KR100320239B1 - Lumen expansion stent and its manufacturing method - Google Patents

Abstract

It relates to a lumen expansion stent and a method of manufacturing the same having excellent expandability and excellent expandability,

Self-contractable and flexible unit member of flexible unit length can be reciprocated in a zigzag shape from one end to the other end of the reference circumferential surface and spirally wound along the reference circumferential surface to cross the mesh structure. When the unit member and the unit member intersect with each other, the unit members are twisted at least once, and the unit members are twisted to each other at this intersection to form a cylindrical shape as a whole.

Description

Lumen expanding stent and its manufacturing method

The present invention relates to a lumen expanding stent, and more particularly, to a lumen expansion stent inserted into a constricted portion of the lumen to expand the lumen or prevent the expanded lumen from being narrowed again.

In general, due to diseases occurring in the human body, the lumens in the human body may become narrowed and may be in a state in which no function may occur in severe cases.

For example, when the lumen is narrowed, esophageal cancer may cause narrowing of the esophagus, when arterial sclerosis does not allow for a smooth blood circulation, or a track in which a dimple coming out of the liver may flow.

Since the food, blood, or bile cannot flow smoothly in the state where the lumen is constricted, the constricted lumen should be expanded to maintain the passage. In this case, for example, as a method for expanding and maintaining the constricted passage, A stent is inserted into the lumen.

Such stents generally have a cylindrical structure in overall shape, and have an elastic force so that the stent can be contracted by applying an external force, and when the external force is removed, the self-expanding method is widely used.

The self-expandable stent must have various characteristics, that is, expandability to inflate the lumen, flexibility to flexibly adapt to the bent portion of the lumen, and shrinkage to shrink to a constant diameter. Will be able to exercise properly.

If the stent lacks the expandability of the characteristics of the stent, it is easy to move from the initial insertion position of the lumen, and if the lack of flexibility, the so-called shortening phenomenon occurs shortening to the stenosis when the stent expands in the stenosis, shrinkage If this is insufficient, the size of the inserting device for inserting the stent will increase.

Therefore, a number of stents have been proposed to solve this problem. Among them, Korean Patent Application No. 97-1573 consists of a unit length of wire and has a longitudinal axis in a cylindrical stent. The stent has peaks and valleys. Have at least a first turn and a second turn of a plurality of straight lines of equal length connected by a plurality of bending points to have parts, the valleys having a short straight shape, the peaks of the second turn being the Twisted with the valleys of the straight line of the first turn, and the end of the last straight part of the first turn is twisted and connected to a straight valley formed between the first straight part of the first turn and the adjacent straight part of the first turn; A cylindrical stent is disclosed that extends to the first straight portion of two turns.

The conventional stent has excellent expandability because the peaks and the valleys are connected by twisting at least two times, and the flexibility and shrinkage are remarkably inferior, resulting in a shortening phenomenon and a large stent insertion device. There is this.

In order to solve the above problems, as shown in Fig. * Korean Patent Application No. 97-51355 has one long filament N from the starting point which is one point on the N equal circumference constituting one end of the tube form It is a circumferential point of circumference, spiraling along the tube-shaped wall, and then zigzag back and forth between the two ends of the tube-like, at the same time intersecting with each other to form a number of spiral filaments that make a mesh on the wall. A stent is disclosed in which one elongate filament constitutes the entire tube form.

Compared to the stent disclosed in the above-mentioned Korean Patent Application No. 97-1573, the above-described conventional stents have very good flexibility and shrinkage while the expansion force is lowered, so that there is still a problem of being easily moved from the first implanted point of the lumen.

Therefore, the present invention has been proposed to solve the above problems, and an object of the present invention is to provide an excellent lumen expansion stent and a method of manufacturing the same while having excellent flexibility and shrinkage.

In order to achieve the above object, the present invention, the contraction and expansion of the self-contained unit member having a constant unit length of flexibility and reciprocating in a zigzag shape from one end to the other end of the reference circumferential surface and the reference circumferential surface Therefore, it is wound spirally and intersecting with each other to form a mesh structure, and when the unit member and the unit member cross each other, at least one or more times to be filtered, connecting the unit members to each other by twisting each other at the intersection to form a cylindrical shape as a whole Is done.

Preparing a unit member having a predetermined unit length, which can be contracted and expanded by itself and has flexibility; The unit member reciprocates from one end of the reference circumferential surface to the other end in a zigzag shape to form a peak portion and a valley portion and a spiral portion connecting them, and also spirally wound the spiral portion along the reference circumferential surface while the spiral portions intersect. When forming a mesh structure; And forming a connection by twisting the intersection at least once or more by twisting the spiral and the spiral when the spirals cross each other.

Accordingly, since the spirals of the unit member and the spirals intersect at least one or more times, the spirals are connected to each other by twisting at least once, and thus the flexibility secured by the mesh structure formed while the spirals intersect is formed. While retaining shrinkage, it will have a constant and excellent expansion force along the length of the unit member.

1 is a perspective view showing a lumen expanding stent according to the present invention.

Figure 2 is a view showing a state in which the unit member of the lumen expansion stent according to the invention is wound during the first round trip.

3 is a view showing a state in which the unit member is wound from one end of the reference circumferential surface to the other end in the state of FIG.

4 is a view showing a state in which the unit member of the lumen expansion stent is wound while reciprocating the first two times in accordance with the present invention.

5 shows a state in which the unit member is wound from one end of the reference circumferential surface to the other end in the state of FIG.

6 is a view comparing the expansion force of the stent and the conventional stent according to the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIG. 1, the lumen expanding stent 1 according to the present invention is capable of contracting and expanding on its own and is generally formed in a cylindrical shape along a predetermined reference circumferential surface C. FIG.

The stent 1 crosses each other while the unit member 3 having a constant unit length is reciprocated in a zigzag shape from one end to the other end of the reference circumferential surface C and spirally wound along the reference circumferential surface C. By forming a mesh structure, and when the unit member 3 and the unit member intersect with each other at least one or more times, it can be made by twisting the unit member 3 to each other at this intersection.

The unit member 3 may be made of a wire or filament having flexibility and shrinkage and expansion as well as flexibility.

The unit member 3 includes peaks 5 formed at one end of the reference circumferential surface C; Valleys 7 formed at the other end of the reference circumferential surface; The peaks 5 and the valleys 7 may be connected to each other, and the spirals 9 may be wound in a spiral along the reference circumferential surface C. FIG.

The peak portion 5 and the valley portion 7 may be formed in a curved shape as shown in FIG. 1 for easy fabrication, and the present invention is not limited thereto, and may be formed in a straight line.

The spiral portion 9 and the spiral portion 9 intersect to form a mesh structure along a reference circumferential surface, and when the spiral portions 9 cross each other, the spiral portion is filtered at least once or more. (9) and the spiral portion (9) by twisting to form a connecting portion (11).

The connection portion 11 is preferably made of a twist once while regularly filtering at least one or more intersections of the spiral portion 9 to ensure expansion while retaining excellent flexibility and shrinkability.

Looking at the manufacturing process of the lumen expansion stent, preparing a unit member (3) having a predetermined unit length;

Reciprocating the unit member 3 from one end of the reference circumferential surface C to the other end in a zigzag shape to form a peak portion 5, a valley portion 7, and a spiral portion 9 connecting them; And forming a mesh structure when the spirals 9 cross while spirally winding the spirals 9 along the reference circumferential surface C;

When the spirals 9 intersect with each other in the above step, forming the connecting portion 11 by twisting the crossing portion at least once or by twisting the spiral portion 9 and the spiral portion 9. Can be.

The connection part 11 is most preferably made of a twist once while regularly filtering at least one or more crossing portions of the spiral part 9 to secure the expandability while maintaining excellent flexibility and shrinkage.

Accordingly, in the lumen expanding stent 1 of the present invention, the unit member 9 forms a peak portion 5 at one end of the reference circumferential surface, and the unit along the other end at one end of the reference circumferential surface C. The spiral 9 of the member 3 is wound in a spiral shape.

Then, the unit member 3 forms a valley portion 7 at the other end of the reference circumferential surface C, and then again follows the spiral portion 9 of the unit member along one end at the other end of the reference circumferential surface. It is wound in a spiral shape, where the connecting portion 11 is formed by twisting once when the spiral portion 9 and the spiral portion 9 intersect.

By the above-described method, the unit member 3 forms the peak portion 5 and the valley portion 7 at both ends of the reference circumferential surface, and at one end of the reference circumferential surface C as shown in FIGS. 3 to 5. And the other end is reciprocated in a zigzag shape and wound in a spiral shape, and when the spiral portion 9 and the spiral portion 9 cross each other, the process of forming the connecting portion 11 while filtering the intersection portion once is repeated. If done, the stent as shown in Figure 1 is finally completed while forming a mesh structure.

Therefore, the lumen expansion stent 1 of the present invention is zigzag while the spiral portion 9 of the unit member 3 is connected to the peak portion 5 and the valley portion 7 at both ends of the reference circumferential surface C. It reciprocates in shape and is wound spirally along the reference circumferential surface C, and the spiral portion 9 and the spiral portion 9 intersect to form a mesh structure, thereby providing excellent flexibility and shrinkability.

In addition, when the spiral portion 9 and the spiral portion 9 intersect, the spiral is formed at least once, while the spiral portions 9 are connected to each other once by twisting to form the connecting portion 11. The flexibility and shrinkage secured by the mesh structure formed by the intersecting portion 9 acts around the connecting portion 11 while maintaining the flexibility and shrinkability almost intact, and along the length of the unit member 3. But it will have excellent expansion force.

When comparing the results obtained by testing the lumen expansion stent of the present invention (hereinafter referred to as "new type") and the stent disclosed in the Republic of Korea Patent Application No. 97-51355 (hereinafter referred to as "existing type").

* Stent making type

Table 1

division diameter Length Wire thickness Heat treatment condition Cross angle Existing Type 16 mm 6.5 cm 0.22mm 500 ℃, 30 minutes About 100 ° New type 16 mm 6.5 cm 0.22mm 500 ℃, 30 minutes 90 °

First, the length, diameter, wire thickness, and heat treatment conditions of the two types were tested in the state shown in Table 1.

However, the new type was connected by twisting the intersections, and the existing type was made by simply crossing and the angle at the crossing was increased to increase the expansion force.

* Stent expansion force test

The two types of stent inflation experiments are shown in Table 2 and FIG. 6 when the repulsive force is measured when the diameter of the stent is reduced due to partial stress using a hardness tester.

Table 2

Diameter (mm) 16 14 12 10 8 6 4 Repulsive force of conventional type 0 0 0 0 0 One 2 New type of repulsion 0 0 2 5 11 18 24

The existing type showed only 2shore forces when the diameter was reduced from 16mm to 4mm, but the new type stent improved about 12 times when the force was measured about 24shore when reduced from 16mm to 4mm.

Stent shortening

Two types of stents were mounted on a sheath for 3 mm internal stent to measure the change in length from the original length and how long the shortening occurred.

The calculation of the shortening is as follows.

Shortening = t100 (%)

Where the constrained stent length is the length of the stent as it is placed in the sheath,

Deployed Stent Length: Shows the length of the original stent or the length after being deployed from the sheath. Table 3 compares the experimental results of the two types.

Table 3

type Original length (cm) Length after installation in insertion tube (cm) Change in length (cm) shortening(%) Conventional type 6.5 cm 10 cm 3.5 cm 35% New type 6.5 cm 9 cm 2.5cm 27%

Here, the two types were made with the same original length (6.5 cm), but the stent of the existing type had a change of 3.5 cm in length, whereas the new type of stent was 2.5 cm, which is not changed more severely than the existing type of stent.

* Conclusion of the experiment

Although the existing type of stent increased the cross angle by increasing the number of rotations in the longitudinal direction to compensate for the low expansion force, the expansion force was significantly lower than that of the new type of stent as shown in Table 2, and the shortening occurred significantly. Insertion of the right part of the stent will be more difficult than with newer stents.

As described above, since the present invention possesses excellent flexibility and shrinkability, and also has excellent expandability, shortening phenomenon of shortening of the length to the narrowing part when expanding in the lumen can be minimized, and the size of the inserting device for inserting the stent can be as small as possible. It is effective in not moving easily from the initial implantation point of the lumen.

Claims (6)

Self-contractable and flexible unit member of flexible unit length can be reciprocated in a zigzag shape from one end to the other end of the reference circumferential surface and spirally wound along the reference circumferential surface to cross the mesh structure. When the unit member and the unit member is formed to cross each other, the forming member is twisted one or three times at this intersection, the unit members are twisted with each other, and formed in a cylindrical shape as a whole. The method of claim 1, wherein the unit member comprises: peak portions formed at one end of the reference circumferential surface; Valleys formed at the other end of the reference circumferential surface; A lumen expansion stent comprising a spiral portion wound spirally along a reference circumferential surface while connecting the peak portions and valley portions to each other. The stent for expanding lumen according to claim 2, wherein when said spirals intersect with each other, said crossings are filtered one to three times to form a connection by twisting the spiral and said spiral. The stent for lumen expansion according to claim 2 or 3, wherein the connection part is made of one twist while uniformly filtering the intersection of the helix one to three times so as to secure expandability while maintaining excellent flexibility and shrinkability. Preparing a unit member having a predetermined unit length, which can be contracted and expanded by itself and has flexibility; The unit member reciprocates from one end of the reference circumferential surface to the other end in a zigzag shape to form a peak portion and a valley portion and a spiral portion connecting them, and also spirally wound the spiral portion along the reference circumferential surface while the spiral portions intersect. When forming a mesh structure; When the spirals cross each other in the above step, the method of manufacturing the lumen expansion stent comprising the step of forming a connection by twisting the spiral portion and the spiral portion 1 to 3 times by crossing the intersection. The method of claim 5, wherein the connecting portion has a superior flexibility and shrinkage while still having expansion, and thus stirs one to three times at regular intervals of the crossing portion of the spiral portion, thereby producing a lumen expanding stent.