KR20210002645A - Stents and medical devices - Google Patents

Abstract

It provides a stent and the like capable of suppressing positional displacement during treatment. The stent 11 is formed using one or more wire rods W1, and has a mesh-like structure 111 having a cylindrical structure extending along the axial direction Z of the stent 11. In this mesh structure 111, a plurality of unit structures (unit structures U1, U2) are arranged side by side in each of both end regions (end regions Aea, Aeb) and non-end regions Am along the axial direction Z. have. The unit structure U2 in at least one end region of both end regions compared to the first axial length (axial length L1) which is the length along the axial direction Z of the unit structure U1 in the non-end region Am The second axial length (axial length L2), which is the length along the axial direction Z of, is relatively short.

Description

Stents and medical devices

The present invention relates to, for example, a stent applied to a coronary organ in the body such as the digestive tract and blood vessels, and a medical device such as a covered stent or a stent graft having such a stent.

A stent applied (attracted) to the digestive tract (digestive tract stent) is used to push and open the lumen of the digestive tract constricted by a tumor. Further, the stent is used not only for the digestive tract but also for other coronary organs in the body such as blood vessels. A stent applied to such a tubular organ in the body generally has a mesh-like structure using one or more wire rods (for example, see Patent Document 1).

Japanese Patent Publication No. 2009-501049

By the way, with such a stent, it is generally required to suppress the positional displacement during treatment (when the stent is placed in the above-described coronary organ in the body). It is desirable to provide a stent capable of suppressing positional displacement during treatment, and a medical device provided with such a stent.

A stent according to an embodiment of the present invention is formed using one or a plurality of wire rods, and has a mesh structure having a cylindrical structure extending along the axial direction of the stent. In this mesh-like structure, a plurality of unit structures are arranged side by side in each of both end regions and non-end regions along the axial direction. In addition, the axial direction of the unit structure in at least one of the two end regions is compared with the first axial length, which is the length along the axial direction of the unit structure in the non-end region. The length along the second axis is relatively short.

A medical device according to an embodiment of the present invention includes a cylindrical member and at least one stent according to an embodiment of the present invention disposed on at least a portion of the cylindrical member.

In the stent and medical device according to an embodiment of the present invention, compared with the length in the first axial direction in the non-end region, the second axial direction in at least one of the two end regions. The length is relatively short (the first axial length> the second axial length). Thereby, for example, the stent is inserted in a reduced diameter state in a predetermined delivery sheath, and the delivery sheath is transported to the vicinity of the affected part (part to be treated) in the coronal organ, and then the stent is deployed from the delivery sheath. When the diameter is enlarged, it becomes as follows. That is, since the length in the second axial direction is relatively short in the at least one end region, the time until the unit structure for one row along the axial direction protrudes outward from the delivery sheath is relatively Is shortened. As a result, for example, in the at least one end region, as compared to the case where the unit structure has a length in the first axial direction, as in the non-end region, the end region of the stent is earlier (with a short protruding length). ) It becomes easy to enlarge the diameter.

In the stent and the medical device according to the embodiment of the present invention, in the at least one end region, a plurality of rows may be arranged in parallel along the axial direction of the unit structure having the second axial length. In this case, since a plurality of rows of unit structures having the second axial length exist in the at least one end region, when this stent is deployed from within the delivery sheath, it is as follows. In other words, since the at least one end region as a whole tends to gradually (continuously) expand in diameter, the end region of this stent becomes more liable to expand in diameter earlier, resulting in further stent positional displacement during treatment. Is suppressed.

In addition, in the stent and the medical device according to the embodiment of the present invention, the braiding pattern of the wire in the mesh-like structure may be different from each other in the non-end region and the at least one end region. In this case, for example, by setting the braided pattern in the at least one end region to a pattern that is relatively easily enlarged in diameter compared to the braided pattern in the non-end region, this stent is within the delivery sheath. When deployed from, the diameter can be expanded earlier. As a result, the displacement of the stent during treatment is further suppressed.

In addition, in the stent and medical device according to the embodiment of the present invention, the second axial length is relatively short compared to the first axial length in the both end regions, and the second At least one of the number of rows arranged in parallel along the axial direction of the unit structure having two axial lengths and the size of the second axial length is in one end region of the both end regions and the other end region. , May be different (they may be asymmetrical). In this case, since the characteristics of the stent (deployment profile, etc.) can be made different from each other in the one end region and the other end region, for example, the characteristics of the stent can be changed according to the purpose of the stent or the use situation. Can be set optionally. As a result, the convenience when using the stent is improved.

According to the stent and medical device according to the embodiment of the present invention, the second axial length is relatively short compared to the first axial length, and thus the following is achieved. That is, for example, when the stent is expanded in diameter from a reduced diameter state within a predetermined delivery sheath, the end region of the stent tends to be expanded in diameter early. Therefore, when the stent is placed in the affected area (the area to be treated), the stent is quickly fixed to the affected area, and as a result, it becomes possible to suppress the stent position shift during treatment.

1 is a schematic perspective view showing a schematic configuration example of a stent according to an embodiment of the present invention.
FIG. 2 is a schematic exploded view showing a detailed configuration example of main parts in the stent shown in FIG. 1.
3 is a schematic developed view showing a configuration example of a main part of a stent according to a comparative example.
4 is a schematic developed view showing a configuration example of a main part in a stent according to Modification Example 1. FIG.
5 is a schematic developed view showing a configuration example of a main part in a stent according to a second modification.
6 is a schematic exploded view showing a configuration example of a main part in a stent according to a third modification.
7 is a schematic developed view showing a configuration example of a main part in a stent according to Modification Example 4. FIG.
8 is a schematic perspective view showing a schematic configuration example of a medical device according to an application example.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, explanation is performed in the following order.

1. Embodiment (example of satisfying (L2<L1) in multiple rows of both end regions)

2. Modification

Modification 1 (Example of satisfying (L2<L1) in 1 row of both end regions)

Modification 2 (Example when the number of rows and the size of L2 are asymmetrical between both end regions)

Modified Example 3 (Example in which the braid patterns of the wire rod are different in the non-end region and the end region)

Modification 4 (example of satisfying (L2<L1) only in one end region)

3. Application example (example of applying the stent of the embodiment and each modified example to a medical device)

4. Other variations

<1. Embodiment>

[Schematic composition]

Fig. 1 is a schematic perspective view showing an example of a schematic configuration of a stent (stent 11) according to an embodiment of the present invention. The stent 11 is, for example, an instrument applied to the digestive tract as a coronary organ in the body, and is used to push and open the lumen of the digestive tract constricted by a tumor, as described later. Specifically, the stent 11 is placed in a site to be treated (for example, in a digestive tract such as a large intestine). In addition, this stent 11 corresponds to a specific example of the "stent" in the present invention.

As shown in FIG. 1, this stent 11 has a cylindrical (cylindrical) structure extending along the axis direction Z (Z axis direction). Further, the stent 11 has both end regions (end regions Aea, Aeb) and non-end regions Am (intermediate regions located between both end regions) along its axial direction Z (see FIG. 1 ). ). Further, the length of the entire stent 11 along the axial direction Z is, for example, about 3 to 20 cm, and the lengths of the end regions Aea and Aeb are, respectively, about 3 to 40 mm. On the other hand, the outer diameter of the stent 11 at the time of expansion is, for example, about 10 to 50 mm.

In the example shown in Fig. 1, the stent 11 is configured using one type of wire W1 (elemental wire), and has a cylindrical structure as described above. Specifically, in the present embodiment, while the tubular structure is constituted by a mesh-like structure, such a tubular mesh-like structure is formed by braiding each of the wire rods W1 in a predetermined pattern (a mesh pattern to be described later). Has been. In addition, details of the mesh-like structure (braided pattern of wire W1) and the like in this stent 11 will be described later (FIG. 2).

Here, as the material of such a wire rod W1, a metal wire rod is preferable, and a shape memory alloy in which a shape memory effect or superelasticity is imparted by heat treatment is particularly preferably employed. However, depending on the application, stainless steel, tantalum (Ta), titanium (Ti), platinum (Pt), gold (Au), tungsten (W), or the like may be used as the material of the wire rod W1. As the above-described shape memory alloy, for example, a nickel (Ni)-Ti alloy, a copper (Cu)-zinc (Zn)-X (X = aluminum (Al), iron (Fe), etc.) alloy, and Ni-Ti-X (X=Fe, Cu, vanadium (V), cobalt (Co), etc.) alloys and the like are preferably used. Further, as such a wire rod W1, for example, a synthetic resin or the like may be used. In addition, a composite wire in which the surface of a metal wire is coated with Au, Pt, etc. by means of plating, or a core material containing a radiopaque material such as Au, Pt is covered with an alloy, as wire W1. You may use it.

[Detailed configuration]

Next, with reference to FIG. 2, a detailed configuration example of the stent 11 shown in FIG. 1 (configuration example such as the above-described mesh-like structure) will be described. FIG. 2 is a schematic diagram showing a detailed configuration example of the main portion (near the aforementioned end regions Aea and Aeb) in the stent 11, and each of the axial direction Z and the circumferential direction R shown in FIG. 1 It is shown along the direction.

In this stent 11, first, as shown in FIG. 2, it is comprised using one type of mesh-like structure 111. As shown in FIG. That is, this stent 11 is constituted by the mesh-like structure 111 formed using the wire rod W1 described above. This mesh structure 111 constitutes the above-described cylindrical structure, and extends along the axial direction Z of the stent 11 (over the entire length). In addition, as a wire diameter of such wire rod W1, about 0.18 mm is mentioned, for example.

The mesh-like structure 111 is formed by intersecting a wire W1 forming a wavy shape (zigzag shape) including a straight portion s1 and a curved portion b1, as shown in FIG. 2, in the straight portion s1. Therefore, in this mesh-like structure 111, the crossing part (wire crossing part) which is a part where the straight part s1 of the wire rod W1 intersects is formed.

In addition, in this mesh-like structure 111, as shown in FIG. 2, the connecting part C11 (engaging part) which is formed by connecting (interlocking) with each other in the bent part b1 is formed the wire rod W1. That is, the mesh-like structure 111 is constituted by a mesh pattern formed by advancing a wire rod W1 forming a wavy shape including a straight portion s1 and a bent portion b1 along the circumferential direction R along the axial direction Z.

Specifically, the mesh pattern of each row (for one row) is formed by rotating the wire rod W1 around two times along the circumferential direction R while forming the above-described corrugated shape. Specifically, in the loop at the 1st lap and the loop at the 2nd lap, the phases of the wave shape are shifted by half a pitch (1/2 pitch) from each other along the circumferential direction R in the mesh pattern of each row. Thereby, in the mesh pattern of each row, the above-described intersection portions are arranged in parallel along the circumferential direction R. In addition, in such an intersection, the loop at the first week and the loop at the second week are alternately raised and lowered to cross each other.

In addition, although omitted in Fig. 2, after the wire rod W1 is rotated around twice along the circumferential direction R to form a mesh pattern (N: an integer greater than or equal to 1) for the first row (Nth row), the end of the loop at the second week Is as follows. That is, to the formation position of the mesh pattern in the next row (the (N+1) row), the mesh pattern is formed in the same manner as above, proceeding along the axial direction Z. In addition, the (N+1)-th bent portion is woven so as to be connected to each other with the N-th bent portion.

In this way, the mesh-like structure 111 in which the mesh pattern is provided along the axial direction Z is formed, and the stent 11 is configured.

Such a mesh-like structure 111 is composed of a plurality of unit structures (unit structures U1 and U2), which are two-dimensionally arranged side by side along each of the axial direction Z and the circumferential direction R, as shown in FIG. 2. have. Specifically, in this mesh structure 111, in the non-end region Am (intermediate region) described above, a plurality of unit structures U1 are two-dimensionally arranged, and in the above-described end regions Aea and Aeb, respectively, A plurality of unit structures U2 are arranged two-dimensionally (see Fig. 2). In other words, each row of the mesh pattern constituting the end regions Aea and Aeb is formed by arranging a plurality of unit structures U2 side by side along the circumferential direction R. On the other hand, each row of the mesh pattern constituting the non-end region Am is formed by arranging a plurality of unit structures U1 side by side along the circumferential direction R.

In the example shown in Fig. 2, each unit structure U1 has the axial direction Z as the major axis direction and the circumferential direction R as the minor axis direction, and two bent portions b1 and two wire rod intersections (the above-described wire rod W1 It has a substantially rhombus shape with an intersection) as a vertex. Therefore, in this example, the length along the axial direction Z in each unit structure U1 (the length in the axial direction L1) is the wave height of each wire rod W1 in the non-end region Am (the axial direction Z in the above-described waveform shape). Length), and match (see Fig. 2).

In the example shown in Fig. 2, each unit structure U2 has a substantially rhombus shape in which the axial direction Z and the circumferential direction R are respectively axial directions, and two bent portions b1 and two wire rod intersections are vertices. Therefore, in this example, the length along the axial direction Z in each unit structure U2 (axial length L2) coincides with the wave height of each wire rod W1 in the end regions Aea and Aeb (see Fig. 2).

In particular, in this embodiment, as shown in FIG. 2, in both end regions Aea and Aeb, unit structures U2 having such an axial length L2 are arranged in a plurality of rows side by side along the axial direction Z. have. That is, in these end regions Aea and Aeb, the number of rows along the axial direction Z in the unit structure U2 is plural (two rows each in this example) (see Fig. 2).

In addition, the axial length L1 described above corresponds to a specific example of the "first axial length" in the present invention, and the axial length L2 is one of the "second axial length" in the present invention. It corresponds to a specific example.

Here, in the mesh structure 111 in the stent 11 of the present embodiment, the length L1 in the axial direction of each unit structure U1 in such a non-end region Am, and each of the end regions Aea and Aeb. The magnitude relationship between the axial length L2 of the unit structure U2 is as follows. That is, as shown in Fig. 2, compared with the axial length L1 in the non-end region Am, the axial length L2 in the end regions Aea and Aeb is relatively short. In other words, the magnitude relation of (axial length L2 < axial length L1) is satisfied.

In other words, the stent 11 is formed so as to have different crest values in the mesh pattern constituting the end regions Aea and Aeb and the mesh pattern constituting the non-end region Am (see Fig. 2). As shown in Fig. 2, the wave height value in the mesh pattern constituting the non-end region Am is larger than the wave height value in the mesh pattern constituting the end regions Aea and Aeb.

In addition, the axial length L1 is, for example, about 8 to 24 mm, and the axial length L2 is, for example, about 1 to 18 mm. In addition, as a numerical range of the ratio ((L2/L1)×100) of the axial length L2 to the axial length L1, it is preferably 12.5 to 75%, more preferably 30 to 60%. .

[Action/Effect]

(A. Basic operation)

This stent 11, when treating a tumor in the vicinity of the digestive tract in a patient, pushes the lumen of the digestive tract constricted by the tumor by being attracted to the site to be treated (for example, in the digestive tract such as the large intestine). It becomes possible to open it.

At this time, specifically, first, the stent 11 is inserted in a reduced diameter state in a predetermined delivery sheath, and the delivery sheath is inserted into the digestive tract, thereby transporting the stent 11 to the vicinity of the affected area. Then, the stent 11 is deployed from within the delivery sheath and is enlarged in diameter, so that the stent 11 is attracted to the affected part (the part to be treated).

(B. Action and effect in the stent (11))

Next, with reference to Fig. 3 in addition to Figs. 1 and 2, the action and effect of the stent 11 will be described in detail while comparing with the comparative example.

(B-1. Comparative Example)

Fig. 3 is a schematic diagram showing a configuration example of a main portion (near end regions Aea and Aeb) in a stent (stent 100) according to a comparative example, and each direction in the axial direction Z and the circumferential direction R is shown. Therefore, it is showing.

As shown in FIG. 3, the stent 100 of this comparative example is comprised by the mesh-like structure 101 formed using the wire rod W1. In the mesh-like structure 101 of this comparative example, both end regions Aea and Aeb were also subjected to a mesh pattern constituting the non-end region Am in the mesh-like structure 111 of the present embodiment (see FIG. 2). It is different from the mesh-like structure 111 of this embodiment in that it is formed. That is, in the whole of the mesh structure 101, only one type of unit structure U1 is two-dimensionally arranged. Therefore, in the mesh structure 101, the axial length of the unit structure (unit structure U1) in these end regions Aea and Aeb, and the axial length of the unit structure (unit structure U1) in the non-end region Am Are all L1 (see Fig. 3).

In the stent 100 of the comparative example having such a configuration, for example, as described above, after being inserted in a reduced diameter state in a predetermined delivery sheath, the delivery sheath is transported to the vicinity of the affected part in the digestive tract, and then from within the delivery sheath. When it expands and expands in diameter, it becomes as follows.

That is, in this stent 100 (net-eye structure 101), since the axial length L1 of each unit structure U1 in the end regions Aea and Aeb (and the non-end region Am) is long, the end region (end region The protrusion length until the Aea or the end region Aeb) is enlarged in diameter (returns to the original diameter) becomes longer. Therefore, it takes time until the unit structure U1 for one row along the axial direction Z protrudes from the inside of the delivery sheath to the outside.

Here, in the stent 100 of this comparative example, as described above, for the factor requiring time until the unit structure U1 for one row along the axial direction Z protrudes to the outside (from within the delivery sheath), the following The problems (A) and (B) are illustrated and described in detail. Here, for convenience of explanation, the first and second columns are used as examples, but the same can be said when generalized as the Nth and (N+1)th columns.

(A) When the first row begins to protrude

When the first column (the shortest row) in the end region (end region Aea or end region Aeb) expands from within the delivery sheath and expands in diameter, even if this first row begins to protrude, each unit structure in the end region A part of U1 is accommodated in the delivery sheath. In such a state, the diameter of the first row in the end region cannot be sufficiently expanded.

(B) When the entire area of the first row is projected and the second row is still stored

When the entire region of the first row in the end region protrudes from the inside of the delivery sheath to the outside, and the second row is still accommodated in the delivery sheath, it is as follows. That is, in this case, the distal end in the first row is enlarged in diameter and returns to its original diameter, while the proximal end in the first row becomes the same as the diameter of the distal end in the second row. Does not return to the diameter of (at the stage where the entire region in the first row protrudes, the diameter of the proximal end in the first row becomes the same as the inner diameter of the delivery sheath). This is because the bent portion b1 on the proximal side in the first row and the bent portion b1 on the distal side in the second column are connected (interlocked) as described above. Then, in this case, the proximal end in the first row is not sufficiently enlarged in diameter, and the first row becomes a state in which the diameter is enlarged obliquely (tapered state).

In this way, in the stent 100 of the comparative example, since it takes time until the end region is sufficiently enlarged in diameter, when the stent 100 is placed in the affected area (at the time of treatment), the stent 100 It takes time until) is fixed enough. As a result, in this comparative example, there is a concern that a shift (position shift) may occur in the indwelling position of the stent 100.

In addition, in such a comparative example, even after the stent 100 is held, it can be said that, for example, the following problem (C) may occur.

(C) After the stent (100) is attracted

In general, when a stent is held against a constriction to be treated, the stent is held by being placed on the constriction. Specifically, for example, stents having a predetermined length (eg, 2 cm or more) are held on both sides of the constriction portion. Here, for example, when the indwelling position of the stent 100 is shifted due to a delay during the indwelling, or if a positional deviation (migration) occurs after the indwelling of the stent 100, it is as follows. In other words, if the delivery sheath is only changed to a constriction, for example, a part of the first row is pressed by a tumor and the diameter is reduced, the situation is the same as that of the problem (A). For example, a part of the second row is a tumor. When the diameter is reduced by being pressed, the situation is similar to that of the problem (B).

In contrast to this comparative example, in the case where both the end regions Aea, Aeb and the non-end regions Am are configured using unit structure U2 (when the axial length of the unit structure is all set to L2), for example, the following There is a risk of the same problem occurring. That is, in this case, compared to the stent 11 of the present embodiment, since the number of bent portions b1 and the number of connecting portions between the bent portions b1 are increased, the diameter reduction in the stent decreases, or the stent can be removed from the delivery sheath. It can be said that there is a possibility that the resistance of the time will increase.

(B-2. This embodiment)

On the other hand, in the stent 11 of this embodiment, as shown in FIG. 2, compared with the axial length L1 of each unit structure U1 in the non-end region Am, each unit in the end regions Aea and Aeb The axial length L2 of the structure U2 is relatively short (axial length L2 < axial length L1). Thereby, for example, as described above, after the stent 11 is inserted in a reduced diameter state in a predetermined delivery sheath, and the delivery sheath is transported to the vicinity of the affected part in the digestive tract, the stent 11 is in the delivery sheath. When it expands from and expands in diameter, it becomes as follows.

That is, since the axial length L2 in the end regions Aea and Aeb is relatively short, the time until the unit structure U2 for one row along the axial direction Z protrudes from the delivery sheath to the outside (the protruding part The length of the stent 11) is relatively short compared to the case of the comparative example (when the end regions Aea and Aeb are configured using the unit structure U1). As a result, in the present embodiment, for example, in the end regions Aea and Aeb as in the comparative example, the unit structure (unit structure U1) is the axial length L1 (> axial length L2) as in the non-end region Am. Compared with the case of having (see Fig. 3), it becomes as follows. That is, in the present embodiment, compared with the above comparative example, the end region (end region Aea or end region Aeb) of the stent 11 is easily enlarged in diameter early (with a short protrusion length).

In this way, in the present embodiment, for example, when the stent 11 is expanded in diameter from a reduced diameter state in the delivery sheath and the diameter is enlarged, the end region of the stent 11 is easily enlarged in diameter early (originally As a result, it becomes as follows. That is, since the end region of the stent 11 is easily enlarged in diameter early, when the stent 11 is placed in the affected area, the stent 11 is quickly fixed to the affected area. Specifically, since the axial length L2 of the first row (the shortest row) in the end region is relatively short, for example, the above-described problem (A) can be avoided as a result, as described above. , The stent 11 is quickly fixed to the affected part. Therefore, in the present embodiment, it becomes possible to suppress the displacement of the stent 11 during treatment as compared with the above comparative example.

In addition, in this embodiment, as described above, since the end region of the stent 11 is easily enlarged in diameter early (it becomes easy to return to the original diameter early), for example, the following effects are also obtained. Lose.

That is, first, the constriction to be treated can be hung and held in a portion whose diameter is enlarged in the end region, so that it is possible to make it easier to hold in place more accurately.

Further, if the diameter cannot be enlarged with a short protruding length, for example, the following concerns arise, whereas in the present embodiment, such concerns can be avoided. In other words, if the diameter cannot be enlarged with a short protrusion length, for example, if it deviates from the constriction (a case of misrepresentation or migration occurs, etc.), a case where the length of the protrusion becomes short due to a misselection of the stent size by a doctor, etc. There is a fear that the end region of the stent is not enlarged in diameter.

In addition, in this embodiment, as described above, since the axial length L2 in the end regions Aea and Aeb is relatively short, unlike the comparative example, the above-described problem (C) may occur, and it is also possible to avoid. It becomes. In particular, in the stent 11 of the present embodiment, since the axial length L2 is relatively short compared to the axial length L1 in both end regions Aea and Aeb, this problem (C) may occur. What can be avoided is a great advantage.

In addition, in the present embodiment, in the end regions Aea and Aeb, the number of rows along the axial direction Z of the unit structure U2 having the axial length L2 is made into a plurality (see Fig. 2). Become together. That is, in the end regions Aea and Aeb, since a plurality of rows of unit structures U2 having an axial length L2 exist, when the stent 11 is deployed from within the delivery sheath, the end region (end region Aea or end region Aeb) As a whole, it tends to gradually (continuously) expand in diameter.

Specifically, for example, first, when the entire region of the first row (the shortest row) in the end region protrudes from the inside of the delivery sheath to the outside, and the second row is accommodated in the delivery sheath, it is as follows. That is, in this case, the distal end in the first row is enlarged in diameter and returns to its original diameter, while the proximal end in the first row is the same as the diameter of the distal end in the second row, as described above. Because it is done, it does not return to its original diameter. Next, as the second row protrudes, the proximal end in the first row also expands in diameter, and when the entire region in the second row protrudes, the distal end in the second row returns to its original diameter, The proximal end in the first row also returns to its original diameter.

In this way, in addition to the axial length L2 of the first row (the shortest row) in the end region, the axial length L2 of the second row is also relatively short, so, for example, the above-described problem (B) may occur. Can be avoided. That is, as described above, it is possible to avoid a state in which the proximal end in the first column is not sufficiently expanded in diameter and the first column is diagonally expanded in diameter (tapered state), and the proximal end side in the first column is also rapidly expanded in diameter. do.

In addition, for convenience of explanation, the first and second columns have been described as examples, but the same can be said for the case of generalizing as the Nth column and the (N+1) column as in the above case.

In this way, by setting the plurality of rows (at least 2 rows) in the end regions Aea and Aeb as the unit structure U2 having the axial length L2 (relatively small wave height value), the end regions of the stent 11 are more It becomes easy to enlarge the diameter early. As a result, in the present embodiment, it becomes possible to further suppress the displacement of the stent 11 during the treatment described above.

<2. Variation example>

Subsequently, modified examples (modified examples 1 to 4) of the above embodiment will be described. In addition, in these Modification Examples 1 to 4, the same reference numerals are given to the same components as those in the embodiment, and descriptions thereof are omitted as appropriate.

[Modified Example 1]

FIG. 4 is a schematic diagram showing a configuration example of a main portion (near end regions Aea, Aeb) in a stent (stent 11A) according to Modification Example 1, in each direction of the axial direction Z and the circumferential direction R Is shown accordingly. In addition, the stent 11A of this modification 1 also corresponds to a specific example of the "stent" in the present invention.

As shown in Fig. 4, the stent 11A is constituted by a mesh-like structure 111A formed using a wire W1. This mesh-like structure 111A corresponds to the change in the number of rows of the unit structure U2 in each end region Aea and Aeb in the mesh-like structure 111 (see Fig. 2) of the embodiment, and a different configuration Is basically the same.

Specifically, as shown in Fig. 4, in the end regions Aea and Aeb in the mesh structure 111A, the number of rows along the axial direction Z of the unit structure U2 having the axial length L2 is one (one column ). In other words, in the end regions Aea and Aeb of the mesh-like structure 111A, one row of mesh patterns formed by arranging a plurality of unit structures U2 in parallel along the circumferential direction R is formed.

Also in the stent 11A of the present modification having such a configuration, basically, the same effect can be obtained by the same operation as that of the stent 11 of the embodiment.

[Modified Example 2]

Fig. 5 is a schematic diagram showing a configuration example of a main part (near end regions Aea and Aeb) in the stent (stent 11B) according to Modification 2, in each direction of the axial direction Z and the circumferential direction R Is shown accordingly. In addition, the stent 11B of this modification example 2 also corresponds to a specific example of the "stent" in the present invention.

As shown in FIG. 5, this stent 11B is comprised by the mesh-like structure 111B formed using the wire rod W1. This mesh structure 111B corresponds to a change in the number of rows of the unit structure U2 in the end region Aeb in the mesh structure 111 (see Fig. 2) of the embodiment, and other configurations are basically It is likewise.

Specifically, as shown in Fig. 5, in the end region Aeb of the mesh structure 111B, the number of rows along the axial direction Z of the unit structure U2 having an axial length L2 is one (one row). Has been. On the other hand, in the end region Aea, as in the case of the mesh structure 111, the number of rows along the axial direction Z of the unit structure U2 having an axial length L2 is two (2 rows) (see Fig. 5). . That is, in this mesh-like structure 111B, the number of rows along the axial direction Z of the unit structure U2 having the axial length L2 is different from one end region Aea and the other end region Aeb (because they become asymmetrical have). In other words, in the mesh structure 111B, a mesh pattern formed by arranging a plurality of unit structures U2 in parallel along the circumferential direction R is formed in two rows in the end region Aea, and one row in the end region Aeb.

Also in the stent 11B of this modified example having such a configuration, basically, the same effect can be obtained by the same operation as that of the stent 11 of the embodiment.

In addition, in particular, in the stent 11B of this modified example, the number of rows along the axial direction Z of the unit structure U2 having the axial length L2 is made to be different in one end region Aea and the other end region Aeb. Becomes like That is, since the characteristics (deployment profile, etc.) of this stent 11B can be made different from one end region Aea and the other end region Aeb, for example, depending on the purpose or use situation of the stent 11B. , Its characteristics can be set selectively. As a result, it becomes possible to improve the convenience when using the stent 11B.

In addition, in the present modified example, a case where the number of rows of the unit structure U2 having an axial length L2 in one end region Aea and the other end region Aeb are different from each other (which are asymmetrical) has been described as an example. For example, it may be as follows. That is, for example, in one end region Aea and the other end region Aeb, the size (length) of the axial length L2 may be different from each other. In addition, for example, in one end region Aea and the other end region Aeb, both the number of rows of the unit structure U2 having the axial length L2 and the size of the axial length L2 may be different from each other.

[Modified Example 3]

6 is a schematic diagram showing a configuration example of a main portion (near end regions Aea, Aeb) in a stent (stent 11C) according to Modification Example 3, in each direction of the axial direction Z and the circumferential direction R Is shown accordingly. In addition, the stent 11C of this modification 3 also corresponds to a specific example of the "stent" in the present invention.

As shown in FIG. 6, this stent 11C is comprised by the mesh-shaped structure 111C formed using the wire rod W1. This mesh-like structure 111C corresponds to a change in the braiding pattern of the wire rod W1 in the non-end region Am in the mesh-like structure 111 (see Fig. 2) of the embodiment, and other configurations are basically It has become likewise.

On the other hand, the braiding pattern of the wire rod W1 in each of the end regions Aea and Aeb is the same as the braiding pattern described above in the mesh-like structure 111 (see Fig. 6). That is, in this mesh structure 111C, the braiding pattern of the wire rod W1 differs from each other in the non-end region Am and the end regions Aea and Aeb.

(Configuration example of braided pattern in the non-end region Am)

Here, with reference to FIG. 6, a structural example of the braided pattern in the non-end region Am in the mesh-like structure 111C of this modification is demonstrated in detail.

The braided pattern in the non-end region Am in the mesh structure 111C is formed of a wire rod W1 that forms a wave shape including a straight portion s1 and a curved portion b1, as shown in FIG. 6. Specifically, the braiding pattern in the non-end region Am will be described below by exemplifying and describing the braiding patterns in the first to third columns on the end region Aea side. That is, the braiding patterns in the first to third rows on the side of the end region Aea are, as shown in Fig. 6, the intersection of the wire rods W11a and W11b, the intersection of the wire rods W12a and W12b, and the wire rods W13a and W13b. It is formed using the intersection of each other.

More specifically, as shown in Fig. 6, the wire rod W11a and the wire rod W11b are disposed so as to intersect each other in the straight portion s1 (to form a wire rod intersection portion). The wire rod W13a and the wire rod W13b are arranged so as to intersect each other in their straight portion s1. The wire rod W12a and the wire rod W12b are arranged so as to intersect each other in their straight portion s1.

Further, as shown in Fig. 6, the connecting portion C12 is formed by connecting the crossing portion (wire crossing portion) between the wire rods W11a and W11b and the bent portion b1 of the wire rod W12a or the wire rod W12b. The connecting portion C14 is formed by connecting the crossing portion (wire crossing portion) between the wire rods W13a and W13b and the bent portion b1 of the wire rod W12a or the wire rod W12b. The connecting portion C13 is formed by connecting the crossing portions (wire crossing portions) between the wire rods W12a and W12b and the bent portions b1 of the wire rods W11a and W13a, or the bent portions b1 of the wire rods W11b and W13b.

As described above, the braided pattern in the non-end region Am includes the straight portion s1 and the bent portion b1, and the wire rod W1 (the above-described wire rods W11a, W11b, W12a, W12b, W13a, W13b, etc.) forming a wavy shape in the circumferential direction R The mesh pattern formed by advancing along the line is configured by being connected along the axial direction Z. Further, the bent portion b1 in the wire rod W11a and the bent portion b1 in the wire rod W13a are disposed so as to be adjacent to each other. Similarly, the bent portion b1 in the wire rod W11b and the bent portion b1 in the wire rod W13b are disposed so as to be adjacent to each other.

In addition, each unit structure U1 in such a non-end region Am is a region surrounded by six wire rods W1 (wire rods W11a, W11b, W12a, W12b, W13a, W13b, etc.), as shown in FIG. Consists of. Specifically, each unit structure U1 has a substantially rhombus shape in which the axial direction Z is the major axis direction, the circumferential direction R is the minor axis direction, and the two bent portions b1 and the two wire rod intersections are vertices. Therefore, also in this modification, the axial length L1 in each unit structure U1 coincides with the wave height of each wire rod W11a, W11b, W12a, W12b, W13a, W13b in the non-end region Am (Fig. 6 Reference).

Here, also in the mesh-like structure 111C in the stent 11C of this modified example, the axial length L1 of each unit structure U1 in such a non-end region Am, and each of the end regions Aea and Aeb. The magnitude relationship between the axial length L2 of the unit structure U2 is as follows. That is, as shown in Fig. 6, compared with the axial length L1 in the non-end region Am, the axial length L2 in the end regions Aea and Aeb is relatively short. In other words, the magnitude relation of (axial length L2 < axial length L1) is satisfied.

(Action/effect)

Also in the stent 11C of the present modification having such a configuration, basically, the same effect can be obtained by the same operation as that of the stent 11 of the embodiment.

In addition, in particular, in the stent 11C of the present modified example, the braiding pattern of the wire rod W1 in the mesh-like structure 111C is different from each other in the non-end region Am and the end regions Aea and Aeb, so it is as follows. .

That is, first, in the braided pattern in the non-end region Am in the mesh structure 111C, compared to the braiding pattern in the non-end region Am in the mesh structure 111, 111A, 111B, the stent The diameter expansion force in (stent 11C) can be improved. Accordingly, in the stent 11C of the present modification, the diameter expansion force in the non-end region Am is improved, while the end regions Aea and Aeb have a structure that is easy to expand in diameter early when deployed as described so far. In this way, in the present modified example, by making the braided pattern in the end regions Aea and Aeb a relatively easy-to-diameter pattern compared to the braided pattern in the non-end region Am, this stent 11C is delivered When deployed from the inside, the diameter can be expanded earlier. As a result, in the stent 11C of this modified example, it becomes possible to further suppress the positional shift during the treatment described above.

[Modified Example 4]

Fig. 7 is a schematic diagram showing a configuration example of a main part (near end regions Aea and Aeb) in a stent (stent 11D) according to Modification Example 4, in each direction of the axial direction Z and the circumferential direction R Is shown accordingly. In addition, the stent 11D of this modification example 4 also corresponds to a specific example of the "stent" in the present invention.

This stent 11D is constituted by a mesh-like structure 111D formed using a wire W1, as shown in FIG. 7. This mesh-like structure 111D corresponds to the change of the unit structure U2 in the end region Aeb to the unit structure U1 in the mesh-like structure 111 (see Fig. 2) of the embodiment, and other configurations are It's basically the same.

Specifically, as shown in FIG. 7, the end region Aeb in the mesh structure 111D is constituted by a mesh pattern formed by a plurality of unit structures U1 having an axial length L1 arranged side by side along the circumferential direction R. Has been. In other words, in the mesh-like structure 111D of the stent 11D, the mesh pattern constituting Aeb is similar to the mesh pattern constituting the non-end region Am. On the other hand, in the end region Aea, as in the case of the mesh structure 111, the number of rows along the axial direction Z of the unit structure U2 having an axial length L2 is two (2 rows) (see Fig. 7). . That is, in this mesh structure 111D, a mesh pattern formed by arranging a plurality of unit structures U2 having an axial length L2 in parallel along the circumferential direction R is formed only in one end region Aea.

As described above, in the stent 11D of this modified example, unlike the stents 11, 11A to 11C described so far, it is as follows. That is, in only one end region of both end regions Aea and Aeb in the stent 11D, the axial length L2 is relatively short compared to the axial length L1 ((L2<L1) is satisfied and have).

Also in the stent 11D of this modified example having such a configuration, basically, the same effect can be obtained by the same operation as that of the stent 11 of the embodiment.

<3. Application example>

Subsequently, examples of application of the stents (stents 11, 11A to 11D) according to the above-described embodiments and modifications 1 to 4 to medical devices will be described.

Fig. 8 is a schematic perspective view showing a schematic configuration example of a medical device (medical device 1) according to the present application example. The medical device 1 includes any of the stents 11, 11A, 11B, 11C, and 11D described above, and a cylindrical member 12 described below. This medical device 1 is a device applied to coronary organs in the body, such as the digestive tract and blood vessels, for example. Specifically, the medical device 1 is a medical device such as a covered stent or a stent graft adapted to blood vessels for treatment of aortic dissociation, or the like.

(Cylindrical member (12))

The cylindrical member 12 has a cylindrical (cylindrical) shape as shown in Fig. 8, and is disposed so as to cover (cover) at least a part of the stents 11 (11A to 11D). Specifically, in this example, the cylindrical member 12 is arranged so as to cover the outer peripheral side of the stent 11 (11A to 11D).

In addition, this cylindrical member 12 is connected to the stent [11 (11A to 11D)] by means such as sealing, bonding, welding, etc., so as to cover the stent [11 (11A to 11D)]. Has been. In addition, the connection portion between the cylindrical member 12 and the stent [11 (11A to 11D)] is, for example, the end regions Aea and Aeb of the stent [11 (11A to 11D)] or the non-end region Am (intermediate Area) and the like, as appropriate.

Here, in the example of Fig. 8, stents 11 (11A to 11D) are disposed in all regions (end regions Aea, Aeb, and non-end regions Am) along the axial direction Z of the cylindrical member 12. However, the present invention is not limited to this example, and the stents 11 (11A to 11D) may be disposed only in a partial region of the cylindrical member 12 along the axial direction Z. That is, the medical device 1 is a region in which the stent [11 (11A to 11D)] is disposed along the axial direction Z (the stent placement region) and the region where the stent [11 (11A to 11D)] is not disposed (Stent non-arrangement area) may be provided.

As such a tubular member 12, for example, a resin formed into a tubular shape by a molding method such as extrusion molding or blow molding, a knitted fabric containing resin fibers or ultrafine metal wires formed into a tubular shape, or formed into a tubular shape. Nonwoven fabrics containing resin or ultrafine metal, resin sheets or porous sheets formed in a cylindrical shape, structures formed in a thin cylindrical shape using resin dissolved in a solvent, and the like can be used.

Here, as the above-described knitted fabric, known knitted fabrics or fabrics such as plain weave and twill weave can be used. In addition, wrinkled ones such as crimping may be used.

In addition, examples of the above-described resin include polyolefins such as polyethylene, polypropylene, and ethylene-α-olefin copolymer, polyamide, polyurethane, polyethylene terephthalate, polybutylene terephthalate, polycyclohexane terephthalate, polyethylene- Polyesters such as 2,6-naphthalate, vinyl resins such as polyvinyl chloride, vinyl acetate, and ethylene-vinyl acetate copolymer, fluorine resins such as polyethylene fluoride or polypropylene, polyamide, polyamide elastomer, polyurethane , Silicone resins, natural rubbers, etc., and resins with less durability and tissue reaction can be used. In addition, among these, polyesters such as polyethylene terephthalate and silicone resins such as polyethylene terephthalate, polyethylene terephthalate, and silicone resins, which are chemically stable, have high durability, and have little structure reaction, can be preferably used.

Also in the medical device 1 of this application example, basically, the same effect can be obtained by the same operation|movement as the embodiment and the modification examples 1-4.

Further, in particular, in the case of a stent graft applied to a blood vessel for treatment of an aortic aneurysm or aortic dissociation, for example, the following effects are obtained. That is, in a stent graft applied to such a blood vessel, in some cases, accurate operation cannot be performed at the time of indwelling, and there is a case where it is shifted from the target site. In addition, there are cases in which the stent graft is moved from the indwelled site due to migration. In that case, there is a fear that blood flows into the lump and ruptures, or blood flows into the gastric cavity, and the outer membrane of the blood vessel is torn and bleeding. From these points of view, it can be said that, like the medical device 1 of this application example, suppressing the positional displacement during treatment has a large clinical effect.

<4. Other variations>

In the above, the present invention has been described with reference to embodiments, modifications, and application examples, but the present invention is not limited to these embodiments, and various modifications are possible.

For example, the shape, arrangement position, size, number, material, etc. of each member described in the above-described embodiments are not limited, and other shapes, arrangement positions, sizes, numbers, materials, etc. may be used. Specifically, for example, in the above embodiment, for example, in the end regions Aea and Aeb, the number of rows along the axial direction Z of the unit structure U2 having the axial length L2 is one (one row) or two (two Column) has been described as an example, but is not limited to this example. That is, the number of such rows may be about 1 to 10 rows depending on the length of the entire stent or the length of the axial length L2. In addition, the cylindrical member may cover the inner circumferential side of the stent, or may cover both the inner and outer circumferential sides of the stent.

In addition, the arrangement shape (braid pattern) of each wire rod in the stent is not limited to the one exemplified in the above embodiment, and may be a different arrangement shape.

In addition, in the above application example, the case where only one stent is disposed in the medical device is described as an example, but the present invention is not limited thereto, and two or more stents are individually in the medical device (for example, the axial direction Z is Therefore, it may be arranged in a separate state).

In addition, in the above embodiment and the like, a case in which a stent is formed using one type of wire (element) has been described, but is not limited to this case. That is, for example, a stent may be formed using a plurality of types (two or more) of wire rods (elements) having different wire diameters.

Incidentally, in the above embodiments and the like, stents and medical devices applied to treatment of the digestive tract, such as the large intestine, are mainly described as examples, but the present invention is not limited thereto. That is, the stent and the medical device of the present invention can be applied to the treatment of other digestive tracts other than the large intestine and coronary organs in the body other than the digestive tract, such as blood vessels such as the aorta.

Claims (5)

It is a stent applied to the coronary organs in the body,
It is formed using one or a plurality of wire rods, and has a mesh-shaped structure having a cylindrical structure extending along the axial direction of the stent,
In the mesh-like structure, a plurality of unit structures are arranged side by side in each of both end regions and non-end regions along the axial direction,
The axial direction of the unit structure in at least one end region of the both end regions is compared with a first axial length that is a length along the axial direction of the unit structure in the non-end region. A stent having a relatively short length along the second axial direction. The method of claim 1,
In the at least one end region,
A stent having a plurality of rows of the unit structure having the second axial length and arranged side by side along the axial direction. The method according to claim 1 or 2,
The braided pattern of the wire rod in the mesh structure,
The stent is different from each other in the non-end region and the at least one end region. The method according to any one of claims 1 to 3,
In the both end regions, the second axial length is relatively short compared to the first axial length,
At least one of the number of rows of the unit structure having the second axial length and arranged side by side along the axial direction and the size of the second axial length,
A stent that is different from one end region of the two end regions and the other end region. With a cylindrical member,
Having at least one stent disposed on at least a portion of the tubular member,
The stent,
It is formed using one or a plurality of wire rods and has a mesh-shaped structure having a cylindrical structure extending along the axial direction of the stent,
In the mesh-like structure, a plurality of unit structures are arranged side by side in each of both end regions and non-end regions along the axial direction,
The axial direction of the unit structure in at least one end region of the both end regions is compared with a first axial length that is a length along the axial direction of the unit structure in the non-end region. A medical device in which the second axial length, which is the length along the line, is relatively short.

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