Particle stent for portal vein, particle stent for lumen, and kit thereof

Abstract

Disclosed are a particle stent for a portal vein, a particle stent for a lumen, and a kit thereof. The particle stent comprises a fixing part; a first parallel part comprising a plurality of first edges parallel to the length direction of the particle stent; a second parallel part comprising a plurality of second edges parallel to the length direction of the particle stent; a support part extending in a circumferential direction of the particle stent to provide a radial support force for the first edges and the second edges; and a particle filling part. Each group of nitinol wires is mutually wound from a first end to a support starting point to form a first edge. Moreover, the first edge divides into two nitinol wires from the support starting point, and each of the nitinol wires is bent at a support end point and mutually wound with an adjacent group of nitinol wires from the support end point to a second end to form a second edge. The particle stent can not only achieve the accurate arrangement of radioactive particles but also prevent tumor thrombi from being displaced.

Description

Particle stent for portal vein, particle stent for cavity and kit thereof Technical Field

[0001] The present invention relates to a particle stent for portal vein, also relates to a particle stent for cavity, and also relates to a particle stent kit comprising the particle stent, belonging to the technical field of medical devices. Background Art

[0002] Treatment options for portal vein cancer thrombus formation include surgical resection, liver transplantation, targeted drugs, and portal vein stent implantation. Surgical resection is ineffective, with a median survival of only six months. Liver transplantation has a low long-term survival rate and can waste liver resources. Targeted drugs are expensive, with survival often limited to two to three months. Portal vein stent implantation has no therapeutic effect on cancer thrombus formation and shortens blood flow.

[0003] To treat cancer thrombi in the main portal vein, some have proposed seed-loaded portal vein stents, based on conventional portal vein stent implantation. These stents are designed to treat cancer thrombi by loading them with radioactive particles. However, there are currently no internal radiotherapy stents specifically designed for portal vein cancer thrombi on the market, only conventional stents designed to shunt portal hypertension. These conventional stents only provide palliative treatment for portal hypertension. Their structure serves only to dilate the portal vein and lacks the long-term therapeutic effect of radiotherapy on cancer thrombi, thus eliminating the need for the placement of radioactive particles. Furthermore, due to the limited delivery path during portal vein cancer thrombus surgery, the radial dimensions of portal vein stents cannot be large. Consequently, the mesh structure of conventional portal vein stents lacks sufficient space to store radioactive particles and cannot achieve precise placement, resulting in insufficient doses to meet treatment requirements. Furthermore, due to the fluidity of blood, there is a significant risk of cancer thrombus metastasis. Therefore, there is an urgent need for a specialized seed-loaded stent for treating portal vein cancer thrombi. Summary of the Invention

[0004] The primary technical problem to be solved by the present invention is to provide a particle stent for portal vein.

[0005] Another technical problem to be solved by the present invention is to provide a particle support for a cavity.

[0006] Another technical problem to be solved by the present invention is to provide a particle holder kit including the above-mentioned particle holder.

[0007] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

[0008] According to a first aspect of an embodiment of the present invention, there is provided a particle stent for a portal vein, the particle stent being braided from nickel-titanium alloy wires, comprising:

[0009] A fixing portion, comprising a first end and a second end, located at both ends of the particle holder, and used to fix the particle holder in the portal vein;

[0010] a first parallel portion located in a middle region of the particle holder and close to the first end of the particle holder, the first parallel portion comprising a plurality of first edges parallel to a length direction of the particle holder;

[0011] a second parallel portion located in a middle region of the particle holder and close to the second end of the particle holder, the second parallel portion comprising a plurality of second edges parallel to the length direction of the particle holder;

[0012] a support portion connected between the first parallel portion and the second parallel portion, extending along the circumferential direction of the particle support to provide radial support force to the first edge and the second edge, each first edge or the second edge being wound by nickel-titanium alloy wire;

[0013] The particle filling part includes a plurality of particle capsules for filling radioactive particles, wherein the plurality of particle capsules are evenly arranged on the first edge and the second edge.

[0014] The first parallel portion and the second parallel portion are woven differently from the fixing portion, so that the fixing portion has a greater supporting force than the first parallel portion and the second parallel portion; and the first edge and the second edge are of equal length.

[0015] Among them, each group of nickel-titanium alloy wires are wound around each other from the first end to the support starting point to form the first edge; and the first edge is dispersed into two nickel-titanium alloy wires from the support starting point, each nickel-titanium alloy wire is bent at the support end point, and is wound around each other with the adjacent group of nickel-titanium alloy wires from the support end point to the second end to form the second edge.

[0016] Preferably, the plurality of first edges and the plurality of second edges are staggered and parallel to each other;

[0017] A plurality of dispersed support wires are connected between the plurality of first edges and the plurality of second edges, and each of the support wires is arranged in a circumferential direction around the particle support to jointly constitute the support portion.

[0018] Preferably, the plurality of first edges correspond to the plurality of second edges one by one, and each of the first edges and the corresponding second edge are located on the same straight line;

[0019] A plurality of dispersed support filaments are formed between the plurality of first edges and the plurality of second edges, and each of the support filaments is arranged in a circumferential direction around the particle support to jointly constitute the support portion.

[0020] Preferably, the plurality of first edges are a plurality of mutually parallel first spiral wires, and the plurality of second edges are a plurality of mutually parallel second spiral wires;

[0021] The plurality of first spiral wires and the plurality of second spiral wires form a preset angle, and a plurality of dispersed support wires are formed between the plurality of first spiral wires and the plurality of second spiral wires, and each of the support wires is arranged in a circumferential direction around the particle support to jointly constitute the support portion.

[0022] Preferably, the particle capsule is formed on the first edge and the second edge by using a jet spinning process, so as to increase the supporting force of the first edge and the second edge and reduce the thickness of the particle capsule.

[0023] Preferably, the jet spinning process comprises the following steps:

[0024] S1: installing a preforming mold on a first edge and a second edge in sequence; wherein the preforming mold includes particles and a fixing structure, wherein the particles are larger than the radioactive particles and are made of a soluble or heat-meltable material, and the fixing structure fixes the particles on one side of the first edge or the second edge;

[0025] S2: spraying a solution of the vascular membrane material onto each preformed mold in the form of a thread through a jet spinning device to form a particle capsule having a preset size that encapsulates the preformed mold;

[0026] S3: Pause for a preset time until each particle capsule is cooled and shaped;

[0027] S4: Immerse the entire particle support in a special solution to completely dissolve the preformed mold, thereby exposing the capsule structure of the particle capsule;

[0028] S5: Cleaning the entire particle scaffold to form a particle scaffold having a plurality of particle capsules.

[0029] Preferably, a first support grid is formed between two adjacent first edges, and a second support grid is formed between two adjacent second edges.

[0030] The first support grid is a grid formed by winding a plurality of nickel-titanium alloy wires between the first edges; the second support grid is a grid formed by winding a plurality of nickel-titanium alloy wires between the second edges.

[0031] In the circumferential direction of the stent, the first support grid and the second support grid do not cover the entire circumference.

[0032] According to a second aspect of an embodiment of the present invention, there is provided a particle stent for a cavity, which is woven from metal wires and includes:

[0033] A fixing portion, comprising a first end and a second end, located at both ends of the particle holder, and used to fix the particle holder in the portal vein;

[0034] a first parallel portion located in a middle region of the particle holder and close to the first end of the particle holder, the first parallel portion comprising a plurality of first edges parallel to a length direction of the particle holder;

[0035] a second parallel portion located in a middle region of the particle holder and close to the second end of the particle holder, the second parallel portion comprising a plurality of second edges parallel to the length direction of the particle holder;

[0036] a supporting portion connected between the first parallel portion and the second parallel portion, extending along the circumferential direction of the particle holder to provide radial supporting force to the first edge and the second edge;

[0037] The particle filling part includes a plurality of particle capsules for filling radioactive particles, wherein the plurality of particle capsules are evenly arranged on the first edge and the second edge.

[0038] The first parallel portion and the second parallel portion are woven differently from the fixing portion, so that the fixing portion has a greater supporting force than the first parallel portion and the second parallel portion;

[0039] Each group of metal wires is wound around each other from the first end to the support starting point to form the first edge; and the first edge is dispersed into two metal wires from the support starting point, each metal wire is bent at the support end point, and is wound around each other with the adjacent group of metal wires from the support end point to the second end to form the second edge.

[0040] Preferably, the particle capsule is formed on the first edge and the second edge by using a jet spinning process, so as to increase the supporting force of the first edge and the second edge and reduce the thickness of the particle capsule.

[0041] Preferably, a first support grid is formed between two adjacent first edges, and a second support grid is formed between two adjacent second edges.

[0042] The first support grid is a grid formed by winding a plurality of nickel-titanium alloy wires between the first edges; the second support grid is a grid formed by winding a plurality of nickel-titanium alloy wires between the second edges.

[0043] In the circumferential direction of the stent, the first support grid and the second support grid do not cover the entire circumference.

[0044] According to a third aspect of an embodiment of the present invention, there is provided a particle support kit, comprising:

[0045] The aforementioned particle stent for portal vein, or the aforementioned particle stent for cavity;

[0046] A plurality of radioactive seeds are respectively filled into the seed capsules of the seed stent based on the TPS (treatment planning system) preoperative planning;

[0047] The expandable stent is braided into a cylindrical shape so as to be in a contracted state when under stress and in an expanded state when not under stress;

[0048] The expandable stent can be delivered into the particle stent in a contracted state and provide radial support force to the particle stent in an expanded state.

[0049] Compared with the prior art, the present invention has the following technical effects:

[0050] 1. Able to achieve precise arrangement of radioactive particles.

[0051] First, the fixed parts at both ends of the particle stent have a mesh structure that is woven differently from the parallel parts in the middle area. Therefore, the fixed parts have greater support force, making the support at both ends of the stent stronger, thereby fixing the particle stent in the portal vein and preventing the stent from shifting.

[0052] Secondly, two or more parallel parts parallel to each other are formed in the middle area of ​​the particle holder, and each parallel part is arranged with a particle capsule for filling with radioactive particles; and the parallel parts are connected to each other with supporting wires to increase the supporting force of the two parallel parts, prevent the parallel parts from collapsing, and ensure that the parallel parts have a certain supporting strength, thereby avoiding radial deviation of the radioactive particles and affecting the dosage accuracy, and realizing the precise arrangement of the radioactive particles.

[0053] Third, the axial length of the seed stent remains unchanged in the compressed or expanded state, so the radioactive seeds in the seed capsule will not shift in position, thereby ensuring accurate positioning of the radioactive seeds and improving the radiotherapy effect.

[0054] Fourthly, since the middle portion of the particle stent consists of only a plurality of parallel portions and a plurality of particle capsules, the size is small in the contracted state, and is suitable for stent delivery in tortuous cavities.

[0055] Fifth, the jet-spinning process creates a compact and stable particle capsule with strong fiber connections, making it less likely to fall out of or shift relative to the parallel portion. Therefore, compared to sewing processes, the particle capsule is less likely to deform, damage, or shift during use, ensuring that the radioactive particles remain in the position planned before TPS surgery, improving accuracy.

[0056] 2. It can prevent the displacement of cancer thrombus.

[0057] First, the supporting wires connecting the two parallel parts can increase the supporting force of the two parallel parts, thereby utilizing the supporting force of the parallel parts to squeeze the particle capsule toward the inner wall of the cavity, thereby supporting and fixing the cancer thrombus to avoid the metastasis of the cancer thrombus under the action of blood flow.

[0058] Secondly, more preferably, a support grid may be provided in a partial area on the two parallel portions to support the cancer thrombus using the support grid, thereby improving the fixation effect on the cancer thrombus.

[0059] Third, if the support of the parallel parts is not sufficient to support the cancer thrombus, an internal stent can be released between the parallel parts for support, or a balloon can be used to expand the stent to ensure stable support for the cancer thrombus and prevent its displacement. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] FIG1 is a schematic structural diagram of a particle stent for portal vein provided by a first embodiment of the present invention;

[0061] FIG2 is a schematic diagram of particle dosage of a particle stent for portal vein provided by the first embodiment of the present invention;

[0062] FIG3 is a schematic structural diagram of another particle stent for portal vein provided by the first embodiment of the present invention;

[0063] FIG4 is a schematic structural diagram of a particle stent for portal vein provided by a second embodiment of the present invention;

[0064] FIG5 is a schematic diagram of particle dosage of a particle stent for portal vein provided by a second embodiment of the present invention;

[0065] FIG6 is a schematic structural diagram of a particle stent for portal vein provided by a third embodiment of the present invention;

[0066] FIG7 is a schematic diagram of particle dosage of a particle stent for portal vein provided by a third embodiment of the present invention;

[0067] FIG8 is a schematic structural diagram of a particle stent kit for portal vein provided by a fourth embodiment of the present invention;

[0068] FIG9 is a schematic diagram of the front structure of an expanded stent in a fourth embodiment of the present invention;

[0069] FIG10 is a schematic structural diagram of another particle stent kit for portal vein provided by the fourth embodiment of the present invention. DETAILED DESCRIPTION

[0070] The technical content of the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0071] The particle stent and kit for portal vein provided in the embodiments of the present invention can be used in cavities, including blood vessels, airways, urethra, cervix, etc., and the portal vein is used as an example for illustration, but this does not constitute a limitation of the present invention.

[0072] As is known to all, obstruction of portal vein blood flow is one of the main causes of portal hypertension. Increased portal vein pressure will form collateral circulation. Therefore, the portal vein stent needs to ensure smooth blood flow to avoid inducing or aggravating portal hypertension due to the stent. In other words, the stent as a whole (whether it is the end of the stent or the middle) needs to have sufficient wall adhesion to ensure that the stent has the least effect on the blood flow rate. Moreover, the tortuosity of the portal vein makes the stent design more difficult (the stent compliance must be high during delivery; the stent support force must be high during release). Therefore, conventional grid-like vascular stents often have insufficient support force and are easy to fall off after implantation. To this end, the particle stent for the portal vein provided in the embodiment of the present invention can solve these problems.

[0073] First embodiment

[0074] As shown in Figures 1 and 2, a first embodiment of the present invention provides a particle stent 10 for use in a portal vein, comprising a fixing portion 11, a supporting portion 12, a first parallel portion 13, a second parallel portion 14, and a particle-filling portion 15. The fixing portion 11, supporting portion 12, first parallel portion 13, second parallel portion 14, and particle-filling portion 15 are all distributed circumferentially around the particle stent, thereby avoiding obstruction of blood flow and ensuring that the expanded stent is delivered to the interior of the particle stent (described in detail later).

[0075] Specifically, in the present embodiment, fixed part 11 is positioned at the two ends of particle stent 10 and matches with the size of portal vein, for particle stent 10 being fixed in portal vein.Under the release state (expanded state) that is not subject to external force, the weaving mode of fixed part 11 is different from parallel parts, makes the supporting force of fixed part greater than the first parallel part and the second parallel part.Such design, makes fixed part 11 after releasing in portal vein, the supporting force to cavity inner wall is larger, thus positioning effect is better.But, because the supporting force of the first parallel part and the second parallel part is less than fixed part, in addition be fixed with particle capsule and radioactive particles, so the first parallel part and the second parallel part are difficult in radial expansion.

[0076] The first parallel portion 13 is located in the middle area of ​​the particle holder 10 and near the first end of the particle holder (i.e., end A in FIG1 ). The first parallel portion 13 includes multiple first edges 101 parallel to the length direction of the holder. The second parallel portion 14 is located in the middle area of ​​the particle holder 10 and near the second end of the particle holder (i.e., end D in FIG1 ). The second parallel portion 14 includes multiple second edges 102 parallel to the length direction of the holder. The support portion 12 is connected between the first parallel portion 13 and the second parallel portion 14 to support the inner wall of the cavity of the portal vein and to keep multiple first edges 101 parallel and multiple second edges 102 parallel. The particle filling portion 15 includes multiple particle capsules 151 for filling with radioactive particles. Multiple particle capsules 151 are evenly arranged on the first edge 101 and the second edge 102. Here, the parallel first edge and the second edge only extend in the length direction and do not extend in the circumferential direction. Here, the parallel first edge and the second edge only extend in the length direction and do not extend in the circumferential direction. Such a design ensures that the lengths of the first parallel portion and the second parallel portion do not change in the longitudinal direction, that is, the bracket does not experience axial shrinkage.

[0077] In this embodiment, the particle stent 10 is woven into a cylindrical shape by a plurality of nickel-titanium alloy wires 1, so that the two ends of the particle stent respectively form a fixing portion 11, and the middle part of the particle stent is formed with a support portion 12 for supporting the inner wall of the portal vein. Each nickel-titanium alloy wire 1 corresponds to a preset path, so that each nickel-titanium alloy wire can be wound and formed according to its own preset path. The nickel-titanium alloy wires with overlapping paths are intertwined to form edges; each nickel-titanium alloy wire 1 is bent in the middle of the particle stent 10 to form a support wire of a preset length, and all the support wires located in the middle of the particle stent together constitute the support portion 12.

[0078] Specifically, in the present embodiment, many nickel-titanium alloy wires of this particle support 10 are divided into many groups.Only take nickel-titanium alloy wire as example to illustrate at this, also can be the quantity of other metal wire (magnesium alloy) nickel-titanium alloy wires is 2 times of the quantity of parallel portion.That is, each first edge or the second edge in the parallel portion are wound and obtained by 2 nickel-titanium alloy wires.Each group of nickel-titanium alloy wires is mutually wound to the support starting point (i.e. point B in Fig. 1) from the first end (i.e. the A end in Fig. 1) of particle support 10, to form the first edge 101, and many first edges 101 constitute the first parallel portion together.And, the first edge 101 is dispersed into two nickel-titanium alloy wires from the support starting point B, and each nickel-titanium alloy wire is all bent at the support terminal C, and is mutually wound to the second end (i.e. the D end in Fig. 1) of particle support with the nickel-titanium alloy wire of adjacent group from the support terminal C, to form the second edge 102, and many second edges 102 constitute the second parallel portion together. Thus, by intertwining adjacent or opposing first edges 101 at end A and intertwining adjacent or opposing second edges 102 at end D, fixing portions 11 are formed at both ends of the particle support 10. Accordingly, all dispersed nickel-titanium alloy wires between the support starting point B and the support end point C collectively constitute the support portion 12. In other words, each of the first edges 101 is wound with two nickel-titanium alloy wires; and each of the second edges 102 is wound with two nickel-titanium alloy wires.

[0079] For example, the first first edge is wound by X11 and X12 (X11 and X12 are called "pair wires" to each other, the second first edge is wound by X21 and X22; the third first edge is wound by X31 and X32, and the fourth first edge is wound by X41 and X42. The first second edge is wound by Y11 and Y12, the second second edge is wound by Y21 and Y22; the third second edge is wound by Y31 and Y32, and the fourth second edge is wound by Y41 and Y42. At point B, X11 to X42 are divided into 8 nickel-titanium alloy wires (at right angles to the support). The structure extends circumferentially along the length of the frame); at point C, each is wound with an adjacent, non-paired nickel-titanium alloy wire to form a second edge. Taking the first edge as an example, at point B, the intertwined wires X11 and X12 are separated into single wires and dispersed circumferentially to form support portions 12. X11 is adjacent to X42, the fourth first edge. Thus, X11 and X42 are wound as Y11 and Y12, respectively, to form the first second edge. Similarly, X12 is adjacent to X21, the second edge. X12 and X21 are wound as Y21 and Y22, respectively, to form the second second edge.

[0080] More preferably, the first edge 101 and the second edge 102 are equal or nearly equal in length. This design allows the support portion to be located in the middle in the length direction, resulting in a better support effect.

[0081] It is understood that the fixing portions 11 at both ends of the particle holder 10 not only conform to the shape of the portal vein, thereby facilitating insertion into the portal vein, but also provide a certain degree of support to ensure the stability of the particle holder 10 and prevent displacement. Furthermore, because the central region of the particle holder 10 is formed with a circumferentially extending support portion 12, it is possible to prevent the central region of the particle holder 10 from collapsing or closing, thereby providing stable support for the radioactive particles and preventing displacement of the relative position of the radioactive particles and the cancer thrombus, thereby ensuring the effectiveness of radiotherapy.

[0082] In addition, in this embodiment, the plurality of first edges 101 and the plurality of second edges 102 are offset and parallel to each other, and a plurality of dispersed support wires are connected between the plurality of first edges 101 and the plurality of second edges 102, each of which is arranged in the circumferential direction of the particle holder 10 to collectively constitute the support portion 12. Thus, the support portion 12 can increase the supporting force of the two parallel portions, prevent the parallel portions from collapsing, and ensure that the two parallel portions have a certain supporting strength, thereby preventing radial deviation of the radioactive particles and affecting the dosage accuracy, thereby facilitating the precise arrangement of the radioactive particles.

[0083] In addition, in the above embodiment, preferably, the fixing portion 11 can elastically contract along the axial direction of the particle stent 10, and since the middle region of the particle stent forms two parallel portions, which have no compression-elongation characteristics in the length direction of the stent, the axial length of the parallel portions remains unchanged in both the compressed state and the expanded state, thereby ensuring reliable positioning of the particle-filled portion in the length direction of the stent. Thus, by radially compressing the particle stent 10, it is possible to facilitate delivery of the particle stent 10 into the cavity, and since the axial length of the particle stent 10 remains unchanged when changing between the contracted state and the expanded state, the radioactive particles mounted on the particle stent 10 will not be displaced, thereby facilitating precise radiotherapy of the radiation particle dose.

[0084] As shown in Figure 2, in the above embodiment, the monofilaments in the support portion 12 extend in both the length and circumferential directions of the stent, so the first edge 101 and the second edge 102 are offset and parallel (i.e., any one of the first edges 101 and any one of the second edges are not on the same straight line, but are offset from each other in the circumferential direction). This offset parallelism improves the radial support force of the stent. Therefore, preoperative planning can be performed through the radiotherapy planning system (TPS) to determine the particle dose size, which is conducive to the precise implementation of the particle dose. In addition, accurate postoperative assessment can be carried out to safely and effectively achieve the effect of internal radiotherapy.

[0085] In the above embodiment, preferably, as the length of the fixing portion 11 is shortened, the support strength of the particle holder 10 increases. It is understood that, because the supporting portion 12 provides support, the length of the fixing portion 11 can be shortened (appropriately reducing the support force), so that when multiple particle holders 10 are placed, adjacent particle holders can be closer together to avoid the possibility of radiotherapy being unable to be achieved due to excessive distance between adjacent particle holders 10 (such areas being unable to arrange radioactive particles), thereby improving the effectiveness of radiotherapy.

[0086] In the above embodiment, the particle capsule 151 is preferably made of vascular membrane or silicone, which facilitates compression of the particle capsule 151 for delivery into the cavity. Furthermore, the outer surface of the particle capsule 151 is coated with a superlubricating coating to reduce friction between the blood and the particle capsule 151, thereby preventing thrombosis and improving the safety of the particle stent implant. Furthermore, the inner surface of the particle capsule 151 is sprayed with a sustained-release targeted drug, allowing for simultaneous radiotherapy using radioactive particles and drug therapy using the sustained-release targeted drug, providing a more effective treatment option.

[0087] In the above embodiment, preferably, as shown in FIG3 , a first support grid 110 is formed between two adjacent first edges 101, and a second support grid 120 is formed between two adjacent second edges 102. The first support grid 110 and / or the second support grid 120 are each formed by interlacing multiple nickel-titanium alloy wires. The first support grid is formed by multiple nickel-titanium alloy wires interlaced between the first edges; the second support grid is formed by multiple nickel-titanium alloy wires interlaced between the second edges. Furthermore, in the circumferential direction of the stent, neither the first support grid nor the second support grid covers the entire circumference. For example, among the four first edges, the first support grid is formed between the first and second first edges; and the first support grid is formed between the third and fourth first edges. However, there is no first support grid between the second and third first edges, and between the first and fourth first edges. This design balances the stent design requirements of high support force (improving wall adhesion) and small radial size (facilitating delivery).

[0088] It is understood that the use of the first support grid 110 and the second support grid 120, in conjunction with the support portion 12, can further enhance the support strength of the particle stent 10, thereby ensuring the support effect of the particle stent 10 on the inner wall of the portal vein and preventing collapse or close-up of any position of the particle stent 10. In addition, in the above embodiment, preferably, structural reinforcement points 130 (only one reinforcement point is shown in FIG3 ) are also formed on the first support grid 110 and / or the second support grid 120 to further enhance the structural strength of the particle stent 10.

[0089] Second embodiment

[0090] As shown in FIG4 and FIG5 , the particle stent for portal vein provided by the second embodiment of the present invention is different from the first embodiment in that the particle stent has a different structure.

[0091] Specifically, in this embodiment, the plurality of first edges 101 correspond to the plurality of second edges 102 one-to-one, and each first edge 101 is located on the same straight line as the corresponding second edge 102. Furthermore, a dispersed support wire is formed between adjacent first edges 101. Each support wire is arranged in the circumferential direction of the particle support 10 to connect adjacent first edges 101, and all support wires together constitute the support portion 12.

[0092] It is understood that in this embodiment, the winding path of each nickel-titanium alloy wire is different from the winding path of each nickel-titanium alloy wire in the first embodiment, thus forming two different structural forms of particle stents. In this embodiment, the winding path of each nickel-titanium alloy wire can be adaptively set as needed, which is not elaborated in detail here. However, it is necessary to ensure that: first, the winding method cannot be too complicated; second, there can be no breakpoints or overlaps during the winding process; and third, the size of the particle stent after winding is required to be delivered into the portal vein.

[0093] In this embodiment, the functions of the fixing portion 11 and the supporting portion 12 are the same as those in the first embodiment, except that the specific structural forms are slightly different, which will not be elaborated here.

[0094] In addition, it should be noted that, since each first edge 101 is located on the same straight line as the corresponding second edge 102 , it is easier to sew the particle capsule 151 , thereby improving production convenience.

[0095] Third embodiment

[0096] As shown in FIG6 and FIG7 , the particle stent for portal vein provided by the third embodiment of the present invention is different from the first embodiment in that the structure of the particle stent 10 is different.

[0097] Specifically, in this embodiment, the plurality of first edges 101 are a plurality of mutually parallel first spiral threads, and the plurality of second edges 102 are a plurality of mutually parallel second spiral threads. Furthermore, the plurality of first spiral threads 101 and the plurality of second spiral threads 102 form a predetermined angle, and a plurality of support filaments are formed between the plurality of first spiral threads 101 and the plurality of second spiral threads 102. Each support filament is arranged circumferentially around the particle stent to collectively constitute the support portion 12. Here, the parallel first and second edges extend not only in the longitudinal direction but also in the circumferential direction.

[0098] In this embodiment, the functions of the fixing portion 11 and the supporting portion 12 are the same as those in the first embodiment, except that the specific structural forms are slightly different, which will not be elaborated here.

[0099] Fourth embodiment

[0100] As shown in FIG8 , a fourth embodiment of the present invention provides a seed stent kit for use in the portal vein, comprising the seed stent 10 of the first or second embodiment and a plurality of radioactive seeds 20. The seed stent 10 is delivered to the lesion site of the portal vein to support the portal vein; the plurality of radioactive seeds 20 are respectively filled into seed capsules 151 at specific locations based on preoperative TPS planning for radiotherapy.

[0101] In this embodiment, each particle capsule 151 is formed on the first edge 101 or the second edge 102 by a jet spinning or sewing process. Furthermore, a particle capsule 151 is provided at a specific interval (e.g., 10 mm) on the first edge 101 and the second edge 102, thereby forming a plurality of particle capsules 151 (e.g., 3 to 5). Each particle capsule 151 is sealed at one end and has a notch at a predetermined angle formed at the other end. This notch allows radioactive particles 20 to be loaded into the bottom of the particle capsule. This allows the number of radioactive particles loaded to be selected as needed to accommodate different radiotherapy situations.

[0102] It can be understood that in this embodiment, a support portion 12 can be formed on the particle bracket 10 to increase the supporting force of the particle bracket 10, and a particle capsule is formed around the first edge and / or second edge of the particle bracket 10 by cooperating with the jet spinning or sewing process, thereby ensuring that the particle bracket 10 has sufficient supporting strength and reducing the overall size of the particle bracket 10 to facilitate delivery.

[0103] It should be noted that the use of a jet spinning process to form particle capsules can improve the support of the parallel portions of the particle stent to increase the support force of the stent. The jet spinning process tightly and reliably attaches the fibers to the nickel-titanium alloy wire. The tightly attached fibers are equivalent to increasing the nickel-titanium alloy wire diameter, thereby improving the rigidity of the nickel-titanium alloy wire and then improving the support force of the parallel portions. Moreover, since the particle capsules formed by the jet spinning process are firmly connected to each other and are not easy to fall off or move, a particle capsule with a thinner thickness can be used, which is conducive to reducing the size of the stent (or increasing the number of the first edge and the second edge at the same size, thereby increasing the number of particle capsules, and then increasing the number of particles that can be loaded to improve the range and intensity of radiotherapy). The jet spinning process has the characteristics of a short process flow, and the fibers are directly made into cloth, thereby reducing the time and labor required in the sewing process and significantly improving production efficiency. Moreover, since the first edge and the second edge are disconnected by the supporting wire in the first embodiment of the present invention, it is impossible to sew the particle capsules on the first edge and the second edge simultaneously using a single sewing process, which requires sewing twice, increasing manufacturing costs. However, the use of jet spinning can form particle capsules on the first edge and the second edge simultaneously. For the parallel part of the spiral, since it is not a straight line, the sewing process is not applicable and only the jet spinning process can be used.

[0104] In this embodiment, the process of forming the radioactive particles 20 by jet spinning is as follows:

[0105] S1: Installing a preform mold on the first edge 101 and the second edge 102 in sequence; wherein the preform mold includes particles and a fixing structure, wherein the particles are larger than the radioactive particles and are made of a soluble or heat-meltable material, and the fixing structure fixes the particles on one side of the first edge 101 or the second edge 102;

[0106] S2: spraying a solution of the vascular membrane material onto each preformed mold in the form of a thread through a jet spinning device to form a particle capsule having a preset size that encapsulates the preformed mold;

[0107] S3: Pause for a preset time until each particle capsule is cooled and shaped;

[0108] S4: Immersing the entire particle support 10 in a special solution to completely dissolve the preformed mold, thereby exposing the capsule structure of the particle capsule;

[0109] S5: Cleaning the entire particle holder 10 to form a particle holder 10 having a plurality of particle capsules.

[0110] In the above embodiment, preferably, the particle stent kit also includes an expansion stent 30. Specifically, as shown in Figure 9, the expansion stent 30 is woven into a cylindrical shape so as to be in a contracted state under stress and in an expanded state under non-stress. Thus, the expansion stent 30 can be delivered to the inside of the particle stent 10 in a contracted state, and then released to provide sufficient supporting force to the particle stent in an expanded state. It can be understood that, as shown in Figure 10, in this embodiment, the expansion stent 30 is used as an auxiliary support tool. When the support strength of the particle stent 10 itself in a specific cavity cannot meet the support requirements, the expansion stent 30 can be inserted into the particle stent 10 to improve the support capacity of the particle stent 10.

[0111] It is understandable that the expansion stent 30 can directly use the internal stent commonly used in the art, which will not be described here.

[0112] In summary, the particle stent for portal vein provided by the embodiments of the present invention has the following technical effects:

[0113] 1. Able to achieve precise arrangement of radioactive particles.

[0114] First, the fixed parts at both ends of the particle stent have a mesh structure that is woven in a different way than the parallel parts in the middle area. Therefore, the supporting force of the fixed parts is greater, thereby making the supporting force at both ends of the stent stronger, thereby fixing the particle stent in the portal vein and preventing the stent from shifting.

[0115] Secondly, two or more parallel parts parallel to each other are formed in the middle area of ​​the particle holder, and each parallel part is arranged with a particle capsule for filling with radioactive particles; and the parallel parts are connected to each other with supporting wires to increase the supporting force of the two parallel parts, prevent the parallel parts from collapsing, and ensure that the parallel parts have a certain supporting strength, thereby avoiding radial deviation of the radioactive particles and affecting the dosage accuracy, and realizing the precise arrangement of the radioactive particles.

[0116] Third, the axial length of the seed stent remains unchanged in the compressed or expanded state, so the radioactive seeds in the seed capsule will not shift in position, thereby ensuring accurate positioning of the radioactive seeds and improving the radiotherapy effect.

[0117] Fourthly, since the particle stent has only a plurality of parallel portions and a plurality of particle capsules in the middle, the size is small in the contracted state, and is suitable for stent delivery in tortuous cavities.

[0118] Fifth, the jet-spinning process creates a dense and stable particle capsule with strong fiber connections, making it less likely to fall out of or shift relative to the parallel portion. Therefore, compared to sewing processes, the particle capsule is less likely to deform, damage, or shift during use, ensuring that the radioactive particles remain in the position planned before the TPS procedure.

[0119] 2. It can prevent the displacement of cancer thrombus.

[0120] First, the supporting wires connecting the two parallel parts can increase the supporting force of the parallel parts, which not only prevents the particle stent from shifting to reduce the detachment and metastasis of the cancer thrombus, but also uses the supporting force of the parallel parts to squeeze the particle capsule toward the inner wall of the cavity, thereby supporting and fixing the cancer thrombus to avoid the metastasis of the cancer thrombus under the action of blood flow.

[0121] Secondly, more preferably, a support grid may be provided in a partial area on the two parallel portions to support the cancer thrombus using the support grid, thereby improving the fixation effect on the cancer thrombus.

[0122] Third, if the support of the parallel parts is not sufficient to support the cancer thrombus, an internal stent can be released between the parallel parts for support, or a balloon can be used to expand the stent to ensure stable support for the cancer thrombus and prevent its displacement.

[0123] Fourthly, the particle capsule is formed by the jet spinning process, and the fiber is used to increase the supporting force of the parallel part to prevent the metastasis of cancer thrombus.

[0124] 3. The support wire is used to ensure that after the stent is released, both the end and the parallel part can adhere well to the wall (radial expansion) to maintain smooth blood flow; and the jet spinning process is used to reduce the thickness of the particle capsule, which is more conducive to improving the wall adhesion effect of the parallel part.

[0125] 4. Use jet spinning technology to improve production efficiency and reduce costs.

[0126] It should be noted that the above embodiments are only examples, and the technical solutions of the various embodiments can be combined and are all within the protection scope of the present invention.

[0127] It should be understood that the terms "thickness", "up", "down", "horizontal", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0128] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0129] The above describes in detail the particle stent for portal vein, particle stent for lumen, and kit provided by the present invention. Any obvious modification to the invention without departing from the essence of the invention will constitute an infringement of the patent rights of the present invention and will result in corresponding legal liability.

Claims

1. A particle stent for portal vein, woven from nickel-titanium alloy wire, characterized in that include: A fixing portion, comprising a first end and a second end, located at both ends of the particle holder, and used to fix the particle holder in the portal vein; a first parallel portion located in a middle region of the particle holder and close to the first end of the particle holder, the first parallel portion comprising a plurality of first edges parallel to a length direction of the particle holder; a second parallel portion located in a middle region of the particle holder and close to the second end of the particle holder, the second parallel portion comprising a plurality of second edges parallel to the length direction of the particle holder; a support portion connected between the first parallel portion and the second parallel portion, extending along the circumferential direction of the particle support to provide radial support force to the first edge and the second edge, each first edge or the second edge being wound by nickel-titanium alloy wire; a particle filling portion, comprising a plurality of particle capsules for filling with radioactive particles, wherein the plurality of particle capsules are evenly arranged on the first edge and the second edge; The first parallel portion and the second parallel portion are woven differently from the fixing portion, so that the fixing portion has a greater supporting force than the first parallel portion and the second parallel portion; and the first edge and the second edge are of equal length. Each group of nickel-titanium alloy wires are wound around each other from the first end to the support starting point to form the first edge; and the first edge is dispersed into two nickel-titanium alloy wires from the support starting point, each nickel-titanium alloy wire is bent at the support end point, and is wound around each other with the adjacent group of nickel-titanium alloy wires from the support end point to the second end to form the second edge.

2. The particle support according to claim 1, wherein: The plurality of first edges and the plurality of second edges are staggered and parallel to each other; A plurality of dispersed support wires are connected between the plurality of first edges and the plurality of second edges, and each of the support wires is arranged in a circumferential direction around the particle support to jointly constitute the support portion.

3. The particle support according to claim 1, wherein: The plurality of first edges correspond to the plurality of second edges one by one, and each of the first edges and the corresponding second edge are located on the same straight line; A plurality of dispersed support filaments are formed between the plurality of first edges and the plurality of second edges, and each of the support filaments is arranged in a circumferential direction around the particle support to jointly constitute the support portion.

4. The particle support according to claim 1, wherein: The plurality of first edges are a plurality of mutually parallel first spiral wires, and the plurality of second edges are a plurality of mutually parallel second spiral wires; The plurality of first spiral wires and the plurality of second spiral wires form a preset angle, and a plurality of dispersed support wires are formed between the plurality of first spiral wires and the plurality of second spiral wires, and each of the support wires is arranged in a circumferential direction around the particle support to jointly constitute the support portion.

5. The particle support according to any one of claims 1 to 4, characterized in that: The particle capsule is formed on the first edge and the second edge by using a jet spinning process, so as to increase the supporting force of the first edge and the second edge and reduce the thickness of the particle capsule.

6. The particle support according to claim 5, characterized in that The jet spinning process comprises the following steps: S1: installing a preforming mold on a first edge and a second edge in sequence; wherein the preforming mold includes particles and a fixing structure, wherein the particles are larger than the radioactive particles and are made of a soluble or heat-meltable material, and the fixing structure fixes the particles on one side of the first edge or the second edge; S2: spraying a solution of the vascular membrane material onto each preformed mold in the form of a thread through a jet spinning device to form a particle capsule having a preset size that encapsulates the preformed mold; S3: Pause for a preset time until each particle capsule is cooled and shaped; S4: Immerse the entire particle support in a special solution to completely dissolve the preformed mold, thereby exposing the capsule structure of the particle capsule; S5: Cleaning the entire particle scaffold to form a particle scaffold having a plurality of particle capsules.

7. The particle support according to claim 5, characterized in that: A first support grid is formed between two adjacent first edges, and a second support grid is formed between two adjacent second edges; The first support grid is a grid formed by winding a plurality of nickel-titanium alloy wires between the first edges; the second support grid is a grid formed by winding a plurality of nickel-titanium alloy wires between the second edges. In the circumferential direction of the stent, the first support grid and the second support grid do not cover the entire circumference.

8. A particle stent for a cavity, woven from metal wires, characterized in that include: A fixing portion, comprising a first end and a second end, located at both ends of the particle holder, and used to fix the particle holder in the portal vein; a first parallel portion located in a middle region of the particle holder and close to the first end of the particle holder, the first parallel portion comprising a plurality of first edges parallel to a length direction of the particle holder; a second parallel portion located in a middle region of the particle holder and close to the second end of the particle holder, the second parallel portion comprising a plurality of second edges parallel to the length direction of the particle holder; a supporting portion connected between the first parallel portion and the second parallel portion, extending along the circumferential direction of the particle holder to provide radial supporting force to the first edge and the second edge; The particle filling part includes a plurality of particle capsules for filling radioactive particles, wherein the plurality of particle capsules are evenly arranged on the first edge and the second edge. The first parallel portion and the second parallel portion are woven differently from the fixing portion, so that the fixing portion has a greater supporting force than the first parallel portion and the second parallel portion; Each group of metal wires is wound around each other from the first end to the support starting point to form the first edge; and the first edge is dispersed into two metal wires from the support starting point, each metal wire is bent at the support end point, and is wound around each other with the adjacent group of metal wires from the support end point to the second end to form the second edge.

9. The particle support according to claim 8, wherein: The particle capsule is formed on the first edge and the second edge by using a jet spinning process, so as to increase the supporting force of the first edge and the second edge and reduce the thickness of the particle capsule.

10. The particle support according to claim 9, wherein: A first support grid is formed between two adjacent first edges, and a second support grid is formed between two adjacent second edges; The first support grid is a grid formed by winding a plurality of nickel-titanium alloy wires between the first edges; the second support grid is a grid formed by winding a plurality of nickel-titanium alloy wires between the second edges. In the circumferential direction of the stent, the first support grid and the second support grid do not cover the entire circumference.

11. A particle support kit, characterized in that include: The particle stent for portal vein according to any one of claims 1 to 7, or the particle stent for cavity according to any one of claims 8 to 10; A plurality of radioactive seeds are used to be respectively filled into the seed capsules of the seed stent based on the TPS preoperative planning; The expandable stent is braided into a cylindrical shape so as to be in a contracted state when under stress and in an expanded state when not under stress; The expandable stent can be delivered into the particle stent in a contracted state and provide radial support force to the particle stent in an expanded state.

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