the vessel via an expanding mechanism (e.g., a balloon, shape-memory materials, etc.) associated with a delivery assembly.

At step604, the occlusion device200is guided to an occlusion position within a vessel via a catheter206. The catheter206may be a flexible tubing configured for traversal through one or more body vessels. The catheter206may be sized and shaped to be traversed through a vein of a user to the occlusion position. The catheter206may define a lumen208into which the vascular occlusion device200and a suitable delivery assembly (e.g., a pushing mechanism or deployment tube) are inserted. At step608, the structural component102of the vascular occlusion device200is expanded such that the vascular occlusion device200contacts a vessel wall202and occludes the vessel via the sintered seal, as depicted inFIG.2B. For example, the vascular occlusion device200may be removed from the catheter206via a delivery mechanism disposed therein. As a result of being removed from the catheter206, the structural component102may radially expand to contact the walls of the vessel. As a result, one or more of the first end portion110and the second end portion112occludes blood flow in the vessel via the first sintered seal114and/or the second sintered seal116.

Embodiments can be described with reference to the following numerical clauses:1. A vascular occlusion device comprising a structural component comprising an axis; and a membrane that contacts the structural component and is constructed of a polymeric material, wherein: the membrane comprises a first end and a second end, and at least one of the first end and the second end extends axially beyond the structural component along the axis and includes a sintered seal that closes an end of the structural component.2. The vascular occlusion device of any preceding clause, wherein the structural component comprises a nitinol coil.3. The vascular occlusion device of any preceding clause, wherein the structural component comprises a stent graft.4. The vascular occlusion device of any preceding clause, wherein both the first end and the second end extend axially beyond the structural component.5. The vascular occlusion device of any preceding clause, wherein both the first end and the second end comprise sintered seals.6. The vascular occlusion device of any preceding clause, wherein the sintered seal comprises a melted joint of the polymeric material.7. The vascular occlusion device of any preceding clause, wherein the melted joint extends an entirety of a distance between two opposing portions of an outer surface of the membrane such that a cavity is completely closed off from an environment external to the vascular occlusion device at the at least one of the first end and the second end.8. The vascular occlusion device of any preceding clause, wherein the polymeric material comprises expanded polytetrafluoroethylene (ePTFE).9. The vascular occlusion device of any preceding clause, further comprising one or more anchors extending radially outward from the membrane.10. The vascular occlusion device of any preceding clause, wherein the one or more anchors comprises portions of the structural component extending through the membrane.11. The vascular occlusion device of any preceding clause, wherein the one or more anchors comprises a first anchor extending through a first portion of the membrane proximate the first end and a second anchor extending through a second portion of the membrane proximate the second end.12. A vascular occlusion device comprising: a structural component; and an expanded polytetrafluoroethylene (ePTFE) membrane surrounding the structural component, wherein the ePTFE membrane comprises: a substantially cylindrical-shaped tube having a wall thickness; and a sintered end comprising melted and re-solidified ePTFE, wherein there is a distance separating the sintered end and an end of the structural component.13. The vascular occlusion device of any preceding clause, wherein the structural component comprises a coil.14. The vascular occlusion device of any preceding clause, wherein the structural component comprises a stent graft.15. The vascular occlusion device of any preceding clause, wherein the sintered end extends an entirety of a distance between two opposing portions of an outer surface of the ePTFE membrane.16. The vascular occlusion device of any preceding clause, further comprising one or more anchors extending radially outward from the membrane.17. The vascular occlusion device of any preceding clause, wherein the one or more anchors comprises a portion of the structural component extending through the membrane.18. A method of forming a vascular occlusion device, the method comprising: positioning a structural component in an expanded polytetrafluoroethylene (ePTFE) membrane such that an end of the ePTFE membrane extends beyond an end of the structural component; and sintering the end of the ePTFE membrane to seal off a cavity delineated by the ePTFE membrane.19. The method of any preceding clause, further comprising sintering a second end of the ePTFE membrane to completely enclose the structural component within the cavity.20. The method of any preceding clause, wherein the structural component comprises at least one of a coil and a stent graft.21. A method of occluding a vessel comprising: guiding a vascular occlusion device to an occlusion position within a catheter and removing the catheter, the vascular occlusion device comprising: a structural component comprising an axis; and a membrane that contacts the structural component and is constructed of a polymeric material, wherein: the membrane comprises a first end and a second end, and at least one of the first end and the second end extends axially beyond the structural component along the axis and includes a sintered seal; and expanding the structural component such that the occlusion device contacts a vessel wall and occludes the vessel via the sintered seal.22. The method of any preceding clause, wherein the structural component comprises a nitinol coil.23. The method of any preceding clause, wherein the structural component comprises a stent graft.24. The method of any preceding clause, wherein the sintered seal comprises a melted joint of the polymeric material.25. The method of any preceding clause, wherein the polymeric material comprises expanded polytetrafluoroethylene (ePTFE).

It should now be understood that embodiments of the present disclosure are directed to vascular occlusion devices that occlude blood flow within a vessel via one or more sintered seals of polymer material. For example, a closure device may include a structural component and a membrane including an end portion extending axially beyond the structural component. The membrane may be formed of a suitable polymeric material such as ePTFE. The end portion may extend radially inward and contain one or more sintered seals where portions of the polymeric material are joined together to close an end of the vascular occlusion device. The closed end may serve to block blood flow within the vessel. Accordingly, since the sintered seal of polymeric material is used to occlude the blood flow, open-ended structural components may be used that are more easily fabricated than structural components associated with existing vascular occlusion devices.