CN110960341A

CN110960341A - Support conveying system

Info

Publication number: CN110960341A
Application number: CN201811152171.0A
Authority: CN
Inventors: 梅奇峰; 孙智慧; 常志峰
Original assignee: Shanghai Xinrui Medical Technology Co ltd
Current assignee: Shanghai Xinrui Medical Technology Co ltd
Priority date: 2018-09-29
Filing date: 2018-09-29
Publication date: 2020-04-07

Abstract

The invention relates to a stent delivery system, which comprises an outer sheath and a pushing assembly, wherein the outer sheath is used for accommodating a stent, the pushing assembly is arranged in the outer sheath in a sliding manner, and the pushing assembly can push the stent out of the distal end of the outer sheath; the propelling movement subassembly is close to be provided with the restraint piece on the tip of support, the restraint piece adopts elastic material to make, the internal diameter of restraint piece is to outer sheath pipe distal end direction crescent, the big one end of restraint piece internal diameter is used for restraining the support towards the one end of outer sheath pipe near-end. The stent conveying system has the technical effect that the stent can be recycled before the stent is not completely unfolded.

Description

Support conveying system

Technical Field

The invention relates to the technical field of medical instruments, in particular to a stent conveying system.

Background

The incidence of aneurysm vascular diseases has increased remarkably in recent years, and currently, a stent graft or a dense mesh stent is used as a means for treating aneurysm. The covered stent refers to a stent formed by coating a metal stent with a special film material (polytetrafluoroethylene, terylene, polyester, polyurethane and the like). Not only retains the function of the metal bracket, but also has the characteristics of the membranous material. The dense-mesh stent is generally formed by weaving a multilayer structure or different weaving modes, and the outer layer is free of a flow resistance film.

The stent is delivered to the lesion site through a delivery system and released. However, due to the elasticity of the stent, when the stent is deployed by using the delivery system shown in fig. 1 during the surgical implantation process, the axial length of the stent is shortened after the stent is released from the sheath, and the stent is displaced proximally along with the release, so that the positioning of the stent in the lesion area cannot be accurately controlled during the surgical process, the release position is not ideal, and the stent cannot be recovered to adjust the deployment position of the stent after the stent is partially released. On the other hand, the loading and sheath-retracting of the current stent are also troublesome.

Accordingly, there is a need for an improved stent delivery system that addresses at least one of the problems described above.

Disclosure of Invention

It is an object of the present invention to provide a new solution for a stent delivery system.

According to one aspect of the present invention, there is provided a stent delivery system comprising an outer sheath for receiving a stent and a pusher assembly slidably disposed within the outer sheath, the pusher assembly being capable of pushing the stent out of the distal end of the outer sheath;

the propelling movement subassembly is close to be provided with the restraint piece on the tip of support, the restraint piece adopts elastic material to make, the internal diameter of restraint piece is to outer sheath pipe distal end direction crescent, the big one end of restraint piece internal diameter is used for restraining the support towards the one end of outer sheath pipe near-end.

Optionally, the side wall between the two ends of the restraint is a net structure.

Optionally, the resilient material is a memory metal.

Optionally, the restraint is woven from a memory metal wire made of memory metal.

Optionally, the memory metal is nitinol.

Optionally, the constraining member is funnel-shaped, and the end of the constraining member with the small inner diameter is fixed on the end part of the pushing assembly close to the bracket.

Optionally, the restraining member is bonded or snapped to the pushing assembly.

Optionally, the end of the constraining member with the larger inner diameter constrains the length of the stent to 10% -30% of the length of the stent.

Optionally, the sheath further comprises a guide wire tube, the guide wire tube is arranged in the outer sheath, the guide wire tube penetrates through the pushing assembly, and the support is sleeved outside the guide wire tube.

Optionally, the device further comprises a TIP head, the TIP head is arranged at the distal end of the outer sheath and is communicated with the guide wire tube, and the TIP head closes the distal end of the outer sheath.

The stent conveying system has the technical effect that the stent can be recycled before the stent is not completely unfolded.

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

Drawings

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

Fig. 1 is a prior art stent delivery system.

Fig. 2 is a schematic illustration of an expanded configuration of some embodiments of the present invention.

Fig. 3 is a schematic view of a stent first loading sheath retracting or releasing process according to some embodiments of the present invention.

Fig. 4 is a schematic view of a stent secondary loading sheath retraction or release process according to some embodiments of the present invention.

Fig. 5 is a schematic view of a third loading sheath retracting or releasing process of a stent according to some embodiments of the present invention.

Fig. 6 is a schematic view of a stent in a loaded or unreleased state according to some embodiments of the invention.

Fig. 7 is a schematic view of a fully released state of a stent according to some embodiments of the present invention.

In the figure: sheath 1, pushing assembly 2, stent 3, constraining member 4, side wall 41, guide wire tube 5, TIP 6, blood vessel 7.

Detailed Description

Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that: the relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise.

The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

Techniques and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail, but are intended to be considered a part of the specification where appropriate.

In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

A stent delivery system provided by the present invention, in some embodiments, with reference to fig. 2-7, includes a sheath 1 and a pusher assembly 2. The sheath 1 is used to accommodate a stent 3. The stent 3 may be a dense mesh stent or a stent graft, which is not limited in the present application.

The pushing assembly 2 is arranged in the sheath tube 1 in a sliding mode. The pushing component 2 is pushed from the proximal end of the sheath tube 1 to the distal direction, the pushing component 2 can push the stent 3 out of the distal end of the sheath tube 1, and the stent 3 can be released and arranged in the blood vessel 7 when the sheath tube is positioned in the blood vessel 7. The pushing assembly 2 may include a push rod and other structures in the prior art, and the present application is not limited thereto.

The end part of the pushing component 2 close to the bracket 3 is provided with a restraint piece 4. The restraining element 4 is made of an elastic material.

Further, the elastic material may be a memory metal. In some other embodiments, the elastic material may also be some materials, such as polymer materials, which have elasticity and can be deformed by force.

Furthermore, the restraint part 4 can be formed by weaving memory metal wires made of memory metal, so that the restraint part has a dense mesh structure, can be the same as the main structure of some dense mesh supports or film-covered supports, and is convenient to match with the support 3.

Further, the memory metal may be a metal material having elasticity, such as nitinol.

The inner diameter of the constraining member 4 gradually increases toward the distal end of the outer sheath 1. The specific shape of the restraint part 4 can be funnel-shaped, and can also be a structure with one end having an inner diameter larger than that of the other end, such as a round table shape, a horn shape and the like. The end of the restraint piece 4 with the small inner diameter is fixed on the end part of the pushing assembly 2 close to the bracket 3. Further, the constraining member 4 may be fixed on the pushing assembly 2 by bonding or clipping.

The big one end of 4 internal diameters of about piece is used for retraining the one end of support 3 towards the near-end of outer sheath pipe 1, promptly the one end of the near-end of support 3 towards outer sheath pipe 1 is retrained in the big one end of 4 internal diameters of about piece, and about piece 4 is located between propelling movement subassembly 2 and support 3, for propelling movement subassembly 2 and support 3 play the connection effect, through in outer sheath pipe 1, about piece 4 is to the constraint of 3 one ends of support, makes propelling movement subassembly 2 can drive through about piece 4 the near-end or the distal end direction of 3 outer sheath pipes 1 of support remove.

The pushing assembly 2 drives the support 3 to move towards the proximal direction of the outer sheath 1 through the restraining part 4, so that on one hand, when the support 3 is loaded in the outer sheath 1, a special loading device is not needed;

referring to fig. 2, the end of the restraint member 4 with a large inner diameter is moved until the distal end of the outer sheath 1 is exposed;

referring to fig. 3, one end of the stent 3 is then inserted into the end of the constraining member 4 having the larger inner diameter;

referring to fig. 4, the stent 3, the restraint member 4 and the pushing assembly 2 are kept still, the outer sheath tube 1 moves towards the distal direction, the restraint member 4 is pressed by the distal end of the outer sheath tube 1, so that the inner diameter of the restraint member 4 is gradually reduced, and the end of the restraint member 4 with the large inner diameter drives the end of the stent 3 to be also reduced along with the change of the inner diameter, so that the stent 3 can enter the outer sheath tube 1;

referring to fig. 5, the stent 3 enters into the sheath 1 as the sheath 1 moves;

referring to fig. 6, the loading of the stent 3 into the outer sheath 1 is completed.

The pushing component 2 drives the stent 3 to move towards the far end direction of the outer sheath tube 1 through the restraining part 4, and the stent 3 can be normally arranged in a blood vessel.

Referring to fig. 6, the stent 3 is not released;

referring to fig. 5 to 4 to 3, the pushing assembly 2 drives the stent 3 to move towards the distal end of the sheath tube 1 through the constraining member 4, and the stent 3 is gradually released;

referring to fig. 7, the stent 3 is fully released in the vessel 7 and the deployment of the stent delivery system is completed.

Further, when the position of the stent 3 is deviated during the intravascular deployment, for example, as shown in fig. 4, when the stent 3 is not completely deployed and separated from the sheath tube 1, the friction force between the undeployed constraining member 4 and the stent 3 is greater than the friction force between the stent 3 and the blood vessel, and the constraining member 4 can drive the stent 3 to return into the sheath tube 1 by retracting the pushing assembly 2, so that the deployment position of the stent 3 can be readjusted. Or in the case shown in fig. 3, the stent 3 has already left the outer sheath 1, the constraining member 4 is completely opened but not separated from the stent 3, the pushing assembly 2 can be kept still, the outer sheath 1 is pushed to move in the distal direction, the constraining member 4 is pressed by the distal end of the outer sheath 1 so that the inner diameter of the constraining member 4 is gradually reduced, and the end of the constraining member 4 with the larger inner diameter drives the end of the stent 3 to become smaller along with the change of the inner diameter, so that the stent 3 can be reloaded into the outer sheath 1. Further, the manner of pushing the sheath tube 1 to move in the distal direction is also applicable to the case that the stent 3 shown in fig. 4 is not completely unfolded and separated from the sheath tube 1, and a person skilled in the art can select the recovery manner according to the actual situation, which is not limited in the present application.

Further, when the stent 3 is completely deployed away from the sheath 1 in the blood vessel, the pushing assembly 2 is retracted, and the friction force between the completely deployed stent 3 and the blood vessel is greater than the friction force between the deployed constraining member 4 and the stent 3, so that the constraining member 4 is disengaged from the stent 3, see fig. 7, and the deployment of the stent 3 in the blood vessel 7 is completed.

The invention can simplify the loading of the bracket and has flexible usability. The stent can be recovered before the position where the restraint piece and the stent are overlapped is not separated, so that the operability of the conveying system is improved.

In some embodiments, referring to fig. 2-7, the side wall 41 between the two ends of the constraint 4 is a mesh structure to facilitate elastic deformation. The net structure can be formed by weaving the memory metal wires, so that the friction force between the restraint piece 4 and the bracket 3 can be increased. The mesh structure may also be formed by cutting the memory metal, which is not limited in this application.

In some embodiments, the end of the restraint member 4 with the large inner diameter restrains the length of the stent 3 to 10% -30% of the length of the stent 3, so that enough restraint friction force can be kept between the restraint member 4 and the stent 3, and the restraint member 4 can not be separated from the stent 1 in the blood vessel 7 due to too large friction force, so that the stent 1 is displaced or recovered to cause the failure of the deployment.

In some embodiments, referring to fig. 2-7, the stent delivery system further comprises a guidewire tube 5, the guidewire tube 5 being disposed within the sheath 1 for cooperating with a guidewire to move the sheath 1 along the guidewire to a desired location in a blood vessel. And the wire guide pipe 5 penetrates through the pushing assembly 2, and the support 3 is sleeved outside the wire guide pipe 5.

Further, in some embodiments, referring to fig. 2-7, the stent delivery system further comprises a TIP head 6, the TIP head 6 being disposed at the distal end of the sheath 1 in communication with the guidewire tube 5 such that the stent delivery device is movable along the guidewire. The TIP head 6 closes the distal end of the outer sheath 1, and prevents blood from flowing directly into the outer sheath 1.

Although some specific embodiments of the present invention have been described in detail by way of illustration, it should be understood by those skilled in the art that the above illustration is only for the purpose of illustration and is not intended to limit the scope of the invention. It will be appreciated by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.

Claims

1. A stent delivery system comprising an outer sheath for receiving a stent and a pusher assembly slidably disposed within the outer sheath, the pusher assembly being capable of pushing the stent out of the distal end of the outer sheath;

2. The stent delivery system of claim 1, wherein the sidewall between the ends of the constraint is a mesh structure.

3. The stent delivery system of claim 1, wherein the resilient material is a memory metal.

4. The stent delivery system of claim 3, wherein the constraining member is woven from a memory wire made of a memory metal.

5. The stent delivery system of claim 3, wherein the memory metal is nitinol.

6. The stent delivery system of claim 1, wherein the restraining member is funnel-shaped, and the end of the restraining member having a smaller inner diameter is secured to the end of the pusher assembly adjacent the stent.

7. The stent delivery system of claim 6, wherein the restraint is bonded or snapped onto the pusher assembly.

8. The stent delivery system of claim 1, wherein the end of the constraining member having the larger inner diameter constrains the length of the stent from 10% to 30% of the length of the stent.

9. The stent delivery system of claim 1, further comprising a guidewire tube disposed within the outer sheath, the guidewire tube extending through the pusher assembly, the stent being disposed outside the guidewire tube.

10. The stent delivery system of claim 9, further comprising a TIP head disposed at a distal end of the sheath in communication with the guidewire tube, the TIP head closing the distal end of the sheath.