JP6832290B2 - Stent - Google Patents

Description

The present invention relates to an improvement of a stent used for treating a disease such as an aneurysm. More particularly, the present invention can be used to treat extended disease (aneurysm, etc.) and stenotic diseases or other diseases of the arteries, it relates to a stent for use in the treatment of such the aneurysm, safety of the affected area indwelled at a site about the stent to be used as an artificial blood vessel.

In Patent Document 1, the patent applicant has disclosed an invention of a stent form (skeleton) capable of improving the safety and followability of a stent graft or the like at a patient's treatment site with respect to a stent and a stent graft for aortic aneurysm. That is, specifically, in order to deal with the bending of the aortic arch, a stent having a pre-bent form formed by connecting annular units and the outer circumference of the stent are made of a synthetic resin tubular member (referred to as "graft"). The invention of a coated stent graft has been disclosed.
Further, Patent Document 2 discloses an invention of a stent and a stent graft that can be placed at an accurate position of an affected area. In the present invention, as shown in FIG. 10, a hook was formed on the greater side of the terminal annular unit. The hook is locked to a leading tip to transport a stent graft or the like to the affected area. As described above, the locking hook is usually formed on the curvature side, and the stent graft is pulled and placed along the curved wall surface on the curvature side.

Patent No. 4064724 (Claims, FIG. 1) Japanese Patent No. 47733341 (8th page, FIG. 10)

However, in some cases, the condition of the affected area of an individual patient, such as the flexed state of the aorta, the placement position of the stent graft, etc., may not always be standard or normal (for example, as shown in FIG. 4 described later). (When the flexion curve CS on the lesser curvature side is extremely steep) In order to adopt and apply a specific treatment technique suitable for these, it became necessary to form a hook on the lesser curvature side.

Therefore, as shown in FIGS. 4 to 5, the present inventors move the hook 106 of the annular unit 104DE (104n) on the terminal side from the greater curvature side to the lesser curvature side, and together with the hook (of the annular unit). Attempts were also made to move and place the connecting struts. (The hook is formed so as to straddle the adjacent mountain portions of the annular struts constituting the terminal annular unit (that is, straddle the mountain portion as a fulcrum), and the connecting strut is the end on which the hook is formed. The valley of the lateral annular strut and the peak of the second terminal annular unit facing it are connected.)

However, in such a situation, along with the movement of the hook to the lesser curvature side, the position of the connecting strut 105ST of the second terminal side annular unit 104n + 1 having the above-mentioned relationship is simply moved to the lesser curvature side and arranged. However, the stent graft, which is a tubular member bent in advance, does not have a curved shape along the aortic arch, and contrary to expectations, only the terminal annular unit 104DE is upward (as shown in FIG. 4 below). It was found that there was an unexpected problem that the shape was extremely unnatural, that is, it protruded in the third side (S3 direction) and bent uncontrollably. This makes it impossible to construct a stent graft for stable placement in a safe position on the affected area.

Therefore, as a result of diligent studies to solve the above novel problems, the present inventor unexpectedly affects the morphology of the terminal annular unit of the stent due to the delicate connection morphology of the connecting struts formed near the hook. By identifying the above and specifying this arrangement, the problem of the present invention was solved and the following invention was reached.

In the present invention, a plurality of annular units are connected by a plurality of connecting struts to form a substantially tubular body extending in the longitudinal direction.
The substantially tubular body has a curvature side bending curve and a lesser curvature side bending curve.
Each of the plurality of annular units is formed in a substantially zigzag shape continuously in the circumferential direction substantially orthogonal to the longitudinal direction, and has a first bent portion on the proximal end side and a second bent portion on the terminal end side. ,
At one end of the terminalmost annular unit of the plurality of annular units on the terminal side,
And a hook is placed near the bending curve on the lesser curvature side.
The plurality of connecting struts include the two connecting struts that connect the first annular unit and the second annular unit longitudinally adjacent to the first annular unit.
The two connecting struts
And connecting the second bending portion of the first bending portion and the front Stories second annular unit of the first annular unit, in the connecting struts, the connecting position between the first bent portion and the second bent portion Provided is a stent in which the connection positions of the above are arranged so as to be offset in the circumferential direction substantially orthogonal to the longitudinal direction, and the direction of deviation of each connection position of one of the connection struts is different from that of the other connection strut.

According to the present invention, by specifying the connection position of the consolidated strut be formed hooks into small弯側, for normal without causing deformation of the end annular units was inevitable, lesser curvature It is possible to obtain a stent that corresponds to a steep bend on the side and has a curved shape along the aortic arch in the longitudinal direction.
Therefore, it is possible to provide a stent that can be widely adapted according to the condition of various affected parts of an individual patient (for example, the bending state of the aorta, the placement position of the stent, etc.).

FIG. 1 is an overall view (front view / schematic view) of the stent 1 of the present invention. FIG. 2 is a partially enlarged view of the vicinity of the terminal annular unit 4DE of the stent 1 (expanded view developed by τ = 360 ° in the circumferential CR direction during assembly / placement of the affected area). (Here, τ is a polar coordinate display with the center of the front surface (circular opening) of the annular unit as the origin (the position around the annular unit) when the terminal annular unit is assembled from the developed view. Indicates the argument τ when. The same shall apply hereinafter.) FIG. 3 is a partially enlarged view of FIG. FIG. 4 is an overall view (front view / schematic view) of the stent 101 of the comparative example. FIG. 5 is a partially enlarged view (expanded view developed in the circumferential CR direction at the time of assembly / placement of the affected area) in the vicinity of the terminal annular unit 4DE of the stent 101.

Hereinafter, the present invention will be described in detail with reference to the drawings.
First, in order to clearly explain the present invention, the following definitions are made with reference to the arrangement shown in FIG. In FIG. 1, in order to avoid complication of the description of each line, the struts 4ST and 5ST are shown so as to substantially overlap when viewed from the front direction to the back direction.
(Definition 1) As shown in FIG. 1, the “first side portion S1 side” means the front side of the paper surface and the front direction of the stent. Hereinafter, "... side" may be described as "... direction".
(Definition 2) As shown in FIG. 1, the “second side portion S2 side” means the back side of the paper surface and the back side direction of the stent.
(Definition 3) As shown in FIG. 1, the “terminal DE side” means the left side of the paper.

(Definition 4) The “base end PE side” means the right side of the paper as shown in FIG.
(Definition 5) As shown in FIG. 1, the “third side portion S3 side” means the upper side of the paper surface.
(Definition 6) As shown in FIG. 1, the “fourth side portion S4 side” means the lower side of the paper surface.

(Definition 7) “Longitudinal L direction” means the longitudinal direction of the stent as shown in FIG.
(Definition 8) The “circumferential CR direction” means a direction extending from the center C in the longitudinal L direction of the stent to the “side S side”, and is also referred to as the “side S direction”.
The side S direction includes the first side S1 side, the second side S2 side, the third side S3 side, the fourth side S4 side, and all the directions between them.

(Definition 9)
A part of the above circumferential CR (side S) direction is described as "one direction of the side portion", and a side opposite to or different from the "one direction of the side portion" is described as "one direction of the other side portion". May be done.
For example, the third side portion S3 side is one direction of the side portion, and the opposite fourth side portion S4 side (via the first side portion S1 or the second side portion S2 in the middle) is one direction of the other side portion. May be described as.
For example, the first side portion S1 side (or the second side portion S2 side) is one direction of the side portion, and the fourth side portion S4 side (or the third side portion S3 side) on a different side is one of the other side portions. It may be described as a direction.

(Definition 10)
Further, after the code of each part, a code indicating a direction such as S3 may be described.
For example, 4STS3 means the annular strut 4ST on the third side, and MS3 means the mountain part M on the third side.
Further, for example, with respect to the center line VC-MC connecting the center MC of the mountain portion M and the center VC of the valley portion V, the terminal DE side of the connecting strut 5ST is the fourth side of the valley portion VS2 on the second side portion S2 side. The position to be connected to the S4 side is described as <VS2S4> (see FIG. 2-3).

(Definition 11)
The "strut" is also referred to as a strut, and is a substantially linear or wire-shaped member forming the "annular unit 4" and the "connecting unit 5".
In addition, the "struts" constituting the "annular unit 4" may be described as "annular struts 4ST" or simply "struts 4ST" in the sense of "struts constituting the annular unit".
The members constituting the "connecting unit 5" may be described as "connecting strut 5ST" or simply "strut 5ST".

Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings based on the above definition.
As shown in FIG. 1, the stent 1 of the present invention has a so-called substantially tubular shape.

[Circular unit 4]
The annular unit 4 is an annular member in which a plurality of (annular) struts 4ST are continuously formed (arranged) in a so-called "substantially zigzag shape" in the circumferential CR direction. (This is also referred to as "approximately zigzag pattern" or "approximately wave shape pattern".)
For example, referring to FIGS. 1 and 2, the annular unit 4 has a bent portion 4C on the terminal DE side and the base end PE side. Hereinafter, the bent portion 4C on the terminal DE side will be referred to as “mountain portion M”, and the bent portion on the base end PE side will be referred to as “valley portion V”. (Of the bent portions 4C, the peak portion M may be referred to as 4C (M) and the valley portion V may be referred to as 4C (V).)
The "mountain part M" and the "valley part V" in the circumferential CR direction are connected by a so-called substantially linear "strat 4ST" so as to form a substantially zigzag pattern.
There is a predetermined space SP between the adjacent mountain part M and the mountain part M, and between the valley part V and the valley part V.

"Connecting unit 5"
The connecting unit is, for example, a member that connects the nth row (4n), the n + 1st row (4n + 1), and two "annular units 4". It is composed of a plurality of so-called substantially linear connecting struts 5ST (two in the example of FIG. 1).

As shown in FIG. 1, the stent 1 of the present invention is on the terminal DE side of the annular unit 4DE on the terminal side of the stent 1, at one end (S4) in the circumferential CR (side S) direction, and on the lesser curvature side. The hook 6 is arranged near the bending curve CS. (Note: Assuming that the position of S4 in the developed view 2 is the origin of the polar coordinate display (argument τ = 0 °), S1 and S2 are τ = 90 ° (however, S1 is clockwise and S2 is counterclockwise, respectively. τ = 90 °), S3 is τ = 180 °. Therefore, assuming that the position of S4 forming the hook faces the wall surface on the small side, τ = 180 ° of S3. The position is almost the position facing the wall surface on the lord side.) (The arrangement of the hook 6 will be described in detail later.)

In the annular unit, the annular unit 4DE / 4n on the first terminal DE side and the annular unit 4n + 1 on the second terminal DE side are connected by two connecting struts. Specifically, as shown in FIG. 2, for example, the connecting struts 5STS1 arranged in one direction of the side portion S and the other side portions S with respect to the center C in the longitudinal L direction of the lesser curvature side bending curve CS. It is connected by two struts of the connecting struts 5STS2 arranged in one direction.

The end DE side of each of the connecting strut 5STS1 and the connecting strut 5STS2 is connected to the valley V (VS1, VS2) of the annular unit 4DE / 4n, and the base end PE side is the second. It is connected to the mountain part M (MS1, MS2) of the annular unit 4n + 1.
The connecting strut 5STS1 and the connecting strut 5STS2 do not overlap the connection positions of the terminal DE side and the base end PE side in the longitudinal L direction (that is, even if one strut is moved to the other strut as it is, both of them They are connected in an arrangement that cannot be overlapped.
The connection (also referred to as joining) between the connecting strut 5ST and the mountain portion M (valley portion V) is not particularly limited, and is connected by, for example, heat welding, caulking with a metal pipe, or other fixing means (not shown). (Join).

Hereinafter, the binding mode of the connecting strut 5ST will be described in more detail.
As shown in FIG. 2, the connecting strut 5STS1 is connected to one direction of the side portion S of the valley portion V on the terminal DE side, and is one of the other side portions S of the mountain portion M on the proximal end PE side. Connected to the direction. Further, the connecting strut 5STS2 is connected to one direction of the other side portion S of the valley portion V on the terminal DE side and is connected to the other direction of the side portion S of the mountain portion M on the proximal end PE side. (The significance of this ("one-way side") will be discussed in more detail later).

[Hook 6 etc.]
The hook 6 has the base end PE side at a predetermined angle (varies depending on the specifications of each stent skeleton) from the center C (fourth side portion S4) in the longitudinal L direction of the lesser curvature side flexion curve CS, and the first side portion S1. / It is placed on the right side of the page. By arranging in this way, basically, the stent (stent graft) is locked and pulled by the hook 6 on the tip of the tip, and smoothly transported along the bending wall of the lesser curvature side along the bending wall surface of the lesser curvature. It is considered that the hook and the tip of the tip do not come into direct contact with the wall surface of the blood vessel and damage it during transportation.

However, as already described, in this case, as shown in FIG. 4, the terminal annular unit to which the hook is connected bends into an unexpectedly unnatural shape, and stable placement cannot be realized. There is.

This point will be described in more detail with reference to FIG. 2 (a partially enlarged view of the vicinity of the terminal annular unit 4DE of the stent 1 of FIG. 1 and a developed view in the circumferential CR direction). The annular unit 4DE / 4n on the first terminal DE side and the second terminal DE side with respect to the center C (fourth side portion S4, τ = 0 °) in the longitudinal L direction of the bending side bending curve CS. The annular unit 4n + 1 has one direction of the side S (first side S1, clockwise τ = 90 °) and one direction of the other side S (second side S2, counterclockwise τ = 90 °). ), The two mountain parts M and the valley parts V are described, respectively.

As shown in FIG. 2, the mountain portion M and the valley portion V on the side passing through the center C or near the center C are described as the mountain portion MS4 and the valley portion VS4, respectively, and one direction of the side portion S (first). The mountain portion M and the valley portion V on the side closer to one direction (second side portion S2) of the side portion S1) and the other side portion S are described as the mountain portion MS1, MS2, the valley portion VS1, and VS2, respectively. ..
As will be described in detail below, in the present invention, conventionally, the shape of the mountain part M and the valley part V of the annular strut has not been deeply examined, and simply roughly "mountain part M" and "tani part". Although it was treated as "V", in order to clearly define the features of the present invention, it is required to specify the morphology of the mountain portion M and the valley portion V in more detail and specify the connection position. That is, (i) the mountain portion M needs to be treated as being composed of a mountain peak that gently bends upward and two "posts" that extend downward from substantially vertical directions from both sides of the mountain peak. (Ii) It was found that the valley V needs to be treated as being composed of a valley bottom that gently bends downward and two "posts" that rise substantially vertically from both sides of the valley bottom.

FIG. 3 is a partially enlarged view of FIG. 2 (however, the description of the mountain portion MS4 and the valley portion VS4, which are the mountain portion M and the valley portion V on the side near the center C, and the strut 4ST forming these is omitted. doing.)
Further explaining along the above viewpoint, attention is paid to the mountain part M (MS1) shown at the lower part in the annular strut on the right side (S1, clockwise τ = 90 °) of the center line C (τ = 0 °). Then, the right side (S1 side) and the left side (S4 side) have struts, respectively. The column on the S1 side of the mountain part MS1 is referred to as <MS1S1>, and the column on the S4 side of the mountain part MS1 is referred to as <MS1S4>. (See Fig. 3)

Similarly, in the annular strut on the right side (S1, clockwise τ = 90 °) of the center line C (τ = 0 °), focusing on the valley V (VS1) shown at the top, the right side (S1 side). ) And the left side (S4 side), respectively. The column on the S1 side of the valley VS1 is referred to as <VS1S1>, and the column on the S4 side is referred to as <VS1S4>.

On the other hand, in the annular strut on the left side (S2, counterclockwise τ = 90 °) of the center line C (τ = 0 °), focusing on the mountain part M (MS2) shown at the bottom, the right side (S4 side). It has struts on the left side (S2 side) and on the left side (S2 side). The column on the S4 side of the Yamabe MS2 is referred to as <MS2S4>, and the column on the S2 side is referred to as <MS2S2>.

Similarly, in the annular strut on the left side (S2, counterclockwise τ = 90 °) of the center line C (τ = 0 °), focusing on the valley V (VS2) shown at the top, the right side (S4). It has struts on the left side (side) and the left side (S2 side), respectively. The column on the S4 side of the valley VS2 is referred to as <VS2S4>, and the column on the S2 side is referred to as <VS2S2>.

Based on the above, in the present invention, the connection positions of the two connecting struts 5STS1 and 5STS2 and each mountain portion M and valley portion V are configured as follows.
As described above, for example, focusing on the valley portion VS1 on the right side of the first side portion S1 side (clockwise τ = 90 °) with respect to the center C (fourth side portion S4), the center C (fourth side portion). The connection position (the column on the S4 side of the valley VS1) on the side closer to S4) (S4 side) is indicated as <VS1 S4>.
Further, at the mountain portion MS1 on the right side of the first side portion S1 with respect to the center C (fourth side portion S4), the connection position on the side closer to the first side portion S1 (the column on the S1 side of the mountain portion MS1) is set to < It is displayed as MS1 S1>.
Furthermore, the valley portion VS2 and the mountain portion MS2 on the left side of the second side portion S2 with respect to the center C (fourth side portion S4) are the same (that is, the columns to be connected to each are <VS2S4> (VS2). S4 side support column), <MS2S2> (MS2 S2 side support column).
The above description is the same as that of the reference example stent 101 (FIG. 5).

Both the stent 1 of the present invention shown in FIGS. 1, 2 and 3 and the stent 101 of the comparative example shown in FIGS. 4 and 5 are one ends of the terminal annular units 4DE and 104DE on the circumferential CR direction on the terminal DE side. In addition, the hooks 6 and 106 are arranged in the vicinity of the lesser curvature side bending curve CS, which is common.
However, the stent 1 of the present invention and the stent 101 of the comparative example differ in the connection positions of the two connecting struts 5ST and 105ST constituting the connecting units 5 and 105 as follows. That is, the differences are as follows.

First, the stent 101 of the comparative example shown in FIGS. 4 and 5 has two connecting struts 105STS1 and 105STS2 that connect the annular unit 104DE (104n) on the terminal DE side and the annular unit 104n + 1 on the second terminal DE side. The connection position between the terminal DE side and the base end PE side is set to "the same position" when viewed in the longitudinal L direction.
The connecting strut 105STS1 connects the terminal DE side and the base end PE side (on the first side S1 side of the center line C) with columns in the same side S direction (first side S1 direction). This is referred to as 105STS1.

On the other hand, the other connecting strut, the connecting strut 105STS2, has a strut (on the second side S2 side of the center line C) with the terminal DE side and the base end PE side in the same side S direction (second side S2 direction). They are connected to each other.
The two connecting struts 105STS1 and 105STS2 formed (connected and arranged) in this manner are the valleys of the (annular) struts 104ST of the annular unit 104DE (104n) when the terminal DE side and the base end PE side are viewed in the longitudinal L direction. It is connected so as to be substantially parallel to the center line VC-MC connecting the center VC of the portion V and the center MC of the mountain portion M of the annular unit 104n + 1. When connected in this way, the two connecting struts 105STS1 and 105STS2 can be superposed on each other.

That is, with respect to the center line VC-MC, the right connecting strut 105STS1 has the terminal DE side (on the first side portion S1 side of the center line C) and the first side portion of the valley portion VS1 on the first side portion S1 side. S1 side (post on S1 side of valley VS1): Connect with <VS1S1>, and connect the base end PE side to the first side S1 side of mountain part MS1 on the first side S1 side (S1 side of mountain part MS1). Support): Connected by <MS1S1>.
Further, the left connecting strut 105STS2 has the terminal DE side (on the second side S2 side of the stent central axis C) and the second side S2 side of the valley VS2 on the second side S2: (S2 of the valley VS2). Side strut): Connect with <VS2S2>, and connect the base end PE side with the second side S2 side of the mountain part MS2 on the second side S2 side (the strut on the S2 side of the mountain part MS2): <MS2S2>. You are connected.

On the other hand, the stent 1 of the present invention shown in FIGS. 1, 2 and 3 is, as described above, at one end in the circumferential CR direction of the terminal side annular unit 4DE on the terminal DE side and is small. It is common that the hook 6 is arranged near the curvature curve CS.
However, the two struts (connecting struts) connected to the annular unit 4DE (4n) on the first terminal DE side and the annular unit 4n + 1 on the second terminal DE side are lateral S as viewed from the center C. In the two connecting struts 5STS1 and 5STS2 in one direction (first side portion S1 direction) and one direction of the other side portion S (second side portion S2 direction), the terminal DE side and the base end PE side The connection positions are arranged so that they do not overlap when viewed in the longitudinal L direction (that is, both struts have a mirror image relationship with respect to the center line C and cannot be overlapped). It is set up.

More specifically, as shown in FIG. 3, the connecting strut 5STS1 has a support column in one direction (first side portion S1 side) of the side portion of the mountain portion MS1 when viewed from the center line C: <MS1S1> is this. And the support column in the side S direction (fourth side S4 side) of the valley portion VS1 which is different in position: <VS1S4> is connected. [That is, the stanchions in one direction (first side S1 direction) of the side portion S of the mountain portion MS1: <MS1S1> and the stanchions in one direction (fourth side portion S4 direction) of the side portion S of the valley portion VS1: It is connected to <VS1S4>. ]

Further, the connecting strut 5STS2 is a support column in one direction (second side portion S2 side) of the other side portion of the mountain portion MS2 when viewed from the center line C: <MS2S2> is a valley portion VS2 whose position is different from this. Support column in the side S direction (fourth side S4 side): Connected to <VS2S4>.
[In short, the column in one direction (second side S2 direction) of the side portion S of the mountain portion MS2: <MS2S2> and one direction (fourth side portion) of the other side portion S of the side portion S of the valley portion VS2. Supports in the S4 direction): Connected to <VS2S4>. ]

That is, as shown in FIG. 3, with respect to the center line VC-MC, the connecting strut 5STS1 has the terminal DE side (on the first side portion S1 side of the center line C) and the valley portion VS1 on the first side portion S1 side. Of the two valley struts, the struts on the fourth side S4 side are connected by <VS1S4>, and the base end PE side is connected to the two ridges of the ridge MS1 on the first side S1. Of these, the columns on the first side S1 side: <MS1S1> are connected.
Further, the connecting strut 5STS2 connects the terminal DE side (on the second side S2 side of the center line C) with the support column on the fourth side S4 side of the valley portion VS2 on the second side S2 side: <VS2S4>. The base end PE side is connected by a strut on the second side S2 side of the mountain portion MS2 on the second side S2 side: <MS2S2>.

In the present invention, as described above, by arranging the connection positions of the two connecting stents 5ST as defined in the present invention, the hook 6 is formed on the lesser curvature side as shown in FIG. However, it is possible to obtain a stent that responds to a sharp bend on the lesser curvature side and has a curved shape along the aortic arch in the longitudinal direction without causing deformation of the terminal annular unit, which was normally unavoidable. be able to.

[Other embodiments]
In the embodiment shown in FIG. 3, the connecting strut 5STS1 connecting the valley VS1 and the mountain MS1 connects the valley support <VS1S4> and the mountain support <MS1S1>, and the valley VS2. The connecting strut 5STS2 that connects the mountain part MS2 and the mountain part MS2 connects the valley part support <VS2S4> and the mountain part support <MS2S2>.
On the other hand, it is easily understood that the columns of the valley V and the columns of the mountain M to be connected may be used as the columns of the other side.
That is, the connecting strut 5STS1 connecting the valley VS1 and the mountain MS1 connects the valley support <VS1S1> and the mountain support <MS1S4>, and also connects the valley VS2 and the mountain MS2. The connecting strut 5STS2 may connect the support column <VS2S2> in the valley portion and the support column <MS2S4> in the mountain portion.
Even when the connecting struts are arranged at such a connection position, the connecting struts 5STS1 and 5STS2 are in a mirror image relationship with each other and cannot be overlapped with each other, so that the object of the present invention can be achieved.

[Material of stent 1 (metal material)]
The materials forming the annular strut 4ST, annular unit 4, connecting strut 5ST, connecting unit 5, and hook 6 constituting the stent 1 of the present invention are not particularly limited, and are, for example, stainless steel such as SUS316L; Ti—Ni alloy and the like. Superelastic alloy; preferably formed from a metal wire made of a titanium alloy, a Co—Cr alloy, Ta, Ti, W, Au or the like. In addition, a stent (annular unit, annular strut, connecting strut, hook) is made of a polymer material such as urethane, which is commonly used for stents formed from these metals, a physiologically active substance such as heparin and urokinase, and a thin film of an antithrombotic drug such as argatroban. ) Is also preferable because it can impart a function of preventing the formation of thrombi on the surface of the stent.

[Synthetic resin tubular member (graft)]
Further, the stent 1 can be used as it is, but usually the stent can be formed by coating the outer surface of the stent with a graft which is a tubular member made of synthetic resin with the stent as a skeleton. A film-like or fibrous material is preferable as the material for forming the graft. For example, a film made of a fluororesin (PTFE: polytetrafluoroethylene, PFA: tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer) (single layer). Or two or more layers), coated with a synthetic resin tubular member (graft) made of Dacron, Mylar (registered trademark, polyethylene terephthalate) fiber, etc. to form a stent graft.

[Construction of stent graft]
For example, as an example, a stent having a diameter of 40 mm at no load is reduced to 30 mm (75%). A stent graft can be formed by sewing the end portion and an arbitrary portion of a fluororesin (PTFE) tubular member (graft) having a diameter of 31 mm to a stent with a suture to fix and cover the stent.
In the stent graft, the stent 1 itself has a spring action, and is coated with a flexible synthetic resin tubular member (graft) and composited to form a stent graft. Therefore, the blood vessel 3 Can follow dimensional bending.

According to the present invention, by specifying the connection position of the two connecting struts 5ST connecting the terminal annular unit and the second annular unit facing the terminal annular unit, even if a hook is formed on the lesser curvature side, the terminal annular unit It is possible to obtain a stent that can cope with a steep bend on the lesser curvature side and has a curved shape along the aortic arch in the longitudinal direction without causing deformation. As described above, since it is possible to provide a stent (stent graft) that can be widely adapted to the condition of various affected parts of an individual patient (for example, the flexed state of the aorta, the placement position of the stent graft, etc.) The availability is extremely high.

1, 101 stent (1 is the present invention, 101 is a comparative example)
3 Fixing means 4 Ring unit 4DE Terminal side ring unit 4ST Ring strut 4C Bending part C Center of L in the longitudinal direction of the stent (central axis in the long axis direction of the stent tubular body)
CR Circumference CL Greater curvature side bending curve CS Lesser curvature side bending curve VC-MC Center line M through the center VC of each opposite valley and the center MC of the mountain M valley V Mountain 5 Connecting 5ST Connecting strut 6, 106 hook

Claims (3)

A plurality of annular units are connected by a plurality of connecting struts to form a substantially tubular body extending in the longitudinal direction.
The substantially tubular body has a curvature side bending curve and a lesser curvature side bending curve.
Each of the plurality of annular units is formed in a substantially zigzag shape continuously in the circumferential direction substantially orthogonal to the longitudinal direction, and has a first bent portion on the proximal end side and a second bent portion on the terminal end side. ,
A hook is arranged at one end on the terminal side of the first annular unit on the most terminal side of the plurality of annular units and in the vicinity of the bending curve on the lesser curvature side.
The plurality of connecting struts include the two connecting struts that connect the first annular unit and the second annular unit longitudinally adjacent to the first annular unit.
The two connecting struts
And connecting the second bending portion of the first bending portion and the front Stories second annular unit of the first annular unit, in the connecting struts, the connecting position between the first bent portion and the second bent portion A stent in which the connection positions of the stents are arranged so as to be offset in the circumferential direction substantially orthogonal to the longitudinal direction, and the direction in which each connection position of one connection strut is displaced is different from that of the other connection strut. The stent according to claim 1, wherein the two connecting struts are arranged so as to be displaced in the circumferential direction with respect to the hook. The first annular unit and the second annular unit are arranged so that the first bent portion of the first annular unit and the second bent portion of the second annular unit face each other in the longitudinal direction.
The two connecting struts are formed on one side of the first annular unit in the circumferential direction of the first bent portion and on the opposite side of the second annular unit from the one side of the second bent portion in the circumferential direction. The stent according to claim 1 or 2, wherein the stent is connected to another side portion.

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