Disclosure of Invention
The invention aims to provide a particle bracket for portal vein.
Another technical problem to be solved by the present invention is to provide a particle scaffold for a lumen.
Another object of the present invention is to provide a particle scaffold kit comprising the particle scaffold.
In order to achieve the technical purpose, the invention adopts the following technical scheme:
according to a first aspect of an embodiment of the present invention, there is provided a particle scaffold for portal vein, woven from nitinol wires, comprising:
The fixing part comprises a first end and a second end, is positioned at two ends of the particle bracket and is used for fixing the particle bracket in a portal vein;
a first parallel portion located in a middle region of the particle scaffold and proximate to the first end of the particle scaffold, the first parallel portion comprising a plurality of first edges parallel to a length direction of the particle scaffold;
A second parallel portion located in a middle region of the particle scaffold and proximate to the second end of the particle scaffold, the second parallel portion comprising a plurality of second edges parallel to a length direction of the particle scaffold;
the support part is connected between the first parallel part and the second parallel part and extends along the circumferential direction of the particle bracket so as to provide radial supporting force for the first edge and the second edge, and each first edge or each second edge is formed by winding 2 nickel-titanium alloy wires;
The particle filling part comprises a plurality of particle capsules for filling radioactive particles, the particle capsules are uniformly distributed on the first edge and the second edge,
Wherein the first parallel part and the second parallel part are different from the fixed part in weaving mode, so that the supporting force of the fixed part is larger than that of the first parallel part and the second parallel part, the lengths of the first edge and the second edge are equal,
And the first edge is dispersed into two nickel-titanium alloy wires from the supporting starting point, each nickel-titanium alloy wire is bent at the supporting end point, and the nickel-titanium alloy wires are mutually wound to the second end from the supporting end point and an adjacent group of nickel-titanium alloy wires to form the second edge.
Wherein preferably, the first edges and the second edges are offset and parallel to each other;
A plurality of scattered supporting wires are connected between the first edges and the second edges, and each supporting wire is arranged around the circumferential direction of the particle bracket so as to jointly form the supporting part.
Preferably, the first edges and the second edges are in one-to-one correspondence, and each first edge and the corresponding second edge are positioned on the same straight line;
And a plurality of scattered supporting wires are formed between the first edges and the second edges, and each supporting wire is arranged around the circumferential direction of the particle bracket so as to jointly form the supporting part.
Preferably, the first edges are a plurality of first spiral threads parallel to each other, and the second edges are a plurality of second spiral threads parallel to each other;
The first spiral wires and the second spiral wires form a preset included angle, a plurality of scattered supporting wires are formed between the first spiral wires and the second spiral wires, and each supporting wire is arranged around the circumferential direction of the particle bracket so as to jointly form the supporting part.
Wherein preferably, the particle capsule is formed on the first edge and the second edge by adopting 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.
Wherein preferably, the jet spinning process comprises the steps of:
S1, sequentially installing a preformed mould on a first edge and a second edge, wherein the preformed mould comprises particles and a fixing structure, the particles are larger than the radioactive particles in size and are soluble or heat-fusible materials, and the fixing structure fixes the particles on one side of the first edge or the second edge;
s2, spraying a solution of vascular membrane material on each preforming die in a silk thread mode through spray spinning equipment to form particle capsules of a capsule preforming die with preset size;
S3, stopping for a preset period of time until each particle capsule is cooled and shaped;
s4, immersing the whole particle bracket in a special solution to completely dissolve the preformed mould so as to expose the saccular structure of the particle capsule;
S5, cleaning the whole particle scaffold to form the particle scaffold with a plurality of particle capsules.
Preferably, a first supporting grid is further formed between two adjacent first edges, and a second supporting grid is further formed between two adjacent second edges;
Wherein the first support grid is a grid formed by a plurality of nickel-titanium alloy wires wound between the first edges, the second support grid is a grid formed by a plurality of nickel-titanium alloy wires wound 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.
According to a second aspect of embodiments of the present invention, there is provided a particle scaffold for a lumen, woven from wire, comprising:
The fixing part comprises a first end and a second end, is positioned at two ends of the particle bracket and is used for fixing the particle bracket in a portal vein;
a first parallel portion located in a middle region of the particle scaffold and proximate to the first end of the particle scaffold, the first parallel portion comprising a plurality of first edges parallel to a length direction of the particle scaffold;
A second parallel portion located in a middle region of the particle scaffold and proximate to the second end of the particle scaffold, the second parallel portion comprising a plurality of second edges parallel to a length direction of the particle scaffold;
The support part is connected between the first parallel part and the second parallel part and extends along the circumferential direction of the particle bracket so as to provide radial supporting force for the first edge and the second edge;
The particle filling part comprises a plurality of particle capsules for filling radioactive particles, the particle capsules are uniformly distributed on the first edge and the second edge,
The first parallel part and the second parallel part are different from the fixed part in weaving mode, so that the supporting force of the fixed part is larger than that of the first parallel part and the second parallel part;
And the first edge is dispersed into two metal wires from the supporting starting point, each metal wire is bent at the supporting ending point, and the metal wires of the adjacent group are mutually wound to the second end from the supporting ending point to form the second edge.
Wherein preferably, the particle capsule is formed on the first edge and the second edge by adopting 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.
Preferably, a first supporting grid is further formed between two adjacent first edges, and a second supporting grid is further formed between two adjacent second edges;
Wherein the first support grid is a grid formed by a plurality of nickel-titanium alloy wires wound between the first edges, the second support grid is a grid formed by a plurality of nickel-titanium alloy wires wound 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.
According to a third aspect of embodiments of the present invention, there is provided a particle scaffold kit comprising:
A particle scaffold for portal vein as previously described, or for a lumen as previously described;
a plurality of radioactive particles for filling in particle pockets of the particle scaffold, respectively, based on a TPS (treatment planning system) preoperative planning;
An expandable stent which is knitted in a tubular shape to be in a contracted state in a stressed state and in an expanded state in a non-stressed state;
Wherein the expanded stent is capable of being delivered within the particle stent in a contracted state and providing radial support force to the particle stent in an expanded state.
Compared with the prior art, the invention has the following technical effects:
1. can realize the accurate arrangement of the radioactive particles.
First, the mesh structure that the fixed part that has at the both ends of particle support, for the parallel portion in middle region, adopt different weaving modes to obtain, consequently the holding power of fixed part is bigger to make the supportability at support both ends stronger, thereby can fix the particle support in the portal vein, prevent that the support from shifting.
Two or more parallel parts parallel to each other are formed in the middle area of the particle support, particle sacs for filling the radioactive particles are distributed on each parallel part, and supporting wires are connected between the parallel parts to increase the supporting force of the two parallel parts, prevent the parallel parts from collapsing and ensure that the parallel parts have certain supporting strength, thereby avoiding the radial deflection of the radioactive particles to influence the dosage precision and realizing the accurate distribution of the radioactive particles.
Thirdly, the axial length of the particle bracket is unchanged at the compression state or the expansion state, so that the radioactive particles in the particle capsules cannot shift in position, the accurate positioning of the radioactive particles is ensured, and the radiotherapy effect is improved.
Fourth, since the middle portion of the particle scaffold has only a plurality of parallel portions and a plurality of particle capsules, the size is small in a contracted state, and the particle scaffold is suitable for scaffold delivery in a tortuous lumen.
Fifth, more preferably, the particle bag formed by adopting the jet spinning process has compact and stable structure, firm connection between fibers and difficult occurrence of the phenomenon of falling off from the parallel part or displacement relative to the parallel part. Therefore, compared with the sewing technology, the particle capsule is not easy to deform, damage or shift in the use process, so that the radioactive particles are kept at the planned position before TPS operation, and the accuracy is improved.
2. Can avoid cancer plug displacement.
Firstly, the supporting force of the two parallel parts can be increased through the supporting wires which are connected with each other between the two parallel parts, so that the particle capsules are extruded to the inner wall of the cavity by the supporting force of the parallel parts, and then the cancer plug is supported and fixed, so that the metastasis of the cancer plug under the action of blood flow is avoided.
Secondly, it is more preferable that a supporting grid is further provided in a partial region on the two parallel portions so as to support the cancer plug by the supporting grid, thereby improving the fixing effect on the cancer plug.
Thirdly, if the supportability of the parallel parts is insufficient to support the cancer plug, an inner bracket can be released between the parallel parts for supporting, or the bracket is expanded by using a balloon, so that the stable support of the cancer plug is ensured, and the displacement of the cancer plug is avoided.
Detailed Description
The technical contents of the present invention will be described in detail with reference to the accompanying drawings and specific examples.
The particle stent and the kit for portal vein provided by the embodiment of the invention can be used in the lumen, including blood vessels, airways, urethra, cervix uteri and the like, and only the portal vein is taken as an example for illustration, but the invention is not limited thereto.
It is well known that obstruction of portal blood flow is one of the main causes of portal hypertension, and that portal pressure increases, creating side branch circulation. Therefore, portal stents are required to ensure blood flow patency and avoid the induction or aggravation of portal hypertension due to the stent. In other words, the stent as a whole (whether at the ends or in the middle of the stent) needs to have sufficient adhesion to ensure that the stent has minimal impact on the flow rate of the blood flow. Moreover, tortuosity of the portal vein results in greater stent design difficulties (high stent compliance during delivery; high stent support force during release). Therefore, the conventional grid-shaped vascular stent is often insufficient in supporting force and easy to fall off after implantation. For this reason, the particle scaffold for portal vein provided by the embodiment of the invention can solve the problems.
First embodiment
As shown in fig. 1and 2, a particle scaffold 10 for portal vein according to a first embodiment of the present invention includes 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, the supporting portion 12, the first parallel portion 13, the second parallel portion 14, and the particle filling portion 15 are all distributed in the circumferential direction of the particle scaffold, thereby not only avoiding obstruction of blood flow, but also ensuring delivery of the expanded scaffold to the interior of the particle scaffold (described in detail later).
Specifically, in the present embodiment, the fixing portions 11 are located at both ends of the particle scaffold 10 and match the size of the portal vein for fixing the particle scaffold 10 in the portal vein. In a released state (expanded state) free from an external force, the fixing portion 11 is knitted in a manner different from the parallel portions so that the supporting force of the fixing portion is greater than the first and second parallel portions. By adopting the design, after the fixing part 11 is released in the portal vein, the supporting force on the inner wall of the cavity is larger, so that the positioning effect is better. However, since the supporting force of the first parallel portion and the second parallel portion is smaller than that of the fixed portion, and the particle capsules and the radioactive particles are fixed, the first parallel portion and the second parallel portion are difficult to expand in the radial direction.
The first parallel portion 13 is located in the middle region of the particle support 10 near the first end (i.e. the a-end in fig. 1) of the particle support, and the first parallel portion 13 comprises a plurality of first edges 101 parallel to the length direction of the support. The second parallel portion 14 is located in the middle region of the particle support 10 near the second end (i.e. end D in fig. 1) of the particle support, and the second parallel portion 14 comprises a plurality of second edges 102 parallel to the length of the support. The support portion 12 is connected between the first and second parallel portions 13 and 14 for supporting the inner wall of the meatus of the portal vein such that the plurality of first edges 101 remain parallel and the plurality of second edges 102 remain parallel. The particle filling part 15 includes a plurality of particle capsules 151 for filling radioactive particles, and the plurality of particle capsules 151 are uniformly arranged on the first edge 101 and the second edge 102. The first and second parallel edges extend only in the longitudinal direction and do not extend in the circumferential direction. The first and second parallel edges extend only in the longitudinal direction and do not extend in the circumferential direction. By the design, the length of the first parallel part and the length of the second parallel part are not changed in the length direction, namely the bracket has no axial shrinkage phenomenon.
In this embodiment, the particle scaffold 10 is woven in a cylindrical shape from a plurality of nitinol wires 1 such that both ends of the particle scaffold are respectively formed with fixing portions 11, and a middle portion of the particle scaffold is formed with a supporting portion 12 for supporting an inner wall of a portal vein. Each nitinol wire 1 corresponds to a preset path, so that each nitinol wire can be wound and formed according to the preset path. The nickel-titanium alloy wires with coincident paths are mutually wound into a whole to form edges, each nickel-titanium alloy wire 1 is bent at the middle part of the particle bracket 10 to form a supporting wire with a preset length, and all the supporting wires positioned at the middle part of the particle bracket jointly form a supporting part 12.
Specifically, in the present embodiment, the plurality of nitinol wires of the particle beam 10 are equally divided into a plurality of groups. The nickel-titanium alloy wire is described only as an example, but the number of other wires (magnesium alloy) nickel-titanium alloy wires may be 2 times the number of parallel portions. Namely, each first edge or each second edge in the parallel part is wound by 2 nickel-titanium alloy wires. Each set of nitinol wires is intertwined from a first end (i.e., end a in fig. 1) of the particle scaffold 10 to a support starting point (i.e., point B in fig. 1) to form a first edge 101, the plurality of first edges 101 together forming a first parallel portion. The first edges 101 are separated into two nitinol wires from the support starting point B, each nitinol wire is bent at the support ending point C, and the nitinol wires from the support ending point C and the adjacent group of nitinol wires are intertwined to the second end (i.e., the D end in fig. 1) of the particle bracket to form the second edges 102, and the plurality of second edges 102 together form the second parallel portion. Thus, the fixing portions 11 are formed at both ends of the particle holder 10, respectively, by intertwining the adjacent or opposite first edges 101 at the a end and the adjacent or opposite second edges 102 at the D end. Accordingly, all of the dispersed nitinol wires between the support start point B and the support end point C together constitute the support 12. In other words, each of the first edges 101 is wound with 2 nitinol wires, and each of the second edges 102 is wound with 2 nitinol wires.
For example, the 1 st first edge is wound by X11 and X12 (X11 and X12 are mutually called as "paired filaments", the 2 nd first edge is wound by X21 and X22; the 3 rd first edge is wound by X31 and X32; the 4th first edge is wound by X41 and X42. The 1 st second edge is wound by Y11 and Y12; the 2 nd second edge is wound by Y21 and Y22; the 3 rd second edge is wound by Y31 and Y32; the 4th second edge is wound by Y41 and Y42. At point B, X11-X42 is divided into 8 nickel titanium alloy filaments (extending in the circumferential direction perpendicular to the length direction of the stent) and at point C, respectively, the 1 nickel titanium alloy filaments adjacent to and not paired filaments are wound as second edges. At point B, as an example, the X11 and X12 wound together are divided into filaments and dispersed in the circumferential direction into a supporting part 12, wherein the X11 and the 4th edges X21 and X42 are wound as adjacent to X21 and X12, respectively, and the X21 and X42 are wound as adjacent to X21 and X12, respectively.
More preferably, the lengths of the first edge 101 and the second edge 102 are equal or nearly equal, and the supporting part is positioned in the middle of the length direction by the design, so that the supporting effect is better.
It can be appreciated that the fixing portions 11 at both ends of the particle bracket 10 can be shaped to conform to the shape of the portal vein so as to be convenient to extend into the portal vein, and the fixing portions 11 can also provide a certain supporting effect to ensure the stability of the particle bracket 10 and prevent the bracket from being displaced. In addition, since the support portion 12 extending in the circumferential direction is formed in the middle region of the particle support 10, the middle region of the particle support 10 can be prevented from collapsing or gathering, thereby providing stable support for the radioactive particles, preventing the relative positions of the radioactive particles and the cancer plug from being shifted, and further ensuring the radiation treatment effect.
In addition, in the present embodiment, the first edges 101 and the second edges 102 are offset and parallel to each other, and a plurality of dispersed supporting wires are connected between the first edges 101 and the second edges 102, and each supporting wire is disposed around the circumferential direction of the particle stand 10 to jointly form the supporting portion 12. Therefore, the supporting force of the two parallel parts can be increased by utilizing the supporting part 12, the collapse of the parallel parts is prevented, and the two parallel parts are ensured to have certain supporting strength, so that the influence on the dosage precision caused by radial deflection of the radioactive particles is avoided, and the accurate arrangement of the radioactive particles is facilitated.
Further, in the above-described embodiment, it is preferable that the fixing portion 11 is elastically contractible in the axial direction of the particle scaffold 10, and since the middle region of the particle scaffold forms two parallel portions which have no compressive elongation characteristic in the scaffold length direction, the axial length of the parallel portions is kept unchanged in either the compressed state or the expanded state, thereby ensuring reliable positioning of the particle filling portion in the scaffold length direction. Therefore, the particle stent 10 can be delivered into the cavity by radially compressing the particle stent 10, and the radial length of the particle stent 10 is unchanged when the particle stent 10 is changed between the contracted state and the expanded state, so that the radioactive particles mounted on the particle stent 10 cannot be shifted, thereby being beneficial to accurate radiotherapy of the dosage of the radioactive particles.
As shown in fig. 2, in the above embodiment, the monofilaments in the support portion 12 extend in both the length direction and the circumferential direction of the stent, and thus the first edge 101 and the second edge 102 are offset in 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). The dislocation is parallel, and the radial supporting force of the bracket is improved. Therefore, the particle dose size can be determined by preoperative planning by the radiation therapy planning system (TPS, treatment Planning System), thereby facilitating accurate implementation of the particle dose. And moreover, accurate postoperative evaluation can be performed, and the effect of internal radiotherapy can be safely and effectively exerted.
In the above embodiment, it is preferable that the supporting strength of the particle scaffold 10 increases as the length of the fixing portion 11 is shortened. It will be appreciated that, due to the support provided by the support 12, the length of the fixing portion 11 may be shortened (the support is suitably reduced) so that when a plurality of particle holders 10 are placed, the adjacent particle holders may be more closely spaced to avoid that the distance between the adjacent particle holders 10 is too large (the radiation particles cannot be arranged in this area) to achieve radiation therapy, which is advantageous for improving the radiation therapy effect.
In the above embodiment, the particle bag 151 is preferably made of a vascular membrane material or a silica gel material, so as to facilitate compression of the particle bag 151 for the entire delivery into the lumen. And, the outer surface of the particle capsule 151 is coated with a super-lubrication coating to reduce friction between blood and the particle capsule 151, thereby avoiding thrombus formation and improving the safety of implantation of the particle stent. In addition, the inner surface of the particle pocket 151 is also sprayed with a slow-release targeting drug, so that the radioactive particle can be used for radiotherapy and the slow-release targeting drug can be used for drug treatment at the same time, thereby providing a more effective treatment scheme.
In the above embodiment, preferably, as shown in fig. 3, a first supporting grid 110 is further formed between two adjacent first edges 101, and a second supporting grid 120 is further formed between two adjacent second edges 102. Wherein, the first support grid 110 and/or the second support grid 120 are formed by interlacing a plurality of nickel titanium alloy wires. The first support grid is a grid formed by a plurality of nickel-titanium alloy wires wound between the first edges, and the second support grid is a grid formed by a plurality of nickel-titanium alloy wires wound between the second edges. Moreover, in the circumferential direction of the bracket, neither the first support grid nor the second support grid covers the entire circumference, for example, of 4 first edges, a first support grid is formed between the 1 st and 2 nd first edges, and a first support grid is formed between the 3 rd and 4 th first edges. But there is no first support grid between the 2 nd and 3 rd, and 1 st and 4 th first edges. The design combines the design requirements of a stent with larger supporting force (improving adherence) and smaller radial dimension (facilitating delivery).
It can be appreciated that, by using the first support grid 110 and the second support grid 120, the supporting strength of the particle bracket 10 can be further improved by the cooperation of the supporting portion 12, so as to ensure the supporting effect of the particle bracket 10 on the inner wall of the portal vein, and avoid collapsing or gathering any position of the particle bracket 10. In addition, in the above embodiment, it is preferable that the first support grid 110 and/or the second support grid 120 further have structural reinforcing points 130 (only one reinforcing point is shown in fig. 3) formed thereon to further increase the structural strength of the particle scaffold 10.
Second embodiment
As shown in fig. 4 and 5, a particle scaffold for portal vein according to a second embodiment of the present invention is different from the first embodiment in the structural form of the particle scaffold.
Specifically, in the present embodiment, the first edges 101 and the second edges 102 are in one-to-one correspondence, and each first edge 101 and the corresponding second edge 102 are located on the same straight line. And, a dispersed supporting wire is formed between the adjacent first edges 101. Each support wire is arranged around the circumference of the particle scaffold 10 to connect adjacent first edges 101, all support wires together constituting the support 12.
It will be appreciated that in this embodiment, the winding path of each nitinol wire is different from that of the first embodiment, and thus, two different structural forms of the particle scaffold are formed. In this embodiment, the winding path of each nitinol wire may be adaptively set according to the need, which is not described herein, but it is guaranteed that the first winding mode cannot be too complex, the second winding mode cannot be broken or overlapped, and the third winding mode requires that the size of the particle scaffold after the winding is completed can be delivered into the portal vein.
In this embodiment, the functions of the fixing portion 11 and the supporting portion 12 are the same as those of the first embodiment, except for a slight difference in specific structural form, which is not specifically described herein.
In addition, it should be noted that, since each first edge 101 and the corresponding second edge 102 are located on the same straight line, sewing of the particle capsules 151 is more convenient, and convenience of production is improved.
Third embodiment
As shown in fig. 6 and 7, a third embodiment of the present invention provides a particle scaffold for portal vein, which is different from the first embodiment in the structural form of the particle scaffold 10.
Specifically, in the present embodiment, the first edges 101 are first spiral threads parallel to each other, and the second edges 102 are second spiral threads parallel to each other. And, the first spiral threads 101 and the second spiral threads 102 form a preset included angle, and a plurality of supporting threads are formed between the first spiral threads 101 and the second spiral threads 102, and each supporting thread is arranged around the circumferential direction of the particle bracket to jointly form the supporting part 12. The first and second parallel edges extend not only in the longitudinal direction but also in the circumferential direction.
In the present embodiment, the functions of the fixing portion 11 and the supporting portion 12 are the same as those of the first embodiment, except for a slight difference in specific structural form, which is not specifically described herein.
Fourth embodiment
As shown in fig. 8, a fourth embodiment of the present invention provides a particle scaffold kit for portal vein, comprising the particle scaffold 10 of the first or second embodiment and a plurality of radioactive particles 20. Wherein the particle scaffold 10 is for delivery to a lesion site of a portal vein to support the portal vein, and a plurality of radioactive particles 20 are respectively filled in particle sacs 151 at specific positions based on a TPS preoperative plan for radiation treatment.
In this embodiment, each particle capsule 151 is formed on the first edge 101 or the second edge 102 by a process of jet spinning or sewing, and one particle capsule 151 is disposed on each of the first edge 101 and the second edge 102 at a specific distance (e.g., 10 mm) therebetween, so that a plurality of particle capsules 151 (e.g., 3 to 5 particle capsules) are formed. One end of each particle capsule 151 is closed, and the other end forms a cut at a preset angle, so that the radioactive particles 20 can be filled into the bottom of the particle capsule from the cut, and the quantity of the radioactive particles can be selected according to the needs, so as to adapt to the radiotherapy of different situations.
It can be appreciated that in this embodiment, the supporting portion 12 may be formed on the particle stand 10 to increase the supporting force of the particle stand 10, and the particle capsules are formed around the first edge and/or the second edge of the particle stand 10 in combination with the jet spinning or sewing process, so that the overall size of the particle stand 10 can be reduced to facilitate delivery while ensuring that the particle stand 10 has sufficient supporting strength.
It should be noted that the formation of the particle capsules by the jet spinning process can improve the supportability of the parallel portions of the particle scaffold to increase the supporting force of the scaffold. The spray spinning technology is used for tightly and reliably attaching the fibers to the nickel-titanium alloy wires, and the diameters of the nickel-titanium alloy wires are increased by the tightly attached fibers, so that the rigidity of the nickel-titanium alloy wires is improved, and the supporting force of the parallel parts is further improved. Moreover, because the particle bag fibers formed by the spray spinning process are firmly connected and are not easy to fall off or move, the particle bag with thinner thickness can be used, which is beneficial to reducing the size of the bracket (or increasing the number of the first edge and the second edge under the same size, thereby increasing the number of the particle bags and further increasing the number of loadable particles so as to improve the radiation treatment range and strength). The jet spinning process has the characteristic of short process flow, and the fabric is directly formed by the fibers, so that the time and labor force required in the sewing process are reduced, and the production efficiency is remarkably improved. In addition, since the first edge and the second edge are disconnected by the supporting wire in the first embodiment of the invention, the particle capsules cannot be sewn on both the first edge and the second edge at the same time by utilizing one sewing process, thus two times of sewing are needed, and the manufacturing cost is increased. However, the use of jet spinning allows the formation of particle pockets on both the first and second edges. For the parallel parts of the spiral, the sewing process is not applicable because of being not straight, and only the jet spinning process can be adopted.
In this embodiment, the process of forming the radioactive particles 20 by jet spinning is as follows:
S1, sequentially installing a preformed mould on a first edge 101 and a second edge 102, wherein the preformed mould comprises particles and a fixed structure, the particles are larger than the radioactive particles in size and are soluble or heat-fusible materials, and the fixed structure fixes the particles on one side of the first edge 101 or the second edge 102;
s2, spraying a solution of vascular membrane material on each preforming die in a silk thread mode through spray spinning equipment to form particle capsules of a capsule preforming die with preset size;
S3, stopping for a preset period of time until each particle capsule is cooled and shaped;
s4, immersing the whole particle bracket 10 in a special solution to completely dissolve the preformed mould so as to expose the saccular structure of the particle capsule;
S5, cleaning the whole particle scaffold 10 to form the particle scaffold 10 with a plurality of particle capsules.
In the above embodiments, the particle stent kit preferably further comprises an expansion stent 30. Specifically, as shown in fig. 9, the stent 30 is woven in a tubular shape so as to be contracted in a stressed state and expanded in an unstressed state. Thus, the expanded stent 30 can be delivered inside the particle stent 10 in a contracted state and then released to provide sufficient support force to the particle stent in an expanded state. It will be appreciated that in the present embodiment, as shown in fig. 10, the stent 30 is used as an auxiliary supporting tool, and the supporting capability of the particle beam 10 can be improved by inserting the stent 30 into the particle beam 10 when the supporting strength of the particle beam 10 itself cannot meet the supporting requirement in a specific channel.
It will be appreciated that the stent 30 may be selected from the group consisting of inner stents commonly used in the art, and will not be described in detail herein.
In summary, the particle scaffold for portal vein provided by the embodiment of the invention has the following technical effects:
1. can realize the accurate arrangement of the radioactive particles.
First, the mesh structure that the fixed part that has at the both ends of particle support, for the parallel portion in middle region, adopt different weaving modes to obtain, consequently the holding power of fixed part is bigger to make the holding power at support both ends stronger, thereby can fix the particle support in the portal vein, prevent that the support from shifting.
Two or more parallel parts parallel to each other are formed in the middle area of the particle support, particle sacs for filling the radioactive particles are distributed on each parallel part, and supporting wires are connected between the parallel parts to increase the supporting force of the two parallel parts, prevent the parallel parts from collapsing and ensure that the parallel parts have certain supporting strength, thereby avoiding the radial deflection of the radioactive particles to influence the dosage precision and realizing the accurate distribution of the radioactive particles.
Thirdly, the axial length of the particle bracket is unchanged at the compression state or the expansion state, so that the radioactive particles in the particle capsules cannot shift in position, the accurate positioning of the radioactive particles is ensured, and the radiotherapy effect is improved.
Fourth, because the particle stent is provided with a plurality of parallel parts and a plurality of particle sacs in the middle, the particle stent has small size in a contracted state and is suitable for stent delivery in a tortuous cavity.
Fifth, more preferably, the particle bag formed by adopting the jet spinning process has compact and stable structure, firm connection between fibers and difficult occurrence of the phenomenon of falling off from the parallel part or displacement relative to the parallel part. Therefore, compared with the sewing process, the particle capsule is not easy to deform, damage or shift during the use process, so that the radioactive particles are kept at the planned position before TPS operation.
2. Can avoid cancer plug displacement.
Firstly, through the supporting wire of interconnect between two parallel portions can increase the holding power of parallel portion, both avoided the particle support to shift in order to reduce cancer bolt and drop the metastasis, utilize the holding power of parallel portion again with the granule bag to the extrusion of cavity inner wall, and then play the fixed effect of support to cancer bolt to avoid taking place cancer bolt metastasis under the blood flow effect.
Secondly, it is more preferable that a supporting grid is further provided in a partial region on the two parallel portions so as to support the cancer plug by the supporting grid, thereby improving the fixing effect on the cancer plug.
Thirdly, if the supportability of the parallel parts is insufficient to support the cancer plug, an inner bracket can be released between the parallel parts for supporting, or the bracket is expanded by using a balloon, so that the stable support of the cancer plug is ensured, and the displacement of the cancer plug is avoided.
Fourthly, the spray spinning process is adopted to form the particle capsule, and the fiber is utilized to increase the supporting force of the parallel part, so that the metastasis of cancer embolism is avoided.
3. The support wire is used for ensuring that the support can be well adhered to the end part or the parallel part (radial expansion) after being released, so that the blood flow is kept smooth, and the particle bag thickness is reduced by adopting the jet spinning process, so that the adhesion effect of the parallel part is more beneficial to being improved.
4. The jet spinning technology is utilized to improve the production efficiency and reduce the cost.
It should be noted that the above embodiments are only examples, and the technical solutions of the embodiments may be combined, which are all within the protection scope of the present invention.
It should be understood that the terms "thickness," "upper," "lower," "horizontal," and the like indicate an orientation or positional relationship based on that shown in the drawings, and are merely for convenience in describing and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the invention.
Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present invention, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.
The particle scaffold for portal vein, the particle scaffold for cavity and the kit thereof provided by the invention are described in detail. Any obvious modifications to the present invention, without departing from the spirit thereof, would constitute an infringement of the patent rights of the invention and would take on corresponding legal liabilities.