CN116269966A - Delivery assembly and stent delivery system with same - Google Patents

Abstract

The application relates to a delivery assembly, which comprises a core wire, a pushing piece, a jogging piece and a clamping piece; the pushing piece, the jogged piece and the clamping piece are sequentially arranged at the position of the core wire close to the distal end along the direction from the proximal end to the distal end of the core wire; the distal end of the pushing piece is provided with a pushing table for pushing the bracket; the maximum length of the jogged piece in the radial direction of the core wire is smaller than the maximum length of the pushing piece and the clamping piece in the direction, so that a jogged groove is formed between the pushing piece and the clamping piece, and the jogged groove is suitable for being clamped and fixed with the proximal end of the bracket. Through advancing piece gomphosis piece and joint spare that sets up in order at the axial of core silk, and the radial length of gomphosis piece is minimum to realize forming the gomphosis groove between advancing piece and joint spare, so that with the support phase-match that the near-end has the development portion, in the transportation, the person of implementing in the art moves through the core silk drive advancing piece, realizes the support is delivered to the distal end to the butt platform of advancing piece.

Description

Delivery assembly and stent delivery system with same

Technical Field

The application relates to the technical field of medical instruments, in particular to a delivery assembly and a stent conveying system with the same.

Background

Minimally invasive interventional surgery is a common treatment means for treating intracranial aneurysms, and the main treatment technology for the intracranial aneurysms currently comprises different methods such as spring coil stuffing, stent graft implantation, stent-assisted spring coil stuffing, blood flow guiding devices and the like.

However, for some more complex intracranial aneurysms, such as large and giant saccular aneurysms, wide carotid aneurysms, fusiform and dissection aneurysms, the intraoperative treatment is complex, the intraoperative and postoperative complications rate is high, and the postoperative recurrence rate is high. So the traditional spring ring or stent auxiliary spring ring filling technology is used for treatment, the time consumption in the operation is long, the neck of the aneurysm is difficult to be completely blocked, and the aneurysm is not completely blocked; while most of the film covered stent is difficult to be used for bending blood vessels, in-place is difficult, and siphon bending and above parts are not applicable; blood flow guiding devices, which are currently popular in the market, are increasingly favored by doctors due to their better compliance, neck covering effect and blood flow guiding capability.

Further, the adherence effect, mechanical properties and positioning rivets of blood flow guiding devices are always important points of clinical interest. At present, complications caused by a blood flow guiding device after operation are mostly stenoses in a stent, namely, the stent is not adhered to the wall due to insufficient mechanical properties, so that the radial opening and supporting capability of the braided stent are particularly critical.

The mechanical performance of the dense net stent at the focus is closely related to the arrival capacity. The method has great significance on reducing the resistance of the stent in the conveying process, stabilizing the structure of the stent and improving the clinical treatment effect after the stent is in place. Based on this, a stent with good mechanical properties and delivery effect and a delivery system thereof are needed to improve the treatment effect of the above lesions.

Disclosure of Invention

In view of the above, the present application provides a delivery assembly including a core wire, a pushing member, a fitting member and a clamping member; the pushing piece, the jogged piece and the clamping piece are sequentially arranged at the position of the core wire close to the distal end along the direction from the proximal end to the distal end of the core wire; the distal end of the pushing piece is provided with a pushing table for pushing the bracket; the maximum length of the embedded piece in the radial direction of the core wire is smaller than the maximum length of the pushing piece and the clamping piece in the direction, so that an embedded groove is formed between the pushing piece and the clamping piece, and the embedded groove is suitable for being clamped and fixed with the proximal end of the bracket.

In one possible implementation, the device further comprises a friction boosting member; the friction boosting piece is of a circular tube structure and is located at the far end of the clamping piece, the radial length of the friction boosting piece is larger than that of the clamping piece, and the radial length of the friction boosting piece is smaller than that of the boosting piece.

In one possible embodiment, the pushing element, the engagement element, the locking element and the friction aid are arranged concentrically on the core wire.

In one possible implementation manner, the friction boosting member is made of a polymer material, and the friction boosting member is adhered and fixed with the core wire.

In one possible implementation, the clamping member is a hollow tube structure.

In one possible implementation, the clamping member is a gear structure.

In one possible implementation, the end surfaces between the pushing element and the jogging element, between the jogging element and the clamping element, and between the clamping element and the friction boosting element, which are adjacent to each other, are in contact; the propelling piece is fixedly connected with the core wire; the embedded piece is fixedly connected with the core wire; the clamping piece is fixedly connected with the core wire.

In another aspect, the present application also provides a stent delivery system comprising a delivery assembly, a binding cavity, and a braided body as described in the above implementations; the delivery assembly fits into the restraint cavity in mating relationship with the braided body; the braiding main body is of a double-layer structure and comprises an inner layer pipe and an outer layer pipe, and the outer layer pipe is sleeved on the periphery of the inner layer pipe; the braiding wires of the inner layer tube and the braiding wires of the outer layer tube are mutually wound and fixed at the end part of the braiding main body; and a plurality of developing parts are arranged at least at the proximal end of the braiding main body along the circumferential direction, and the braiding main body is clamped and fixed with the jogged groove through the developing parts.

In one possible implementation, the braided body is divided in its axial direction into a proximal delivery segment, a middle choke segment and a distal opening segment; the braiding wires of the inner layer tube are twisted with the braiding wires of the outer layer tube on the proximal end side of the middle flow blocking section, and the twisting part is the proximal end conveying section; the braiding wires of the inner layer tube are twisted with the braiding wires of the outer layer tube at the far end side of the middle flow blocking section, and the twisting part is the far end opening section; the braiding layers of the outer layer pipe and the inner layer pipe are arranged in staggered layers at the middle flow blocking section.

In one possible implementation, both ends of the braided body are of a closed twist structure; the braiding wires of the inner layer pipe are adjacent to the first braiding wires and/or the second braiding wires, and are twisted and fixed at the two ends of the braiding main body in the same direction or opposite directions to form a closed twisting structure.

In one possible implementation manner, in the proximal conveying section, the braided wires of the inner layer tube and the braided wires of the outer layer tube are twisted and fixed in the same direction or opposite directions at two end positions of the braided main body to form a closed twisting structure; or in the proximal conveying section, part of the braiding wires of the inner layer tube and the first braiding wires and/or the second braiding wires are twisted and fixed at the two ends of the braiding main body in the same direction or opposite directions to form a semi-closed twisting structure.

In one possible implementation, two adjacent closed twist structures are arranged offset along the circumference of the braiding body.

In one possible implementation, the developing part is a cylindrical structure, and the developing part is a developing material.

In one possible implementation manner, the outer layer tube is provided with more than two first braiding wires along a first direction, and more than two second braiding wires along a second direction, and the first braiding wires and the second braiding wires are interwoven along a first preset angle; the outer tube is provided with a cross-weave structure disposed between at least partially adjacent first weave filaments and/or between at least partially adjacent second weave filaments.

In one possible implementation, the cross-weave structure is uniformly laid over the outer tube.

In one possible implementation, the material of the braided wire is nickel-titanium material containing a developing material or cobalt-chromium material containing a developing material.

In one possible implementation manner, the outer layer tube is woven by nickel-titanium woven wires and platinum woven wires in a mixed mode, or the outer layer tube is woven by cobalt-chromium woven wires and the platinum woven wires in a mixed mode; the inner layer tube is woven by nickel-titanium woven wires and platinum woven wires in a mixed mode, or the inner layer tube is woven by cobalt-chromium woven wires and platinum woven wires in a mixed mode; two kinds of knitting yarns with different materials are uniformly distributed in the circumferential direction of the knitting main body respectively.

In one possible implementation, when the outer tube is woven by nickel-titanium woven wire or cobalt-chromium woven wire and the platinum woven wire, the wire diameter of the platinum woven wire is larger than the wire diameter of the nickel-titanium woven wire or the cobalt-chromium woven wire.

In one possible implementation, the woven body has a different pore density; wherein the braided body comprises a dense braided section and at least one of the sparse braided sections; the dense braid segment has a void density greater than the void density of the sparse braid segment.

In one possible implementation, when the braided body is released into a blood vessel, the braided body is pushed, the braided body is capable of forming dense protrusions at tumor diameter positions, and the pore density of the dense protrusions is greater than that of the rest positions of the braided body.

In one possible implementation, during release, the sidewall of the braided body being released makes an angle of between 45-75 degrees with the axial direction of the stent.

In one possible implementation, the ratio of the length of the developing portion in the axial direction of the knitted body to the total axial length of the knitted body is 1:200-1:20.

In one possible implementation, the woven body is integrally formed.

The beneficial effects of this application: through advancing piece gomphosis piece and joint spare that set up in order at the axial of core silk, and the radial length of gomphosis piece is minimum for realize forming the gomphosis groove between advancing piece and joint piece, the gomphosis groove can cooperate with the support that has the development part in the proximal end, accomplishes the joint fixedly. In the conveying process, a person in the field drives the pushing member to move through the core wire, so that the support is pushed to the far end by the abutting table of the pushing member. The relative sliding between the bracket and the conveying guide wire is effectively avoided, the transmission efficiency of conveying force is improved, the loss of force value is avoided, and the clinical conveying resistance is further reduced.

When the stent is pressed into the introducing sheath, under the conditions of the same metal coverage rate and the same number of braiding heads, the total length of the compressed state of the double-layer stent is shorter than that of the single-layer stent, and the shortening rate is lower, so that the friction force between the stent and the wall of a guide tube in the pushing process is reduced, the reduction of the conveying resistance of a worker in clinic is obviously facilitated, and meanwhile, the shortening of the compressed state of the whole length is obviously reduced when the stent is released, so that the positioning and the release of the stent by the worker are more facilitated; in addition, compared with the traditional stent, the metal coverage rate of the double-layer braided stent can be 1.0 times or more than that of the original stent, and the double-layer braided stent is also obviously helpful for improving the compact blocking of the tumor neck and guiding the blood flow direction. In sum, in the double-layer braided stent, the outer layer tube is provided with a cross braided structure, so that the double-layer braided stent has the remarkable characteristics of high radial supporting force, high metal coverage rate and low shrinkage rate, has higher blood flow guiding capability, and has certain advantages for treating hemorrhagic aneurysm diseases in clinical use.

Other features and aspects of the present application will become apparent from the following detailed description of exemplary embodiments, which proceeds with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate exemplary embodiments, features and aspects of the present application and together with the description, serve to explain the principles of the present application.

FIG. 1 illustrates a partial enlarged view of a delivery device and stent assembly according to an embodiment of the present application;

FIG. 2 illustrates a schematic side view of a delivery device and stent assembly of an embodiment of the present application;

FIG. 3 shows a schematic perspective view of a delivery device according to an embodiment of the present application;

FIG. 4 illustrates a partial enlarged view of a delivery device and stent assembly of an embodiment of the present application;

FIG. 5 illustrates a partial enlarged view of a delivery device and stent assembly according to another embodiment of the present application;

FIG. 6 is a schematic diagram illustrating a stent delivery system according to an embodiment of the present application releasing a stent;

FIG. 7 shows a schematic view of a double-layered braided stent of an embodiment of the present application in an aneurysm location;

FIG. 8 shows a schematic view of a stent delivery system of an embodiment of the present application at the location of an aneurysm;

FIG. 9 shows a block diagram of a clip according to an embodiment of the present application;

FIG. 10 shows a schematic structural view of a double-layered woven stent having woven layers of different pore densities according to an embodiment of the present application;

FIG. 11 is a schematic cross-sectional view of a double-layer woven stent with an outer layer tube woven with a blend of different materials according to an embodiment of the present application;

FIG. 12 is a schematic side view showing the structure of a cross-weave structure of an outer layer tube according to an embodiment of the present application;

fig. 13 is a schematic side view showing a side structure of an outer tube according to another embodiment of the present application;

FIG. 14 illustrates a partial enlarged view of a cross-weave structure according to an embodiment of the present application;

FIG. 15 shows a partial schematic view of a cross-weave structure according to a first embodiment of the application;

FIG. 16 shows a partial schematic view of a cross-weave structure according to a second embodiment of the application;

FIG. 17 shows a partial schematic view of a cross-weave structure according to a third embodiment of the application;

FIG. 18 illustrates a partial schematic view of the cross-weave structure of FIG. 12 according to the present application;

FIG. 19 shows a partial schematic view of a cross-weave structure according to a fourth embodiment of the application;

FIG. 20 shows a partial schematic view of a cross-weave structure according to a fourth embodiment of the application on the side of an outer tube;

FIG. 21 shows a schematic structural view of a double-layered braided stent in an aneurysmal vessel according to an embodiment of the present application;

FIG. 22 shows a schematic side view of a double-woven stent according to an embodiment of the present application;

FIG. 23 illustrates a side partial enlarged view of an end of a double-layered braided stent in a closed twist configuration in accordance with an embodiment of the present application;

FIG. 24 is an axial view of the embodiment shown in FIG. 23;

FIG. 25 illustrates a side partial enlarged view of an end portion of a double-layered braided stent in a closed loop configuration in accordance with an embodiment of the present application;

FIG. 26 is an axial view of the embodiment shown in FIG. 25;

FIG. 27 shows an enlarged partial view of a closed twist structure with the ends of a double woven stent in a staggered arrangement in accordance with an embodiment of the present application;

FIG. 28 illustrates a partial enlarged view of a semi-closed twist structure with the ends of a double woven stent in a staggered arrangement in accordance with an embodiment of the present application;

FIG. 29 shows a partial enlarged view of a closed loop structure with end portions of a double woven stent in a staggered arrangement in accordance with an embodiment of the present application;

FIG. 30 illustrates a partial schematic view of a braided wire of an embodiment of the present application in preparing a closed loop structure at the end of a mandrel.

Detailed Description

Various exemplary embodiments, features and aspects of the present application will be described in detail below with reference to the accompanying drawings. In the drawings, like reference numbers indicate identical or functionally similar elements. Although various aspects of the embodiments are illustrated in the accompanying drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

It should be understood, however, that the terms "center," "longitudinal," "transverse," "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counter-clockwise," "axial," "radial," "circumferential," and the like indicate or are based on the orientation or positional relationship shown in the drawings, and are merely for convenience of description or to simplify the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be configured and operated in a particular orientation, and therefore should not be construed as limiting the present application.

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 application, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

The word "exemplary" is used herein to mean "serving as an example, embodiment, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

In addition, numerous specific details are set forth in the following detailed description in order to provide a better understanding of the present application. It will be understood by those skilled in the art that the present application may be practiced without some of these specific details. In some instances, methods, means, elements, and circuits have not been described in detail as not to unnecessarily obscure the present application.

As shown in fig. 1-30, a delivery assembly is presented herein, comprising: acore wire 601, an advancingmember 602, afitting member 603 and a clampingmember 604; the pushingmember 602, thefitting member 603 and the clampingmember 604 are sequentially arranged at a position close to the distal end of thecore wire 601 along the direction from the proximal end to the distal end of thecore wire 601; the distal end of the pushingmember 602 has a pushing table for pushing the stent; the maximum length of thejogger 603 in the radial direction of thecore wire 601 is smaller than the maximum length of the pushingmember 602 and the clampingmember 604 in the direction, so that a jogging groove is formed between the pushingmember 602 and the clampingmember 604, and the jogging groove is suitable for being clamped and fixed with the proximal end of the bracket.

Through thethrust piece 602, thejogged piece 603 and theclamping piece 604 that set up in the axial of core silk in order, and the radial length ofjogged piece 603 is minimum for realize forming the jogged groove betweenthrust piece 602 and clampingpiece 604, the jogged groove can cooperate with the support that has thedevelopment part 300 in the proximal end, accomplishes the joint fixedly. During the conveying process, a person skilled in the art drives the pushing member to move through thecore wire 601, so that the support is pushed to the distal end by the abutting table of the pushingmember 602. The relative sliding between the bracket and the conveying guide wire is effectively avoided, the transmission efficiency of conveying force is improved, the loss of force value is avoided, and the clinical conveying resistance is further reduced.

In one embodiment, thefriction assisting member 605 is further included, thefriction assisting member 605 is in a circular tube structure and is located at the distal end of the clampingmember 604, the radial length of thefriction assisting member 605 is greater than the radial length of the clampingmember 604, and the radial length of thefriction assisting member 605 is less than the radial length of the pushingmember 602.

In this embodiment, afriction booster 605 is further fixed on thecore wire 601 in a penetrating manner, thefriction booster 605 is located at the distal end of theclamping piece 604 and is fixed to thecore wire 601, thefriction booster 605 may contact with the distal end of theclamping piece 604, or thefriction booster 605 and theclamping piece 604 are both fixed to thecore wire 601 only with a certain interval therebetween, and only the outer peripheral side wall of thefriction booster 605 needs to be ensured to be attached to the inner wall of the bracket, so that the friction between thefriction booster 605 and the braiding main body is increased, and the delivery work to the distal end is facilitated.

In one embodiment, the friction booster is made of a polymer material, and thefriction booster 605 is bonded and fixed to thecore wire 601.

In this embodiment, thefriction booster 605 made of a polymer material has a large surface roughness, so that the friction force between thefriction booster 605 and the bracket can be further increased. Particularly in a curved blood vessel, the section of the blood vessel at the curved position is a non-circular structure which tends to be flat, when the blood vessel is delivered to the distal end, the embedded structure is positioned and clamped with thebraided body 100, and when the structure is excessively bent in the tortuous blood vessel, the delivery of the stent is not facilitated only from the proximal end of the stent, but also thefriction boosting piece 605 is additionally arranged, the delivery force point is increased from the inside of thebraided body 100, the matching between the proximal end and the inner wall of thebraided body 100 and the double force point is realized, and the double-layer braided stent is more beneficial to the completion of pushing the double-layer braided stent to the distal end in the curved blood vessel.

In one embodiment, thepusher 602, the fitting 603, theclip 604, and thefriction booster 605 are disposed concentrically on the core wire 60601.

In this embodiment, the developing part is inserted through thecore wire 601, and the clampingmember 604 on thewoven body 100 is clamped and embedded on the outer periphery of the clampingmember 604, that is, the clampingmember 604 is located in the embedding groove.

In one embodiment, theclip 604 is a hollow tube structure.

As shown in fig. 9a and 9b, in one embodiment, the clampingmember 604 is a gear structure.

In this embodiment, the clampingmember 604 is a gear structure, usually a spur gear, and the braided wires on the side of the bracket near the proximal end are clamped in the tooth space, so that the proximal end of the bracket and the clampingmember 604 can be clamped and fixed by this design, and the retracting function is achieved.

Moreover, the gear structure of theclamping piece 604 can ensure that the developing part at the proximal end of the bracket is kept still in the circumferential direction compared with the hollow tube structure, so that the force transmission efficiency is higher during conveying, and the conveying resistance is reduced. When the gear is retracted, the clamping capacity of the gear is stronger than that of the outer wall of the tubular structure, and the retraction stability is higher.

It should be noted that, no matter what the structure of the clampingmember 604 is, the maximum length of the clampingmember 604 in the radial direction of thecore wire 601 is smaller than that of the pushingmember 602 and the clampingmember 604, so that at least a certain clamping capability of the clampingmember 604 is ensured.

In one embodiment, adjacent end surfaces of the pushingmember 602 and thefitting member 603, between thefitting member 603 and the clampingmember 604, and between the clampingmember 604 and thefriction assisting member 605 are in contact; the pushingpiece 602 is fixedly connected with thecore wire 601; thejogger 603 is fixedly connected with thecore wire 601; theclamping piece 604 is fixedly connected with thecore wire 601.

Thefriction boosting piece 605 made of high polymer materials is adhered and fixed on thecore wire 601, and thefriction boosting piece 605 made of metal materials with rough outer walls can be fixed on thechild core wire 601 in a welding mode.

The application also provides a stent conveying system, includingdelivery subassembly 600,restraint chamber 700 and weavemain part 100 in the embodiment that thedelivery subassembly 600 and weavemain part 100 assorted assembly torestraint intracavity 700, wherein, weavemain part 100 and be bilayer structure, includinginlayer pipe 111 andouter pipe 101, the periphery ofinlayer pipe 111 is established toouter pipe 101 cover, the braided wire ofinlayer pipe 111 and the braided wire ofouter pipe 101 twine fixedly each other at the tip of weavingmain part 100, and be provided with a plurality of developingparts 300 along the circumferencial direction at least at the proximal end of weavingmain part 100, weavemain part 100 and be fixed through developingpart 300 and gomphosis groove joint.

In another aspect, the present application discloses a stent delivery system comprising adelivery assembly 600, abinding lumen 700, and abraided body 100;delivery assembly 600 fits into bindingcavity 700 in mating relation withbraided body 100; wherein, the braidingmain body 100 has a double-layer structure and comprises aninner layer tube 111 and anouter layer tube 101, and theouter layer tube 101 is sleeved on the periphery of theinner layer tube 111; the braided wires of theinner tube 111 and the braided wires of theouter tube 101 are intertwined and fixed at the end of thebraided body 100; at least at the proximal end of theknitted fabric body 100, a plurality of developingunits 300 are provided in the circumferential direction, and theknitted fabric body 100 is engaged with the fitting grooves by the developingunits 300.

The application also discloses this double-deck support of weaving includes: abraided body 100, wherein thebraided body 100 has a double-layer structure, and comprises aninner layer tube 111 and anouter layer tube 101, and theouter layer tube 101 is sleeved on the outer periphery of theinner layer tube 111; theouter tube 101 is provided with more than twofirst braiding wires 1011 along a first direction and more than twosecond braiding wires 1012 along a second direction, thefirst braiding wires 1011 and thesecond braiding wires 1012 being interwoven along a first preset angle; the braiding wires of the adjacentinner tube 111 are fixed to both ends of thebraiding body 100 with thefirst braiding wires 1011 and/or thesecond braiding wires 1012; theouter tube 101 has disposed thereon across-braid structure 102, thecross-braid structure 102 being disposed between at least partially adjacentfirst braid wires 1011 and/or thecross-braid structure 102 being disposed between at least partially adjacentsecond braid wires 1012.

In this embodiment, the double-layered braided stent in which the inner and outer layer structures are stable is constructed by fitting theouter layer tube 101 around the outer periphery of theinner layer tube 111 and fixing the braided wires of the two-layered structure at both ends thereof. And this application also carries out the cross braiding in the braided structure ofouter tube 101, forms special "cross braiding structure 102" onouter tube 101 to make the braided wire of different directions (i.e. thefirst braided wire 1011 of first direction and thesecond braided wire 1012 of second direction) produceextra cross point 201, increase the frictional force between many wires, thereby improve and weave the holistic radial holding power ofmain part 100, so that the double-deck braided stent of this application has better mechanical properties. In short, the method of increasing the number of the crossing points 201 of the braiding wires in theouter layer tube 101 without changing the number of the braiding wires improves the radial force of the braiding stent, can effectively avoid the possibility of stenosis complication in the stent, and has certain advantages for treating thehemorrhagic aneurysm 500 diseases in clinic.

Moreover, the double-layer braided stent of this application compares in single-layer support structure, under the same circumstances of braiding silk number, metal coverage rate and porosity, its axially shortened length is only about half of single-layer support structure, and the easy art person is in the position release of art, and the release position of support is more easy to control, reduces the operation degree of difficulty of operation.

More specifically, when the stent is pressed into the introducer sheath, the compression state stent is more easily shortened than the traditional single-layer stent in terms of the shortening degree of the stent, so that the stent has remarkable help to reduce the conveying resistance of an operator in clinic, and in addition, the double-layer braided stent has the metal coverage rate which is 1.0 times or more than that of the traditional stent, so that the stent can improve the compact blocking of the tumor neck and guide the blood flow trend. In sum, in the double-layer braided stent, theouter layer tube 101 is provided with thecross-braided structure 102, so that the stent has the remarkable characteristics of high radial supporting force, high metal coverage rate and low shrinkage rate, has higher blood flow guiding capability, and has certain advantages for treatinghemorrhagic aneurysm 500 diseases in clinical use.

It should be specifically explained that the double-layer braided stent in the present application has consistent metal coverage and porosity compared to the conventional single-layer braided stent, and is braided to the same axial length, and each braided wire of the double-layer braided stent is wound in the circumferential direction with a smaller wire length than that of the single-layer braided stent; so that the total length of the double-layer braided stent is smaller than that of the traditional single-layer braided stent in the lumen compressed into the same inner diameter; based on this, release is in the blood vessel of same diameter, the axial length variation of double-deck support is littleer, and the short volume of shrinking of double-deck establishment support is littleer promptly, and the operator carries out the support release operation, and the variation of support axial length is littleer, and the operator easily holds the release position of support to reduce the operation degree of difficulty that the operator carried out the operation.

The preset angle α between the first direction and the second direction referred to herein is: when theouter tube 101 is unfolded in a plane, the firstknitted filaments 1011 in the first direction form an angle with the secondknitted filaments 1012 in the second direction. Twist is herein intended to be: and winding and binding two or more adjacent braided wires.

It should be further noted that, theinner tube 111 is a conventional braided stent, such as a single-use stent, which can better achieve the blood guiding effect and the blood blocking at the tumor diameter, but has insufficient support, and long-term use has the risk of intravascular stenosis. And the outer layer tube structure of this application is like the exclusive use, because of having unconventional alternately weavingstructure 102 on its lateral wall, the hole of this structural position weaving layer is great, though has better supporting role, but can't realize the tight shutoff effect of conventional close net support in alternately weaving the position, so design this kind of double-deck weaving support, when realizing that the inlayer has better water conservancy diversion effect, outer support is guaranteed to the support whole better supportability to compared withsingle inlayer tube 111, bilayer structure's mesh has further improved the blood water conservancy diversion function of support. And under the condition that the number of the braided wires, the metal coverage rate and the porosity are consistent, the double-layer bracket has the advantage of small shrinkage compared with the single-layer bracket.

In one embodiment, the double-layered braided stent is formed such that the braided filaments of theouter tube 101 are intertwined with the braided filaments of theinner tube 111 at least at the proximal end position, and a plurality of adjacent braided filaments are fixed by the developingportions 300 to form a plurality of developingportions 300 uniformly distributed along the circumferential direction thereof at the proximal end of the stent. The delivery device in this application is particularly suitable for such a double-layered braided stent with a developingportion 300 at the proximal end, and the developingportion 300 at the proximal end can mechanically engage with the engaging groove of the delivery assembly to fix the double-layered braided stent and thedelivery assembly 600 in thebinding cavity 700.

In one embodiment, when thewoven body 100 is released into a blood vessel, thewoven body 100 is pushed, thewoven body 100 can form adense protrusion 103 at the tumor diameter, and the pore density at thedense protrusion 103 is greater than the pore density at the rest of thewoven body 100.

In this embodiment, as shown in fig. 7, when the double-layer braided stent covers the position of the tumor neck, an operator can push thedelivery assembly 600 to make the double-layer stent generate stacking protrusions, specifically, formdense protrusions 103 with a convex arc surface structure on the side wall of thebraided body 100, so as to achieve the effect of more densely blocking the double-layer braided stent at the position of the tumor neck.

In one embodiment, as shown in fig. 8, thelumen 700 of the double stent and the fillingdelivery tube 702 of the intratumoral filling 800 may be delivered to the lesion site via thesame access catheter 701. Under these conditions, the double stent can be half-released to the site of the aneurysm, followed by the tamponade of theaneurysm 500 with theintratumoral filler 800. At this time, the support of the fillingmaterial 800 in the aneurysm can be realized through the stent, and the rest part of the double-layer stent is released after the fillingmaterial 800 is completely filled, so that theaneurysm 500 is further blocked.

In one embodiment, the double-layer stent is delivered to the position of 10-15 mm far from the focus through the binding cavity, then the binding cavity is stabilized and the delivery device is pushed, so that the marking end of the double-layer stent is pushed out from the binding cavity and is opened to be attached to the vascular wall; and then the double-layer stent conveying system is wholly retracted until the marking end of the double-layer stent is positioned at the position of 5-6 mm far from the focus, then the delivery device is fixed, the binding cavity is retracted, the diversion main body of the double-layer stent is naturally expanded and attached to the vascular wall, the focus aneurysm neck is gradually covered, the binding cavity can be fixed and the advancing device is pushed to enable the double-layer stent to be tightly blocked at the tumor neck, then the advancing device is continuously fixed and the binding cavity is retracted until the delivery end of the double-layer stent is released from the binding cavity and attached to the vascular wall at the near end of the focus aneurysm.

Further, in the process of releasing the double-layer stent and in the process of retracting the binding cavity, the length of the double-layer stent in the blood vessel is 60% -90% of the retracting distance, the length of the double-layer stent is gradually reduced along with the length increase and the outer diameter increase in the stent specification, and the minimum length can be 60%.

In this embodiment, with the double braided stent described in this application, the required length in the axial direction of the stent is longer than conventional stents during its pushing out of the catheter to fully attach the vessel wall.

More specifically, in one embodiment, during release, the sidewall of the braided body being released forms an angle β between 45-75 degrees with the axial direction of the stent.

Briefly, as shown in fig. 5, in the process of releasing the double-layer braided structure to completely attach to the vessel wall, the stent structure at the releasing part is in a sharp cone shape, and the ordinary braided stent can be immediately attached to the wall after being pushed out, so that the shape is round, and the double-layer braided structure is in a cone structure in releasing, compared with the ordinary stent which is attached to the wall after being released, the double-layer braided structure is easier for a surgeon to carry out withdrawing operation.

In one embodiment, the ratio of the length of the developing part in the axial direction of the woven body to the total axial length of the woven body is 1:200-1:20.

In this embodiment, it can be understood that the developing part is located in the embedding groove, so that the operator can always perform the retracting operation, that is, when the released length of the stent is 90% and 95% of the total length of the stent, the operator can perform the retracting operation again, and still can perform the retracting operation, so that the more suitable releasing position is reselected, and the operation is more friendly to the operator.

Further, the braid wires of the adjacentinner tube 111 are fixed to both ends of thebraid body 100 with thefirst braid wires 1011 and/or thesecond braid wires 1012. The axial lengths of theinner layer tube 111 and theouter layer tube 101 are the same, and the braiding wires of theinner layer tube 111 and the braiding wires of theouter layer tube 101 are fixed at the two ends of the braidingmain body 100, so that theinner layer tube 111 and theouter layer tube 101 do not displace in the axial direction of the braidingmain body 100, a plurality of connection points between theinner layer tube 111 and theouter layer tube 101 are ensured, and the overall structure is more stable.

In one embodiment, the braided filaments of theinner tube 111 and the braided filaments of theouter tube 101 adjacent thereto are twisted around each other at the end of thebraided body 100 to form a closed end at the end of thebraided body 100.

In one embodiment, thewoven body 100 is integrally formed.

In this embodiment, the yarn carrier for processing the inner layer tube and the yarn carrier for processing the outer layer tube are simultaneously woven from the same side of the weaving mandrel, so as to prepare a double-layer woven support with the inner layer tube and the outer layer tube twisted and fixed at the ends, and the specific processing mode can be directly implemented by a person skilled in the art, so that the description thereof is omitted herein.

In one embodiment, one strand of thecross-woven structure 102 is formed by multiple crossing of two cross-woven wires along a first direction to form multiplefirst crossing points 2011, and the secondwoven wire 1012 is threaded between two adjacentfirst crossing points 2011, or multiple crossing of two cross-woven wires along a second direction to form multiple second crossing points 2012, and the first wovenwire 1011 is threaded between two adjacent second crossing points 2012.

In this embodiment, compared with the conventional stent braiding structure, thecross braiding structure 102 in theouter layer tube 101 in the present application forms more intersecting points 201 through the mutually intersecting braiding wires under the same number of braiding wires, so that the radial force of the whole formed stent is effectively improved, the stent is easier to open in thearterial vessel 400, the wall attachment and anchoring effect is better, and the anti-kink capability is better.

It should be specifically noted that, theintersection point 201 is two intersecting braided wires arranged in the same direction, and the intersection point is theintersection point 201 by alternating the upper and lower relationship of the intersecting braided wires; further, the interweavingpoints 202 referred to herein are all points of intersection where thecross-woven structure 102 intersects with one braided wire in an opposite direction.

In one specific embodiment, the braiding direction of the braiding wires in theinner tube 111 is the same as the braiding direction of the braiding wires in theouter tube 101, wherein theinner tube 111 is provided with more than two third braiding wires 1111 in the first direction, more than two fourth braiding wires 1112 in the second direction, and the third braiding wires 1111 and the fourth braiding wires 1112 are interwoven in the first preset angle. Theinner tube 111 is generally woven by a conventional method, and only two ends of the inner tube are twisted and fixed with theouter tube 101, so that theinner tube 111 will not be described in detail herein.

In this embodiment, therefore, the predetermined angle α is: when theouter tube 101 is unfolded in a plane, the firstknitted wire 1011 in the first direction and the secondknitted wire 1012 in the second direction form an angle; and an angle formed between the third knitted yarn 1111 in the first direction and the fourth knitted yarn 1112 in the second direction when theinner tube 111 is unfolded in a plane. The knitting structure of theinner tube 111 and the knitting structure of theouter tube 101 are identical to each other, except that the surface of theouter tube 101 has thecross knitting structure 102, and the knitting structures of theinner tube 111 and theouter tube 101 are identical to each other.

In one embodiment, the total number of braided filaments on theouter tube 101 is an even number; the number of thefirst knitting yarn 1011 and the number of thesecond knitting yarn 1012 are the same, and the number of the intersecting knitting yarn in the first direction and the number of the intersecting knitting yarn in the second direction are the same.

In this embodiment, the distribution of thecross-woven structure 102 determines the number ofcross-points 201 of theouter tube 101, i.e. the radial force of the stent. The distribution of thecross-weave structures 102 in the stent may be varied, desirably, theouter tube 101 has a weave wire count of m=2n, where m is an even number greater than or equal to 4, and n is the weave wire count in one of the first and second directions in the stent.

In one embodiment, thecross-weave structure 102 is uniformly distributed over theouter tube 101.

In one embodiment, as shown in fig. 12, the number of strands of thecross-weave structure 102 is generally even and may be two strands evenly distributed over the outer tube 101 (as shown in fig. 12).

As shown in fig. 13, the two cross-braid wires incross-braid structure 102 may be crossed in such a way that one is over and the other is under; or one can be under and the other can be on top. The braiding track of the braiding wires around the circumference of the stent is a cycle, and in the cycle, two crossed braiding wires can form a multi-time crossedbraiding structure 102 according to a certain distribution rule.

In one particular embodiment, the spacing between twofirst filaments 1011 or twosecond filaments 1012 provided with thecross-woven structure 102 is greater than the spacing between the remaining adjacent filaments.

In one embodiment, the braiding wires arranged in the first direction and the braiding wires arranged in the second direction are braiding wires in different directions from each other, and theintersection point 202 is the intersection point of thecross-braiding structure 102 and the braiding wires in the different directions; the number offirst crossover points 2011 or the number ofsecond crossover points 2012 of a strand ofcross-woven structure 102 is equal to or less than the number of interweavingpoints 202 of thecross-woven structure 102 with filaments of different directions.

The number of intersectingpoints 201 at which two intersecting filaments can form an intersecting weave in one cycle is an integer a, and the number of interlacingpoints 202 between two intersecting filaments and filaments in different directions is b, so that a is not more than b.

As shown in fig. 15, in one embodiment, a=b, that is, two cross-knitting yarns are interwoven with the same knitting yarn in different directions 1 time and then cross-knitting is performed;

as shown in fig. 16, in one embodiment, a=b/2, that is, two cross-knitting yarns are interwoven with the same knitting yarn in different directions 2 times respectively and then cross-knitting is performed;

as shown in fig. 17, in one embodiment, a=b/3, two cross-knitting yarns are interwoven with the same yarn in different directions 3 times, and then the cross-knitting is performed.

Further, two cross-knit wires in the second direction may also form thecross-knit structure 102 simultaneously with two cross-knit wires in the first direction.

In one specific embodiment, a=b/2, two cross-knitting yarns in the first direction and the second direction are interwoven 2 times, and then cross-knitting is performed respectively, so as to form a structure as shown in fig. 18;

in one embodiment, two adjacentfirst braiding wires 1011 are arranged to cross in a first direction and have the same structure as thecross braiding structure 102; two adjacentsecond filaments 1012 are arranged crosswise in the second direction and have the same structure as thecross-weave structure 102.

Further, across-weave structure 102 may be formed between t sets of weave filaments in the stent, t.ltoreq.n.

In one embodiment, the set of t=b/2 wires in the stent are interwoven with each other and then cross-woven to form the structure shown in fig. 18 and 20, and briefly, fig. 20 is a partial schematic view of theouter tube 101 shown in fig. 18.

As shown in fig. 12, in this embodiment, thefirst braiding wires 1011 in the first direction and thesecond braiding wires 1012 in the second direction form a predetermined angle α in the range of 20 ° -160 °.

Further, in one embodiment, in theouter tube 101, thefirst filaments 1011 in the first direction form the same angle with the axial direction of theknitted body 100 as thesecond filaments 1012 in the second direction form the same angle with the axial direction of theknitted body 100. In other words,first braid wires 1011 in the first direction andsecond braid wires 1012 in the second direction are symmetrically disposed along the axis ofbraid body 100.

In another embodiment, in theinner tube 111, an angle formed between the third filaments 1111 in the first direction and the axial direction of theknitted body 100 and an angle formed between the fourth filaments 1112 in the second direction and the axial direction of theknitted body 100 are symmetrically arranged along the axis of theknitted body 100.

In one embodiment, thewoven body 100 is axially divided into aproximal delivery segment 121, a middleflow blocking segment 122, and adistal opening segment 123, the woven filaments of theinner tube 111 are twisted with the woven filaments of theouter tube 101 on the proximal side of the middleflow blocking segment 122, the twisted portion is theproximal delivery segment 121, the woven filaments of theinner tube 111 are twisted with the woven filaments of theouter tube 101 on the distal side of the middleflow blocking segment 122, and the twisted portion is thedistal opening segment 123.

In this embodiment, the proximal conveyingsection 121 and thedistal opening section 123 are formed by twisting the braiding wires of theinner tube 111 and the braiding wires of theouter tube 101, so as to ensure that theinner tube 111 and theouter tube 101 are respectively twisted and fixed from the proximal end side and the distal end side, respectively, and the braiding layers of theouter tube 101 and theinner tube 111 located in themiddle choke section 122 are arranged in a staggered manner, that is, the braiding wires of theinner tube 111 and the braiding wires of theouter tube 101 are not overlapped in the radial direction of thebraiding body 100 at the same position of the side wall of thebraiding body 100.

It should be specifically explained here that the braid of theouter tube 101 and the braid of theinner tube 111 are staggered at the position of themiddle choke section 122, which means that: in themiddle choke section 122 of theknitted body 100, the knitted layer of theinner layer tube 111 is attached to the knitted layer of theouter layer tube 101, and the two knitted layers are staggered and non-overlapped in the circumferential direction of theknitted body 100, so that the knitted pores of theknitted body 100 are more compact through the knitted structure of the staggered layers, thereby realizing effective and durable embolization of theaneurysm 500.

More specifically, theinner layer tube 111 and theouter layer tube 101 are arranged in a staggered manner, and only if the braiding directions in the inner layer tube and the outer layer tube are the same (both braiding in the first direction and the second direction), the inner braiding layer and the outer braiding layer can be always kept parallel and always kept in a staggered state, and it can be understood that thestaggered braiding bodies 100 are arranged in a staggered manner, and the intersecting points in theinner layer tube 111 and the intersecting points in theouter layer tube 101 are arranged in a staggered manner on the circumferential side surface of thebraiding body 100.

Further, compared with a single-layer bracket, the double-layer woven bracket with the staggered arrangement of the inner layer and the outer layer of the double-layer woven bracket has the advantages that the number of turns of the woven wires of each layer around the woven core rod is only half of that of the single-layer woven wires. For example, the single-layer stent is woven for 10 circles around the weavingmandrel 250, and the double-layer woven stent with staggered layers can achieve the same porosity as the single-layer stent by only 5 circles around the weavingmandrel 250, so that the double-layer woven stent is smaller in shrinkage rate on the premise that the axial woven length, the porosity and the metal coverage rate are the same, and then the double-layer woven stent is compressed into a catheter, and the axial total length of the double-layer woven stent is shorter than that of the single-layer stent.

Moreover, double-deck support of weaving, compare in single-layer support structure, under the same circumstances of weaving silk number, its length that shortens in the axial is only about half of single-layer support structure, and the easy art person is in the position release of art, and the release position of support is more easy to control, reduces the operation degree of difficulty of operation.

In one embodiment, the braided filaments of theouter tube 101 and the braided filaments of theinner tube 111 are preferably the same gauge braided filaments, and the wire diameter is in the range of 0.001 inch to 0.004 inch.

In this embodiment, the material of the braided wire may be nickel titanium, cobalt chromium, stainless steel, polymer, tantalum or a mixture thereof.

In one embodiment, the braiding wires of the adjacentinner tube 111 are twisted and fixed with thefirst braiding wires 1011 and/or thesecond braiding wires 1012 in the same direction or in opposite directions at both end positions of thebraiding body 100 to form aclosed twist structure 131.

In one embodiment, the outer diameter of thebraided body 100 is between 1.5mm and 7mm, and the two axial side ends of theouter tube 101 are connected by braiding wires to form a closed structure.

As shown in fig. 23, 24 and 27, in one embodiment, the braiding wires of theinner tube 111, thefirst braiding wire 1011 and/or thesecond braiding wire 1012 adjacent thereto are twisted and fixed in the same direction or opposite directions at both end positions of thebraiding body 100 to form a closedtwisted structure 131.

In one embodiment, for theproximal delivery segment 121, the braided filaments of theinner tube 111 are twisted and fixed in the same direction or opposite directions at both ends of thebraided body 100 to form a closedtwisted structure 131 with thefirst braided filaments 1011 and/or thesecond braided filaments 1012 adjacent thereto; or part of the braiding wires of theinner tube 111 are twisted and fixed with thefirst braiding wires 1011 and/or thesecond braiding wires 1012 in the same direction or opposite directions at both end positions of thebraiding body 100, thereby forming a semi-closedtwisted structure 132.

It should be noted that the distal end of thebraided body 100 must be aclosed twist 131 or otherwise processed to form an overall distal end with a curved surface to avoid injury to the human body, while theproximal delivery segment 121 does not require excessive protective measures due to its direct contact with the delivery instrument. Only part of the inner and outer layer braiding wires can be twisted and fixed in the same direction or opposite directions to form asemi-closed twisting structure 132, as shown in fig. 28; may also be formed in aclosed twist structure 131 consistent with the structure of thedistal opening section 123.

In one particular embodiment, when thebraided body 100 has a closedtwist structure 131, the number of strands of theclosed twist structure 131 is 3, 4, 6, 8, 10, or 12.

In one embodiment, more than two braided wires are twisted together, and the twisted ends are sleeved with a developingtip 300 and fixed by welding. Similarly, for thesemi-closed twisting structure 132, the end of the twisting of more than two filaments is sleeved with the developingtip 300, and the remaining non-twisted filaments are woven in the original direction until cut off.

More specifically, theclosed twist structure 131 is: at the beginning or ending of braiding, the total filament head z involved in braiding is first divided into several parts, and the braided filaments in each part are further divided into two bundles which are rotated in the same direction or opposite directions respectively to form stable filament bundles, and then the two filament bundles are bound together in parallel to form the completeclosed twist structure 131.

In another embodiment, thesemi-closed twist structure 132 consists of: when knitting is started or finished, cutting the equal number of knitting yarns which are uniformly distributed in the circumferential direction and rotate in the same direction or opposite directions in part of the total spinning head z participating in knitting, further dividing the rest of knitting yarns into a plurality of parts, dividing the knitting yarns in each part into two bundles which rotate clockwise and anticlockwise respectively to form stable yarn bundles, and then binding the two yarn bundles together in parallel to form a final semi-closed twisting end.

Further, the singleclosed twist structure 131 or the singlesemi-closed twist structure 132 of the double-layered braided stent is typically fixed by welding.

As shown in fig. 25, 26 and 29, in one embodiment, at least the distal end of thebraided body 100 is aclosed loop structure 133, and the braided filaments are bent arcuately at the end of thebraided body 100 to form theclosed loop structure 133.

More specifically, as shown in fig. 30, one method of closed end wrap around weave design is: thebraiding mandrel 250 is perforated and fitted withstainless steel nails 251, the braiding wires on the carrier are passed around thestainless steel nails 251 to form aclosed loop structure 133, and the braiding wires passed around thestainless steel nails 251 are then connected to another carrier. On this basis, the carrier is woven in accordance with a predetermined trajectory to form a support with aclosed loop structure 133 at the end. After braiding to the other end, thebraiding mandrel 250 is removed and the braiding wires are manually maneuvered around the stainless steel pins 251 to form anotherclosed loop structure 133.

In one embodiment, when the braidingmain body 100 has the closedtwisting structure 131 or theclosed wrapping structure 133, two adjacentclosed twisting structures 131 are arranged in a staggered manner along the circumferential direction of the braidingmain body 100; or adjacent two of theclosed loop structures 133 are offset in the circumferential direction of theknitted body 100.

As shown in fig. 27-29, in this embodiment, at the end of the wovenmain body 100, adjacent closed structures are offset from each other along the circumferential direction of the stent, and when the double-layer woven stent of the present application is compressed, the offset of the end enables a plurality of adjacent closed structures to better yield, so that the stent is easier to compress.

In one embodiment, the sum of the number of braided filaments used for theinner tube 111 and theouter tube 101 is z, z=24+6k, where k is a natural number.

In one embodiment, the number of braiding filaments used in theouter tube 101 is m, m=z-12 c, where c is a positive integer; the number offirst braid wires 1011 is the same as the number ofsecond braid wires 1012, and the number of cross braid wires in the first direction is the same as the number of cross braid wires in the second direction.

In one embodiment, the number ofcross-woven structures 102 is s, s=m/r, where r is a positive even number and r is less than or equal to m.

In one embodiment, thecross-weave structure 102 is uniformly distributed over theouter tube 101.

In one embodiment, the material of the braided wire is nickel titanium containing a developing material or cobalt chromium containing a developing material.

In this embodiment, the braided wire may be made of nickel-titanium, cobalt-chromium, or other materials with shape memory properties, alone or in combination, and the double-layer stent may be made entirely of platinum-containing nickel-titanium tubes or platinum-containing cobalt-chromium-nickel tubes, so as to achieve the effect of developing the entire stent.

In one embodiment, theouter layer tube 101 is woven by nickel-titanium woven wires and platinum wovenwires 1015 in a mixed manner, or theouter layer tube 101 is woven by cobalt-chromium woven wires and platinum wovenwires 1015 in a mixed manner, and two woven wires with different materials are respectively uniformly distributed in the circumferential direction of theouter layer tube 101.

In one embodiment, the wire diameter ofplatinum braid 1015 is greater than the wire diameter of nickel titanium braid orcobalt chromium braid 1016.

Preferably, the number of nickel titanium braid wires or cobaltchromium braid wires 1016 is greater than the number ofplatinum braid wires 1015.

In this embodiment, theouter layer tube 101 is mixed-woven, and the wire diameter of theplatinum braiding wire 1015 is large, so that the attaching area of theouter layer tube 101 and the microcatheter during delivery can be effectively reduced, and the frictional resistance can be reasonably reduced.

In one embodiment, the relationship between the number of filaments x of a nickel titanium braid or cobalt chromium braid and the number of filaments y of a platinum wire is x=l×y, where l is a positive integer and l is less than or equal to 48.

In one embodiment, the outer diameter of thewoven body 100 is 1.5mm-7mm and the axial length of thewoven body 100 is 10mm-70mm.

In one embodiment, the braided filaments have a filament diameter in the range of 20 μm to 100 μm.

In one particular embodiment, the ends of thewoven body 100 face outwardly Zhou Kuokou of thestructure 140.

As shown in fig. 10, in one particular embodiment, the void densities of thebraided body 100 are different, wherein thebraided body 100 includes adense braided section 151 and at least onesparse braided section 152; the void density of the densely wovensections 151 is greater than the void density of the sparsely wovensections 152.

In this embodiment, in the case of thearterial vessel 400 with thebranched vessel 401 beside the position of theaneurysm 500, thebraided body 100 with different pore densities in the axial direction is used, and the operator needs to ensure that thedense braided section 151 is released to the position of theaneurysm 500 during the operation of releasing the double stent of the present application, and accordingly, thesparse braided section 152 reduces the influence on the blood flow of thebranched vessel 401.

More specifically, the number of thesparse braiding segments 152 may be one, or thesparse braiding segments 152 may be disposed on two sides of thedense braiding segment 151 according to specific situations such as a disease position, and a person skilled in the art may prepare a double-layer braiding stent more fitting the current scheme according to the above thought and specific situations, so that the present invention is not limited too much.

It is also to be appreciated that the void density of thewoven body 100 referred to herein is: the braid of theouter tube 101 and the braid of theinner tube 111 are superimposed at corresponding positions, and then collectively constitute the pore density of the entirebraided body 100.

The embodiments of the present application have been described above, the foregoing description is exemplary, not exhaustive, and not limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the various embodiments described. The terminology used herein was chosen in order to best explain the principles of the embodiments, the practical application, or the improvement of technology in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.

Claims (23)

1. A delivery assembly, which is characterized by comprising a core wire, a pushing piece, a jogging piece and a clamping piece;

the pushing piece, the jogged piece and the clamping piece are sequentially arranged at the position of the core wire close to the distal end along the direction from the proximal end to the distal end of the core wire;

the distal end of the pushing piece is provided with a pushing table for pushing the bracket;

the maximum length of the embedded piece in the radial direction of the core wire is smaller than the maximum length of the pushing piece and the clamping piece in the direction, so that an embedded groove is formed between the pushing piece and the clamping piece, and the embedded groove is suitable for being clamped and fixed with the proximal end of the bracket.

2. The delivery assembly of claim 1, further comprising a friction booster;

the friction boosting piece is of a circular tube structure and is located at the far end of the clamping piece, the radial length of the friction boosting piece is larger than that of the clamping piece, and the radial length of the friction boosting piece is smaller than that of the boosting piece.

3. The delivery assembly of claim 2, wherein the pusher, the fitting, the snap fitting, and the friction booster are disposed concentrically on the core wire.

4. The delivery assembly of claim 2, wherein the friction booster is a polymeric material, and the friction booster is adhesively secured to the core wire.

5. The delivery assembly of claim 1, wherein the clip is a hollow tube structure.

6. The delivery assembly of claim 1, wherein the clip is a gear structure.

7. The delivery assembly of any one of claims 2-4, wherein end surfaces between the pusher and the engaging member, between the engaging member and the engaging member, and between the engaging member and the friction enhancing member are in contact with each other adjacent end surfaces;

The propelling piece is fixedly connected with the core wire;

the embedded piece is fixedly connected with the core wire;

the clamping piece is fixedly connected with the core wire.

8. A stent delivery system comprising the delivery assembly of any one of claims 1-7, a tether lumen, and a braided body;

the delivery assembly fits into the restraint cavity in mating relationship with the braided body;

the braiding main body is of a double-layer structure and comprises an inner layer pipe and an outer layer pipe, and the outer layer pipe is sleeved on the periphery of the inner layer pipe;

the braiding wires of the inner layer tube and the braiding wires of the outer layer tube are mutually wound and fixed at the end part of the braiding main body; and a plurality of developing parts are arranged at least at the proximal end of the braiding main body along the circumferential direction, and the braiding main body is clamped and fixed with the jogged groove through the developing parts.

9. The stent delivery system of claim 8, wherein the braided body is divided in its axial direction into a proximal delivery segment, a middle flow-blocking segment, and a distal opening segment;

the braiding wires of the inner layer tube are twisted with the braiding wires of the outer layer tube on the proximal end side of the middle flow blocking section, and the twisting part is the proximal end conveying section;

The braiding wires of the inner layer tube are twisted with the braiding wires of the outer layer tube at the far end side of the middle flow blocking section, and the twisting part is the far end opening section;

the braiding layers of the outer layer pipe and the inner layer pipe are arranged in staggered layers at the middle flow blocking section.

10. The stent delivery system of claim 9, wherein both ends of the braided body are of a closed twist structure;

the braiding wires of the inner layer tube and the braiding wires of the outer layer tube adjacent to the braiding wires are twisted and fixed at the two ends of the braiding main body in the same direction or opposite directions to form a closed twisting structure.

11. The stent delivery system of claim 9, wherein in the proximal delivery section, the braided filaments of the inner tube and the braided filaments of the outer tube are twisted together and secured in the same direction or in opposite directions at both end locations of the braided body to form a closed twisted structure;

or in the proximal conveying section, part of the braiding wires of the inner layer tube and the braiding wires of the outer layer tube are twisted and fixed at the two ends of the braiding main body in the same direction or opposite directions to form a semi-closed twisting structure.

12. A stent delivery system according to any one of claims 10 or 11, wherein two adjacent closed twist formations are offset in the circumferential direction of the braided body.

13. The stent delivery system of claim 8, wherein the developing section is a cylindrical structure and the developing section is a developing material.

14. The stent delivery system of claim 8, wherein the outer tube is provided with more than two first braided wires in a first direction and more than two second braided wires in a second direction, the first braided wires being interwoven with the second braided wires along a first predetermined angle;

the outer tube is provided with a cross-weave structure disposed between at least partially adjacent first weave filaments and/or between at least partially adjacent second weave filaments.

15. The stent delivery system of claim 14, wherein the cross-woven structure is uniformly disposed over the outer tube.

16. The stent delivery system of claim 8, wherein the braided wire is made of nickel titanium material containing a developing material or cobalt chromium material containing a developing material.

17. The stent delivery system of claim 16, wherein the outer tube is woven with nickel titanium woven wire and platinum woven wire or wherein the outer tube is woven with cobalt chromium woven wire and platinum woven wire;

the inner layer tube is woven by nickel-titanium woven wires and platinum woven wires in a mixed mode, or the inner layer tube is woven by cobalt-chromium woven wires and platinum woven wires in a mixed mode;

two kinds of knitting yarns with different materials are uniformly distributed in the circumferential direction of the knitting main body respectively.

18. The stent delivery system of claim 17, wherein when the outer tube is braided with the platinum braided wire using nickel titanium braided wire or cobalt chromium braided wire, the platinum braided wire has a wire diameter greater than the wire diameter of the nickel titanium braided wire or cobalt chromium braided wire.

19. The stent delivery system of claim 8, wherein the braided bodies differ in pore density;

wherein the braided body comprises a dense braided section and at least one sparse braided section;

the dense braid segment has a void density greater than the void density of the sparse braid segment.

20. The stent delivery system of claim 8, wherein the braided body is pushed when released into a vessel, the braided body is capable of forming dense projections at tumor diameter locations, and wherein the density of pores at the dense projections is greater than the density of pores at the remaining locations of the braided body.

21. The stent delivery system of any one of claims 8-11, 13-20, wherein during release, a sidewall of the braided body being released forms an angle with an axial direction of the stent of between 45-75 degrees.

22. The stent delivery system of any one of claims 8-11, 13-20, wherein a ratio of a length of the developing portion in an axial direction of the braided body to an overall axial length of the braided body is 1:200-1:20.

23. The stent delivery system of any of claims 8-11, 13-20, wherein the braided body is integrally formed.

Images