Disclosure of Invention
The invention provides an enhanced micro-catheter and a conveying system, which are used for solving the problems that the stability of the traditional micro-catheter in an intermediate catheter is poor and the contrast is inconvenient; meanwhile, when the intravascular stent is not completely adhered after being released, the existing microcatheter cannot enable the stent to be completely adhered; or, the distal end of the existing microcatheter presents a technical problem of being easily spring-loaded out of the aneurysm sac.
The invention discloses an enhanced microcatheter, comprising a microcatheter and a flexible braided tube body, the microcatheter configured into a lumen of an intermediate catheter; one end of the flexible braided tube body is arranged on the micro-catheter; the self-expanding braided tube is formed by braiding a plurality of braided wires, and the flexible braided tube is provided with a plurality of meshes; when the microcatheter is disposed within the lumen, the flexible braided tube is disposed between the intermediate catheter and the microcatheter.
Further, the flexible braided tube body is sleeved on the micro-catheter and is in contact with the outer tube wall of the micro-catheter.
Further, one end of the flexible braided tube body is fixed at a position, close to the distal end, of the microcatheter through a fixing ring; the fixing ring is made of any developing material of platinum tungsten, platinum iridium and tantalum.
Further, wherein the flexible braided tube body is changeable from a compressed state to an uncompressed state; when the flexible braided tube body is in a non-compressed state, the cross-sectional area of the flexible braided tube body gradually increases and then gradually decreases from the distal end of the microcatheter to the proximal end of the microcatheter.
Further, at least two flexible braided tube bodies are sequentially arranged along the microcatheter and connected end to end; and/or at least two flexible braided tube bodies are sequentially arranged at intervals along the microcatheter.
Further, one end or two ends of the flexible braided tube body are provided with binding rings, and the binding rings are used for limiting the diameter of one end or two ends of the flexible braided tube body.
Further, the binding ring is made of any one of development materials such as platinum tungsten, platinum iridium and tantalum.
Further, one end of the braided wire has a wire diameter of 0.02mm to 0.1mm, and the other end of the braided wire has a wire diameter of 0.05mm to 0.1mm.
Further, the flexible braided tube body comprises a first braided part and a second braided part which is arranged opposite to the first braided part; the first braid has a braid density greater than a braid density of the second braid.
Further, at least two developing wires which are wound around the flexible braided tube body in a crossing way are arranged on the flexible braided tube body; the developing wire is made of any one of platinum tungsten, platinum iridium and tantalum developing materials.
The invention also discloses a delivery system comprising an enhanced microcatheter as described in any of the embodiments above.
Intravascular stents are increasingly used in the prior art as a conventional treatment for a number of vascular diseases, such as cardiovascular and cerebrovascular diseases like aneurysms, atherosclerosis. Especially in tortuous vessels, when the stent is released, this may lead to kinking of the unreleased stent or the already released stent (i.e. at the distal end of the microcatheter) as the microcatheter may be retracted or rotation may occur, resulting in a risk that the stent cannot be opened.
Compared with the prior art, in the embodiment, the coaxiality of the micro-catheter and the middle catheter can be ensured by arranging the flexible braided tube body on the micro-catheter, and the stability of the micro-catheter in the middle catheter can be further improved. The microcatheter is also prevented from rotating within the intermediate catheter. Meanwhile, when the contrast medium is needed to be imaged, the contrast medium can circulate through a plurality of meshes on the flexible braided tube body. The reinforced microcatheter can be used for conveying intravascular interventional instruments such as intravascular stents, spring rings and the like.
When fully released within the vessel, the stent does not conform to the vessel wall. The distal end of the pushing guide wire is positioned at the distal end of the bracket, the distal end of the micro-catheter is positioned at the proximal end of the bracket, the micro-catheter is continuously moved to the distal end along the pushing guide wire, at this time, the flexible braided tube body on the micro-catheter is in a non-compressed state by moving the micro-catheter to the distal end or the proximal end, and the flexible braided tube body extrudes the bracket and plays a role of massaging, so that the bracket can be completely adhered to the wall after being released in a blood vessel. The flexible braided tube body is arranged on the microcatheter, so that the stability of the microcatheter in the aneurysm is improved, and the risk that the distal end of the microcatheter is popped out of the aneurysm sac by the spring ring is reduced.
The foregoing general description and the following description are exemplary and explanatory only and are not restrictive of the invention.
Detailed Description
For a more complete understanding of the nature and the technical content of the embodiments of the present invention, reference should be made to the following detailed description of embodiments of the invention, taken in conjunction with the accompanying drawings, which are meant to be illustrative only and not limiting of the embodiments of the invention. In the following description of the technology, for purposes of explanation, numerous details are set forth in order to provide a thorough understanding of the disclosed embodiments. However, one or more embodiments may still be practiced without these details. In other instances, well-known structures and devices may be shown simplified in order to simplify the drawing.
The terms first, second and the like in the description and in the claims of embodiments of the invention and in the above-described figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate in order to describe embodiments of the invention herein. Furthermore, the terms "comprise" and "have," as well as any variations thereof, are intended to cover a non-exclusive inclusion.
In the embodiments of the present invention, the terms "upper", "lower", "inner", "middle", "outer", "front", "rear", and the like indicate the azimuth or the positional relationship based on the azimuth or the positional relationship shown in the drawings. These terms are only used to facilitate a better description of embodiments of the invention and their examples and are not intended to limit the scope of the indicated devices, elements or components to the particular orientation or to be constructed and operated in a particular orientation. Also, some of the terms described above may be used to indicate other meanings in addition to orientation or positional relationships, for example, the term "upper" may also be used to indicate some sort of attachment or connection in some cases. The specific meaning of these terms in embodiments of the present invention will be understood by those of ordinary skill in the art in view of the specific circumstances.
In addition, the terms "disposed," "connected," "secured" and "affixed" are to be construed broadly. For example, "connected" may be in a fixed connection, a removable connection, or a unitary construction; may be a mechanical connection, or an electrical connection; may be directly connected, or indirectly connected through intervening media, or may be in internal communication between two devices, elements, or components. The specific meaning of the above terms in the embodiments of the present invention will be understood by those of ordinary skill in the art according to the specific circumstances.
The term "plurality" means two or more, and "plurality" means two or more.
It should be noted that, without conflict, the embodiments of the present invention and features of the embodiments may be combined with each other.
The applicant found that when a large inner diameter intermediate catheter is used during intravascular delivery of the stent, the microcatheter can slosh within the intermediate catheter, resulting in poor stability of delivery of the device. If the technical solution of reducing the difference between the outer diameter of the micro-catheter and the inner diameter of the intermediate catheter is chosen, the coaxiality can be increased, but the difference becomes smaller, which also means that the gap between the micro-catheter and the intermediate catheter becomes smaller. Contrast injection is extremely difficult when contrast is required during stent delivery.
In view of the foregoing, embodiments of the present invention provide an enhanced microcatheter and delivery system. Next, the technical scheme of the present invention will be described in detail with reference to specific embodiments.
In the present invention, the distal end means an end far from the operator at the time of surgery, and the proximal end means an end near the operator at the time of surgery.
First embodiment
As shown in fig. 1 to 4, the reinforced microcatheter according to the present embodiment includes a microcatheter 2 and a flexible braided tube body 3. Microcatheter 2 may be disposed within lumen 11 of intermediate catheter 1 and microcatheter 2 may be moved distally or proximally within lumen 11 of intermediate catheter 1. One end of the flexible braided tube body 3 is arranged on the outer tube wall of the micro-catheter 2, and the flexible braided tube body 3 is positioned between the middle catheter 1 and the micro-catheter 2. The flexible braided tube body 3 may be braided by a plurality of braided wires 31, and the flexible braided tube body 3 has a plurality of meshes. The flexible braided tube body 3 has the characteristic of self-expansion, and the flexible braided tube body 3 of the embodiment can be a self-expansion braided tube body.
Alternatively, the flexible braided tube 3 may be braided from round wire or flat wire. Preferably, the braided wire 31 is made of nickel-titanium alloy material.
Alternatively, the number of the braided wires 31 is in the range of 8 to 144, and the wire diameter of the braided wires 31 is in the range of 0.02mm to 0.2mm.
As shown in fig. 1 to 4, after the plurality of braided wires 31 are braided into the flexible braided tube body 3, the flexible braided tube body 3 has a passage therein. The flexible braided tube body 3 in a compressed state is tubular, the flexible braided tube body 3 in a compressed state is sleeved on the micro-catheter 2, and the flexible braided tube body 3 is attached to the outer tube wall of the micro-catheter 2. At this time, the microcatheter 2 is passed through the channel of the flexible braided tube body 3. The end of the flexible braided tube body 3 near the proximal end is provided with a fixing ring 41, or the end of the flexible braided tube body 3 near the distal end is provided with a fixing ring 41. One end of the flexible braided tube body 3 is fixed to the outer tube wall of the microcatheter 2 by a fixing ring 41, and both the fixing ring 41 and the braided body are positioned near the distal end of the microcatheter 2. The flexible braided tube body 3 is disposed on the microcatheter 2, and the microcatheter 2 is disposed within the lumen 11 of the intermediate catheter 1.
When the flexible braided tube body 3 is shifted from the compressed state to the uncompressed state, the end of the flexible braided tube body 3 away from the fixing ring 41 moves toward and approaches the end of the flexible braided tube body 3 where the fixing ring 41 is provided, and the middle portion of the flexible braided tube body 3 protrudes in a direction away from the microcatheter 2. When the flexible braided tube body 3 is in the non-compressed state, the cross-sectional area of the flexible braided tube body 3 gradually increases and then gradually decreases from the distal end of the microcatheter 2 toward the proximal end of the microcatheter 2. When the flexible braided tube body 3 is in a non-compressed state, the middle part of the flexible braided tube body 3 is abutted against the cavity wall of the lumen 11 of the middle catheter 1, so that a gap between the micro catheter 2 and the middle catheter 1 can be filled, the stability of the micro catheter 2 and the middle catheter 1 is improved, and the meshes of the flexible braided tube body 3 are beneficial to the passing of contrast agents.
In this embodiment, the fixing ring 41 may be made of any one of development materials of platinum tungsten, platinum iridium, tantalum. The flexible braided tube body 3 is convenient to develop, and the operator can observe the position of the flexible braided tube body 3 conveniently.
Intravascular stents are increasingly used in the prior art as a conventional treatment for a number of vascular diseases, such as cardiovascular and cerebrovascular diseases like aneurysms, atherosclerosis. Especially in tortuous vessels, when the stent is released, this may lead to kinking of the unreleased stent or the already released stent (i.e. at the distal end of the microcatheter 2) as the microcatheter 2 may be retracted or rotation may occur, resulting in a risk that the stent may not be opened.
Compared with the prior art, in the present embodiment, by providing the flexible braided tube body 3 on the micro-catheter 2, the coaxiality of the micro-catheter 2 and the intermediate catheter 1 can be ensured, and the stability of the micro-catheter 2 in the intermediate catheter 1 can be further improved. It is also possible to prevent the microcatheter 2 from rotating within the intermediate catheter 1. Meanwhile, when contrast is required, the contrast agent can circulate through a plurality of mesh openings on the flexible braided tube body 3.
In the prior art, when the stent is completely released in the blood vessel, the stent may have incomplete adhesion, and a method which is more common at present is to withdraw the delivery wire of the stent, then make the micro-guide wire enter through the micro-catheter 2 and make massaging in the stent by using the micro-guide wire to form loops so as to enable the stent to be completely adhered.
In contrast to the prior art, in this embodiment, after the stent is completely released within the vessel, but not against the vessel wall. The distal end of the pushing guide wire is positioned at the distal end of the bracket, the distal end of the micro-catheter 2 is positioned at the proximal end of the bracket, the micro-catheter 2 is continuously moved to the distal end along the pushing guide wire, at this time, the flexible braided tube body 3 on the micro-catheter 2 is in a non-compressed state by moving the micro-catheter 2 to the distal end or the proximal end, the flexible braided tube body 3 extrudes the bracket, and plays a role in massaging, so that the bracket can be completely adhered to the wall after being released in a blood vessel.
Second embodiment
This embodiment also proposes an enhanced microcatheter. The second embodiment is a further improvement based on the first embodiment, the main improvement being that:
One or both ends of the flexible braided tube body 3 are provided with a tie ring 42, and the tie ring 42 is used for limiting the diameter of one or both ends of the flexible braided tube body 3.
Alternatively, the confinement ring 42 is made of any one of platinum tungsten, platinum iridium, tantalum developing materials.
In this embodiment, the binding ring 42 is arranged in two ways, specifically as follows:
Alternatively, as shown in fig. 1 and 2, one end of the flexible braided tube body 3 is provided with a binding ring 42, and the other end of the flexible braided tube body 3 is provided with a fixing ring 41. The restraint ring 42 at one end of the flexible braided tube 3 limits the diameter of that end of the flexible braided tube 3, avoiding the risk of intravascular hemorrhage due to self-bulging of the flexible braided tube 3. The fixing ring 41 may serve the same function as the binding ring 42 for the flexible braided tube 3, except that one end of the flexible braided tube 3 may be fixed to the microcatheter 2. The binding ring 42 is made of any developing material of platinum tungsten, platinum iridium and tantalum, so that the flexible braided tube body 3 can be developed conveniently, and an operator can observe the position of the flexible braided tube body 3 conveniently.
Optionally, both ends of the flexible braided tube body 3 are provided with tie rings 42, and the tie rings 42 are used to limit the diameter of both ends of the flexible braided tube body 3. A fixing ring 41 is provided at one end of the flexible braided tube body 3, at this time, one end of the fixing ring 41 is fixedly connected with one end of one of the binding rings 42, and the binding ring 42 is provided between the flexible braided tube body 3 and the fixing ring 41. The fixing ring 41 serves only to fix one end of the flexible braided tube body 3 to the microcatheter 2. And the restraint rings 42 positioned at the two ends of the flexible braided tube body 3 limit the diameters of the two ends of the flexible braided tube body 3, so that the risk of intravascular hemorrhage caused by self-expansion of the flexible braided tube body 3 is avoided. The binding ring 42 is made of any developing material of platinum tungsten, platinum iridium and tantalum, so that the flexible braided tube body 3 can be developed conveniently, and an operator can observe the position of the flexible braided tube body 3 conveniently.
In this embodiment, one of the above two alternative solutions is optional.
In both of the above alternative solutions, either the two binder rings 42 or the fixing ring 41 may be made of a developing material.
Compared with the prior art, in the present embodiment, after the technical scheme that the binding ring 42 is arranged on the flexible braided tube body 3 is combined with the technical scheme that the flexible braided tube body 3 is arranged on the microcatheter 2 and positioned at the far end, the stent can be completely adhered to the wall after being released, and the damage to the inner wall of the blood vessel can be avoided. Specifically, after the stent is completely released in the blood vessel, the distal end of the pushing guide wire is positioned at the distal end of the stent, the distal end of the micro-catheter 2 is positioned at the proximal end of the stent, and the micro-catheter 2 is continuously moved to the distal end along the pushing guide wire, at this time, the flexible braided tube body 3 on the micro-catheter 2 is in a non-compressed state by moving the micro-catheter 2 to the distal end or the proximal end, and the flexible braided tube body 3 extrudes the stent and plays a role of massaging, so that the stent can be completely attached to the wall after being released in the blood vessel.
Compared with the prior art, in the embodiment, after the technical scheme that the binding ring 42 is arranged on the flexible braided tube body 3 is combined with the technical scheme that the flexible braided tube body 3 is arranged on the microcatheter 2 and positioned at the far end, not only the damage to the inner wall of the blood vessel can be avoided, but also the flexible braided tube body 3 in a non-compressed state can be stably fixed in the middle catheter 1 or the blood vessel, so that the shaking of the far end of the microcatheter 2 in the blood vessel is reduced, the stability of the microcatheter 2 in the aneurysm is improved, and the risk that the far end of the microcatheter 2 is popped out of the aneurysm sac by a spring ring is reduced.
Third embodiment
This embodiment also proposes an enhanced microcatheter. The third embodiment is a further improvement based on the first or second embodiment, the main improvement being that:
As shown in fig. 3, the enhanced micro-catheter of the present embodiment further includes at least two developing wires 43, where the at least two developing wires 43 are wound around the outer circumference of the flexible braided tube body 3 in a crossing manner, and the developing wires 43 are made of any developing material of platinum tungsten, platinum iridium, and tantalum.
In this embodiment, the development of the flexible braided tube 3 can be facilitated by providing the development wire 43 on the flexible braided tube 3, so that the operator can observe the position of the flexible braided tube 3.
Of course, any one of the binding ring 42, the fixing ring 41 and the developing wire 43 may be made of a developing material, or the binding ring 42 and the developing wire 43 may be developed in a matching manner, or the fixing ring 41 and the developing wire 43 may be developed in a matching manner, or the binding ring 42, the fixing ring 41 and the developing wire 43 may be developed in a matching manner.
Fourth embodiment
This embodiment also proposes an enhanced microcatheter. The fourth embodiment is a further improvement based on the first or second or third embodiment, the main improvement being:
As shown in fig. 3 and 4, after the plurality of braided wires 31 are braided into the flexible braided tube body 3, the flexible braided tube body 3 has a passage therein. Similarly, the flexible braided tube body 3 further includes a first braided part 32 and a second braided part 33, and the first braided part 32 is disposed opposite to the second braided part 33.
Alternatively, the diameter D of one end of the braided wire 31 is 0.02mm to 0.1mm, and the diameter D of the other end of the braided wire 31 is 0.05mm to 0.1mm.
In this embodiment, the following optional technical solutions exist for the flexible braided tube body 3, specifically as follows:
Alternatively, as shown in fig. 3, after the plurality of braided wires 31 are braided into the flexible braided tube body 3, the flexible braided tube body 3 has the first braided part 32 and the second braided part 33 thereon, and the braiding density of the first braided part 32 is greater than that of the second braided part 33. The large knitting density of the first knitted portion 32 results in the small mesh area of the first knitted portion 32, the small knitting density of the second knitted portion 33 results in the large mesh area of the second knitted portion 33, the mesh of the first knitted portion 32 is smaller than the mesh of the second knitted portion 33, and such arrangement enables the supporting force of the first knitted portion 32 to be stronger than the supporting force of the second knitted portion 33, and the supporting area to be larger. When the flexible braided tube body 3 faces to the condition of vascular tortuosity, the supporting force on one side is larger than the supporting force on the other side, so that the micro-catheter 2 can be turned and passed conveniently.
Alternatively, as shown in fig. 4, the braided wire 31 has a larger wire diameter at one end than at the other end, which enables one end of the flexible braided tube 3 to support more force than the other end thereof. The steering and passing of the microcatheter 2 is facilitated when the vascular tortuosity is faced.
Alternatively, as shown in fig. 3 and 4, one end of the braided wire 31 has a wire diameter of 0.02mm, and the other end of the braided wire 31 has a wire diameter of 0.05mm. By such sizing of the braided wire 31, it is convenient to access a medium blood vessel after it is braided into the flexible braided tube body 3.
Optionally, as shown in fig. 3 and 4, an alternative solution in which the knitting density of the first knitting portion 32 is greater than that of the second knitting portion 33 is combined with an alternative solution in which one end of the knitting yarn 31 has a yarn diameter of 0.02mm and the other end of the knitting yarn 31 has a yarn diameter of 0.05 mm. In the flexible braided tube body 3, one end of the braided wire 31 with the diameter of 0.02mm is fixedly connected with the fixed ring 41, the structural strength of the joint of the flexible braided tube body 3 and the fixed ring 41 is high, and the supporting force of the flexible braided tube body 3 in a non-compressed state can be improved, so that the passing performance of the micro-catheter 2 in medium blood vessels and blood vessels with the diameter smaller than the medium blood vessels is further enhanced. At the same time, the contact area of the first braiding part 32 is larger, the supporting force is stronger, and the steering and passing of the micro-catheter 2 are more convenient.
Alternatively, as shown in fig. 4, one end of the braided wire 31 has a wire diameter of 0.1mm, and the other end of the braided wire 31 has a wire diameter of 0.1mm. By such sizing of the braided wire 31, access to large blood vessels is facilitated when it is braided into a flexible braided tube 3.
Optionally, as shown in fig. 3 and 4, the above-mentioned alternative technical scheme that the knitting density of the first knitting portion 32 is greater than that of the second knitting portion 33 is combined with the alternative technical scheme that the wire diameters of the two ends of the knitting wires 31 are both 0.1mm, and in the flexible knitted tube body 3, any one of the two ends of the flexible knitted tube body 3 is fixedly connected with the fixing ring 41, so that the supporting force of the first knitting portion 32 can be increased, and the passing performance of the microcatheter 2 in a large blood vessel can be further enhanced, meanwhile, the steering and passing of the microcatheter 2 are facilitated, and the massaging and the extrusion of the stent in the blood vessel are also facilitated, so that the stent is attached to the inner wall of the blood vessel.
In this embodiment, one of the above six optional solutions is optional.
Fifth embodiment
This embodiment also proposes an enhanced microcatheter. The fifth embodiment is a further improvement based on any one of the first to fourth embodiments, the main improvement being that:
at least two flexible braided tube bodies 3 are sequentially arranged along the microcatheter 2 and are connected end to end; and/or at least two flexible braided tube bodies 3 are sequentially arranged at intervals along the microcatheter 2.
In this embodiment, the following optional technical solutions exist for the flexible braided tube body 3, specifically as follows:
Alternatively, as shown in fig. 5, the number of the flexible braided tube bodies 3 is at least two, and at least two flexible braided tube bodies 3 are sequentially arranged at intervals along the microcatheter 2. The arrangement can improve the coaxiality of the micro-catheter 2 and the middle catheter 1, further improve the stability of the micro-catheter 2 in the middle catheter 1, and facilitate the contrast of operators. When the intravascular stent is required to be massaged and extruded, the flexible braided tube body 3, which is close to the proximal end, on the micro-catheter 2 is in a non-compressed state and is positioned between the middle catheter 1 and the micro-catheter 2, so that the micro-catheter 2 is prevented from rotating in the middle catheter 1. Simultaneously, the flexible braided tube body 3 near the far end on the micro-catheter 2 enters the blood vessel, and massages and extrudes the stent, so that the stent is attached to the inner wall of the blood vessel.
Alternatively, as shown in fig. 6, the number of the flexible braided tube bodies 3 is at least two, and at least two flexible braided tube bodies 3 are sequentially arranged along the microcatheter 2 and connected end to end. Therefore, the coaxiality between the micro-catheter 2 and the middle catheter 1 is further enhanced, and meanwhile, the bracket in the blood vessel does not need to be repeatedly massaged and extruded, so that the bracket can be attached to the inner wall of the blood vessel more conveniently.
Optionally, as shown in fig. 5 and 6, the two alternative solutions are combined, and this arrangement can improve the coaxiality of the microcatheter 2 and the middle catheter 1, further improve the stability of the microcatheter 2 in the middle catheter 1, and facilitate the imaging of the operator. When the intravascular stent is required to be massaged and extruded, the flexible braided tube body 3, which is close to the proximal end, on the micro-catheter 2 is in a non-compressed state and is positioned between the middle catheter 1 and the micro-catheter 2, so that the micro-catheter 2 is prevented from rotating in the middle catheter 1. Simultaneously, the flexible braided tube body 3 which is close to the far end on the micro-catheter 2 enters the blood vessel, and massages and extrudes the stent, so that the stent does not need to repeatedly massage and extrude the stent in the blood vessel, and the stent can be attached to the inner wall of the blood vessel more conveniently.
In this embodiment, one of the above three optional solutions is optional.
Sixth embodiment
This embodiment also proposes an enhanced microcatheter. The sixth embodiment is a further improvement based on the first embodiment, and the main improvement is that:
As shown in fig. 7 and 8, the outer wall of the microcatheter 2 is configured with a groove 21, and the groove 21 is located near the distal end of the microcatheter 2. The flexible braided tube body 3 and the fixing ring 41 are both disposed in the groove 21. By arranging the flexible braided tube body 3 and the fixing ring 41 in the groove 21, the hidden arrangement of the flexible braided tube body 3 and the fixing ring 41 is realized, and the flexible braided tube body 3 is in a compressed state not higher than the outer tube wall of the microcatheter 2. At the same time, the risk of the flexible braided tube body 3 slipping off the microcatheter 2 is also reduced.
Seventh embodiment
The present embodiment proposes a conveying system. A system as disclosed in the seventh embodiment comprises the enhanced microcatheter of any of the first to sixth embodiments, in particular:
As shown in fig. 1 to 8, the delivery system comprises an intermediate catheter 1, a microcatheter 2 and a flexible braided tube body 3, wherein a lumen 11 is formed inside the intermediate catheter 1. Microcatheter 2 is disposed within lumen 11 of intermediate catheter 1 and microcatheter 2 is movable distally or proximally within lumen 11 of intermediate catheter 1. One end of the flexible braided tube body 3 is arranged on the outer tube wall of the micro-catheter 2, and the flexible braided tube body 3 is positioned between the middle catheter 1 and the micro-catheter 2. The flexible braided tube body 3 can move following the movement of the microcatheter 2.
Application scenario of an exemplary embodiment:
as shown in fig. 1 to 5, when the microcatheter 2 is disposed within the lumen 11 of the intermediate catheter 1, the flexible braided tube 3 is in an uncompressed state, i.e., it can be considered that the flexible braided tube 3 is in an expanded state. At this time, the microcatheter 2 is in contact with the lumen wall of the lumen 11 through the flexible braided tube body 3. After the intravascular stent is released, the stent is not completely attached to the inner wall of the blood vessel, and the stent is required to be massaged and extruded.
The microcatheter 2 is moved to the distal end continuously, a flexible braided tube body 3 close to the distal end on the microcatheter 2 enters the blood vessel, the stent is massaged and extruded, and the stent is attached to the inner wall of the blood vessel. While a flexible braided tube 3 on microcatheter 2 near the proximal end remains within lumen 11 preventing microcatheter 2 from rotating within intermediate catheter 1.
The above description and the drawings illustrate embodiments of the invention sufficiently to enable those skilled in the art to practice them. Other embodiments may include structural and other modifications. The embodiments represent only possible variations. Individual components and functions are optional unless explicitly required, and the sequence of operations may vary. Portions and features of some embodiments may be included in, or substituted for, those of others. The embodiment of the present invention is not limited to the structure that has been described above and shown in the drawings, and various modifications and changes may be made without departing from the scope thereof. The scope of the invention is limited only by the appended claims.