CN113058134A

CN113058134A - Medical implant's propelling movement core silk and medical device

Info

Publication number: CN113058134A
Application number: CN202110485678.3A
Authority: CN
Inventors: 陆静雯; 徐俊
Original assignee: Qiju Medical Technology Shanghai Co ltd
Current assignee: Qiju Medical Technology Shanghai Co ltd
Priority date: 2021-04-30
Filing date: 2021-04-30
Publication date: 2021-07-02

Abstract

The invention provides a core wire for pushing a medical implant and a medical device, wherein the core wire for pushing the medical implant comprises a cannula assembly, a mandrel and a recovery assembly, the mandrel is movably arranged in the cannula assembly, the recovery assembly comprises a recovery part and a supporting part, the recovery assembly has a first state and a second state, and when the recovery assembly is in the first state, the recovery assembly is used for keeping a preset distance with the medical implant; when the retrieval assembly is in the second state, the retrieval assembly is adapted to be at least partially pressed against or inserted into the aperture of the medical implant to retrieve the medical implant. The push core wire can reduce the resistance in the push process and the first release process, particularly the resistance when the medical implant is in a bent state through a bent path, and solve the problem of withdrawing and recovering the medical implant.

Description

Medical implant's propelling movement core silk and medical device

Technical Field

The invention relates to the technical field of medical instruments, in particular to a pushing core wire of a medical implant and a medical device.

Background

An aneurysm is a serious arterial vascular disease, and its damage to the human body is mainly manifested in two aspects. Firstly, the aneurysm is enlarged and presses the peripheral nerve and artery and vein tissues, so that the body is not suitable or partial function is lost, secondly, the aneurysm wall is aged or the aneurysm is ruptured due to external reasons, and the life can be threatened in serious cases, particularly, the cerebral apoplexy caused by the rupture of the cerebral aneurysm has quite high lethal disability rate. In recent years, the incidence of aneurysms has increased year by year as people have improved their living standards and worsen their environment.

Among the aneurysms, intracranial aneurysms are the most difficult to treat. Currently, the accepted method of low risk intracranial aneurysm treatment is minimally invasive interventional therapy. The minimally invasive interventional therapy has the advantages of small wound, quick healing, low recurrence rate and less sequelae. Minimally invasive interventional therapy refers to implanting a permanent medical implant such as a dense mesh stent at a vascular lesion, and blocking blood entering aneurysm by using the medical implant so that blood supply of the aneurysm is reduced, further promoting atrophy of the aneurysm, and meanwhile, the medical implant is also used for supporting the blood vessel wall around the aneurysm to ensure normal circulation of blood in the blood vessel.

In the minimally invasive interventional therapy process, an operator utilizes a pushing system to push the medical implant to a diseased blood vessel. In the process of pushing the medical implant to the diseased blood vessel and releasing the medical implant, the position and posture of the medical implant need to be adjusted according to the actual release condition, so that the pushing system is expected to have better recovery performance and lower resistance so as to recover and release the released medical implant.

Disclosure of Invention

The invention aims to provide a push core wire of a medical implant and a medical device, which can recycle and adjust the medical implant according to the actual release condition when the medical implant is pushed to a target part by using the push core wire and then released, and simultaneously reduce the push resistance caused by the radial outward extrusion of the medical implant due to the fixed shape or continuous maintenance of the push core wire during the pushing process, particularly from the near end to the far end of a delivery pipe (such as a microcatheter) and when the delivery pipe passes through a curved path.

In order to achieve the above object, the present invention provides a push core wire of a medical implant for pushing the medical implant, the push core wire comprising:

the cannula assembly comprises a tube body and a pushing block arranged at the proximal end of the tube body, the pushing block and the tube body are kept relatively static, and the pushing block is used for abutting against the proximal end of the medical implant;

the mandrel is partially arranged in the tube body in a penetrating mode and can move along the axial direction of the tube body, and the far end of the mandrel is exposed out of the far end of the tube body; and the number of the first and second groups,

a retrieval assembly located outside the distal end of the cannula and including a retrieval portion and a support portion; the recovery part is connected to the sleeve and arranged on the periphery of the mandrel; the supporting part is arranged on the mandrel and is kept relatively static with the mandrel in the axial direction;

the push core wire has a first state and a second state and is configured to: when the pushing core wire is in the first state, the supporting part is at least partially positioned at the distal end side of the recovery part, and the recovery component is used for keeping a preset distance with the medical implant; when the push core wire is in the second state, the support portion applies a force to the recovery portion and expands the recovery portion radially outward of the mandrel for at least partially pressing against or inserting into an aperture of the medical implant.

Optionally, the recovery part is an elastic sleeve, a proximal end of the elastic sleeve is fixedly connected to the cannula assembly, and a distal end of the elastic sleeve is a free end;

when the core wire is pushed to be in the second state, the support part applies extrusion force which points to the near end along the far end of the mandrel to the elastic sleeve at the far end of the elastic sleeve, and the elastic sleeve is compressed along the axial direction and expanded outwards along the radial direction.

Optionally, the retrieving portion comprises a base and an antenna, wherein the base is connected to the cannula assembly at a proximal end thereof, and extends along an axial direction of the cannula assembly at a distal end thereof; at least one antenna is arranged on one side of the base, which is far away from the mandrel;

when the core wire is pushed to be in the second state, the supporting part is at least partially positioned between the base and the mandrel, and applies a supporting force outwards along the radial direction of the mandrel to the base and radially expands the base; at least one of the antennas is adapted to be inserted into an aperture of the medical implant or to be pressed against an inner surface of the medical implant.

Optionally, there is a gap between the inner surface of the base and the sidewall of the mandrel, the inner surface of the base and the sidewall of the mandrel being parallel to each other when the push core wire is in the first state, or the gap between the inner surface of the base and the sidewall of the mandrel gradually decreasing in a proximal-to-distal direction when the push core wire is in the first state.

Optionally, the recycling portion includes a plurality of the bases, the plurality of the bases are arranged at intervals around an axis of the mandrel, and each of the bases is provided with the antenna.

Optionally, the recovery part further comprises an annular connecting member, and the proximal ends of the bases are both arranged on the annular connecting member and connected to the sleeve through the annular connecting member.

Optionally, the annular connector is connected to the tube body, or the annular connector is connected to a distal end face of the pushing block.

Optionally, the support portion comprises a first wedge-shaped section, the distance from the outer surface of the first wedge-shaped section to the side wall of the mandrel gradually increasing in the proximal-to-distal direction;

the first wedge-shaped segment is at least partially located on a distal side of the recovery portion when the push core wire is in the first state; the first wedge segment is at least partially between the recovery portion and the mandrel when the recovery assembly is in the second state.

To achieve the above object, the present invention also provides a medical device comprising:

a sheath tube;

a push core wire of a medical implant according to any one of the preceding claims, the push core wire being partially threaded into the sheath and being movable in an axial direction of the sheath; and the number of the first and second groups,

the medical implant is compressed in the sheath tube, sleeved on the outer surface of the pushing core wire and positioned on the distal end side of the pushing block;

the medical device is configured such that, when the retrieval assembly is in the first state, the pusher block is for abutment with a proximal end of the medical implant; when the retrieval assembly is in the second state, the retrieval portion is at least partially pressed against an inner surface of the medical implant or inserted into an aperture of the medical implant.

Optionally, the medical implant is a medical stent.

Compared with the prior art, the push core wire and the medical device of the medical implant have the following advantages:

the propelling core wire of the medical implant is used for propelling the medical implant, and comprises: the cannula assembly comprises a tube body and a pushing block arranged at the proximal end of the tube body, the pushing block and the tube body are kept relatively static, and the pushing block is used for abutting against the proximal end of the medical implant; the mandrel is partially arranged in the tube body in a penetrating mode and can move along the axial direction of the tube body, and the far end of the mandrel is exposed out of the far end of the tube body; and a retrieval assembly located outside the distal end of the cannula and including a retrieval portion and a support portion; the recovery part is connected to the sleeve and arranged on the periphery of the mandrel; the supporting part is arranged on the mandrel and is kept relatively static with the mandrel in the axial direction; the push core wire has a first state and a second state. When the pushing core wire is used for pushing and releasing the medical implant for the first time, the pushing core wire is in the first state, at the moment, the supporting part is at least partially positioned on the far end side of the recovery part, and a preset distance is kept between the recovery component and the inner surface of the medical implant, so that no interaction force exists between the recovery component and the medical implant or the pipe fitting (such as a sheath pipe and a microcatheter) in the pushing process, the resistance is reduced, the possibility of generating fragments due to friction between the recovery component and the medical implant or the pipe fitting (such as the sheath pipe and the microcatheter) to cause thrombus is reduced, the safety of treatment is improved, and the treatment effect is ensured; in the process of releasing the medical implant, if the pose of the medical implant is not good, the operator can perform corresponding operation to switch the pushing core wire to the second state, at this time, the supporting part applies acting force to the recovering part and enables the recovering part to radially expand to be capable of pressing against the inner surface of the medical implant or being inserted into the aperture of the medical implant, so that the operator can recover the medical implant, and the pose of the medical implant can be adjusted and released again.

Drawings

The drawings are included to provide a better understanding of the invention and are not to be construed as unduly limiting the invention. Wherein:

FIG. 1 is a schematic view of a push core wire of a medical implant pushing a medical stent in a microcatheter according to one embodiment of the present invention, showing a retrieval assembly in a first state;

FIG. 2 is a schematic view of a medical implant according to an embodiment of the present invention showing a retrieval assembly in a second state when a core wire is advanced to retrieve a medical stent;

[ reference numerals are described below ]:

10-medical stent, 20-microcatheter;

100-a sleeve assembly, 110-a tube body, and 120-a pushing block;

200-a mandrel;

300-recovery assembly, 310-recovery section, 311-base, 312-antenna, 313-annular connector, 320-support, 321-first wedge segment, 322-straight segment, 323-second wedge segment.

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention. It should be noted that the drawings provided in the present embodiment are only for illustrating the basic idea of the present invention, and the components related to the present invention are only shown in the drawings rather than drawn according to the number, shape and size of the components in actual implementation, and the type, quantity and proportion of the components in actual implementation may be changed freely, and the layout of the components may be more complicated.

Furthermore, each of the embodiments described below has one or more technical features, and thus, the use of the technical features of any one embodiment does not necessarily mean that all of the technical features of any one embodiment are implemented at the same time or that only some or all of the technical features of different embodiments are implemented separately. In other words, those skilled in the art can selectively implement some or all of the features of any embodiment or combinations of some or all of the features of multiple embodiments according to the disclosure of the present invention and according to design specifications or implementation requirements, thereby increasing the flexibility in implementing the invention.

As used in this specification, the singular forms "a", "an" and "the" include plural referents, and the plural forms "a plurality" includes more than two referents unless the content clearly dictates otherwise. As used in this specification, the term "or" is generally employed in its sense including "and/or" unless the content clearly dictates otherwise, and the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either fixedly connected, detachably connected, or integrally connected. Either mechanically or electrically. Either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

Herein, the terms "proximal" and "distal" are relative orientations, relative positions, directions of elements or actions with respect to each other from the perspective of an operator using the medical device, although "proximal" and "distal" are not limiting, but "proximal" generally refers to the end of the medical device that is closer to the operator during normal operation, and "distal" generally refers to the end that is first introduced into the patient.

The core idea of the invention is to provide a core wire for pushing a medical implant, which is used for pushing the medical implant, and comprises: the cannula assembly comprises a tube body and a pushing block arranged at the proximal end of the tube body, the pushing block and the tube body are kept relatively static, and the pushing block is used for abutting against the proximal end of the medical implant; the mandrel is partially arranged in the tube body in a penetrating mode and can move along the axial direction of the tube body, and the far end of the mandrel is exposed out of the far end of the tube body; and a retrieval assembly located outside the distal end of the cannula and including a retrieval portion and a support portion; the recovery part is connected to the sleeve and arranged on the periphery of the mandrel; the supporting part is arranged on the mandrel and is kept relatively static with the mandrel in the axial direction; the push core wire has a first state and a second state, the push core wire configured to: when the pushing core wire is in the first state, the supporting part is at least partially positioned at the distal end side of the recovery part, and the recovery component is used for keeping a preset distance with the medical implant; when the push core wire is in the second state, the support portion applies force to the recovery portion and causes the recovery portion to expand radially outward of the mandrel for at least partially pressing against or inserting into an aperture of the medical implant.

When the pushing core wire is in the first state, an operator can push the medical implant to a target position in a patient body by using the pushing core wire and perform first release, and in the process, because the recovery assembly and the medical implant keep a preset distance so that no interaction force exists between the recovery assembly and the medical implant, the resistance of pushing and first release of the medical implant can be effectively reduced, and the possibility that insoluble particles are generated by friction between the recovery assembly and the medical implant and/or a pipe fitting (such as a sheath and a microcatheter, which will be described below) to cause thrombus is also reduced. During the process of releasing the medical stent, as long as the medical implant is not completely released (i.e. the medical implant is at least partially located in the microcatheter), the operator can switch the pushing core wire to the second state by performing corresponding operations, and the recovery of the medical implant is realized by using the recovery assembly, and then the operator can adjust the pose of the medical implant and perform the release again.

As will be appreciated by those skilled in the art, the medical implant may include a medical stent, embolic coil, occluder, turbulator, obturator, valve, or other medical implant having a non-smooth continuous inner sidewall (e.g., mesh, corrugated, porous, etc.). The target site may be a site on a blood vessel where an aneurysm is formed.

Further, the invention also provides a medical device, which comprises the propelling core wire of the medical implant, the medical implant and the sheath tube; the push core wire is partially arranged in the sheath tube in a penetrating mode and can move along the axial direction of the sheath tube. The medical implant is compressed in the sheath tube and sleeved on the outer surface of the pushing core wire and positioned on the far end side of the pushing block. The pusher block is adapted to abut a proximal end of the medical implant when the retrieval assembly is in the first state. When the retrieval assembly is in the second state, the retriever is at least partially pressed against the medical implant or inserted into an aperture of the medical implant.

To further clarify the objects, advantages and features of the present invention, a more particular description of the invention will be rendered by reference to the appended drawings. It is to be noted that the drawings are in a very simplified form and are not to precise scale, which is merely for the purpose of facilitating and distinctly claiming the embodiments of the present invention. The same or similar reference numbers in the drawings identify the same or similar elements.

The embodiment of the invention provides a push core wire of a medical implant, which comprises a sleeve assembly 100, a mandrel 200 and a recovery assembly 300, as shown in fig. 1 and 2. Wherein the cannula assembly 100 includes a tube body 110 and a pusher block 120. The tube 110 has a first inner cavity extending axially therethrough for receiving the mandrel 200. The pushing block 120 is disposed at the proximal end of the tube 110 and is kept stationary relative to the tube 110, and the pushing block 120 is used to abut against the proximal end of the medical implant, so that the pushing block 120 can move synchronously with the tube 110 and push the medical stent 10 distally. The mandrel 200 is partially inserted into the first inner cavity and can move along the axial direction of the first inner cavity, and the distal end of the mandrel 200 is exposed outside the tube body 110. The retrieval assembly 300 is located outside the distal end of the cannula 100 and includes a retrieval portion 310 and a support portion 320. The recovery portion 310 is connected to the cannula assembly 100. The supporting portion 320 is disposed on the mandrel 200 and is axially kept stationary relative to the mandrel 200, so that the supporting portion 320 can move axially in synchronization with the mandrel 200 and can move axially relative to the recovery portion 310. Here, the support portion 320 may be formed separately from the stem 200 and then connected thereto, or may be formed integrally therewith.

The push core wire has a first state and a second state, and the push core wire is configured such that when the push core wire is in the first state, the supporting portion 320 is at least partially located at the distal end side of the recovering portion 310, and the entire recovering member 300 is used to maintain a predetermined interval with the medical implant, so that there is no contact between the recovering member 300 and the medical implant, and thus the interaction force is zero. When the core wire is in the second state, the supporting portion 320 is at least partially located between the recovering portion 310 and the mandrel 200, and the supporting portion 320 applies a supporting force to the recovering portion 310 radially outward of the mandrel 200, and expands the recovering portion 310 radially outward, and the expanded recovering portion 310 is used for at least partially pressing against the medical implant or inserting into the aperture of the medical implant.

It will be appreciated by those skilled in the art that the push core wire is adapted to cooperate with a sheath (not shown) for guiding the medical implant into a delivery tube, such as a microcatheter 20, and then to be released after pushing the medical implant along the microcatheter 20 to a target location in a patient (the method will be described later). Therefore, an embodiment of the present invention further provides a medical device, which includes the push core wire, a medical implant and the sheath, and the embodiment takes the medical implant as a medical stent 10 as an example for description. The sheath has a second lumen extending axially therethrough for loading the push core wire and the medical stent 10. The pusher wire is partially disposed through the second lumen. The medical stent 10 is compressed in the second lumen and is fitted over the outer surface of the pusher core wire and distal to the pusher block 120.

When the medical device is used, the medical stent 10 and the pushing core wire are firstly guided into the micro-catheter 20 through the sheath, and then the medical stent 10 is pushed to a target position in the body of a patient along the micro-catheter 20 for release. Specifically, the operator applies a pushing force to the pushing core wire, which is directed distally along the proximal end of the pushing core wire, so as to move the sheath assembly 100 and the mandrel 200 synchronously, and transmits the pushing force to the medical stent 10 through the pushing block 120, so as to push the medical stent 10 to move toward the distal end of the microcatheter 20 until the distal end of the medical stent 10 reaches the distal end of the microcatheter 20. The microcatheter 20 is then withdrawn to release the medical stent 10 (i.e., first release). In this process, it is preferable that the retrieval member 300 for pushing the core wire is in the first state, which has the advantages that there is no interaction between the medical stent 10 and/or the micro-catheter 20 and the retrieval member 300 when the medical stent 10 is pushed and released for the first time, so as to reduce the resistance, and also reduce the possibility of generating debris due to friction between the retrieval member 300 and the medical stent 10 and/or the micro-catheter 20, and reduce the occurrence probability of adverse consequences such as thrombus. Before the medical stent 10 is completely released, i.e. when the medical stent 10 still has a portion in the microcatheter 20, for example, the distal end of the recovery part 310 does not exceed the distal end of the microcatheter 20, if the posture of the medical stent 10 does not reach the expectation, the operator may switch the recovery assembly 300 to the second state by performing corresponding operations, and then apply a withdrawal force to the push core wire to recover the medical stent 10, and release the medical stent 10 again after adjusting the posture of the medical stent 10.

That is to say, the core wire pushing and treating device provided by the embodiment of the invention not only can solve the problem of recovery of the medical stent 10 in the releasing process, but also can effectively reduce the resistance of the medical stent 10 in the pushing and first releasing process, especially the resistance of the stent in a bending state through a bending part, and further can reduce the possibility of generating fragments due to friction in the whole implanting operation process to cause thrombus, improve the reliability and safety of the implanting operation, and reduce the risk of immediate thrombus complications.

With continued reference to fig. 1 and 2, in one illustrative embodiment, the recycling portion 310 of the recycling assembly 300 includes a base 311, an antenna 312, and a ring connector 313. The annular connector 313 is fitted over the mandrel 200 and can be connected to the distal end of the tube 110 or to the distal end face of the pusher block 120 (not shown). The base 311 extends along the axial direction of the mandrel 200, the proximal end of the base 311 is connected with the annular connecting part 313, and at least one antenna 312 is arranged on the outer surface of the base 311. The "outer surface" refers to the surface of the base 311 away from the mandrel 200.

In the treatment apparatus, when the retraction assembly 300 is in the first state, the base 311 and all of the antennae 312 are maintained at a predetermined spacing from the medical stent 10, it being understood that the predetermined spacing is greater than zero. When the recovery assembly 300 is in the second state, the base 311 and the support 320 are kept relatively stationary in the axial direction, and the base 311 deforms under the action of the support 320 to approach the medical stent 10, so that at least one antenna 312 is inserted into a pore of the medical stent 10 or abuts against the inner side wall of the medical stent 10, if the abutting pressure is large enough, the medical stent can be retracted under the action of the abutting pressure, if the abutting pressure is insufficient, at the initial stage of retracting the medical stent 10, the medical stent 10 and the mandrel 200 generate relative movement, and the antenna 312 moves to the pore of the medical stent 10, and then the medical stent 10 is synchronously retracted along with the mandrel. That is, in the embodiment, the medical stent 10 is connected to the mandrel 200 by the recycling assembly 300, so that the medical stent 10 can be kept relatively stationary with respect to the mandrel 200 in the axial direction, and thus can move synchronously with the mandrel 200 in the axial direction.

The recycling portion 310 includes a plurality of the bases 311, the bases 311 are spaced around the axis of the mandrel 200, and each of the bases 311 is provided with the antenna 312. The number of the antenna 312 disposed on each base 311 may be the same or different, and the positions of the antennas 312 disposed on different bases 311 in the axial direction of the mandrel 200 may be the same or different, which is not limited in the present invention. Preferably, a plurality of the bases 311 are uniformly arranged around the axis of the mandrel 200, so that the recovery part 310 can be connected with the medical stent 10 at a plurality of positions in the circumferential direction, so as to improve the stress balance of the recovery part 310.

Optionally, there is a gap between the inner surface of the base 311 and the sidewall of the mandrel 200, and when the recovery assembly 300 is in the first state, the inner surface of the base 311 and the sidewall of the mandrel 200 are parallel to each other, or the gap between the inner surface of the base 311 and the sidewall of the mandrel 200 gradually decreases in a proximal-to-distal direction. The term "inner surface" as used herein refers to the surface of the base 311 that is adjacent to the mandrel 200.

In order to enable the supporting portion 320 of the recovering assembly 300 to be smoothly inserted between the recovering portion 310 and the sidewall of the mandrel 200, the supporting portion 320 includes a first wedge-shaped section 321 in this embodiment, and the distance from the outer surface of the first wedge-shaped section 321 to the sidewall of the mandrel 200 gradually increases from the proximal end to the distal end. The first wedge-shaped segment 321 is at least partially located on the distal side of the recovery section 310 when the recovery assembly 300 is in the first state; when the recovery assembly 300 is in the second state, the first wedge-shaped segment 321 is at least partially located between the recovery portion 310 and the mandrel 200. That is to say, in this embodiment, the mandrel 200 drives the first wedge-shaped segment 421 to move in the distal-to-proximal direction, so that the portion of the first wedge-shaped segment 321 between the recovery portion 310 and the mandrel 200 is gradually increased, and the push core wire is switched from the first state to the second state.

It should be understood that the first wedge block 321 may extend continuously in one circle in the circumferential direction of the mandrel 200, or may be in an intermittent structure, that is, the first wedge block 321 includes a plurality of sub wedge blocks arranged at intervals in the circumferential direction of the mandrel 200. In addition, on a plane parallel to the axis of the mandrel 200, an edge line of a projection of the outer surface of the first wedge-shaped segment 321 may be a straight line or a curved line, and thus, the first wedge-shaped segment 321 may be formed of a conical structure, or may be a part of a spherical surface or an ellipsoidal surface as long as it can be inserted between the recovery part 310 and the mandrel 200, which is not limited by the present invention.

It should also be understood that the supporting portion 320 may further include a flat section 322 disposed at a distal end of the first wedge-shaped section 321, and a distance from an outer surface of the flat section 322 to a sidewall of the mandrel 200 may be equal to a maximum distance from the outer surface of the first wedge-shaped section 321 to the sidewall of the mandrel 200, so as to provide a more stable supporting force to the recovering portion 310. Alternatively, the distal end of the first wedge-shaped segment 321 may be further provided with a second wedge-shaped segment 323, and the distance from the outer surface of the second wedge-shaped segment 323 to the side wall of the mandrel 200 is gradually reduced in the proximal-to-distal direction. That is, the supporting portion 320 includes at least the first wedge-shaped segment 321, and the distal end of the first wedge-shaped segment 321 may be provided with other structures.

Preferably, the recycling assembly 300 further has developing properties, for example, developing elements are respectively disposed on the recycling portion 310 and the supporting portion 320, so that the relative positions of the recycling portion 310 and the supporting portion 320 can be monitored by a developing device during use, and the state of the recycling assembly 300 can be further determined. Of course, the retractable distance between the tube 110 and the support part 320 can be calibrated in advance by the positioning structure, and the sufficient opening of the recovery part 310 can be ensured by retracting the tube directly by the distance during the use process.

The method of use of the medical device is described below. It will be appreciated that prior to use, the retrieval assembly 300 for the advancing core wire is in the first state.

First, the operator constructs a microcatheter 20 within the patient, with the distal end of the microcatheter 20 extending to the target location.

The operator then introduces the medical device into the microcatheter 20 under the monitoring of a visualization device, such as an X-ray device. For ease of handling, the distal end of the sheath is preferably designed to be of a tapered configuration.

Next, the operator applies a pushing force to the proximal end of the pushing core wire to move the sheath assembly 100 and the mandrel 200 simultaneously to the distal end of the sheath, and transmits the pushing force to the medical stent 10 by using the pushing block 120 to make the pushing core wire carry the medical stent 10 into the microcatheter 20 and withdraw the sheath.

The operator then continues to apply a pushing force on the proximal end of the pusher wire to move the sheath assembly 100 and the mandrel 200 in unison, the pusher wire carrying the medical stent 10 through the microcatheter 20 until the distal end of the medical stent 10 reaches the distal end of the microcatheter 20.

Next, the operator applies a retraction force (distally directed proximally applied force) at the proximal end of the microcatheter 20 to retract the microcatheter 20 for a first release of the medical stent 10.

If the position of the medical stent 10 during the release process always meets the expected position, the operator can continuously withdraw the micro-catheter 20 to fully release the medical stent 10 (i.e. only perform one release process).

If the medical stent 10 is not well positioned during the releasing process of the medical stent 10, the operator may apply a retracting force to the proximal end of the mandrel 200 to move the mandrel 200 carrying the support 320 toward the proximal end of the microcatheter 20 (while the sheath assembly 100 remains stationary), so that the support 320 is inserted between the base 311 of the retrieving portion 310 and the mandrel 200 (taking the case that the support 320 is entirely located at the distal side of the retrieving portion 310 in the first state as an example). Since the distance from the surface of the first wedge-shaped segment 321 of the supporting portion 320 to the sidewall of the mandrel 200 is gradually increased along the proximal-to-distal direction, as the portion of the first wedge-shaped segment 321 inserted between the recovering portion 310 and the mandrel 200 is gradually increased, the supporting portion 320 applies a supporting force to the base 311 radially outward of the mandrel 200, so that the base 311 is gradually close to the inner surface of the medical stent 10 (i.e. the recovering portion 310 is deformed), until the antenna 312 on the base 311 is inserted into the aperture of the medical stent 10 to realize the connection between the mandrel 200 and the medical stent 10, so that the mandrel 200 and the medical stent 10 can be kept axially relatively stationary. Thereafter, the operator may apply a pushing force on the proximal end of the microcatheter 20 to push the microcatheter 20, retrieving the released medical stent 10. It should be noted that the antenna 312 on the base 311 may also be pressed against the inner surface of the medical stent 10, but then when the micro-catheter 20 is pushed, the friction between the micro-catheter 20 and the medical stent 10 may cause the medical stent 10 to move slightly, so that the antenna 312 is inserted into the aperture of the medical stent 10.

After completing the recovery of the medical stent 10, the operator can adjust the pose of the medical stent 10 and release the medical stent 10 again.

After the release of the medical stent 10 is completed, the operator applies a pushing force to the proximal end of the microcatheter 20 to push the microcatheter 20 such that the push core wire is fully advanced into the microcatheter 20. Finally, the operator withdraws the microcatheter 20 and the push core wire together out of the body.

It should be understood that in the above embodiment, the annular connector 313 of the recycling assembly 300 is not necessary, and the annular connector 313 may be omitted when the proximal end of the base 311 is directly connected to the distal end of the tube 110 (or directly connected to the pushing block 120).

In an alternative embodiment, the supporting portion 310 of the recycling assembly 300 is an elastic sleeve, a proximal end of the elastic sleeve is fixedly connected to the cannula assembly 100, and a distal end of the elastic sleeve is a free end. In this way, when the push core wire is in the second state, the supporting portion 310 may apply an axial pressing force to the elastic sleeve at the distal end of the elastic sleeve, which is directed proximally along the distal end of the mandrel 200, so that the elastic sleeve is expanded radially outward by the supporting portion 320. This is because the volume of the elastomeric sleeve can be considered approximately constant at the system force level, and axial compression along the mandrel 200 necessarily results in the elastomeric sleeve expanding radially outward of the mandrel 200. In this manner, at least a portion of the outer surface of the elastic sleeve can be pressed against the inner surface of the medical stent 10, such that there is a high friction between the outer surface of the elastic sleeve and the inner surface of the medical stent 10, which enables the medical stent 10 to remain axially stationary relative to the elastic sleeve 200. The operator may then push the microcatheter 20 to retrieve the medical stent 10. It should be noted that the supporting portion 310 may be partially inserted between the elastic sleeve and the mandrel, or the supporting portion 310 may be located at the distal end of the elastic sleeve.

According to the technical scheme provided by the embodiment of the invention, when the medical implant is conveyed and released for the first time, the recovery assembly for pushing the core wire is in the first state, so that no acting force is exerted between the recovery assembly and the medical implant, and the frictional resistance between the medical implant and the conveying pipe is reduced. It is known that the frictional resistance between the medical implant and the delivery tube does not help to push the medical implant in the delivery tube, but rather causes the medical implant to scrape against the inner wall of the delivery tube due to the squeezing of the medical implant, which is particularly likely to occur when passing through a curved portion. The delivery tube is typically of a polymeric material which is susceptible to the generation of insoluble particles when scratched from the medical implant, thereby increasing the risk of thrombus caused by the particles. Pushing the medical implant from the proximal end of the delivery tube to the distal exit of the delivery tube until reaching the target release site is a necessary route for interventional procedures, and scraping of the medical implant with the delivery tube and insoluble particles resulting from the scraping should be minimized and avoided clinically. Taking the example of implantation of a medical implant in a centripetal vessel, the length of the delivery tube is generally more than 500mm, whereas the length of the delivery tube for implantation of a medical implant in a cerebral vessel is longer, generally more than 1000mm, occupying a substantial part of the friction distance with the delivery tube compared to the intraoperative release length of the implantation instrument itself. Insoluble particles generated during the delivery process are eventually delivered into the blood vessel as the medical implant is pushed. And the implantation instrument retracts the conveying system after implantation, so that the space in the sheath tube is larger, and the debris is not easy to generate. Even the generated debris is mostly taken out of the body along with the delivery system under the condition of keeping the outward blood pressure. Therefore, the pushing core wire provided by the embodiment of the invention can effectively reduce the resistance in the process of pushing and releasing the medical implant for the first time, and reduce the risk of generating fragments and causing thrombus due to friction. When the recovery assembly is switched to the second state, the released medical implant can be recovered, and the pose of the medical implant can be conveniently adjusted.

Although the present invention is disclosed above, it is not limited thereto. Various modifications and alterations of this invention may be made by those skilled in the art without departing from the spirit and scope of this invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

1. A push core wire of a medical implant for pushing the medical implant, the push core wire comprising:

a retrieval assembly located outside the distal end of the cannula and including a retrieval portion and a support portion; the recovery part is arranged on the sleeve and is arranged on the periphery of the mandrel; the supporting part is arranged on the mandrel and is kept relatively static with the mandrel in the axial direction;

2. The push core wire of a medical implant according to claim 1, wherein the retrieving portion is an elastic sheath, and a proximal end of the elastic sheath is fixedly connected to the sheath assembly, and a distal end of the elastic sheath is a free end;

3. The push core wire of a medical implant according to claim 1, wherein the retrieving portion comprises a base and an antenna, a proximal end of the base is disposed on the cannula assembly, and a distal end of the base extends in an axial direction of the cannula assembly; at least one antenna is arranged on one side of the base, which is far away from the mandrel;

4. The push core wire of a medical implant according to claim 3, wherein there is a gap between the inner surface of the base and the sidewall of the mandrel, the inner surface of the base and the sidewall of the mandrel being parallel to each other when the push core wire is in the first state, or the gap between the inner surface of the base and the sidewall of the mandrel being gradually reduced in a proximal to distal direction when the push core wire is in the first state.

5. The push core wire of a medical implant according to claim 3, wherein the retrieving portion comprises a plurality of the seats, the seats being spaced around an axis of the core shaft, and each of the seats having the antenna provided thereon.

6. The push core wire of a medical implant according to claim 5, wherein the retrieving portion further comprises an annular connecting member, and the proximal ends of the bases are both disposed on the annular connecting member and connected to the cannula through the annular connecting member.

7. The push core wire of a medical implant according to claim 6, wherein the annular connector is provided on the tube body or the annular connector is provided on a distal end face of the push block.

8. The push core wire of a medical implant according to claim 1, wherein the support portion comprises a first wedge-shaped section, the distance from the outer surface of the first wedge-shaped section to the side wall of the core shaft gradually increases in the proximal-to-distal direction;

9. A medical device, comprising:

a sheath tube;

the push core wire of the medical implant of any one of claims 1-8, partially disposed in the sheath and movable in an axial direction of the sheath; and the number of the first and second groups,

10. The medical device of claim 9, wherein the medical implant is a medical stent.