Patent Description:
Elongated medical devices for restoring blood flow or remove thrombus from a blood vessel during a thrombectomy intervention have to be advanced, pulled, and kept intact within the blood vessel during the intervention. Control and advancement of these devices are challenging as the elongated devices must undergo push, pull, and torque moves. Because of the length of these elongated devices and the movements and forces that the user must apply to the elongated device during the thrombectomy intervention, it is often difficult to maintain a secure attachment/connection of the elements that are part of the elongated device.

<CIT> discloses an elongated medical device for restoring blood flow or remove thrombus from a blood vessel.

Current technology for blood flow restoration or thrombus removal often breaks or separates during use [<NUM>, <NUM>], which may cause serious health consequences to the patients.

New elongated devices with an improved attachment of the elements/components thereof are therefore needed.

To overcome the drawbacks of the prior art, the present invention proposes, according to one aspect, an elongated device with an improved attachment of their elements. The elongated device can be advanced distally and withdrawn proximally from a proximal end and rotated about a longitudinal axis from the proximal end. The elongated device comprises a working element (e.g., a stent retriever or other medical device) comprising a first connection portion extending proximally, the first connection portion having a first attachment surface; a pusher comprising a second connection portion extending distally, the second connection portion having a second attachment surface facing and extending longitudinally aligned to the first attachment surface to define an overlapping portion and to define first and second seams extending longitudinally along first and second lateral extents of the overlapping portion; a first weld attaching the first and second connection portions, extending from the first seam toward the second seam (i.e. laterally); and a second weld attaching the first and second connection portions, extending from the second seam toward the first seam.

In an embodiment, a cross-sectional shape of the first connection portion perpendicular to the longitudinal axis is a section of an annulus. In another embodiment, a cross-sectional shape of the second connection portion perpendicular to the longitudinal axis is a circle.

In an embodiment, the first weld comprises a plurality of welding points along the first seam. In another embodiment, the second weld comprises a plurality of welding points along the second seam. In some embodiments, the plurality of welding points of the first and second welds are successive, i.e., the points are aligned.

In some embodiments, the first weld can further comprise a plurality of consecutive welding points. In some embodiments, the second weld can further comprise a plurality of consecutive welding points. Thus, a welding seam is provided on top of the welding points previously applied.

In an embodiment, the first weld and the second weld each extend along an entire length of the overlapping portion.

In an embodiment, glue can be added over the first and second welds.

In an embodiment, a ratio of a cross-sectional area of the first connection portion perpendicular to the longitudinal axis to a corresponding cross-sectional area of the second connection portion perpendicular to the longitudinal axis is in a range of <NUM>:<NUM> to <NUM>:<NUM>.

In an embodiment, a radius of the second attachment surface is smaller than a radius of the first attachment surface.

In an embodiment, the elongated device also includes a jacket extending around at least part of the overlapping portion. The jacket can extend proximally from the overlapping portion around at least part of the pusher.

Additionally, the elongated device can also include a radiopaque element disposed at a proximal end of the overlapping portion. In an embodiment, the radiopaque element comprises a coil extending around at least part of the pusher.

In an embodiment, the elongated device also comprises a jacket extending around the radiopaque element. The jacket can extend around at least part of the overlapping portion.

Embodiments of the present invention also provide, according to another aspect, a method for connecting a working element to a pusher to enable the pusher to maneuver the working element (e.g. advance the working element distally, withdraw the working element proximally, and rotate the working element about a longitudinal axis from a proximal end of the pusher), the distal working element comprising a first connection portion extending proximally, the first connection portion having a first attachment surface, the pusher comprising a second connection portion extending distally, the second connection portion having a second attachment surface. The method comprises disposing the first attachment surface longitudinally aligned to the second attachment surface to form an overlapping portion and to form first and second seams extending parallel to the longitudinal axis along first and second lateral extents of the overlapping portion; forming a first weld extending from the first seam toward the second seam, and forming a second weld extending from the second seam toward the first seam.

In an embodiment, the step of forming the first weld comprises forming a plurality of welding points extending from the first seam toward the second seam. In another embodiment, the step of forming the second weld comprises forming a plurality of welding points extending from the second seam toward the first seam. Particularly, the first and second welds are formed by sequentially forming the plurality of welding points (i.e. the welding points are aligned).

In an embodiment, the step of forming the first weld further comprises consecutively forming a plurality of welding points extending from the first seam toward the second seam. In another embodiment, the step of forming the second weld further comprises consecutively forming a plurality of welding points extending from the second seam toward the first seam.

When energy, e.g. laser energy, is applied to form the first and second welds a heat affected zone appears (i.e. accumulation of heat in a specific zone) which can provoke a breakage of the first, the second, or both connection portions. To avoid that breakage, in some embodiments, the step of forming the first weld further comprises forming a first welding point of the plurality of welding points at a distal portion of the first seam and forming each other welding point of the plurality of welding points at a more proximal location along the first seam than a prior formed welding point of the plurality of welding points. In some embodiments, the step of forming the second weld further comprises forming a first welding point of the plurality of welding points at a distal portion of the second seam and forming each other welding point of the plurality of welding points at a more proximal location along the second seam than a prior formed welding point of the plurality of welding points.

In some embodiments, the first weld can extend along an entire length of the first seam and the second weld can extend along an entire length of the second seam.

In an embodiment, the step of forming a first weld comprises forming a first welding point at a proximal end of the first seam and a second welding point between the proximal end and the distal end of the first seam before forming a welding point at any other points along the first seam.

In an embodiment, the step of forming the second weld comprises forming a first welding point at a proximal end of the second seam and a second welding point between the proximal end and the distal end of the second seam before forming a welding point at any other points along the second seam.

In an embodiment, the step of forming the first weld comprises directing energy laterally at the first seam toward the second seam. In an embodiment, the step of forming the second weld comprises directing energy laterally at the second seam toward the first seam.

In an embodiment, the method also comprises the step of adding glue over the first and second welds.

In an embodiment, the method also comprises the step of placing a radiopaque element at a proximal end of the overlapping portion. In an embodiment, the radiopaque element can comprise a coil extending around at least part of the pusher.

In an embodiment, the method also comprises the step of assembling, or placing, the radiopaque element onto a distal end of the pusher and pushing the radiopaque element towards a proximal end of the pusher.

In an embodiment, the method further comprises covering at least part of the overlapping portion with a jacket. In some embodiments, a portion of the pusher proximal to the overlapping portion can also be covered with the jacket.

In an embodiment, the method further comprises covering the radiopaque element with a jacket. In some embodiments, the jacket also extends around at least part of the overlapping portion.

In an embodiment, before inserting the jacket, the method further comprises placing, or pushing back, the radiopaque element to the distal end of the pusher (or at the proximal end of the overlapping portion), without covering the overlapping portion.

In yet another embodiment, the method comprises covering at least part of the overlapping portion with a jacket (or inner jacket), the jacket extending proximally from the overlapping portion around at least part of the pusher; placing a radiopaque element at a proximal end of the overlapping portion, the radiopaque element comprising a coil extending around at least part of the pusher; and covering the radiopaque element with a jacket (or outer jacket), the jacket extending around at least part of the overlapping portion.

In an embodiment, before inserting the inner jacket, the method further comprises assembling, or placing, the radiopaque element onto a distal end of the pusher and pushing the radiopaque element towards a proximal end of the pusher.

In another embodiment, before inserting the outer jacket, the method further comprises placing, or pushing back, the radiopaque element to the distal end of the pusher (or at the proximal end of the overlapping portion), without covering the overlapping portion.

In some embodiments, the working element of the elongated device comprises a working portion having a plurality of crowns (or rows) of cells. Each cell of the working portion includes an open area bordered by struts, where: a distal end of each cell in a first crown of the plurality of crowns is contiguous with a proximal end of a corresponding cell in a third crown of the plurality of crowns, a distal end of each cell in a second crown of the plurality of crowns is contiguous with a proximal end of a corresponding cell in a fourth crown of the plurality of crowns, the second crown is disposed distal to the first crown and proximal to the third crown, and the fourth crown is disposed distal to the third crown. Moreover, first and second opposite midportions of each cell in each of the first, second, third and fourth crowns each are contiguous with a midportion of an adjacent cell in such crown.

In some embodiments, the number of crowns of cells depends on the desired length of the working portion. In some embodiments, the working portion can have at least four crowns of cells.

In some embodiments, the working portion can have between four and twelve crowns of cells. Particularly, the working portion can have between six and ten crowns of cells. More in particular, the working portion can have seven, eight or nine crowns of cells.

In some embodiments, each crown of cells in the working portion can have at least three cells. In some embodiments, each crown of cells in the working portion can have at least four cells. In some embodiments, each crown of cells in the working portion can have between four and ten cells, particularly, between four and eight cells. In an embodiment, each crown of cells in the working portion can have four or six cells.

In an embodiment, each crown of cells in the working portion can have four cells. In another embodiment, each crown of cells in the working portion can have six cells.

In an embodiment, the working portion comprises at least four crowns of cells and each crown of cells comprises at least four cells. In another embodiment, the working portion comprises eight crowns of cells and each crown of cells comprises four cells. In another embodiment, the working portion comprises seven crowns of cells and each crown of cells comprises four cells. In another embodiment, the working portion comprises nine crowns of cells and each crown of cells comprises six cells.

In some embodiments, the working element also comprises a tapered portion extending proximally from the proximal end of the working portion, the tapered portion also having a plurality of struts. In an embodiment, the tapered portion has a smaller diameter at a proximal end than an expanded diameter of the working portion. In another embodiment, at least some of the tapered portion struts have a width greater than a width of the working portion struts.

In an embodiment, first and second tapered portion struts of the plurality of tapered portion struts converge from a proximal end of the working portion to a distal end of a proximal connection portion to partially define a proximal cell. In some embodiments, the elongated device comprises a pusher extending proximally from the proximal connection portion.

In an embodiment, a third tapered portion strut of the plurality of tapered portion struts extends distally from the first tapered portion strut from a point distal to the proximal connection portion. In another embodiment, a fourth tapered portion strut of the plurality of tapered portion struts extends distally from the second tapered portion strut from a point distal to the proximal connection portion, the third and fourth tapered struts partially defining the proximal cell.

In an embodiment, the third and fourth tapered portion struts converge at the proximal end of the working portion.

According to an embodiment, the elongated device is configured to have a compressed (or retracted) configuration (or position or state) with a compressed diameter, and an expanded configuration (or position or state) with an expanded diameter. The elongated device has the compressed configuration for example when it is located within a lumen of a narrow catheter or a lumen of a narrow vessel with a small diameter, and has the expanded configuration for example when it is located within a lumen of a vessel with large diameter. The elongated device is configured to self-expand from the compressed position (with a compressed diameter or first diameter) to an expanded position (with an expanded diameter or second diameter). In other words, the elongated device is self-expandable from the compressed configuration to the expanded configuration. Additionally, the elongated device is configured to adapt its shape to the surrounding blood vessel, thus the elongated device can have a first diameter in a narrow vessel with a small diameter and a second diameter in a wide vessel with a large diameter. Particularly, according to this embodiment, the elongated device, or the working element thereof, should be understood as a clot mobilizer device.

According to some embodiments of the invention, the working portion is configured to expand from a compressed diameter of less than <NUM> to an expanded diameter of at least <NUM> and to exert an outward radial force between <NUM> N and <NUM> N at every diameter between and including the compressed diameter and the expanded diameter.

In an embodiment, the working portion is configured to have a compressed diameter of less than <NUM> and to exert an outward radial force between <NUM> N and <NUM> N when the compressed diameter is around <NUM>. In another embodiment, the working portion is configured to have an expanded diameter of at least <NUM> and to exert an outward radial force between <NUM> N and <NUM> N when the expanded diameter is around <NUM>.

Advantageously, in the proposed elongated device the outward radial forces are maintained for a broad range of vessels, resulting in a flat curve behavior and a better pushability. This behavior allows lower radial forces in small diameters and larger radial forces in large diameters, thus without being out of a limited safety window between <NUM> N and <NUM> N. In an embodiment, the working portion is configured to exert an outward radial force in the range, inside the safety window, between <NUM> N and <NUM> N at every diameter between and including a compressed diameter of <NUM> and an expanded diameter of <NUM>. Remarkably, due to the fact of having less radial force in small diameters, the risk of damaging the vessel is reduced. Moreover, the proposed elongated device can be used in vessels of different diameters (between <NUM>-<NUM>).

In an embodiment, the crowns of cells of the elongated device define a tubular-shaped section forming a cylindrically closed structure. To that effect, the proposed elongated device can be manufactured by producing specified cuts either on a tube or on a wire. In another embodiment, the elongated device is manufactured by producing specified cuts on a wire. In another embodiment, the proposed elongated device also includes a pusher or pusher wire that is manufactured by producing specified cuts on said tube or said wire.

In an embodiment, the cells in the working portion have an almond shape.

In some embodiments, at least some of the working portion struts can have a width between <NUM> and <NUM>, particularly between <NUM> and <NUM> and more particularly <NUM> or <NUM>.

In some embodiments, at least some of the tapered portion struts can have a width between <NUM> and <NUM>, particularly between <NUM> and <NUM> and more particularly <NUM> or <NUM>.

In some embodiments, the working portion in the expanded configuration can have a length between <NUM> and <NUM>, particularly between <NUM> and <NUM> and more particularly <NUM>.

In some embodiments, the working portion in the compressed configuration can have a length between <NUM> and <NUM>, particularly between <NUM> and <NUM> and more particularly <NUM>.

In some embodiments, the tapered portion in the expanded configuration can have a length between <NUM> and <NUM>, particularly between <NUM> and <NUM> and more particularly <NUM>.

In some embodiments, the tapered portion in the compressed configuration can have a length between <NUM> and <NUM>, particularly between <NUM> and <NUM> and more particularly <NUM>. In an embodiment, the tapered portion struts have a thickness equal to a thickness of the working portion struts.

In some embodiments, the elongated device also includes radiopaque markers located at a distal end of the working portion of the working element. In other embodiments the radiopaque markers can be also located at other sections of the working portion, for example at the middle and/or at the proximal end. The radiopaque markers particularly have different lengths to avoid entanglement between them or other devices. The radiopaque markers can be made of a Platinum Iridium alloy or of Tantalum.

In an embodiment, the elongated device is made of a metal including Nitinol. In particular, the Nitinol material complies with the ASTM (American Society of Testing and Materials) F2063 (Standard Specification for Wrought Nickel-Titanium Shape Memory Alloys for Medical Devices and Surgical Implants). Nitinol is well known for applications in self-expanding structures. However, other types of metals or even other types of materials can be also used, for example cobalt-chromium alloys or iron alloys such as stainless steel or spring steel.

Embodiments of the present invention provide, according to yet another aspect, an expandable elongated device for extraction of an occlusion from a blood vessel. The elongated device, which can be considered a clot mobilizer device, comprises a working portion having a plurality of crowns (or rows) of cells. Each cell of the working portion includes an open area bordered by two proximal cell struts, two distal cell struts, and two middle cell struts, where: the proximal cell struts each extends distally from a common proximal end to a proximal end of a respective one of the two middle cell struts, the distal cell struts each extends proximally from a common distal end to a distal end of a respective one of the two middle cell struts, each middle cell strut in each crown borders two adjacent cells in that crown. Each of the middle cell struts is adapted and configured to be more flexible than the distal cell strut and proximal cell strut to which it extends. Thus, the cells comprising middle cell struts are configured to transfer a desired flexibility to the working portion. Likewise, the working portion struts are configured to transfer a desired flexibility to the clot mobilizer to be navigated through the vasculature (e.g., the neuroanatomy).

The expandable elongated device comprises a tapered portion extending proximally from a proximal end of the working portion, the tapered portion also having a plurality of tapered portion struts. The tapered portion has a smaller diameter at a proximal end than a diameter of the working portion in an expanded configuration. Moreover, in some embodiments, the tapered portion struts can also have a width greater than a width of the working portion struts, e.g. the distal cell struts, the proximal cell struts and/or the middle cell struts. The tapered portion struts are configured to augment the radial outward force provided by the working portion and to provide pushability to the clot mobilizer to be navigated through the vasculature (e.g., the neuroanatomy) while minimizing buckling and kinking.

The elongated device is configured to have a compressed (or retracted) configuration (or position or state) with a compressed diameter, and an expanded configuration (or position or state) with an expanded diameter. The elongated device has the compressed configuration for example when it is located within a lumen of a narrow catheter or a lumen of a narrow vessel with a small diameter, and has the expanded configuration for example when it is located within a lumen of a vessel with large diameter. The elongated device is configured to self-expand from the compressed position (with a compressed diameter or first diameter) to an expanded position (with an expanded diameter or second diameter). In other words, the elongated device is self-expandable from the compressed configuration to the expanded configuration. Additionally, the elongated device is configured to adapt its shape to the surrounding blood vessel, thus the elongated device can have a first diameter in a narrow vessel with a small diameter and a second diameter in a wide vessel with a large diameter.

In some embodiments, the working portion is configured to expand from a compressed configuration with a first diameter of less than <NUM> to an expanded configuration with a second diameter of at least <NUM> and to exert an outward radial force between <NUM> N and <NUM> N at every diameter between and including the first diameter and the second diameter.

In some embodiments, the working portion is configured to exert an outward radial force between <NUM> N and <NUM> N in a diameter (first diameter) between <NUM> and <NUM>. In other embodiments, the working portion is configured to exert an outward radial force between <NUM> N and <NUM> N in a diameter (second diameter) between <NUM> and <NUM>.

In an embodiment, the working portion is configured to exert an outward radial force between <NUM> N and <NUM> N in a first diameter around <NUM>; and wherein the working portion is configured to exert an outward radial force between <NUM> N and <NUM> N in a second diameter around <NUM>.

In an embodiment, the working portion is configured to exert an outward radial force between <NUM> N and <NUM> N in a diameter around <NUM>. In an embodiment, the working portion is configured to exert an outward radial force between <NUM> N and <NUM> N in a diameter around <NUM>.

In an embodiment, the plurality of crowns of cells in the working portion of the elongated device define a tubular-shaped section forming a cylindrically closed structure. In other words, the working portion defines a tubular-shaped section forming a cylindrically closed structure. To that effect, the proposed elongated device can be manufactured by producing specified cuts either on a tube or on a wire. In another embodiment, the elongated device comprises a pusher (or pusher wire) manufactured by producing specified cuts on said wire. A pusher is configured to maneuver the clot mobilizer (e.g. advance the device distally, withdraw the device proximally, and rotate the device about a longitudinal axis from a proximal end of the pusher).

In an embodiment, the clot mobilizer is manufactured by providing a tube; having a longitudinal axis therethrough, providing a stationary source of laser radiation, generating a beam of laser radiation using the source of laser radiation, and cutting a desired pattern into the tube by scanning the beam over a desired region of the tube. In another embodiment, the clot mobilizer is manufactured by providing a wire; having a longitudinal axis therethrough, producing predetermined cuts of the cross section of the wire by means of an ultrashort pulse laser in order to produce a predetermined shape of the stent. A suitable manufacturing method is described e.g., in <CIT>.

In an embodiment, each middle cell strut in the working portion can comprise at least a hinge portion. Each hinge portion is disposed between the proximal and distal ends of the middle cell strut. In an embodiment, each middle cell strut in the working portion can comprise a hinge portion. In an embodiment, each middle cell strut in the working portion can comprise a hinge portion disposed between its proximal and distal ends. In another embodiment, each middle cell strut in the working portion can comprise two hinge portions.

In an embodiment, the hinge portion can comprise at least a bend. In an embodiment, the hinge portion can comprise a bend. In some embodiments, the bend is disposed in a central portion of the middle cell strut. In other embodiments, the bend is disposed closer to one end of the middle cell strut than to another end of the middle cell strut.

In an embodiment, the hinge portion can comprise two bends.

In some embodiments, the hinge portion can comprise a section of increased curvature.

In some embodiments, the hinge portion and middle cell strut are two parts of a single structure. The hinge portion is therefore integral with the middle cell strut.

In some embodiments, the middle cell struts bordering each cell in the working portion have a width less than a width of the distal cell struts bordering that cell. In some embodiments, the middle cell struts bordering each cell in the working portion have a width less than a width of the proximal cell struts bordering that cell. In some embodiments, the middle cell struts bordering each cell have a width less than a width of the distal cell struts bordering that cell and less than a width of the proximal cell struts bordering that cell.

In some embodiments, the working portion can comprise at least one crown of intermediate cells. In some embodiments, each intermediate cell can comprise an open area bordered by two proximal cell struts intersecting with two distal cell struts.

In some embodiments, the distal cell struts of each intermediate cell in the at least one crown of intermediate cells can comprise the proximal cell struts of cells in an adjacent crown of cells. In some embodiments, the proximal cell struts of each intermediate cell in the at least one crown of intermediate cells can comprise the distal cell struts of cells in an adjacent crown of cells. The crowns of cells adjacent to the at least one crown of intermediate cells can comprise middle cell struts adapted and configured to be more flexible than the distal cell strut and proximal cell strut to which each middle cell strut extends. Therefore, the cells comprising middle cell struts are configured to transfer a desired flexibility to the working portion. And the intermediate cells are configured to transfer strength to the working portion, thus avoiding kinks (or breaks).

In some embodiments, the number of crowns of cells depends on the desired length of the working portion. In some embodiments, the working portion can have at least four crowns of cells. In some embodiments, the working portion can have between four and twelve crowns of cells. Particularly, the working portion can have between six and ten crowns of cells. More in particular, the working portion can have seven, eight or nine crowns of cells.

In some embodiments, the distal cell struts in the working portion each can have a width greater than or equal to <NUM> and less than or equal to <NUM>. In other embodiments, the distal cell struts in the working portion each can have a width greater than or equal to <NUM> and less than or equal to <NUM>. Particularly, the distal cell struts in the working portion each can have a width of <NUM>, <NUM>, <NUM> or <NUM>.

In some embodiments, the proximal cell struts in the working portion each have a width greater than or equal to <NUM> and less than or equal to <NUM>. In other embodiments, the proximal cell struts in the working portion each can have a width greater than or equal to <NUM> and less than or equal to <NUM>. Particularly, the proximal cell struts in the working portion each can have a width of <NUM>, <NUM>, <NUM> or <NUM>.

In some embodiments, the middle cell struts in the working portion each can have a width greater than or equal to <NUM> and less than or equal to <NUM>. The middle cell struts in the working portion each can have a width greater than or equal to <NUM> and less than or equal to <NUM>. The middle cell struts in the working portion each can have a width greater than or equal to <NUM> and less than or equal to <NUM>. The middle cell struts in the working portion each can have a width of <NUM>, <NUM> <NUM>, <NUM> <NUM> or <NUM>.

In some embodiments, the distal cell struts each have a width greater than or equal to <NUM> and less than or equal to <NUM>, the proximal cell struts each have a width greater than or equal to <NUM> and less than or equal to <NUM>, and the middle cell struts each have a width greater than or equal to <NUM> and less than or equal to <NUM>.

In an embodiment, the distal cell struts and the proximal cell struts can have substantially the same width.

In an embodiment, the elongated device further comprises a pusher extending proximally from the proximal connection portion (or first connection portion).

In an embodiment, the proximal connection portion acts as a pusher connector.

In an embodiment, the proximal connection portion can have two proximally extending arms. In an embodiment, the proximal connection portion acts as pusher connector to connect the pusher to the elongated device through the two extending arms. In an embodiment, the proximal connection portion can have a single proximally extending arm. In an embodiment, the proximal connection portion acts as pusher connector to connect the pusher to the elongated device through the single extending arm.

<FIG> illustrates an elongated device <NUM> according to some embodiments of the present invention. As shown in <FIG>, the proposed elongated device <NUM> comprises a working element <NUM> and a pusher <NUM>. The working element <NUM> can comprise different medical devices, particularly a stent retriever, and includes a first connection portion <NUM> extending proximally, the first connection portion <NUM> having a first attachment surface <NUM> (see <FIG>). The pusher <NUM> can comprise a second connection portion <NUM> extending distally, the second connection portion <NUM> having a second attachment surface <NUM> facing and extending longitudinally aligned to the first attachment surface <NUM> to define an overlapping portion and to define first and second seams extending longitudinally along first and second lateral extents of the overlapping portion.

The elongated device <NUM> also comprises a first weld attaching the first and second connection portions <NUM>, <NUM>, extending from the first seam toward the second seam, and a second weld attaching the first and second connection portions <NUM>, <NUM>, extending from the second seam toward the first seam.

<FIG> illustrates an embodiment of the cross-sectional shape of the first connection portion <NUM> being a section of an annulus and of the cross-section shape of the second connection portion <NUM> being a circle. The black triangles show the direction of how the energy, particularly laser energy, is laterally applied to form the first and second welds. In this embodiment, the radius of the second attachment surface <NUM> is smaller than the radius of the first attachment surface <NUM>.

Particularly, the ratio of the cross-sectional area of the first connection portion <NUM> perpendicular to the longitudinal axis to the corresponding cross-sectional area of the second connection portion <NUM> perpendicular to the longitudinal axis is in the range of <NUM>:<NUM> to <NUM>:<NUM>; more particularly the ratio is <NUM>:<NUM>.

The first weld can comprise multiple welding points along the first seam. Likewise, the second weld can also comprise multiple welding points along the second seam. In an embodiment, the welding points comprise a number between <NUM> and <NUM> welding points. In another embodiment, the welding points comprise a number between <NUM> and <NUM>. The welding points are particularly aligned with each other. In some embodiments, the first weld and the second weld each can additionally comprise a welding seam disposed/arranged over the multiple welding points previously applied and formed by a plurality of consecutive welding points.

In some embodiments, the first weld and the second weld each extend along an entire length of the overlapping portion.

In some embodiments, glue can be added over the first and second welds.

<FIG> illustrates another embodiment of the elongated device <NUM> comprising a jacket <NUM> or outer jacket, a jacket <NUM> or inner jacket, and a coil <NUM> as a radiopaque element extending around the pusher <NUM>. The jacket <NUM> extends proximally from the overlapping portion over a portion of the pusher <NUM>. The jacket <NUM> extends around the radiopaque element <NUM> and part of the overlapping portion. Additionally, a heat shrinkable material can be added to the inner jacket <NUM> and outer jacket <NUM>.

<FIG> illustrates a method for associating (i.e. connecting/assembling) the working element <NUM> to the pusher <NUM> to enable the pusher <NUM> to maneuver the working element <NUM> (i.e. advance the working element <NUM> distally, withdraw the working element <NUM> proximally, and rotate the working element <NUM> about a longitudinal axis from a proximal end of the pusher <NUM>). At step <NUM> the first attachment surface <NUM> of the first connection portion <NUM> is disposed longitudinally aligned to the second attachment surface <NUM> of the second connection portion <NUM> to form an overlapping portion and to form first and second seams extending parallel to the longitudinal axis along first and second lateral extents of the overlapping portion. At step <NUM> a first weld extending from the first seam towards the second seam is formed. At step <NUM> a second weld extending from the second seam toward the first seam is formed.

In some embodiments, step <NUM> comprises forming or applying a plurality of welding points (for example between <NUM> and <NUM>, particularly between <NUM> and <NUM>) extending from the first seam toward the second seam. Likewise, step <NUM> comprises forming or applying a plurality of welding points extending from the second seam toward the first seam. In some embodiments, the plurality of welding points are aligned with each other. In some embodiments, steps <NUM> and <NUM> also comprise forming a welding seam by consecutively forming or applying a plurality of welding points on top of the previously formed/applied welding points.

To avoid accumulation of heat in specific zones, in some embodiments step <NUM> further comprises forming a first welding point of the plurality of welding points at a distal portion of the first seam and forming each other welding point of the plurality of welding points at a more proximal location along the first seam than a prior formed welding point of the plurality of welding points, and step <NUM> further comprises forming a first welding point of the plurality of welding points at a distal portion of the second seam and forming each other welding point of the plurality of welding points at a more proximal location along the second seam than a prior formed welding point of the plurality of welding points. That is, the energy device forming the weld is moved from the distal end of the first (and second) seam to the proximal end of said seam in order to avoid that the first connection portion <NUM>, the second connection portion <NUM>, or both, accumulate the heat which could provoke a breakage thereof.

In certain embodiments, the method includes covering a portion of the pusher <NUM> proximal to the overlapping portion with a jacket <NUM> (or inner jacket); placing a radiopaque element <NUM> at a proximal end of the overlapping portion and extending the radiopaque element <NUM> around the pusher <NUM>; and covering the radiopaque element <NUM> with a jacket <NUM> (or outer jacket) and extending the later at least part of the overlapping portion.

In an embodiment, before inserting the inner jacket <NUM>, the method can further comprise assembling, or placing, the radiopaque element <NUM> onto a distal end of the pusher <NUM> and pushing the radiopaque element <NUM> towards a proximal end of the pusher <NUM>.

In another embodiment, before inserting the outer jacket <NUM>, the method can further comprise placing, or pushing back, the radiopaque element <NUM> to the distal end of the pusher <NUM> (or at the proximal end of the overlapping portion), without covering the overlapping portion.

In some embodiments, before inserting the outer jacket <NUM>, the method can further comprise heat shrinking the inner jacket <NUM> onto the overlapping portion, and after the outer jacket <NUM> has been inserted, heat shrinking the outer jacket <NUM> onto the inner jacket <NUM> and the radiopaque coil <NUM>. The heat shrinking can be made using a suitable shrinkable material, for example a thermoplastic material such as polytetrafluoroethylene (PTFE); fluorinated ethylene propylene (FEP); perfluoroalkoxy alkanes (PFA); ethylene tetrafluoroethylene (ETFE); polyethylene terephthalate (PET) resins, etc..

In other embodiments, the working element <NUM> can be associated (i.e. connected/assembled) to the pusher <NUM> by other suitable attachment techniques, such as chemical or thermally bonding, friction or mechanically fitting, crimping, soldering, brazing, or even by using a connector material or member, or combinations thereof. In another embodiment, the working element <NUM> can be associated to the pusher <NUM> by crimping a coated or plated band disposed around and crimped to the overlapping portion.

The elongated device <NUM> can be made of Nitinol, cobalt-chromium alloys, iron alloys such as stainless steel or spring steel, etc..

With reference to <FIG>, therein different embodiments of the working element <NUM> of the elongated device <NUM> are illustrated. In these embodiments, the working element <NUM> includes a working portion <NUM> comprising a plurality of crowns <NUM>,. <NUM>, of almond-shaped cells <NUM> defining a tubular-shaped section forming a cylindrically closed structure, as can be seen in the 3D representation illustrated in the embodiment of <FIG>, and a tapered portion <NUM> that extends proximally from a proximal end of the working portion <NUM>. For purposes of this disclosure, a "crown" is a closed ring extending circumferentially around the device with alternating longitudinally longer and longitudinally shorter sections. The working portion <NUM> in a compressed diameter can have a length between <NUM> and <NUM>, and the working portion <NUM> in an expanded diameter can have a length between <NUM> and <NUM>.

A distal end of each cell <NUM> in a first crown <NUM>, is contiguous with a proximal end of a corresponding cell <NUM> in a third crown <NUM><NUM>, and a distal end of each cell <NUM> in a second crown <NUM><NUM> is contiguous with a proximal end of a corresponding cell <NUM> in a fourth crown <NUM><NUM>. The midportions of each cell <NUM> in each of the crowns each are also contiguous with a midportion of an adjacent cell <NUM> in such crown.

The working element <NUM> illustrated in <FIG> also include radiopaque markers <NUM>. The radiopaque markers <NUM> can be incorporated at a distal end of the working portion <NUM> only (as in <FIG>) or can be also incorporated at other sections of the working portion <NUM>. In some embodiments, the different radiopaque markers <NUM> have different lengths to avoid entanglement between them or other devices. The radiopaque markers <NUM> can be made of a Platinum Iridium alloy or of Tantalum.

Each one of cells <NUM> has struts <NUM>. Likewise, the tapered portion <NUM> also has at least some wide struts <NUM>. Particularly, the wide struts <NUM> of the tapered portion <NUM> have a width greater than a width of the working portion struts <NUM> (see <FIG> for an enlarged illustration thereof).

For example, in the embodiment shown in <FIG>, first 122a and second 122b struts, extending proximally from the proximal end of the working portion <NUM>, converge at a distal end <NUM> of a proximal connection portion <NUM> of the working element <NUM>. Third 122c and fourth 122d struts extend distally from first 122a and second 122b struts, respectively, and converge at the proximal end of the working portion <NUM>. First 122a, second 122b, third 122c and fourth 122d struts together define a cell <NUM> in the tapered portion <NUM>, and these struts 122a-122d are all thicker than the struts <NUM> in the working portion <NUM>. In the embodiment illustrated in <FIG>, first, second, third and fourth struts 122a-122d are thicker than other struts 122e in the tapered portion <NUM>. These thicker struts 122a-122d help provide greater outward radial force to the working portion <NUM> from its compressed diameter to its expanded diameter, as discussed below. In some embodiments, because the working portion <NUM> and the tapered portion <NUM> of the elongated device <NUM> is formed from a single hypotube, the wide tapered portion struts <NUM> have a thickness equal to the thickness of the working portion struts <NUM>, which is predetermined by the thickness of the tube from which it is made. In some embodiments, the working portion struts <NUM> can have a width between <NUM> and <NUM>, and at least some of the tapered portion struts <NUM> can have a width between <NUM> and <NUM>.

In some embodiments, the working portion <NUM> has a compressed diameter of less than <NUM> and an expanded diameter of approximately <NUM>. In some embodiments, the working portion <NUM> can exert an outward radial force between <NUM> N and <NUM> N at every diameter between and including the compressed diameter and the expanded diameter. In an embodiment, the outward radial force exerted by the working portion <NUM> in a compressed diameter of <NUM> is between <NUM> N and <NUM> N, particularly <NUM> N. In an embodiment, the outward radial force exerted by the working portion <NUM> in an expanded diameter of <NUM> is between <NUM> N and <NUM> N, particularly <NUM> N.

With reference to <FIG>, therein different embodiments of the proposed working element <NUM> of the elongated device (or clot mobilizer device) <NUM> are illustrated. While the various embodiments all have longitudinally extending closed tubes with a tapered proximal end and an open distal end (as shown, e.g., in <FIG> shows opened and flattened particular embodiments to illustrate two-dimensionally the strut and cell patterns of those embodiments.

The working element <NUM> includes a working portion <NUM> comprising a plurality of crowns <NUM><NUM>. <NUM>n of cells <NUM> defining a tubular-shaped section forming a cylindrically closed structure (as can be seen in the 3D representation illustrated in the embodiments of <FIG>). For example, the number of crowns in the plurality of crowns <NUM><NUM>. <NUM><NUM>n can be between <NUM> and <NUM>, more particularly <NUM>, <NUM>, <NUM> or <NUM> (with e.g., n = <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> or <NUM>). As shown in <FIG>, the working portion <NUM> of the working element <NUM> comprises eight crowns of cells. However, the working portion <NUM>, in other embodiments, can comprise seven crowns of cells (not shown) or nine crowns of cells (not shown). For purposes of this disclosure, a "crown" is a closed ring extending circumferentially around the device with alternating longitudinally longer and longitudinally shorter sections. Each crown of cells in the working portion can comprise, for example, four or six cells, and each crown can have components that are shared with one or more adjacent crowns. In some embodiments, the working portion <NUM> can have a length between <NUM> and <NUM>, for example approximately <NUM>.

Each cell <NUM>n in the crowns of cells <NUM>n in the working portion <NUM> has an open area bordered by two proximal cell struts, two distal cell struts, and two middle cell struts <NUM>n. For purpose of the disclosure, "n" is used to reference interrelated features; for example, the first crown is referenced as n=<NUM> and its respective adjacent crown as n+<NUM>=<NUM>, and successively. The distal cell struts of the first crown <NUM>, are disposed in a distal cell strut ring <NUM><NUM> at equal distal cell strut positions along a longitudinal axis of the working element <NUM>, and the proximal cell struts of the first crown <NUM>, are disposed in a proximal cell strut ring <NUM><NUM> at equal positions along the longitudinal axis of the working element <NUM>. In such crowns of cells, the proximal cell struts each extends distally from a proximal end common to one adjacent proximal cell strut to a distal end common to another adjacent proximal cell strut, where it joins a proximal end of a respective one of the two middle cell struts <NUM>n. Similarly, the distal cell struts each extends proximally from a distal end common to one adjacent distal cell strut to a proximal end common to another distal cell strut, where it joins a distal end of a respective one of the two middle cell struts <NUM>n. Each middle cell strut <NUM> in each crown borders two adjacent cells <NUM> in that crown. As shown in <FIG>, the distal strut ring <NUM>n of one crown of cells is the proximal strut ring <NUM>n+<NUM> of the adjacent crown of cells, and the distal cell struts of distal strut ring <NUM>n are the proximal cell struts of proximal strut ring <NUM>n+<NUM>.

The longitudinal and circumferential arrangements of the crowns of cells <NUM>n in the working portion <NUM> of the working element <NUM> can affect the behavior of the device in its unexpanded and expanded configurations. For example, providing a circumferential offset between adjacent crowns of cells can facilitate compression of the working element from the expanded configuration into an unexpanded configuration for delivery through a catheter. This circumferential offset of adjacent crowns of cells can also reduce buckling and kinking during advancement of the working element <NUM> (i.e., clot mobilizer) through the delivery catheter in its unexpanded delivery configuration.

In the embodiment of <FIG> the common proximal ends of the distal cell strut ring <NUM><NUM> of a first crown <NUM>, of cells <NUM> of the plurality of crowns of cells <NUM>,. <NUM>n (i.e., the proximal ends of the middle cell struts <NUM><NUM>) are offset from the common distal ends of the proximal cell strut ring <NUM><NUM> of the first crown <NUM>, of cells <NUM> (i.e., the distal ends of the middle cell struts <NUM><NUM>) in a first circumferential direction, and the common proximal ends of the distal cell strut ring <NUM><NUM> of a second crown <NUM><NUM> of cells <NUM> of the plurality of crowns of cells (i.e., the proximal ends of the middle cell struts <NUM><NUM>) are offset from the common distal ends of the proximal cell strut ring <NUM><NUM> of the second crown <NUM><NUM> of cells <NUM> (i.e., the distal ends of the middle cell struts <NUM><NUM>) in a second circumferential direction opposite to the first circumferential direction. This pattern repeats with subsequent crowns of cells, such that the common distal ends of proximal cell strut rings are alternately offset in the first circumferential direction and in the second circumferential direction in each successive crown of cells. Thus, the crowns are configured one to each other in a zig-zag pattern.

In other embodiments (not shown), the common proximal ends of each distal cell strut ring <NUM>n (i.e., the distal ends of middle cell struts <NUM>n) are circumferentially offset from the common distal ends of the proximal cell strut ring <NUM>n (i.e., the proximal ends of middle cell struts <NUM>n) in the same circumferential direction, such that the middle cell struts <NUM> between these common ends extend in a direction that is not parallel to the longitudinal axis of the working portion <NUM>. Thus, the crowns are oriented one to each other in a helix pattern.

Likewise, in the embodiment of <FIG>, each of the middle cell struts <NUM> is adapted and configured to be more flexible than the distal cell strut and proximal cell strut to which it extends. In this embodiment, the working portion <NUM> and tapered portion <NUM> of the working element <NUM> are cut from a single tube and all elements have the same thickness (i.e., the tube thickness). As shown in the flattened view of <FIG> (which shows the pattern to be cut from the solid tube to make the working element <NUM>), the middle cell struts <NUM> bordering each cell <NUM> have a width less than a width of the distal cell struts bordering that cell <NUM> and less than a width of the proximal cell struts bordering that cell <NUM>, thereby making the middle cell struts <NUM> more flexible than the proximal cell struts and the distal cell struts. For example, the distal cell struts and proximal cell struts can have substantially the same width, e.g., in the range between <NUM> and <NUM>, particularly <NUM>, <NUM> or <NUM>, while the middle cell struts <NUM> can have a width in the range between <NUM> <NUM>, particularly <NUM>, <NUM>, <NUM> or <NUM>.

To enhance the flexibility of the elongated device <NUM>, each middle cell strut <NUM> in the working portion <NUM> also has hinge portions <NUM> to provide additional flexibility to the middle cell strut. As shown in <FIG>, the hinge portions <NUM> are preformed curves or bends in the middle cell strut <NUM> disposed between the proximal and distal ends of the middle cell strut <NUM>. The hinge portions <NUM> of this embodiment include two integral bends, one near the common distal end of the proximal cell struts from which the middle cell strut extends and other near the common proximal end of the distal cell struts to which the middle cell strut extends. In other embodiments (not shown), the hinge portions <NUM> can include a third integral bend in the center of each middle cell strut, much greater than the other two bends. In other embodiments (not shown), the hinge portions <NUM> in some middle struts <NUM> are two bends formed closer to the proximal end of the middle cell strut than to the distal end. In other embodiments, each middle cell strut <NUM> in the working portion <NUM> can comprise fewer or more hinge portions <NUM>. The hinge portion <NUM> can be integral with the middle cell strut, as shown e.g., in <FIG>, forming, e.g., a living hinge in which the hinge portion <NUM> and the other portions of the middle cell strut are parts of the same structure. For example, each hinge portion <NUM> can have an integral section of increased curvature and/or bend. The bend forming the hinge provides added flexibility to the middle cell strut. The additional flexibility of the middle cell struts helps the working element adapt to the shape of the vascular anatomy, e.g., as it is advanced and withdrawn in its unexpanded delivery configuration. The hinges also help the elongated device <NUM> to adapt its shape to the vascular anatomy into which it is expanded to its expanded configuration to capture a clot. In addition, this feature helps avoid kinking and buckling during advancement by providing multiple bending points along the length of the elongated device <NUM> to distribute the advancement force when the device encounters resistance to forward movement. In some embodiments (not shown) not all of the crowns of cells have hinge portions.

In other embodiments of the present invention (not shown), one or more crowns of cells of the plurality of crown of cells in the working portion can lack flexible middle cell struts. The working portion <NUM> can also include at least one crown of intermediate cells, and each intermediate cell can comprise an open area bordered by two proximal cell struts intersecting with two distal cell struts, i.e., omitting the more flexible middle cell struts included in some of the other crowns of cells. The distal cell struts of each intermediate cell in the at least one crown of intermediate cells can comprise the proximal cell struts of cells in an adjacent crown of cells, and the proximal cell struts of each intermediate cell in the at least one crown of intermediate cells can comprise the distal cell struts of cells in an adjacent crown of cells. Therefore, the working portion comprises crowns with flexible middle cells and crowns without flexible middle cells.

The working element <NUM> of <FIG> also includes a tapered portion <NUM> that extends proximally from a proximal end of the working portion <NUM> to a connection portion <NUM>. The tapered portion <NUM> has a plurality of struts <NUM>. At least some of the plurality of tapered portion struts <NUM> border a plurality of tapered portion cells <NUM>. Particularly, the struts <NUM> of the tapered portion <NUM> can have a width greater than a width of the working portion struts, e.g., the distal cell struts, the proximal cell struts and/or the middle cell struts <NUM>, thereby making the tapered portion struts stiffer (i.e., less flexible) than the struts of the working portion. The taper of the tapered portion <NUM> is achieved by the size and number of cells <NUM> in the tapered portion <NUM> compared to the sizes and numbers of cells in the working portion <NUM>, with only a single tapered portion cell <NUM> where struts <NUM> converge to a connection point <NUM> distal to a radiopaque marker <NUM> at a distal end of a proximal connection portion <NUM>.

The tapered portion <NUM> in the embodiment of <FIG> has four tapered portion struts <NUM>, two of which extend proximally from the proximal end of the working portion <NUM> to meet at the connection point <NUM> distal to the radiopaque marker <NUM> and a proximally extending arm <NUM> of a connection portion <NUM> (arm <NUM> may connect to a pusher, as described with respect to <FIG> above). The other two struts <NUM> extend proximally from the proximal end of the working portion to intersect central portions of the first two struts <NUM>. Together, the four struts define three tapered portion cells <NUM>. Once again, the taper of the tapered portion <NUM> is achieved by the size and number of cells <NUM> in the tapered portion <NUM> compared to the sizes and numbers of cells in the working portion <NUM>. The tapered portion struts help at least the proximal end of the working portion provide a radially outward force due to, e.g., the tapered portion strut angle and/or thickness and the shapes of the cells they define. The tapered portion struts also help with pushability by effectively transmitting a distally-directed advancement force to the working portion of the working element <NUM>.

The proximal connection portion <NUM> can comprise one or two proximally extending arms <NUM>. Arms <NUM> may connect to a pusher, as described in other embodiments of the present invention.

The working element <NUM> can comprise radiopaque markers <NUM> incorporated at a distal end of the working portion <NUM> only or can be also incorporated at other sections of the working portion <NUM>. In some embodiments, the different radiopaque markers <NUM> have different lengths to avoid entanglement between them or other devices. The radiopaque markers <NUM> can be made of a Platinum Iridium alloy or of Tantalum. The radiopaque markers <NUM> may be used under fluoroscopy to show the position and degree of expansion of working element <NUM>.

In some embodiments, the working portion <NUM> has a compressed configuration with a first diameter of less than <NUM> and an expanded configuration with a second diameter of at least <NUM>. The working portion <NUM> can exert an outward radial force between <NUM> N and <NUM> N at every diameter between and including the first diameter and the second diameter. In a particular embodiment, the outward radial force exerted by the working portion <NUM> in a first diameter of <NUM> is between <NUM> N and <NUM> N, more particularly <NUM> N, <NUM> N, <NUM> N or <NUM> N; and the outward radial force exerted by the working portion <NUM> in a second diameter of <NUM> is between <NUM> N and <NUM> N, more particularly <NUM> N, <NUM> N, <NUM> N or <NUM> N.

In some embodiments, the working portion <NUM> is configured to exert an outward radial force between <NUM> N and <NUM> N in a diameter between <NUM> and <NUM>. In other embodiments, the working portion <NUM> is configured to exert an outward radial force between <NUM> N and <NUM> N in a diameter between <NUM> and <NUM>. In a particular embodiment, the working portion <NUM> is configured to exert an outward radial force between <NUM> N and <NUM> N in a diameter around <NUM>. In another embodiment, the working portion <NUM> is configured to exert an outward radial force between <NUM> N and <NUM> N in a diameter around <NUM>.

The embodiments previously explained can be combined to form a suitable working element <NUM> such that is configured to exert the proper outward radial force. More examples of working element <NUM> are described in EP Patent Application No. <CIT>.

Following, different examples of the performance of the proposed elongated device <NUM> are detailed. The examples and drawings are provided herein for illustrative purposes, and without intending to be limiting to the present invention.

The purpose of this experimental test was to measure the torque resistance of the attachment between the pusher <NUM> and the working element <NUM> of an elongated medical device <NUM>.

Eight stent retrievers were used in this study: Five stent retrievers manufactured by Anaconda Biomed with different configurations (hereinafter Conda devices) and three manufactured by Medtronic (hereinafter Solitaire devices).

The tools and equipment used during the procedure are exposed in Table <NUM>.

The following Table <NUM> shows the results for both, Conda and Solitaire devices:.

The results showed a higher performance of the Conda devices during torque test compared to Solitaire devices. These results are directly related with the safety of the elongated device <NUM> during the clinical use, therefore, obtaining a higher number of revolutions reduce the possibilities of a premature breakage due to e.g., an incorrect handling of the device. However, the stent retriever devices were not intended for torque during use, so the values obtained for both Conda and Solitaire devices are enough to cover any possible misuse of the elongated device <NUM>.

The purpose of this experimental test was to measure the tensile of the connection between the pusher <NUM> and the working element <NUM> of an elongated medical device <NUM>.

Thirty-five samples, of them, twenty Conda devices, and fifteen Solitaire devices, were used as stent retrievers to evaluate the tensile strength in the attachment/connection.

The results showed a higher performance of the Conda devices in tensile resistance compared to Solitaire devices. These results are related with the safety of the elongated device <NUM> during the clinical use, therefore, obtaining higher values of tensile strength reduce the possibilities of a premature breakage of the attachment/connection due to an excessive tension during retrieval.

Unless otherwise indicated, all numbers expressing measurements, conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term "about". Accordingly, unless indicated to the contrary, the numerical parameters set forth in this specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by the presently disclosed subject matter.

Throughout the description and claims the word "comprise" and its variations such as "comprising" are not intended to exclude other technical features, components, or steps. Additional objects, advantages and features of the invention will become apparent to those skilled in the art upon examination of the description or may be learned by practice of the invention.

The present disclosure and/or some other examples have been described in the above.

According to descriptions above, various alterations may be achieved.

Claim 1:
An elongated device for restoring blood flow or removing thrombus, the elongated device being adapted to be advanced distally and withdrawn proximally from a proximal end and rotated about a longitudinal axis from the proximal end, the elongated device comprising:
a working element (<NUM>) comprising a first connection portion (<NUM>) extending proximally, the first connection portion (<NUM>) having a first attachment surface (<NUM>);
a pusher (<NUM>) comprising a second connection portion (<NUM>) extending distally, the second connection portion (<NUM>) having a second attachment surface (<NUM>) facing and extending longitudinally aligned to the first attachment surface (<NUM>) to define an overlapping portion and to define first and second seams extending longitudinally along first and second lateral extents of the overlapping portion;
a first weld attaching the first and second connection portions (<NUM>, <NUM>), extending from the first seam toward the second seam; and
a second weld attaching the first and second connection portions (<NUM>, <NUM>), extending from the second seam toward the first seam.