JP2018108120A - Stent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stent that resolves a variety of problems arising as wire protection is performed, such as breakage of a guide wire and positional deviation of the stent.SOLUTION: A stent 100 is provided with a linear strut 110 shaping an outer periphery of a cylindrical shape where a gap 111 is formed, and has: a first area 130 which at least partially includes an inclined surface 137 inclined toward an inner peripheral side 110B of the cylindrical shape from a strut outer periphery surface 133 to a strut end surface 135; and a second area 160 which is provided nearer on the end side of an axial direction than the first area 130 and does not include the inclined surface 137.SELECTED DRAWING: Figure 3B

Description

  The present invention relates to a stent that is a medical device.

  Conventionally, a procedure using a balloon catheter or a stent has been performed for the treatment of a blood vessel or the like in which stenosis or occlusion has developed. For example, in general PCI (Percutaneous Coronary Intervention), a stent is treated as a treatment target using a stent delivery system (stent-mounted balloon catheter) described in Patent Document 1 below. The stenosis is expanded by a balloon and a stent is placed in the stenosis.

  In addition, in the PCI procedure, a treatment called “wire protection” is known which is performed when treating a stenosis formed around a bifurcation of a blood vessel.

  In wire protection, a guide wire is inserted into a side branch of a blood vessel prior to expansion of the stenosis. The surgeon places a stent in the stenosis with the guide wire inserted through the side branch of the blood vessel. The guide wire inserted into the side branch of the blood vessel prevents the side branch of the blood vessel from being blocked by a foreign substance such as plaque contained in the narrowed portion when the stenotic portion is pushed and expanded by the balloon. After performing wire protection, the guide wire inserted into the side branch of the blood vessel is pulled to the proximal side (proximal end side) by the operator and removed from the living body.

International Publication No. 2009/045764

  As described above, the guide wire used for wire protection is inserted into the side branch of the blood vessel prior to placement of the stent in the stenosis. For this reason, at the stage where the operation of pulling out the guide wire is performed, a part of the guide wire is sandwiched between the stent and the inner wall (or narrowed portion) of the blood vessel. When the surgeon pulls the guide wire toward the proximal side in such a state, the coil portion of the guide wire may be caught on the stent strut. As a result, the guide wire may be broken or the stent may be displaced.

  Then, this invention aims at provision of the stent which solves the various problems which generate | occur | produce with implementation of wire protection, such as breakage of a guide wire and the position shift of a stent.

  The stent according to the present invention is a stent including a linear strut that forms a cylindrical outer periphery in which a gap is formed, and the strut has a cylindrical outer peripheral side in a cross section along the axial direction of the cylindrical shape. A strut outer peripheral surface facing the cylindrical shape, and a strut distal end surface facing the cylindrical distal end side, and the stent is directed from the strut outer peripheral surface to the strut distal end surface toward the cylindrical inner peripheral side. A first region including at least a portion of the inclined surface; and a second region provided on a distal end side in the axial direction with respect to the first region and not including the inclined surface.

  The stent smoothly moves the guide wire along the inclined surface included in the first region when the guide wire used for wire protection is moved to the proximal end side in order to remove the guide wire from the living body. Therefore, the surgeon can prevent the guide wire from being damaged or the stent from being displaced even when the strut of the stent enters between the coil portions of the guide wire. In addition, the stent is provided on the distal side of the first region, and the second region that does not include an inclined surface can increase the retention force of the stent against a biological lumen such as a blood vessel. For this reason, when the surgeon moves the guide wire used for the wire protection to the proximal end side, it is possible to more effectively prevent the stent from being displaced.

It is a figure showing simply the whole structure of the stent delivery system concerning an embodiment. It is a top view of the stent which concerns on embodiment. It is a perspective sectional view expanding and showing a part of the 1st field of the stent concerning an embodiment. It is a figure which shows the 1st area | region of the stent which concerns on embodiment, and is sectional drawing of the 1st area | region in alignment with the axial direction of a stent. It is a perspective sectional view expanding and showing a part of the 2nd field of a stent concerning an embodiment. It is a figure which shows the 2nd area | region of the stent which concerns on embodiment, and is sectional drawing of the 2nd area | region in alignment with the axial direction of a stent. It is a figure which shows typically the procedure of the procedure which concerns on embodiment, and is sectional drawing which shows a mode when a guide wire is introduce | transduced in the blood vessel. It is a figure which shows typically the procedure of the procedure which concerns on embodiment, and is sectional drawing which shows a mode when the guide wire used for wire protection is introduced into the side branch of the blood vessel. It is a figure which shows typically the procedure of the procedure which concerns on embodiment, and is sectional drawing which shows a mode at the time of arrange | positioning the balloon which mounted | wore the stent in the constriction part formed in the branch part periphery of the blood vessel. It is a figure which shows typically the procedure of the procedure which concerns on embodiment, and is sectional drawing which shows a mode when the constriction part formed in the branch part periphery of the blood vessel is expanded with the balloon. It is a figure which shows typically the procedure of the procedure which concerns on embodiment, and is sectional drawing which shows a mode at the time of extracting the guide wire used for wire protection out of the living body. It is a figure which shows typically the procedure of the procedure which concerns on embodiment, and is sectional drawing which shows a mode when a stent is detained in the stenosis part formed in the branch part periphery of the blood vessel. It is a figure for demonstrating the effect | action of the stent which concerns on embodiment, and is sectional drawing which expands and shows the base end vicinity at the time of extracting the guide wire used for wire protection outside the living body. It is a figure for demonstrating the effect | action of the stent which concerns on embodiment, and is sectional drawing which expands and shows the front-end | tip vicinity of the stent at the time of extracting the guide wire used for wire protection outside the living body. It is a figure which shows the example of a shape of an inclined surface, and is sectional drawing corresponding to FIG. 3B. It is a figure which shows the other example of a shape of an inclined surface, and is sectional drawing corresponding to FIG. 3B. FIGS. 9A and 9B are views showing an anchor portion according to the first modification. FIG. 10A and FIG. 10B are views showing an anchor portion according to the second modification. FIG. 11A and FIG. 11B are diagrams showing an anchor portion according to the third modification.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In addition, the following description does not limit the technical scope and terms used in the claims. In addition, the dimensional ratios in the drawings are exaggerated for convenience of explanation, and may differ from actual ratios.

  1 is a diagram showing a stent delivery system 10 equipped with a stent 100 according to the present embodiment, FIG. 2 is a plan view of the stent 100, and FIGS. 3A to 4B are diagrams for explaining the main part of the stent 100. FIGS. 5A to 6C are diagrams schematically showing a procedure of a procedure using the stent 100, and FIGS. 7A and 7B are diagrams for explaining the operation of the stent 100.

  The stent 100 according to the present embodiment is a medical instrument used for treatment of a stenosis N formed in a biological lumen such as a blood vessel. The stent 100 is introduced to the vicinity of the stenosis N of the blood vessel by the balloon catheter 200 shown in FIG. 1, and is placed in the blood vessel in order to maintain the stenosis N in an expanded state (see FIG. 6B). As will be described later, in the present embodiment, an example will be described in which the stent 100 is applied to the treatment of the stenosis N formed around the blood vessel bifurcation.

  The stent delivery system 10 will be described.

  The stent 100 is configured as a so-called balloon expandable stent, and is prepared in a state of being attached (crimped) to the balloon 210 of the balloon catheter 200 shown in FIG. The stent 100 and the balloon catheter 200 constitute a stent delivery system 10 that is a medical device for delivering the stent 100 to the stenosis N in the blood vessel.

  As shown in FIG. 1, the balloon catheter 200 is a general balloon catheter used for stent placement. The balloon catheter 200 has a flexible structure in which a balloon 210 that expands and contracts with the introduction and discharge of a pressurized medium, a lumen through which the pressurized medium can flow, and a lumen through which the guide wire 310 can be inserted are formed. It has a long shaft 220 and a hub 230 provided with a port through which the pressurized medium is introduced and discharged.

  The balloon catheter 200 is a so-called rapid exchange type balloon catheter in which a guide wire port 221 for inserting and removing the guide wire 310 is formed near the tip of the shaft 220. The structure of each part of the balloon catheter 200 is not particularly limited as long as it has a balloon on which the stent 100 can be attached and the stent 100 can be placed at a desired position in the living body. For example, the balloon catheter 200 may be a so-called over-the-wire balloon catheter in which a guide wire is inserted from the proximal end side of the hub along the axial direction of the shaft.

  Next, the stent 100 will be described.

  In the description of the present specification, the longitudinal direction of the stent 100 (the left-right direction in FIG. 2) is defined as the axial direction and is indicated by an arrow A1 in each figure. Further, the side that is introduced into the living body (intravascular) in the stent 100 is defined as the distal side (distal side, left side in FIG. 2), and the end side opposite to the distal side is the proximal side (proximal side, The right side of FIG. Further, in this specification, the distal end portion means a portion including a certain range in the axial direction from the distal end (the most distal end), and the proximal end portion means a certain range in the axial direction from the proximal end (most proximal end). Means a part containing

  As shown in FIG. 2, the stent 100 includes a linear strut (linear element) 110 that forms a cylindrical outer periphery (skeleton) in which a gap 111 is formed. The gaps 111 are arranged in a predetermined pattern so as to separate adjacent portions in the strut 110.

  The stent 100 has a first region 130 and a second region 160.

  The first region 130 of the stent 100 is a region including at least a part of a strut 131 (hereinafter, referred to as “first strut 131”) in which an inclined surface 137 (see FIG. 3B) described later is formed. The second region 160 of the stent 100 is a region composed of struts 161 (hereinafter referred to as “second struts 161”) in which the inclined surface 137 is not formed.

  The first region 130 and the second region 160 are disposed at different positions in the axial direction of the stent 100. Specifically, the second region 160 is disposed closer to the distal end side in the axial direction of the stent 100 than the first region 130.

  Further, in the present embodiment, the first region 130 is formed over a certain range in the axial direction including the proximal end 103 of the stent 100, and the second region 160 is the axial direction including the distal end 106 of the stent 100. Are formed over a certain range.

  The first strut 131 included in the first region 130 will be described with reference to FIGS. 3A and 3B. 3A shows a perspective cross-sectional view of the first strut 131, and FIG. 3B shows a cross-sectional view of the first strut 131 along the axial direction.

  The first strut 131 has a strut outer peripheral surface 133, a strut inner peripheral surface 134, a strut tip end surface 135, a strut, and a strut along a cylindrical axial direction formed by the strut 110 (the same direction as the axial direction of the stent 100). A proximal end surface 136 and an inclined surface 137 are provided.

  As shown in FIG. 3B, the strut outer peripheral surface 133 of the first strut 131 is disposed so as to face the cylindrical outer peripheral side 110 </ b> A formed by the strut 110. The strut inner peripheral surface 134 of the first strut 131 is disposed so as to face the cylindrical inner peripheral side 110B. The strut distal end surface 135 of the first strut 131 is disposed so as to face the cylindrical distal end side (the distal end side of the stent 100). The strut base end surface 136 of the first strut 131 is disposed so as to face the cylindrical base end side (the base end side of the stent 100). The inclined surface 137 of the first strut is inclined from the strut outer peripheral surface 133 to the strut distal end surface 135 toward the cylindrical inner peripheral side 110B.

  The cylindrical outer peripheral side 110A (hereinafter simply referred to as “outer peripheral side 110A”) means the outer surface side of the stent 100, and the cylindrical inner peripheral side 110B (hereinafter simply referred to as “ The inner peripheral side 110 </ b> B ”means the inner surface side of the stent 100 (the side facing the cylindrical lumen).

  Each surface 133, 134, 135, 136 other than the inclined surface 137 of the first strut 131 is formed as a flat surface (flat surface).

  As shown in FIG. 3B, the inclined surface 137 of the first strut 131 has a cross-sectional shape curved in a convex shape on the outer peripheral side 110 </ b> A in a cross section along the axial direction of the stent 100. The curvature (degree of curvature) of the inclined surface 137 is not particularly limited, but is preferably somewhat large from the viewpoint of preventing breakage of the guide wire 320 used for wire protection (see FIG. 7A). Specifically, the curvature of the inclined surface 137 is such that the wire diameter of a coil of a general guide wire used for wire protection and the diameter of the wire corresponding to the first strut 131 of the stent 100 (the inclined surface 137 is formed). In consideration of the wire rod diameter of the strut 110 in the previous state or the outer peripheral length of the strut 110 on the cross-sectional shape along the axial direction, it is preferably about 5 to 40 (1 / mm).

  The inclined surface 137 in this specification is defined as “a surface inclined toward the inner peripheral side of the cylindrical shape from the outer peripheral surface of the strut to the distal end surface of the strut” as described above. In addition to the shape curved convexly toward the outer peripheral side 110A shown in FIG. 3B, for example, the inclined surface 137 has a shape curved convexly toward the inner peripheral side 110B as shown in FIG. 8B includes a shape inclined substantially linearly from the outer peripheral surface 133 of the strut toward the front end surface 135 of the strut.

  For example, it is also possible to selectively combine inclined surfaces 137 having different cross-sectional shapes as shown in FIG. 3, FIG. 8A, FIG. Further, the cross-sectional shape of each surface other than the inclined surface 137 of the first strut 131 can be formed in a shape other than the flat shape shown in each of the above drawings. Further, for the struts 131 as shown in FIGS. 8A, 8B, etc., for example, the above-described dimension examples can be adopted as the dimensions of each surface.

  In the first region 130 of the stent 100, an inclined surface 137 is formed over the entire circumference in the cylindrical circumferential direction formed by the strut 110 (in the direction of arrow R1 shown in FIG. 2 and in the same direction as the circumferential direction of the stent 100). Has been.

  In the present embodiment, all the struts included in the first region 130 are configured by the first struts 131 including the inclined surface 137. However, a part of the struts included in the first region 130 can be configured by a strut (for example, the second strut 161) in which the inclined surface 137 is not formed. In the case of such a configuration, for example, a part of the portion juxtaposed along the circumferential direction of the stent 100 may include a strut other than the first strut 131, or juxtaposed along the axial direction of the stent 100. You may make it include struts other than the 1st strut 131 in a part of made part.

  When the inclined surface 137 is formed over a predetermined range in the circumferential direction of the stent 100, the first strut 131 exhibits the cross-sectional shape shown in FIG. 3B in all cross-sections along the same axis of the stent 100. In other words, the first strut 131 has a cross-sectional shape different from the shape shown in FIG. 3B in a cross section along a direction orthogonal to the extending direction of the first strut 131 (the arrow b direction shown in FIG. 2). Parts can also be included.

  In addition, as a method of forming the cross-sectional shape of the first strut 131 along the same axis of the stent 100 into the same shape, for example, in a state where the strut 110 forms a cylindrical shape, the outer surface of the strut 110 is pressed. Examples of the method include processing and polishing. By adopting such a method, the inclined surface 137 can be relatively easily formed on a part of the outer peripheral surface 133 of the strut.

  As shown in FIG. 3B, a lubricous coat layer 138 is provided on the strut outer peripheral surface 133 of the first strut 131 and the inclined surface 137 of the first strut 131. The lubricious coating layer 138 can be formed by, for example, applying a known hydrophilic coating agent to each surface 133, 137. Note that the lubricity coat layer 138 can be omitted as appropriate, and the lubricity coat layer 138 can be provided on a part of each of the surfaces 133 and 137 or on only one of the surfaces.

  In the cross section shown in FIG. 3B, the length L21 of the inclined surface 137 is 20 to 90 of the entire length of the strut outer peripheral surface 133 when the inclined surface 137 is not provided (corresponding to the length L22 of the strut inner peripheral surface 134 in FIG. 3B). % Of the length is preferable.

  In the cross section shown in FIG. 3B, the height (length in a direction orthogonal to the axial direction) L31 of the inclined surface 137 is the total length of the strut distal end surface 135 when the inclined surface 137 is not provided (the strut base end surface in FIG. 3B). The length is preferably 10 to 50% of the length L32 of 136).

  By setting each dimension of the inclined surface 137 (the range in which the inclined surface 137 is formed in the first strut 131) as described above, the inclined surface 137 is suitably maintained while maintaining the radial force of the stent 100 and the strength of the stent 100. The guide wire 320 can be smoothly moved along (see FIG. 7A). However, since the said dimension is an illustration, it is not specifically limited.

  Next, the second strut 161 included in the second region 160 will be described with reference to FIGS. 4A and 4B. 4A shows a perspective cross-sectional view of the second strut 161, and FIG. 4B shows a cross-sectional view of the second strut 161 along the axial direction.

  The second strut 161 includes a strut outer peripheral surface 163 facing the outer peripheral side 110 </ b> A, a strut inner peripheral surface 164 facing the inner peripheral side 110 </ b> B, and a strut distal end surface facing the distal end side of the stent 100 in the cross section along the axial direction of the stent 100. 165 and a strut base end face 166 facing the base end side of the stent 100.

  The second strut 161 is formed in a substantially rectangular shape in the cross section shown in FIG. 4B. Each surface 163, 164, 165, 166 of the second strut 161 is formed as a flat surface (flat surface).

  The second strut 161 has an anchor portion 168 that is formed with a larger frictional resistance to act on a biological lumen such as a blood vessel than the first strut 131 in the first region 130.

  The anchor portion 168 is configured by a rough surface portion formed by roughening the strut outer peripheral surface 163 of the second strut 161. The surface roughness (surface roughness) of the strut outer peripheral surface 163 for functioning as the anchor portion 168 and the range of the rough surface portion formed on the strut outer peripheral surface 163 are not particularly limited. For example, product specifications, desired performance, etc. It is possible to set appropriately according to the situation. Moreover, as a formation method of the anchor part 168, it is possible to employ | adopt polishing, a shot peening process, etc., for example.

  For example, the anchor portion 168 may be formed over the entire circumference in the circumferential direction of the second region 160 of the stent 100, or may be formed only in a part in the circumferential direction of the second region 160. However, from the viewpoint of enhancing the anchor function of the second region 160, the anchor portion 168 is preferably formed over a predetermined range (for example, the entire circumference) of the second region 160 in the circumferential direction.

  The second region 160 is defined as a region that does not include the first strut 131 (see FIG. 3B) in which the inclined surface 137 is formed. That is, the second region 160 of the stent 100 is configured only by the second strut 161 in which the inclined surface 137 is not formed. In other words, the cross-sectional shape and structure of the second strut 161 constituting the second region 160 (for example, the presence or absence of the anchor portion 168) are not particularly limited as long as the inclined surface 137 is not formed.

  Next, a preferable range of the length along the axial direction of the first region 130 and the second region 160 will be described. However, since the following description is an illustration, it is not limited to the described dimension.

  Referring to FIG. 2, the length L <b> 11 along the axial direction of the first region 130 is 10 to 90 of the total length L <b> 1 of the stent 100 when the first region 130 is formed in a range including the proximal end 103 of the stent 100. % Of the length is preferable. When the first region 130 is formed over a certain range on the proximal end side of the stent 100 in this way, the surgeon performs the treatment on the stenosis N formed around the bifurcation of the blood vessel. It becomes easy to arrange | position the 1st area | region 130 to the base end side (hand side) rather than side branch B2 of this (refer FIG. 6A).

  Referring to FIG. 2, the length L12 of the second region 160 is 10 to 50% of the total length L1 of the stent 100 when the second region 160 is formed in a range including the distal end 106 of the stent 100. It is preferable to be formed. As described above, when the second region 160 is formed over a certain range on the distal end side of the stent 100, the stent 100 can suitably increase the holding force of the stent 100 on the blood vessel. In addition, when the second region 160 is formed over a certain range on the distal end side of the stent 100 in this way, the surgeon can perform a treatment on the stenosis N formed around the bifurcation of the blood vessel. It becomes easier to arrange the second region 160 on the distal end side than the side branch B2 of the blood vessel (see FIG. 6A). As a result, when the surgeon performs the wire protection procedure, the second region 160 and the anchor portion 168 formed in the second region 160 interfere with the guide wire 320 to prevent the guide wire 320 from being smoothly moved. It becomes possible to prevent.

  As a material constituting the stent 100, for example, a biocompatible metal can be used. Examples of metals having biocompatibility include iron-based alloys such as stainless steel, tantalum (tantalum alloy), platinum (platinum alloy), gold (gold alloy), cobalt-base alloys such as cobalt-chromium alloy, titanium alloys, and niobium. An alloy etc. are mentioned. In addition, the stent 100 may be, for example, a total biodegradable stent composed mainly of a polymer or the like, or a stent partially composed of a biodegradable material.

  In addition, the outer surface of the stent 100 (for example, the strut outer peripheral surface 133 of the first strut 131, the inclined surface 137 of the first strut 131, the strut outer peripheral surface 163 of the second strut 161) carries a predetermined medicine or medicine. It is also possible to provide a drug coat layer containing a drug carrier for the purpose.

  Next, a usage example of the stent 100 according to the present embodiment will be described with reference to FIGS. 5A to 6C. Here, an example will be described in which the stent 100 is applied to the treatment of a stenosis N formed around a branch portion of a blood vessel (coronary artery). Further, here, when performing the procedure of placing the stent 100 on the main trunk B1 of the blood vessel, a foreign substance such as plaque contained in the stenosis N moves to the side branch B2 of the blood vessel and the side branch B2 of the blood vessel is blocked. An example of the technique of “wire protection” performed to prevent this will also be described.

  As shown in FIG. 5A, the operator inserts a guide wire 310 for guiding the balloon catheter 200 into the main trunk B1 of the blood vessel via an introducer (not shown). Then, the surgeon introduces the guide wire 310 to the narrowed portion N.

  Next, as shown in FIG. 5B, the surgeon introduces the guide wire 320 used for wire protection from the main trunk B1 side of the blood vessel to the side branch B2 of the blood vessel.

  Next, as shown in FIG. 5C, the surgeon introduces the balloon catheter 200 with the stent 100 attached along the guide wire 310 into the main trunk B1 of the blood vessel. Then, the surgeon places the balloon 210 in the stenosis N. At this time, the surgeon can arrange the first region 130 of the stent 100 on the proximal end side (near side in the introduction direction) of the stenosis N, and the second region 160 of the stent 100 can be the side branch B2 of the blood vessel. The positions of the balloon 210 and the stent 100 are adjusted so as to be disposed on the distal end side (the back side in the introduction direction) of the stenosis N beyond the distance.

  Next, the surgeon supplies the pressurizing medium to the balloon catheter 200 to expand the balloon 210 as shown in FIG. 6A. The stent 100 is expanded so that the expanded diameter of the first region 130 including the proximal end 103 and the expanded diameter of the second region 160 including the distal end 106 are substantially the same. In addition, the stent 100 expands to expand the stenosis N as the balloon 210 is expanded, the first region 130 is pressed against the vicinity of the proximal end of the stenosis N, and the second region 160 is compressed. Crimp against the vicinity of the tip of N.

  The guide wire 320 inserted in the side branch B2 of the blood vessel prevents the plaque included in the narrowed portion N from moving to the side branch B2 of the blood vessel and closing the side branch B2 when the balloon 210 and the stent 100 are expanded. Further, as the stent 100 expands, the guide wire 320 is sandwiched between the first region 130 of the stent 100 and the narrowed portion N.

  Next, the operator contracts the balloon 210 and removes the balloon catheter 200 from the living body. The stent 100 is placed in the blood vessel in a state where the stenosis N is expanded. In a state where the stent 100 is indwelled in the blood vessel, the proximal end 103 of the stent 100 is disposed in the vicinity of the proximal end portion of the stenosis N, and the distal end 106 of the stent 100 is disposed near the distal end portion of the stenosis N.

  Next, as shown in FIGS. 6B and 6C, the surgeon moves the guide wire 320 used for wire protection to the proximal end side (in the direction of the arrow in FIG. 6B) and removes it from the living body. Thereafter, the surgeon removes the guide wire 310 used for guiding the balloon catheter 200 out of the living body. Through the above procedure, the surgeon can place the stent 100 around the bifurcation of the blood vessel while performing wire protection.

  The operator may remove the guide wire 320 used for wire protection after first removing the guide wire 310 used to guide the balloon catheter 200. In addition, the operator may perform a treatment of expanding the proximal end portion of the stent 100 by using the balloon catheter again after removing the guide wire 320 used for the wire protection.

  Next, with reference to FIG. 7A and FIG. 7B, the effect | action of the stent 100 at the time of extracting the guide wire 320 used for the wire protection is demonstrated. FIG. 7A shows a guide wire 320 used for wire protection. For the wire protection, for example, a known guide wire including a core part (core wire) 321 and a coil part 323 can be used.

  In general stents, the cross-sectional shape of the strut (for example, the cross-sectional shape along the axial direction of the stent) is often formed in a rectangular shape. For this reason, when the guide wire 320 used for wire protection is removed from the living body, the edge portion of the strut is caught by the coil portion 323 of the guide wire 320, and the coil portion 323 is damaged or the stent 100 is displaced. There are things to do.

  In the stent 100 according to this embodiment, an inclined surface 137 is formed on the first strut 131 included in the first region 130. For this reason, when the guide wire 320 used for wire protection is pulled out of the living body, the guide wire 320 smoothly moves toward the proximal end along the inclined surface 137 of the first strut 131 as shown in FIG. 7A. As a result, even if the first strut 131 of the stent 100 enters the coil portion 323 of the guide wire 320, the coil portion 323 of the guide wire 320 is moved relative to the first strut 131. To prevent it from being caught firmly. Thus, the surgeon can prevent the coil portion 323 from being damaged and the stent 100 from being displaced.

  In the stent 100 according to the present embodiment, the inclined surface 137 is not formed on the second strut 161 included in the second region 160. Therefore, as shown in FIG. 7B, it is possible to ensure a relatively large contact area between the strut outer peripheral surface 163 of the second region 160 and the inner wall Bw (or stenosis N) of the blood vessel. As a result, the frictional resistance acting between the second strut 161 and the inner wall Bw of the blood vessel is increased, so that the stent 100 is hardly displaced.

  Furthermore, an anchor portion 168 is formed on the outer peripheral surface 163 of the second strut 161. For this reason, the frictional resistance that the second strut 161 acts on the inner wall Bw of the blood vessel is further enhanced. Therefore, the surgeon can more reliably prevent the displacement of the stent 100 when the guide wire 320 used for wire protection is removed from the living body.

  It should be noted that the stent 100 has a guide wire 320 sandwiched between the stent 100 and the inner wall Bw (or stenosis N) of the blood vessel, regardless of whether the guide wire 320 used for wire protection is removed from the living body. The effect is demonstrated when moving to the base end side. Therefore, the stent 100 preferably prevents the guide wire 320 from being damaged or the stent 100 from being displaced even when the guide wire 320 is inadvertently moved toward the proximal end during the procedure. be able to.

  As described above, the stent 100 according to this embodiment is a stent including the linear struts 110 that form the cylindrical outer periphery in which the gap 111 is formed. The strut 110 has strut outer peripheral surfaces 133 and 163 facing the cylindrical outer peripheral side 110A and strut front end surfaces 135 and 165 facing the cylindrical front end side in a cross section along the axial direction of the cylindrical shape. . The stent 100 includes a first region 130 including at least a part of an inclined surface 137 inclined from the strut outer peripheral surface 133 to the strut distal end surface 135 toward the cylindrical inner peripheral side 110 </ b> B, and the first region 130. And a second region 160 that is provided on the tip end side in the axial direction and does not include the inclined surface 137.

  The stent 100 smoothly moves the guide wire 320 along the inclined surface 137 included in the first region 130 when the guide wire 320 used for wire protection is moved to the proximal end side in order to be pulled out of the living body. Let For this reason, even when the first strut 131 of the stent 100 enters the coil portion 323 of the guide wire 320, the surgeon can prevent the guide wire 320 from being damaged or the stent 100 from being displaced. Can be prevented. In addition, the stent 100 is provided on the distal side of the first region 130, and the second region 160 that does not include the inclined surface 137 holds the stent 100 against the inner wall Bw (or stenosis N) of the blood vessel. Can be increased. For this reason, when the surgeon moves the guide wire 320 used for the wire protection to the proximal end side, it is possible to more effectively prevent the stent 100 from being displaced.

  Further, the first region 130 of the stent 100 is provided in a range including the proximal end 103 of the stent 100. For this reason, when performing wire protection for the treatment of the stenosis N formed around the blood vessel bifurcation, the surgeon sets a certain range on the proximal end side including the first region 130 over the side branch B2 of the blood vessel. It can arrange | position to a base end side. Thereby, the surgeon can smoothly move the guide wire 320 used for the wire protection to the proximal end side of the stent 100.

  Further, the inclined surface 137 of the stent 100 has a cross-sectional shape curved in a convex shape on the outer peripheral side of the cylindrical shape in a cross section along the axial direction of the stent 100. Since the inclined surface 137 has such a cross-sectional shape, the surgeon can move the guide wire 320 used for wire protection along the inclined surface 137 to the proximal side more smoothly.

  In addition, the second strut 161 included in the second region 160 of the stent 100 is formed with a larger frictional resistance that acts on the inner wall Bw (or stenosis N) of the blood vessel than the first strut 131 in the first region 130. And an anchor portion 168. The anchor portion 168 effectively prevents the stent 100 from being displaced when the operator pulls out the guide wire 320 used for wire protection.

  The anchor portion 168 of the second region 160 has a rough surface portion formed by roughening the surface of the second strut 161. For this reason, the anchor portion 168 can be provided relatively easily without performing extensive processing on the second strut 161, and the manufacturing cost of the stent 100 can be reduced and the manufacturing operation can be facilitated.

  Further, the second region 160 of the stent 100 is provided in a range including the distal end 106 of the stent 100. For this reason, when performing the wire protection for the treatment of the stenosis N formed around the bifurcation of the blood vessel, the surgeon sets a certain range on the distal end side including the second region 160 to the distal end than the side branch B2 of the blood vessel. Can be placed on the side. Accordingly, the surgeon can more reliably prevent the displacement of the stent 100 via the second region 160 of the stent 100.

  Further, an inclined surface 137 is formed in the first region 130 of the stent 100 over the entire circumference in the circumferential direction of the cylindrical shape. For this reason, the operator can omit the work of aligning the guide wire 320 at the position where the inclined surface 137 is formed in the circumferential direction of the stent 100 when removing the guide wire 320 used for wire protection. The operation of removing the guide wire 320 can be performed quickly.

  Next, a modified example of the anchor portion will be described. In addition, about the structure similar to embodiment mentioned above, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

<Modification 1>
FIG. 9A is a plan view showing the second strut 161 in which the anchor portion 668 according to Modification 1 is formed, and FIG. 9B is a perspective view showing a part of the second strut 161 in an enlarged manner. It is sectional drawing.

  As shown in FIGS. 9A and 9B, the anchor portion 668 according to the first modification has a plurality of convex protrusions formed on the outer peripheral surface 163 of the second strut 161. The convex projecting portion has a shape extending substantially linearly in a direction intersecting (orthogonal) with the extending direction of the second strut 161 (the direction indicated by the arrow b in the figure).

  The anchor portion 668 according to this modification increases the frictional resistance that the strut outer peripheral surface 163 of the second strut 161 acts on the inner wall Bw (or stenosis N) of the blood vessel. For this reason, when the surgeon moves the guide wire 320 used for wire protection to the proximal end side in order to remove the guide wire 320 from the living body, the surgeon acts between the strut outer peripheral surface 163 of the second strut 161 and the inner wall Bw of the blood vessel. It is possible to more surely prevent the displacement of the stent 100 due to the frictional force.

  The anchor portion 668 is, for example, a convex protrusion disposed in a lattice shape on the plan view shown in FIG. 9A, a convex protrusion extending in parallel with the extending direction of the second strut 161, or the like. You may comprise so that it may have.

<Modification 2>
FIG. 10A is a plan view showing the second strut 161 in which the anchor portion 768 according to Modification 2 is formed, and FIG. 10B is a perspective view showing a part of the second strut 161 in an enlarged manner. It is sectional drawing.

  As shown in FIGS. 10A and 10B, the anchor portion 768 according to the modification 2 has a plurality of minute convex protrusions 768 formed on the outer peripheral surface 163 of the second strut 161. ing.

  Similar to the anchor portion 668 according to the first modified example, the anchor portion 768 according to the present modified example has a frictional resistance that causes the outer peripheral surface 163 of the second strut 161 to act on the inner wall Bw (or the narrowed portion N) of the blood vessel. Increase. For this reason, when the surgeon moves the guide wire 320 used for wire protection to the proximal end side in order to remove the guide wire 320 from the living body, the surgeon acts between the strut outer peripheral surface 163 of the second strut 161 and the inner wall Bw of the blood vessel. It is possible to more surely prevent the displacement of the stent 100 due to the frictional force.

<Modification 3>
FIG. 11A is a plan view showing the second strut 161 in which the anchor portion 868 according to Modification 3 is formed, and FIG. 11B is a perspective view showing a part of the second strut 161 in an enlarged manner. It is sectional drawing.

  As shown in FIGS. 11A and 11B, the anchor portion 868 according to the modification 3 has a coating agent that increases the frictional resistance formed on the outer peripheral surface 163 of the second strut 161. As the coating agent for increasing the frictional resistance, for example, a silicone rubber or a resin material including particles exposed on the surface can be used.

  The anchor portion 868 according to this modification is configured so that the strut outer peripheral surface 163 of the second strut 161 is against the inner wall Bw (or the constricted portion N) of the blood vessel by the coating agent applied to the outer peripheral surface 163 of the second strut 161. The frictional resistance can be increased. For this reason, when the operator pulls out the guide wire 320 used for the wire protection to the proximal end side, the surgeon is positioned on the stent 100 by the frictional force generated between the outer peripheral surface 163 of the second strut 161 and the inner wall Bw of the blood vessel. It is possible to more reliably prevent the deviation from occurring.

  As mentioned above, although the stent which concerns on this invention was demonstrated through embodiment and a modification, this invention is not limited only to the content demonstrated in this specification, It can change suitably based on description of a claim. Is possible.

  For example, the first region may be provided on the proximal end side of the stent relative to the second region in the relative positional relationship with the second region, and may not be provided in a range including the proximal end of the stent. Good. Similarly, the second region may be provided on the distal end side of the stent relative to the first region in the relative positional relationship with the first region, and may not be provided in a range including the distal end of the stent. . In addition, other regions (for example, the struts of the first region and the region between the first region, the region closer to the proximal end than the first region, the region closer to the distal end than the second region, etc.) It is also possible to provide a region having a strut having a different cross-sectional shape from any of the struts in the second region, a region configured so that the magnitude of the frictional resistance acting on the living body lumen differs in the axial direction, etc. is there.

  Further, in the description of the embodiment, the configuration in which the inclined surface is formed over the entire circumference in the circumferential direction of the stent in the first region is exemplified. For example, the inclined surface may be formed in a part of the circumferential direction of the stent. Alternatively, it may be formed intermittently along the circumferential direction of the stent.

  In addition, the anchor portion can be provided in one stent by selectively combining the structures described in the embodiments and the modifications. Further, the anchor portion may be constituted by, for example, a groove portion recessed from the outer peripheral surface of the strut, or may be constituted by a combination of the groove portion and the protruding portion.

  In addition, the specific structure (outer diameter, length, inner diameter, wall thickness, strut design, etc.) of the stent is particularly limited as long as the stent is provided with at least a first region and a second region. There is nothing.

10 Stent delivery system,
100 stents,
103 proximal end of the stent,
106 the tip of the stent,
110 struts,
111 gap,
110A Cylindrical outer peripheral side,
110B cylindrical inner peripheral side,
130 first region,
131 first strut,
133 Strut outer peripheral surface,
134 Strut inner peripheral surface,
135 strut tip,
136 strut proximal end surface,
137 inclined surface,
160 second region,
161 second strut,
163 strut outer peripheral surface,
164 strut inner peripheral surface,
165 strut tip surface,
166 strut proximal end surface,
168, 668, 768, 868 anchor part,
200 balloon catheter,
210 balloon,
310, 320 guide wire,
A1 axial direction of stent (cylindrical shape),
The circumferential direction of the R1 stent (cylindrical shape),
B1, the main trunk of the blood vessel,
B2 Side branch of blood vessel,
Bw inner wall of blood vessel,
N Stenosis.

Claims (7)

A stent comprising linear struts forming a cylindrical outer periphery with a gap formed therein,
The strut has a strut outer peripheral surface facing the outer peripheral side of the cylindrical shape and a strut front end surface facing the cylindrical front end side in a cross section along the axial direction of the cylindrical shape,
The stent includes a first region including at least a part of an inclined surface inclined from the outer peripheral surface of the strut to the distal end surface of the strut toward the inner peripheral side of the cylindrical shape, and the axial direction than the first region. And a second region that is provided on the distal end side and does not include the inclined surface.   The stent according to claim 1, wherein the first region is provided at least in a range including a proximal end of the stent.   The stent according to claim 1, wherein the inclined surface has a cross-sectional shape curved in a convex shape toward the outer peripheral side in a cross section along the axial direction.   The strut included in the second region has an anchor portion formed to have a larger frictional resistance to act on the body lumen than the strut in the first region. The stent according to any one of the above.   The anchor portion includes a rough surface portion formed by roughening the surface of the strut, a convex protrusion formed on the surface of the strut, and a coating agent that increases the frictional resistance coated on the surface of the strut. The stent according to claim 4, comprising at least one of them.   The stent according to any one of claims 1 to 5, wherein the second region is provided at least in a range including a distal end of the stent.   The stent according to any one of claims 1 to 6, wherein the inclined surface is formed in the first region over the entire circumference of the cylindrical shape in the circumferential direction.