JP4727070B2 - Stent - Google Patents

Stent Download PDF

Info

Publication number
JP4727070B2
JP4727070B2 JP2001166672A JP2001166672A JP4727070B2 JP 4727070 B2 JP4727070 B2 JP 4727070B2 JP 2001166672 A JP2001166672 A JP 2001166672A JP 2001166672 A JP2001166672 A JP 2001166672A JP 4727070 B2 JP4727070 B2 JP 4727070B2
Authority
JP
Japan
Prior art keywords
stent
corrugated
wave
element
mm
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
JP2001166672A
Other languages
Japanese (ja)
Other versions
JP2002355315A (en
Inventor
孝史 北岡
陽助 森内
Original Assignee
テルモ株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by テルモ株式会社 filed Critical テルモ株式会社
Priority to JP2001166672A priority Critical patent/JP4727070B2/en
Priority claimed from DE2002634503 external-priority patent/DE60234503D1/en
Publication of JP2002355315A publication Critical patent/JP2002355315A/en
Application granted granted Critical
Publication of JP4727070B2 publication Critical patent/JP4727070B2/en
Application status is Active legal-status Critical
Anticipated expiration legal-status Critical

Links

Images

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an in-vivo stent used for improving a stenosis or occlusion occurring in a lumen of blood vessels, bile ducts, trachea, esophagus, urethra, other organs, etc. It relates to a stent.
[0002]
[Prior art]
In order to treat various diseases caused by stenosis or occlusion of blood vessels or other in-vivo lumens, stents are expanded at the site of stenosis or occlusion and placed at that site to secure the lumen. Generally, it is a tubular medical device.
[0003]
Among such stents, the balloon-expandable stent does not have a self-expanding function like a self-expandable stent, and after being inserted into a target site, the balloon is expanded within the stent, and the stent is expanded (plastic deformation) by the expansion force of the balloon. ) And fixed in close contact with the inner surface of the target lumen.
[0004]
[Problems to be solved by the invention]
In general, the basic functions that a stent should have are delivery performance and restenosis prevention function. Delivery performance is a function of a stent that can be delivered to a target intraluminal site, and since it cannot be naturally placed unless it can be delivered to the target site, it is a basic function. Regarding balloon expandable stents in particular, factors involved in this delivery performance include the stent diameter when mounted on the balloon catheter, the adhesion between the balloon and stent when mounted on the balloon catheter, etc. In particular, the flexibility of the stent when mounted on a balloon catheter is important.
[0005]
The flexibility when mounted on the balloon catheter is a physical property necessary for following the guide wire that is indwelling, particularly for a blood vessel that is bent or meandering. A stent with poor axial flexibility may not be able to follow the guidewire and deliver to the lesion site. This is especially true for long stents. In addition, when passing through a lesion that is bent and further calcified, the stent may be caught by a hard calcified intima and not advance further. In particular, when the stent is bent, a portion of the strut protrudes outward and does not advance against the hard lesion. In addition, as a problem that often occurs in clinical practice, when the stent is pulled back into the guiding catheter because the stent does not pass through the lesion, a part of the stent is caught on the tip of the guiding catheter and cannot be recovered. May fall off the balloon catheter.
[0006]
On the other hand, the restenosis prevention function is a function capable of preventing the portion where the stent is placed from becoming restenosis. The mechanism of restenosis has not been fully elucidated, and the structure of lesions has been complicated and diverse in clinical studies. The fact is that whether stents contribute to a reduction in the rate of restenosis has not been fully elucidated. However, stents with poor axial flexibility are said to be prone to restenosis at the edge of the stent, which is thought to be due to stress on the edge and irritation of the blood vessels because it is stiff. Yes. Thus, it is considered that the stent should be flexible even after the stent is expanded and placed. However, since a stent having no free portion is generally hard in the axial direction, it is said that the restenosis rate at the end edge of the stent is high.
[0007]
Accordingly, an object of the present invention is to provide an axially flexible stent before and after expansion.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present invention is formed in a tubular shape as a whole, has a first outer diameter that can be inserted into a living body lumen, and is given a radially outward expansion force inside. A stent sometimes expandable to a second outer diameter that is larger than the first outer diameter, the longitudinal axis of the stent being spiral An expansion member composed of corrugated elements arranged so as to surround in a shape, and a plurality of corrugated connection members that connect the peaks and peaks of the corrugated elements and / or valleys and valleys of the expansion member, In the corrugated element, peaks and troughs of the wave appear periodically so as to intersect the circumferential direction of the stent, and each corrugated connecting member has a plurality of waves and is adjacent in the axial direction of the stent. An expandable stent is provided that has a wave of greater amplitude than other waves in the gap between the wave elements.
[0009]
In the present invention, it is preferable that the crests and crests and the troughs and troughs of substantially all the corrugated elements adjacent to each other in the longitudinal axis direction of the stent are coupled by the corrugated coupling member.
[0010]
In the present invention, it is preferable that corrugated elements adjacent in the longitudinal axis direction of the stent are arranged so as not to substantially cause a phase difference in the waves.
[0011]
In the present invention, preferably, the width of each corrugated connecting member is ½ or less of the width of the corrugated element, and in particular, the width of each corrugated connecting member is in the range of 0.03 mm to 0.08 mm. is there.
[0012]
Further, in the present invention, preferably, the largest wave in each corrugated connecting member is larger than the width of the corrugated element peak or valley in the state where the stent has the first outer diameter.
[0013]
In the present invention, the total extension of the corrugated connecting member may be 1.3 times or more of the linear distance between the peaks and peaks of the corrugated elements adjacent in the longitudinal axis direction of the stent. preferable.
[0014]
Furthermore, in the present invention, the width of the gap between the corrugated elements adjacent in the longitudinal axis direction of the stent is preferably 0.4 to 1.7 mm.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings.
[0016]
The stent of the present invention is formed in a tubular shape as a whole, has a first outer diameter that can be inserted into a living body lumen, and has a first outer diameter when an expansion force is applied radially outward. It can be expanded to a second outer diameter larger than the diameter.
[0017]
FIG. 1 shows one embodiment of the present invention in a state in which the stent of the present invention is mounted on a balloon catheter, that is, in a state having a first outer diameter that is sufficiently small so that it can be inserted into a living body lumen (non-expanded state). It is an expansion expanded view of the stent which concerns on a form. FIG. 2 is an enlarged view showing a part of the stent shown in FIG.
[0018]
A stent 10 shown in FIGS. 1 and 2 includes an expansion member 11 composed of a corrugated element 111, and crests and peaks of corrugated elements adjacent in the longitudinal axis direction of the stent (indicated by symbol X in FIG. 1) and / or Or the corrugated connection member 12 which connects a trough and troughs is provided.
[0019]
Each of the expansion members 11 expands to a second outer diameter larger than the first outer diameter when a force spreading radially outward is applied to the inside thereof, and when the force is removed, It retains the expanded shape, and is constituted by corrugated elements 111 arranged in a spiral shape so as to surround the longitudinal axis of the stent.
[0020]
The corrugated element 111 is formed in a spiral shape so that peaks and troughs of the wave appear periodically in a direction that intersects the circumferential direction of the expansion member 11 with a predetermined angle.
[0021]
The corrugated elements 111 are arranged in the longitudinal axis direction of the stent 10 with a predetermined interval d (see FIG. 2) in parallel with each other without causing a phase difference between the adjacent waves in the longitudinal axis direction of the stent. Preferably it is. That is, the expansion member 11 is preferably arranged so that peaks and peaks, valleys and valleys in waves adjacent to each other in the longitudinal axis direction of the stent are aligned in parallel to the axial direction of the stent 10 (wave peaks and valleys). Is defined as a valley when the bent portion on one side of the corrugated element 111 is a peak, and for the sake of convenience, in FIG. The bent portion is called a mountain (indicated by M in FIG. 2), and the right bent portion is called a valley (indicated by V in FIG. 2) In the embodiment shown in FIG. The spiral is rotating.
[0022]
Although there is no particular limitation on the waveform of the corrugated element 111 constituting the expansion member 11, it is preferably substantially U-shaped as shown in FIGS. More specifically, referring to FIG. 2, this U-shaped corrugated element 111 connects a substantially straight long segment 111a, a substantially straight short segment 111b, and these straight segments 111a and 111b. The adjacent linear long / short segments 111a and 111b, which are configured by the curved segment 111c, are alternately connected by one curved segment 111c at their ends.
[0023]
As shown in FIG. 2, the corrugated connecting member 12 includes corrugated peak connecting elements 121 and valleys and troughs that connect adjacent wave peaks and peaks in the axial direction of the stent of the corrugated element 111 of the expansion member 11. And a wave-shaped valley connecting element 122 that connects the two. In the case of this stent, the mountain connecting element 121 is connected from the left mountain M to the right mountain M. The mountain connecting element 121 has a plurality of (for example, four) small waves 121b in the gap between the adjacent linear long / short segments 111a and 111b, and between the corrugated elements adjacent in the longitudinal direction of the stent. Then, it has the wave 121c with a larger amplitude than the other wave 121b. By having a wave 121c having a larger amplitude than the other waves in the gap between adjacent corrugated elements 111, the flexibility of the stent 10 is increased. In the case of this stent, the small wave 121b is connected to a linear member 121a that is directly connected to the mountain. Here, the wave shape of the mountain coupling element may be a V-shape, but an S-shape that is less likely to be bent when bent is preferable. It is preferable that all the mountain coupling elements 121 have the same shape. In FIG. 1 and FIG. 2, the mountain connecting element 121 has four small waves between adjacent linear long / short segments 111a and 111b, and is adjacent to the longitudinal axis direction of the stent. Is shown as having one large wave 121c between, but is not limited to this, and the ridge coupling element has a plurality of waves and is adjacent to the corrugated element in the longitudinal direction of the stent. It is only necessary to have a wave having a larger amplitude than the other waves in the gap between them.
[0024]
The corrugated valley coupling element 122 is coupled from the left valley V to the right valley V. The valley coupling element 122, like the mountain coupling element 121, has a plurality of (for example, four) small waves 122b in the gap between adjacent linear long and short segments 111a and 111b in the longitudinal direction of the stent. A wave 122c having a larger amplitude than the other wave 122b is present between the adjacent expansion members 11 between the wave elements adjacent to each other. By having the wave 122c having a larger amplitude than the other waves in the gap between the adjacent expansion members 11, the flexibility of the stent 10 is increased. The large wave 122c preferably has a wave height greater than the width of the gap between adjacent linear segments 111a. The wave shape of the valley coupling element 122 may be V-shaped, but the S-shape is preferred because the directionality when bent is difficult. Moreover, as shown in FIG. 1, it is preferable that all the valley connection elements 122 are the same shape. 1 and 2, the valley coupling element 122 has four small waves 122b between adjacent linear long and short segments 111a and 111b, and is adjacent to the longitudinal direction of the stent. Although shown as having one large wave 122c between the elements, it is not so limited, and the valley coupling element 122 has a plurality of waves and is adjacent to the longitudinal axis of the stent. It is only necessary to have a wave with a larger amplitude than the other waves in the gap between the elements. In a particularly preferred embodiment of the present invention, the peak connecting element 121 and the valley connecting element 122 are all the same shape and only have different orientations, as shown in FIG. Moreover, it is preferable that the peaks and peaks and the valleys and valleys of the corrugated elements adjacent in the longitudinal axis direction of the stent are all connected by the connecting member 12.
[0025]
In the present invention, from the viewpoint of further increasing the flexibility before and after expansion, the wave of the corrugated connecting member (the wave existing in the gap between adjacent expansion members 12) has a wave height H (see FIG. 2), It is preferable that the width w of the peak M or valley V of the corrugated element 111 constituting the expansion member 11 is larger. The width w of the peak M or the valley V is a distance between two points P1 and P2 where one curved segment connects to two linear long / short segments 111a in a state where the stent is deployed.
[0026]
The expansion member 11 is deformed when it is expanded, and needs to exhibit a counter force sufficient to counteract the force when the blood vessel contracts while maintaining the deformed state. It is preferable to have. On the other hand, the connecting member 12 may have a fairly narrow width as long as it only has a role of keeping a constant distance without the expansion members 11 being separated from each other. However, if the connecting member 12 is to have a function of expanding and holding the blood vessel, it needs to have the same width and thickness as the expansion member, so that the expansion holding force is high, but relatively flexible. Become a scarce stent.
[0027]
However, it is an object of the present invention to provide a stent that is axially flexible both before and after expansion. As a result of various studies on such flexibility, the present inventors have made the width of the connecting member 12 (the mountain connecting element 121 and the valley connecting element 122) equal to or less than ½ of the width of the corrugated element 111 constituting the expansion member 11. Thus, it has been found that the flexibility can be further increased, and the distance between the corrugated elements 111 can be kept constant, and the function of the stent can be sufficiently exerted. Specifically, it was found that the width of the connecting member 12 is preferably 0.03 mm to 0.08 mm, and more preferably 0.04 mm to 0.06 mm.
[0028]
Further, if the gap d between the corrugated elements 111 is too wide, the flexibility of the stent 10 increases, but the number per unit length of the expansion member 11 having the function of expanding and holding decreases. Extended holding power is reduced. On the other hand, if the gap d between the expansion members 11 is too narrow, the number of expansion members 11 per unit length increases, so that the expansion holding force is relatively increased, but the flexibility is relatively poor. Therefore, as a result of researches to appropriately balance the conflicting requirements between expansion retention and flexibility, the width of the gap d is preferably 0.4 mm to 1.7 mm, and more preferably 0.6 mm to 1.2 mm. It turned out to be more preferable.
[0029]
In addition, as shown in FIG. 1, the stent 10 has the 2nd waveform element 13 and the 3rd waveform element 14 in the both ends. These second and third corrugated elements 13 and 14 have corrugated tips 111 located at both ends in a state where the corrugated elements 111 are arranged in a spiral shape, and both ends thereof in a direction perpendicular to the longitudinal axis of the stent. It is intended to be flush with each other. The second corrugated element 13 is constituted by two waves, and is directly connected to the wave crest at one end, and the trough and trough and the crest and trough of the spiral corrugated element adjacent thereto are corrugated coupling members 131. And 132, respectively. The third corrugated element 14 is composed of two waves, and is directly connected to the peak of the wave at one end, and the corrugation and the trough and the peak and trough of the spiral corrugated element adjacent thereto are corrugated. The members 141 and 142 are connected to each other. Each of the connecting members 131, 132, 141, 142 does not have a large wave as in the connecting member 12 that connects the spiral wave type elements 111, but there is no particular problem because flexibility at this portion is hardly required.
[0030]
FIG. 3 is a development view in a state in which the stent 10 shown in FIG. 1 is expanded to have the second outer diameter. The corrugated element 111 constituting the expansion member 11 is deformed from a U shape at the time of non-expansion shown in FIG. 1 to a V shape, and the diameter of the stent 10 is expanded accordingly. If the connecting member 12 is a stent expansion in a straight blood vessel that is not curved, its shape and length basically do not change. That is, when the stent is expanded, the axial length of the expansion member 11 changes, but adjacent peaks or valleys connected by the connection member 12 change by the same length in the same direction. The length of 12 will not change. On the other hand, if the wave of the wave element 111 of the expansion member 11 is 180 degrees out of phase, that is, if the wave crest and valley of the wave element 111 are connected, the expansion member And the connecting member 12 extends. In the stent of the present invention, since the expansion members 11 are arranged in the axial direction so that there is no phase difference between the waves of the corrugated element 111, the total length changes even when the stent is extremely expanded. The advantage of being difficult (substantially unchanged) is obtained. If the overall length of the stent is shortened due to the expansion, the entire stenosis of the target blood vessel cannot be expanded, or there is a gap between the placement site assumed under X-ray imaging and the actual placement state of the stent. In some cases, effective stenosis cannot be improved.
[0031]
Further, when the connecting member 12 is corrugated, not only the flexibility of the stent is increased as described above, but also the advantage that the side branch is easily treated can be obtained. The advantage is particularly remarkable in a stent placed in a coronary artery. The coronary artery has various side branches (blood vessels in which a blood vessel thinner than the main tube branches from the main tube) in a main thick blood vessel (hereinafter referred to as a main tube). If the stenosis is at the branch between the main branch and the side branch, the stent may be placed including the branch. At that time, as a result of placing the stent, the degree of stenosis of the side branch may be further increased or occluded. In many cases, since the side branch is a thin blood vessel, clinical symptoms and myocardial infarction do not occur, but sometimes chest pain and infarction symptoms are present and some treatment is required.
[0032]
In that case, a guide wire is inserted into the side branch through the gap 21 of the stent shown in FIG. 3, and a balloon catheter is delivered to the stenosis portion along the guide wire to be expanded and treated. In most cases, the stenosis will be at the entrance of the side branch, so the stent wall will expand together. In addition, in order to exert a sufficient expansion effect, it is necessary to expand with a balloon that is as close as possible to the blood vessel diameter of the side branch. When the balloon is expanded, the straight short segment 111b of the corrugated element 111 defining the gap 21 of the stent, the mountain connecting element 121 and the valley connecting element 122 adjacent to each other in the circumferential direction, and the short segment 111b of the corrugated element 111 and the axial direction The short segment 111b of the corrugated element 111 adjacent to is deformed into a substantially circular shape as the balloon is expanded. Since it is preferable to expand with a balloon as large as possible as described above, it is better that the perimeter is longer. In the present invention, since the connecting member 12 is corrugated, the circumferential length of the gap 21 is longer than that of a straight line, so that a large balloon can be used. From this point of view, it is particularly preferable that each corrugated connecting member 12 has a total extension of 1.3 times or more of the linear distance between the peaks and peaks or the valleys and valleys of the adjacent expansion members 11. The linear long segment 111a of the corrugated element 111, the mountain connecting element 121 and the valley connecting element 122 adjacent in the circumferential direction, and the length of the corrugated element 111 adjacent to the long segment 111a of the corrugated element 111 in the axial direction. The segment 111a constitutes a gap 22 larger than the gap 21. However, since it is unclear whether the guide wire passes through the gap 21 or the gap 22, it can be inserted into the smaller gap 21. It is more convenient to use a small balloon.
[0033]
The material for forming the stent 10 is preferably biocompatible, and examples thereof include stainless steel, tantalum or a tantalum alloy, platinum or a platinum alloy, gold or a gold alloy, and a cobalt base alloy. In addition, noble metal plating (gold, platinum) may be applied after the stent shape is produced. As stainless steel, SUS316L having the most corrosion resistance is suitable. Furthermore, it is preferable to anneal after creating the final shape of the stent 10. By performing the annealing, the flexibility and plasticity of the entire stent are improved, and the indwellability in the bent blood vessel is improved. Compared to the case where annealing is not performed, the force to restore the shape before expansion after expanding the stent, particularly the force to return to the linear shape that appears when expanding at a bent blood vessel site, The physical stimulation applied to the bent inner wall of the blood vessel is reduced, and the factor of restenosis can be reduced. Annealing is preferably performed by heating to 900 to 1200 ° C. in an inert gas atmosphere (for example, argon gas) and then slowly cooling so that an oxide film is not formed on the stent surface.
[0034]
The stent 10 of the present invention can be preferably manufactured by using a method of hollowing out a portion of the stent from a metal pipe. Various methods can be adopted as a method of hollowing out the stent from the pipe. For example, there is a masking method called photofabrication and an etching method using chemicals, an electric discharge machining method using a mold, and a mechanical cutting method.
[0035]
The simplest method with high processing accuracy is based on the laser processing method. As the laser processing machine, a YAG laser (trade name SL116E) manufactured by NEC Corporation can be used. The metal pipe is set on a jig with a rotary motor with a chuck mechanism so that the shaft does not shake, and this is set on an XY table that can be numerically controlled. Then, the XY table and the rotation motor are connected to the personal computer, and the output of the personal computer is set to be input to the numerical control controller and the rotation motor of the XY table. Drawing software is stored in the personal computer, and a developed drawing of the stent having the composition as shown in FIG. 1 is input thereto. Based on the drawing data output from the personal computer, the XY table and the rotary motor are driven. By irradiating a laser there, a stent structure having a shape as shown in FIG. 1 is created. In addition to such a system, a so-called laser marker (galvanometer method) driven by a laser processing machine may be used.
[0036]
Here, as a typical stent placement technique when using a balloon expandable stent, a brief description will be given of the placement technique of a coronary stent. First, in order to secure various blood vessels in order to introduce various catheters into the blood vessels, Place the sheath in the appropriate blood vessels (mainly the femoral, elbow, and radial arteries). The sheath is a device provided with a valve at the end of a thin plastic tube that prevents blood leakage and allows catheters to be inserted and removed. A catheter called a guiding catheter is inserted through this sheath, and its tip is fixed to the right or left coronary artery ostium. As a result, a passage from outside the body to the coronary artery is formed.
[0037]
Next, a thin guide wire having a diameter of, for example, about 0.36 mm (0.014 inch) is inserted into the guiding catheter, and after passing through the stenosis of the coronary artery, a balloon is provided at the tip along the guide wire. The balloon catheter is inserted, the balloon is expanded at the stenosis part to widen the stenosis part, and then the balloon catheter is removed. Thereafter, a contrast medium is injected from the guiding catheter, and the degree of expansion of the stenosis is confirmed. If the stenosis is sufficiently expanded and there are no defects, the procedure is completed. If the expansion is insufficient or the intima is peeled off, the next step is to place the stent. To do.
[0038]
That is, the stent is mounted on the balloon of the balloon catheter (in a folded state), and the balloon catheter is advanced along the guide wire to the stenosis in the same manner as described above. The tip is positioned in the stenosis and the position is confirmed. Thereafter, a contrast medium is injected into the balloon at a high pressure, and the balloon is expanded by the force. By expanding the balloon, the stent is plastically deformed so that its diameter expands in the radial direction, expands (expands) as shown in FIG. 3, and pushes the stenosis. The balloon pressure is then removed and deflated. Since the stent has an expansion retention force (shape retention force) due to plastic deformation, the stent does not contract and stays in that position, and maintains the expanded state of the blood vessel, thereby improving the blood flow disorder. In this case, in the stent of the present invention, since the expansion member is composed of wave-shaped elements arranged in a spiral shape, not only can the expansion state be maintained with a substantially uniform expansion force on the blood vessel, but also in a curved stenosis, It can be easily bent along the curve.
[0039]
【Example】
Hereinafter, the present invention will be further described with reference to specific examples.
[0040]
A long pipe of stainless steel (SUS316L) having a diameter of 1.4 mm and a wall thickness of 0.10 mm was cut to a length of 100 mm, and a desired stent was manufactured from this stainless steel pipe piece by a laser processing method. A YAG laser (trade name SL116E) manufactured by NEC was used as the laser processing machine. The stainless steel pipe piece was set on a jig with a rotary motor with a chuck mechanism so that the shaft would not shake, and this was set on an XY table capable of numerical control. Then, the XY table and the rotary motor were connected to a personal computer, and the output of the personal computer was set to be input to the numerical control controller and the rotary motor of the XY table. Drawing software is stored in the personal computer, and a developed drawing of a stent having a composition as shown in FIG. 1 is input thereto. Thus, on the basis of the drawing data output from the personal computer, the XY table and the rotary motor are driven, and the stainless steel pipe piece that moves with the XY table is irradiated with the laser, whereby the stent structure having the shape as shown in FIG. I made a thing. The laser processing conditions were a current value of 25 A, an output of 1.5 W, and a driving speed of 10 mm / min.
[0041]
In this way, a stent having the shape shown in FIG. 1 was produced. The produced stent had a total length of 15 mm and an outer diameter of 1.4 mm, the width of the corrugated element constituting the expansion member was 0.11 mm, and the width of each connecting member was 0.05 mm. When this stent is mounted on a delivery balloon, the outer diameter of the stent is about 1.0 mm, the peak / valley width of the corrugated element is 0.36 mm, and the height of the largest wave of the connecting member is 0.50 mm. The wave height was larger than the peak / valley width of the wave element. Moreover, the length of the linear long segment of the corrugated element was 1.69 mm, the length of the short segment was 1.29 mm, and the distance between adjacent corrugations was 0.76 mm. The total extension of each connecting member was 4.75 mm. And the linear distance of the peak-to-peak of a wave-shaped element which adjoins, or a trough and a trough was 2.3 mm.
[0042]
The circumference of the aforementioned gap 21 of the stent was 10.34 mm. This is about 3.3 mm when converted into a circle diameter. On the other hand, if it is assumed that the peaks are connected by a straight connecting member, the peripheral length of the gap of the stent at that time is 7.56 mm. This is 2.4 mm when converted into a circle diameter. Therefore, when the stent of the present invention is used, a 3.25 mm balloon can be used for the side branch, but when the connecting member is a straight line, only a 2.25 mm balloon can be used. In terms of cross-sectional area, a diameter of 3.25 mm is a diameter of 2.25 mm. 2.09 This is advantageous in this respect. This is considered to be due to the fact that when the balloon is expanded, it is easily deformed along the balloon because the corrugated connecting member has a small width.
[0043]
【The invention's effect】
The stent of the present invention is constituted by corrugated elements in which expansion members are arranged in a spiral shape, and corrugated elements adjacent in the longitudinal axis direction of the stent are connected by corrugated connecting members having a plurality of waves. Therefore, it has excellent axial flexibility before and after expansion. Therefore, when delivering the stent of the present invention, it is possible to deliver even difficult lesions that are bent and calcified, and the stent can be easily bent even when placed in a bent lesion. Therefore, it can be expected to prevent restenosis at the stent edge. Furthermore, the stent of the present invention includes a corrugated connecting member having a plurality of waves, and since the total extension thereof is longer than a straight line, it has an advantage that a larger balloon can be applied to the side branch.
[Brief description of the drawings]
FIG. 1 is an enlarged development view of a stent before expansion according to an embodiment of the present invention.
FIG. 2 is an expanded view showing a part of the stent shown in FIG.
FIG. 3 is a development view after expansion of the stent shown in FIG. 1;
[Explanation of symbols]
11 ... Expansion member
12 ... Wave connecting member
111 ... Wavy element
111a ... Linear long segment of corrugated element
111b ... Linear short segment of corrugated element
111c ... Curved segment of corrugated element
121 ... Wave type mountain connecting element
122 ... Wave type valley connecting element
121b, 122b ... small wave of corrugated connecting member
121c, 122c ... Big wave of corrugated connecting member
21, 22 ... Gap during stent expansion
M ... Pile of wave elements
V ... Valley valley
X: Axial direction of stent

Claims (8)

  1. The first outer diameter is formed into a tubular shape as a whole and can be inserted into a living body lumen. When an expansion force is applied to the inside in the radial direction, the first outer diameter is larger than the first outer diameter. a expandable stent 2 in outside diameter, and expansion member consisting arranged corrugated element so as to surround the longitudinal axis of the stent in a spiral shape, crests between the said corrugated type element of the extension member And / or a plurality of corrugated connecting members that connect valleys and troughs, and the corrugated element has peaks and troughs that periodically appear so as to intersect the circumferential direction of the stent. The expandable stent is characterized in that the mold coupling member has a plurality of waves and has a wave having a larger amplitude than other waves in a gap between adjacent wave-shaped elements in the axial direction of the stent.
  2. 2. The stent according to claim 1, wherein crests and crests and troughs and troughs of substantially all corrugated elements adjacent to each other in the longitudinal axis direction of the stent are coupled by a corrugated coupling member.
  3. The stent according to claim 1 or 2, wherein corrugated elements adjacent in the longitudinal direction of the stent are arranged so as not to substantially cause a phase difference in the wave.
  4. The stent according to any one of claims 1 to 3, wherein the width of each corrugated connecting member is ½ or less of the width of the corrugated element.
  5. The stent according to claim 3, wherein the width of each corrugated connecting member is in the range of 0.03 mm to 0.08 mm.
  6. 6. The largest wave in each corrugated connecting member is greater than the width of a crest or trough of the corrugated element in a state where the stent has the first outer diameter. The stent according to Item.
  7. The total extension of the corrugated connecting member is 1.3 times or more of a linear distance between the peaks and peaks of the corrugated elements adjacent to each other in the longitudinal axis direction of the stent. 7. The stent according to any one of items 6 to 6.
  8. The stent according to any one of claims 1 to 7, wherein a width of a gap between corrugated elements adjacent to each other in the longitudinal axis direction of the stent is 0.4 to 1.7 mm.
JP2001166672A 2001-06-01 2001-06-01 Stent Active JP4727070B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2001166672A JP4727070B2 (en) 2001-06-01 2001-06-01 Stent

Applications Claiming Priority (9)

Application Number Priority Date Filing Date Title
JP2001166672A JP4727070B2 (en) 2001-06-01 2001-06-01 Stent
DE2002634503 DE60234503D1 (en) 2001-01-15 2002-01-09 stent
KR20037009265A KR100532631B1 (en) 2001-01-15 2002-01-09 Stent
AT02729378T AT449579T (en) 2001-01-15 2002-01-09 Stent
AU2002219569A AU2002219569B2 (en) 2001-01-15 2002-01-09 Stent
EP20020729378 EP1363561B1 (en) 2001-01-15 2002-01-09 Stent
CN 02803749 CN1262252C (en) 2001-01-15 2002-01-09 Fixing mould
PCT/JP2002/000048 WO2002054989A2 (en) 2001-01-15 2002-01-09 Stent
US10/044,969 US7431732B2 (en) 2001-01-15 2002-01-15 Stent with waved connecting members

Publications (2)

Publication Number Publication Date
JP2002355315A JP2002355315A (en) 2002-12-10
JP4727070B2 true JP4727070B2 (en) 2011-07-20

Family

ID=19009176

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2001166672A Active JP4727070B2 (en) 2001-06-01 2001-06-01 Stent

Country Status (1)

Country Link
JP (1) JP4727070B2 (en)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2006035669A1 (en) * 2004-09-28 2006-04-06 Nipro Corporation Soft stent excellent in vascular follow-up and dilation nature
EP1871292B1 (en) 2005-04-04 2019-10-23 Flexible Stenting Solutions, Inc. Flexible stent
US7988723B2 (en) 2007-08-02 2011-08-02 Flexible Stenting Solutions, Inc. Flexible stent
US9149376B2 (en) 2008-10-06 2015-10-06 Cordis Corporation Reconstrainable stent delivery system
EP2588181A1 (en) * 2010-06-30 2013-05-08 SurModics, Inc. Catheter assembly
EP3010451A1 (en) * 2013-06-21 2016-04-27 Boston Scientific Scimed, Inc. Stent with deflecting connector
EP3119354B1 (en) 2014-03-18 2018-06-06 Boston Scientific Scimed, Inc. Reduced granulation and inflammation stent design

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09299486A (en) * 1996-03-10 1997-11-25 Terumo Corp Stent for retention in vivo
WO1998056313A1 (en) * 1997-06-13 1998-12-17 Global Therapeutics, Inc. Enhanced flexibility surgical stent
JP2000024116A (en) * 1998-07-03 2000-01-25 Wc Heraeus Gmbh Supporting structure diametrally expandable in radial direction

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5507767A (en) * 1992-01-15 1996-04-16 Cook Incorporated Spiral stent

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09299486A (en) * 1996-03-10 1997-11-25 Terumo Corp Stent for retention in vivo
WO1998056313A1 (en) * 1997-06-13 1998-12-17 Global Therapeutics, Inc. Enhanced flexibility surgical stent
JP2000024116A (en) * 1998-07-03 2000-01-25 Wc Heraeus Gmbh Supporting structure diametrally expandable in radial direction

Also Published As

Publication number Publication date
JP2002355315A (en) 2002-12-10

Similar Documents

Publication Publication Date Title
US5569295A (en) Expandable stents and method for making same
EP2394611B1 (en) Hybrid stent
US6613079B1 (en) Radially-expandable stent with controllable force profile
EP1399092B1 (en) Stent designs
US6451049B2 (en) Stents for angioplasty
JP4976301B2 (en) Stepped balloon catheter for vascular branch treatment
US6709454B1 (en) Self-expanding stent with enhanced delivery precision and stent delivery system
EP1242005B1 (en) Stent designs for use in peripheral vessels
US8021418B2 (en) Sandwiched radiopaque marker on covered stent
EP1469792B1 (en) Multi-layer stent
KR100455975B1 (en) Expandable stent
DE4432938B4 (en) Implantable transluminal endoprosthesis and method of making the same
EP0679373B1 (en) Intravascular prosthesis with anti-thrombogenic coating
CA2211097C (en) Stent with variable features to optimize support and method of making such stent
US7537607B2 (en) Stent geometry for improved flexibility
EP1954223B1 (en) Stent configurations
AU718869B2 (en) Stent for improved transluminal deployment
JP3112157B2 (en) Stents having structural strength which varies along the length direction
US8641751B2 (en) Vascular bifurcation prosthesis with multiple linked thin fronds
US6520987B1 (en) Expandable intravascular stent
EP1587428B1 (en) Apparatus for treating hardened vascular lesions
EP2374431A2 (en) Intravascular stent
EP1515663B1 (en) Stent with polar radiopaque marker
EP1601490B1 (en) Method for manufacturing an endovascular support device using tumbling operation to round edges of the stent
US7279002B2 (en) Cutting stent and balloon

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20080519

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20110125

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20110316

A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20110405

A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20110413

R150 Certificate of patent or registration of utility model

Free format text: JAPANESE INTERMEDIATE CODE: R150

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20140422

Year of fee payment: 3

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250