KR101643230B1

KR101643230B1 - Stent

Info

Publication number: KR101643230B1
Application number: KR1020150131454A
Authority: KR
Inventors: 김한기; 유현승; 서준혁; 송석범; 박준규; 진규현
Original assignee: 주식회사 바이오알파
Priority date: 2015-09-17
Filing date: 2015-09-17
Publication date: 2016-07-28

Abstract

A stent for minimizing the amount of shrinkage variation of a stent is provided. The stent of the present application is characterized in that the stent has a ring structure in which a plurality of cells are arranged along the longitudinal direction of the stent, a plurality of link members connecting the ring structures neighboring in the longitudinal direction of the stent, Wherein each of the plurality of link members includes a length dummy portion deformed to extend beyond the original length when the stent is expanded and not restored to the original length.

Description

Stent {STENT}

The present invention relates to a stent for reducing recoil of a stent.

Generally, a stent can be inserted into a lesion such as a lumen or a blood vessel of a living body, and is used to secure a passage such as a lumen or a blood vessel.

Typically, a stent is a medical device used to treat an aneurysm, thrombosis, embolism, etc., and is a tubular structure that remains inside the lumen of the tube to alleviate closure.

The stent is inserted in a compressed form and then expanded in situ, either on its own or with the aid of another device. When used in coronary artery surgery to alleviate stenosis, the stent is placed by percutaneous femoral artery placement. In this type of operation, the stent may be delivered through the catheter and inflated by itself or inflated by a balloon.

The self-inflatable stent resiliently restores itself even under contractile force, so that it can withstand pressure and movement and maintain its shape. And the inflatable stent is deployed at a predetermined position as the inflated balloon is expanded, and it is then necessary to maintain the expanded shape without contracting even if the balloon and the catheter are removed.

However, after removal of the balloon and the catheter, the stent may be slightly contracted. If the amount of shrinkage change becomes extremely large, the stent may not function as a stent.

The background technology of the present application is disclosed in Korean Patent Laid-Open Publication No. 10-2012-0044928.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a stent capable of preventing shrinkage of an expanded stent or significantly reducing a shrinkage change amount (recoil amount).

According to an aspect of the present invention, there is provided a stent according to an embodiment of the present invention, the stent having a ring structure including a plurality of cell parts arranged along the longitudinal direction of the stent, Each of the plurality of link members may include a length dummy portion deformed to extend beyond the original length upon expansion of the stent and not restored to the original length.

According to an example of this embodiment, the length dummy portion may be bent at least once.

According to an example of this embodiment, the angle of bending may be an angle that prevents the elasticity of the bent portion from being at least partially lost, so that the bent portion is completely resiliently restored in the direction of bending when expanded have.

According to an embodiment of the present invention, the length dummy portion may include a portion that extends in the other direction with respect to the longitudinal direction of the link member, is bent in one direction, and then extends in the other direction.

According to an example of this embodiment, the link member may be arranged in a structure inclined with respect to the longitudinal direction of the stent.

According to one example of this embodiment, the link member may be extended corresponding to the length of the length dummy portion when the stent is extended.

According to an embodiment of the present invention, the ring structure is repeatedly formed in a zigzag shape along the circumferential direction of the stent, the stent being formed with a floor at one side in the longitudinal direction of the stent and forming a valley at the other side, At least one of the bones may include a bending deformation portion extending in a direction in which they approach each other and then bent in a direction away from each other.

According to one embodiment of the present invention, the angle of bend of the bending deformation portion at least partially dissipates the elasticity of the bending portion, thereby preventing the bending portion from being completely resiliently restored in the bending direction when the bending portion is expanded May be an angle.

According to one example of this embodiment, the bending deformation portion can make the plastic deformation more induced than the elastic deformation.

According to an example of this embodiment, the link members neighboring in the longitudinal direction of the stent may be arranged in a direction staggered with respect to each other.

According to an embodiment of the present invention, the cell portion may include a first wire repeatedly formed in a zigzag shape along the circumferential direction of the stent, and a second wire having a shape symmetrical to the first wire, And the first wire and the second wire may be sequentially formed in the longitudinal direction of the stent.

According to one example of this embodiment, the link member connects a portion of the first wire with a portion of the second wire neighboring the first wire, wherein a portion of the first wire and a portion of the second wire Can be arranged side by side.

According to the above-mentioned problem solving means, since the length dummy portion is expanded by the plastic deformation in the bent state when the stent is expanded, it is possible to prevent the expanded stent from being contracted again due to elastic recovery .

According to a preferred embodiment of the present invention, by providing the bending deformation portion, the stent can be expanded by plastic deformation rather than elastic deformation, thereby preventing the expanded stent from being elastically restored in the direction of retraction.

According to the task solution of the present invention, the amount of recoil of the stent can be remarkably reduced by the interaction of the length dummy portion and the bending deformation portion.

1 is a perspective view of a stent according to an embodiment of the present invention;
2 is an exploded view of a stent according to an embodiment of the present invention;
FIG. 3 is a view showing the entire length dummy portion and the bending deformation portion where the stent is extended, and the length dummy portion and the bending deformation portion after the stent is expanded.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. It should be understood, however, that the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In the drawings, the same reference numbers are used throughout the specification to refer to the same or like parts.

Throughout this specification, when a part is referred to as being "connected" to another part, it is not limited to a case where it is "directly connected" but also includes the case where it is "electrically connected" do.

Throughout this specification, when a member is " on " another member, it includes not only when the member is in contact with the other member, but also when there is another member between the two members.

Throughout this specification, when an element is referred to as "including " an element, it is understood that the element may include other elements as well, without departing from the other elements unless specifically stated otherwise.

In the context of the present application, a stent may have a modulus of elasticity in terms of material and structural aspects. Therefore, the stent may expand or contract. If the expanded stent is contracted, the amount of shrinkage may vary depending on the material of the stent. For example, the material of the stent can be a cobalt chromium alloy and a polymer. When the cobalt chromium alloy is used, the shrinkage variation of the stent is 5-6%, whereas when the polymer is used, the shrinkage change is remarkably larger than that of the cobalt chromium alloy material .

The present invention is a technique of improving the structure of a stent to reduce the amount of change (recoil amount) that is contracted when a stent such as a biodegradable stent using a polymer is expanded and placed in a blood vessel. Such a stent of the present invention can exhibit a greater effect when the polymer is applied to a biodegradable stent having a relatively large amount of shrinkage change as described above. However, the stent of the present invention is not limited to such a biodegradable stent, and may be applied to stents of various uses or materials.

Hereinafter, a stent according to an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a perspective view of a stent according to one embodiment of the present invention, and FIG. 2 is an exploded view of a stent according to an embodiment of the present invention.

The stent 100 may include a cell 110 and a plurality of link members 120.

The cell 110 may have a plurality of ring structures arranged along the longitudinal direction of the stent. The ring structure means that the wires arranged along the circumferential direction of the stent 100 and formed into a band shape are formed as a loop.

For example, the cell 110 may be formed such that the first wire 111 and the second wire 112 are sequentially repeated in the longitudinal direction of the stent 100, as shown in FIG. The first wire 111 is repeatedly formed in a zigzag shape along the circumferential direction of the stent 100. The second wire 112 is formed in a shape symmetrical to the first wire 111, 111).

The first and second wires 111 and 112 arranged in the circumferential direction of the stent 100 constitute a plurality of ring structures R1, R2, R3 ... RN, and the stent 100 As shown in Fig.

For example, the ring structure may be repeatedly formed in a zigzag shape, and a floor may be formed on one side in the longitudinal direction of the stent 100, and a bone may be formed on the other side. (See R1, R2, R3 ... RN in Fig. 1)

Also, at least one of the floor and the bottom of each ring structure (see FIG. 1, R1, R2, R3 ... RN) of the cell 110 may include the bending deformation portion 130.

The bending deformation portions 130 may extend in a direction approaching each other and then be bent in a direction away from each other.

Illustratively, referring to FIG. 2, the bending deformation 130 may be understood to be formed similar to an omega (?) Shape. As a more specific example, the bending deformation portions 130 may refer to portions where both ends of the arc shape in the direction of approaching to each other are bent and extended in directions away from each other by switching directions. 2, the bending deformation portions 130 may be formed on the floor and the valleys of the ring structure, respectively.

The angle of the bending portion of the bending deformation portion 130 may be an angle that at least partially eliminates the elasticity of the bending portion to prevent the bending portion from being completely resiliently restored in the bending direction when the bending portion is expanded. Conventionally, the expanded stent 100 generally has a problem of elastic contraction when a balloon, a catheter or the like is removed. In contrast, according to the present invention, when the stent 100 is expanded, the bending deformation portion 130 where the elasticity is lost is further deformed by the plastic deformation, and the stent 100 is expanded. The stent 100 is resiliently contracted again and the function of the stent 100 is deteriorated. That is, the bending deformation portion 130 may be a region where the elasticity is at least partially lost (plastic deformation region outside the elastic limit) so as to prevent the extended stent 100 from being undesirably contracted.

Such a bending deformation portion 130 can make the plastic deformation more induced than the elastic deformation.

Meanwhile, the plurality of link members 120 may connect adjacent ring structures (R1, R2, R3, ..., RN in Fig. 1) in the longitudinal direction of the stent 100 as shown in Fig. That is, the ring structure R1, the link member 120, the ring structure R2, the link member 120, and the ring structure R3 may be arranged in order from the right side to the left side in Fig.

2, the link member 120 connects a portion of the first wire 111 with a portion of the second wire 112 adjacent to the first wire 111, and the first wire 111 And a portion of the second wire 112 may be parallel to each other. That is, a portion of the first wire 111 and a portion of the second wire 112, which are arranged in parallel to each other, may face each other, and the link member 120 may include a portion of the first wire 111, Two wires 112 may be interconnected.

Further, each of the link members 120 may be arranged in a tilted structure with respect to the longitudinal direction of the stent 100 (see FIG. 2). That is, each of the link members 120 may be at an angle to the longitudinal direction of the stent 100.

Illustratively, the link member 120 may be arranged in the approximate 2 o'clock-8 o'clock direction or approximately 10 o'clock-4 o'clock direction.

Each of the link members 120 is arranged in an inclined structure with respect to the longitudinal direction of the stent 100 so that the link members 120 are extended in the circumferential direction of the stent 100 by being tilted in the longitudinal direction of the stent 100, (100) can be enlarged. That is, each of the link members 120 arranged in an inclined structure can flexibly change the diameter of the stent 100.

In addition, the link members 120 adjacent to each other in the longitudinal direction of the stent 110 may be arranged in a staggered direction. Referring to FIGS. 1 and 2, the link member 120 connecting the R1 ring structure and the R2 ring structure can extend in the 10: 4 direction when viewed in the developed view, while the R2 ring structure and the R3 ring structure The connecting link member 120 may extend in the 8: o'clock direction when viewed on the exploded view.

Each of the plurality of link members 120 may include a length dummy portion 121. The length dummy portion 121 is a means for minimizing recoil of the stent 100. The recoil herein refers to the amount of change in which the expanded stent 100 is contracted when it is contracted. The length dummy portion 121 is formed by plastic deformation at the time of expanding the stent 100 so as to increase its length so that the elasticity can not be restored to its original length to minimize shrinkage or shrinkage.

In addition, the length dummy portion 121 may be deformed so as to be longer than the original length when the stent 100 is expanded, and may not be restored to its original length.

Also, the length dummy portion 121 can be bent at least once.

2, the length dummy portion 121 includes a portion extending in the other direction with respect to the longitudinal direction of the link member 120, and being bent in one direction and then bent and bent in the other direction can do. That is, the length dummy portions 121 may be bent at least one time so that at least a part of the length dummy portions 121 are overlapped with each other (overlapped). As another example, the length dummy portion 121 may be bent into an alphabet S shape or a zigzag shape or the like. As such, the length dummy portion 121 can be formed by variously bending. However, it is preferable that the length dummy portion 121 is formed in a shape and material that can be plastic deformed and extended so that elasticity of the bent portion is at least partially lost, and elasticity can not be recovered when the stent 100 is expanded.

That is, the angle at which the length dummy portion 121 is bent may be an angle that at least partially eliminates the elasticity of the bent portion so that the bent portion is completely resiliently restored in the bent direction when the flat portion is expanded. By way of example, the angle of bending may be between 160 and 180 degrees, preferably 180 degrees.

On the other hand, when the stent 100 is extended, the link member 120 may extend to correspond to the overlapping length of the length dummy portion 121. As the number of bending is increased, the extent of extension of the stent 100 can be widened.

FIG. 3 is a view showing the entire length dummy portion and the bending deformation portion where the stent is extended, and the length dummy portion and the bending deformation portion after the stent is expanded. 3 (a) is a view showing a length dummy portion 121 and a bending deformation portion 130 before the stent 100 is expanded. FIG. 3 (b) is a view showing the length dummy portion 121 and the bending deformation portion 130 of the first embodiment.

When the stent is expanded, the length dummy portion 121 shown in FIG. 3 (a) is expanded in a substantially straight line as shown in FIG. 3 (b). At this time, the length L1 'of the length dummy portion 121 may be extended twice as long as the length (L1'-L1) of the length dummy portion 121 overlapped.

3 (a), when the stent is expanded, the length L2 between one side and the other side of the bending deformation portion 130 is widened between one side and the other side as shown in Fig. 3 (b) (L2 ') can be increased.

The stent 100 according to the present invention has an effect that the length dummy portion 121 and the bending deformation portion 130 interact with each other to significantly reduce the amount of recoil of the stent 100 when the stent 100 is to be kept in an extended state . For example, when the stent 100 is expanded, the length dummy portion 121 whose length is extended through plastic deformation prevents the bent portion from being restored to its original shape (a state of returning to the bending direction) And the ring structure is plastically deformed in the direction deviating from the elastic limit by the bending deformation portion 130. This makes it possible to prevent the expanded stent 100 from being contracted by the elastic recovery as much as possible and to remove the balloon, It is possible to more strongly resist the contraction force acting upon contracting of the next blood vessel.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or essential characteristics thereof. You can understand that. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

100: stent
110:
120: Link member
121:
130: Bending deformation section

Claims

A stent having a cylindrical structure with both open ends in the longitudinal direction,
A ring structure having a plurality of ring structures arranged along the longitudinal direction of the stent;
And a plurality of link members connecting the ring structures neighboring in the longitudinal direction of the stent,
Wherein each of the plurality of link members includes a length dummy portion that is deformed to extend beyond an original length upon expansion of the stent and is not restored to the original length,
The length dummy portion includes a portion that is bent at least once, extends in the other direction with respect to the longitudinal direction of the link member, is bent in one direction, and then extends in the other direction,
The bent portion in one direction and the bent portion in the other direction are bent at an angle of 180 degrees,
Wherein when the stent is expanded, a portion of the elasticity at least partially disappears is plastically deformed while being stretched by an angle range of 180 degrees so as to prevent elastic recovery of the length dummy portion.

delete

The method according to claim 1,
The link member
Wherein the stent is arranged in an inclined structure with respect to the longitudinal direction of the stent.

The method according to claim 1,
The link member
And wherein when the stent is expanded, the length dummy portion extends corresponding to the overlapping length.

The method according to claim 1,
The ring structure comprises:
The stent is repeatedly formed in a zigzag shape along the circumferential direction of the stent,
A floor is formed on one side in the longitudinal direction of the stent and a bone is formed on the other side,
Wherein at least one of the floor and the bones includes a bending deformation portion extending in a direction to approach each other and then bent in a direction away from each other.

delete

8. The method of claim 7,
Wherein the bending deformation portion allows the plastic deformation to be induced more than the elastic deformation.

The method according to claim 1,
And the link members neighboring in the longitudinal direction of the stent are arranged in a direction staggered from each other.

The method according to claim 1,
The cell unit includes:
A first wire repeatedly formed in a zigzag shape along the circumferential direction of the stent;
And a second wire which is symmetrical with the first wire and is arranged adjacent to the first wire,
Wherein the first wire and the second wire are formed to be sequentially repeated in the longitudinal direction of the stent.

12. The method of claim 11,
The link member
Connecting a portion of the first wire with a portion of a second wire adjacent the first wire, wherein a portion of the first wire and a portion of the second wire are parallel to each other.