WO2012130848A1

WO2012130848A1 - Stent for transluminal implantation in hollow organs, and insertion catheter

Info

Publication number: WO2012130848A1
Application number: PCT/EP2012/055417
Authority: WO
Inventors: Erik Flaxmeier; Michael Ehrlinspiel
Original assignee: Variomed Ag
Priority date: 2011-03-31
Filing date: 2012-03-27
Publication date: 2012-10-04
Also published as: DE102011015738A1

Abstract

The invention relates to a stent (10) for transluminal implantation in hollow organs, with a substantially tubular main body (14) that comprises at least one wire (12) and that can be converted from a compressed state having a minimal cross-sectional diameter to an expanded state having an enlarged cross-sectional diameter, and with at least one retention element (18), which is secured on the wire at a proximal or distal end of the stent and which is designed for coupling the stent to a positioning element of an insertion catheter, wherein the wire, in the area of the retention element, has at least two coupling portions (20) and a loop portion (22) that forms a loop of the wire, wherein the coupling portions, starting from the main body of the stent, extend through the retention element and, at their ends remote from the main body, are interconnected via the loop portion. The invention further relates to an insertion catheter with such a stent.

Description

The present invention relates to a stent for transluminal implantation into hollow organs or vessels having a substantially tubular basic body comprising at least one wire which changes from a compressed state having a minimum cross-sectional diameter to an expanded state having an enlarged cross-section - Diameter is feasible. Furthermore, the invention is directed to an insertion catheter with such a stent.

Stents of the type mentioned are usually placed in their compressed state on a stylet of a Einführkatheters and then fixed with a wound on the stylet outer shell on the stylet. The stent is positioned with the introducer catheter to the desired location within the lumen, whereupon the outer sheath is retracted to expose the stent. Self-expanding stents autonomously assume their expanded state after retraction of the outer sheath, while non-self-expanding stents can be converted to the expanded state, for example, by inflating a balloon.

In order to avoid, in particular with self-expanding stents, that the stent automatically springs out of the outer shell due to the forces occurring during self-expansion before the outer shell is completely withdrawn in a controlled manner, it is known to provide a retaining element on the stent, which is used to couple the stent with a Positioning element of a delivery catheter is formed. Through the acting on the support member with the positioning member, the stent may be held in position until the outer sheath is fully retracted in a controlled manner so as to avoid misplacement due to unwanted springing of the stent and allow repositioning of the stent to this point. By the outer shell while the holding member is held in the radial direction to the outside, thereby preventing disengagement between the holding member of the stent and the positioning prevents until the outer shell is pushed back so far that the holding member is exposed and in the radial direction to the outside can move, whereby it comes out of engagement with the positioning.

In the case of cut stents, which are produced by creating a cut pattern in a tubular starting body, holding elements described above can be cut out of the starting body as it were, so that the holding elements form an integral part of the main body of the stent. On the other hand, it has proved difficult to provide a stent formed by a wire with such a holding element.

In particular, it is difficult to provide a mechanically sufficiently reliable and durable connection between a main body of a

To produce wire stents and a holding element. In addition, the additional space requirement created by the holding element, which can restrict a minimum diameter of the stent and thus miniaturization thereof, is also critical. Last but not least, there is a need for a wire stent with a retainer that gently conforms to a hollow organ of a human body into which the stent is inserted and avoids sharp edges that can result in injury thereto. It is therefore an object of the invention to provide a stent of the type mentioned, which has a reliable and permanently connected to the main body of the stent holding member.

To solve this problem, a stent with the features of claim 1 is provided.

The object is achieved in that the at least one wire in the region of the holding member has at least two coupling portions and a loop of the wire forming loop portion, wherein the coupling portions extending from the base body of the stent through the holding member and extend to their from the main body opposite ends are connected to each other via the loop portion.

The loop portion interconnecting the coupling portions of the wire extending through the holding member restricts movement of the holding member relative to the wire along the coupling portion of the wire, thus preventing the holding member from disengaging from the wire. At the same time, a rounded end region of the stent is created by the loop portion, which largely avoids injury to the hollow organ. Moreover, the described connection between the holding element and the base body can be produced in a simple manner, for example by inserting the wire into a corresponding groove of a holding element or through a corresponding opening of the holding element during manufacture of the stent. In addition, the described connection can be realized in the smallest space, wherein in particular one Extension of the retaining element in the radial direction of the stent can only be insignificantly greater than the thickness of the wire, so that an additional space requirement largely avoided and a virtually unlimited miniaturization of the stent, in particular based on the diameter, allowed.

Advantageous embodiments of the invention are described in the dependent claims, the description and the figures. According to an advantageous embodiment, at least one of

Coupling sections received in a extending through the holding element extending groove of the holding element. The at least one groove of the retaining element preferably runs - at least approximately - in the axial direction of the stent through the retaining element. Such a groove is formed so that the wire in the manufacture of the

Stents can be inserted transversely to its longitudinal direction in the groove, so that wire and holding element can be easily connected to each other. The groove of the retaining element, viewed in its cross-section, preferably has an undercut profile. The coupling portion is preferably at least partially received in a section forming the undercut of the groove. In this way, the coupling portion of the wire received in the groove can be held particularly effectively in the groove.

According to an advantageous embodiment, at least a portion of the holding element with the coupling portion accommodated in the groove forms an effective rear surface in the radial direction of the stent. cutting, so that the holding element is connected in this direction captive with the wire.

According to an advantageous embodiment, the at least one coupling section accommodated in the groove bears against a section of the retaining element delimiting the groove in the circumferential direction of the stent under a prestress acting in the circumferential direction of the stent. The bias thus holds the coupling portion in the groove, so that a retention of the coupling portion is ensured in the groove.

In principle, both coupling sections of the stent can be accommodated in a groove of the retaining element. In this case, both coupling sections can be accommodated in the same groove, or in each case in one of two separate grooves. In the latter case, the two grooves are preferably separated from one another by a protruding portion arranged between the grooves. This protruding portion cooperates with the loop portion of the wire to limit movement of the holding member relative to the wire in the longitudinal direction of the coupling portions, thus preventing loss of the holding member. According to a further advantageous embodiment, at least one of the coupling sections extends through a continuous opening of the retaining element. It is also possible for both holding sections to extend through in each case one of two openings, wherein the openings are preferably separated from one another such that passage of the loop section of the wire through the holding element is prevented. As a result, the retaining element is held captive on the wire.

In the context of the invention, it is also possible that one of the coupling sections is received in a groove of the holding element, while the other coupling portion extends through an opening of the holding member therethrough. As a groove of the holding element is herein referred to a recess of the holding element, which is formed so that the coupling portion in the manufacture of the stent laterally, ie transversely to its longitudinal direction, can be inserted into the groove. The term opening here refers to a recess into which the respective coupling section can be threaded only lengthwise in the production of the stent, ie the cross section of the opening is limited so that insertion into the opening transversely to the longitudinal direction of the wire is not possible. This formation of an opening has the advantage that the wire can not be released from the opening transversely to its longitudinal direction. The use of a groove, however, has the advantage that the coupling portion does not have to be threaded lengthwise in the production, but can be inserted laterally into the groove.

An opening preferably extends at least approximately in the axial direction of the stent, whereby a connection between the holding element and the wire body is realized, which has a small extent in the radial direction of the stent and thus allows a substantial miniaturization of the same.

The coupling portions of the wire are preferably materially connected to the retaining element, for example welded. In particular, a plurality of spot welds can connect a coupling section to the holding element.

According to an advantageous embodiment, the holding element has at least one fixing opening, through which one of the coupling sections is accessible from the outside. Such a fixing opening, in particular arranged laterally with respect to a longitudinal direction of the stent may be used for welding or otherwise connecting the coupling portion with the holding element. For example, in the manufacture of the stent, a laser beam or other energetic beam may be passed through the fixation opening onto the coupling portion to effect connection, for example, fusion or fusion, of the coupling portion to the support member. A coupling portion of the stent can accordingly be welded to the holding element at least in the region of the fixing opening or connected in a materially cohesive manner in another way.

The loop portion of the wire may be formed by an at least approximately semi-circular bent wire section. Such a loop section is particularly suitable for connecting two essentially parallel coupling sections, which allows a particularly simple design of the retaining element and ensures a smooth contour of the stent in the region of the loop section.

The stent can be designed as a braided wire stent, in particular wherein the braided wire forms approximately rhombic cells of the tube or cylinder wall formed by the main body of the stent.

According to an advantageous embodiment, the two coupling sections each comprise a substantially straight connecting section of the wire arranged between the base body and the retaining element. The two connecting sections can thereby run at least approximately in the axial direction of the stent. In this way, a defined axial spacing of the holding element from the main body of the stent can be achieved, through which at a partial withdrawn outer shell and thus a partially expanded stent a substantially directed in the axial direction of force on the retaining element is effected, whereby a particularly reliable mounting of the stent is ensured via the retaining element. The length of a connecting portion may be, for example, between 0.5 and 5 mm, in particular between 1 and 3 mm.

The retaining element preferably defines a projection or a plurality of projections of the stent, wherein a projection is formed in order to form, with a positioning element of an insertion catheter, an undercut which is effective in the axial direction of the stent, in order to restrict a stent movement in the axial direction.

The holding element can define, for example, two projections of the stent. Advantageously, a projection of the stent formed by the holding element is designed so that it protrudes in the circumferential direction of the stent. In this case, the projection may be partially and preferably at least approximately completely accommodated between the inner and the outer diameter of the base body, without protruding in the radial direction inwards or outwards, whereby a particularly narrow design is achieved. In the compressed and / or expanded stent state, the retaining element is preferably arranged at least partially and preferably at least approximately completely in the region of the outer diameter of the base body. In this way, an additional space requirement formed by the holding element in the radial direction can be minimized.

According to an advantageous embodiment, an outer contour and / or an inner contour of the holding element, which limits the cross section of the holding element radially outward or radially inwardly, in the compressed state stent at least partially and approximately the shape of a running around the central longitudinal axis of the stent circular arc segment. The holding element may in particular approximately have the shape of a bent plate.

In the embodiment described above, the inner contour of the retaining element can define an inner diameter of the retaining element that preferably corresponds at least approximately to an inner diameter of the compressed stent, and the outer contour can define an outer diameter of the retaining element which preferably corresponds at least approximately to an inner diameter of the compressed stent. In this way, a holding element can be created whose cross-section, at least in the compressed stent state, substantially corresponds to the stent cross-section and does not create excessive additional radial space requirement. The angle of a circular arc segment defined by the outer and / or inner contour may, for example, be between 60 ° and 90 ° and in particular approximately 75 °. As described above, when the stent is deployed in an introducer catheter system, the stent, including the retainers, is prevented from radial expansion by the deferred outer sheath so that the retainers are held in engagement with the deployment member of the delivery catheter until the outer sheath is retracted to the extent that it is retracted the holding elements releases and thus the holding elements move radially outward and thereby can get out of engagement with the positioning.

In particular, in an annular embodiment of the positioning element is preferably additionally prevented that a holding element in compressed stent state by a movement radially inwardly - for example, in a directed transversely to the longitudinal direction of force on the stent - undesirably disengaged from the positioning.

For this purpose, the holding element and a recess of the positioning element designed to receive the holding element can each have, for example, a cross-section which widens radially outward. According to one embodiment, the cross section of the holding element in the circumferential direction of the stent is limited by side surfaces which are designed to form a radially effective undercut with corresponding side walls of a positioning element.

A holding element of the stent can in principle be formed from a radiopaque material and thus simultaneously act as a stent marker. The holding element may also be coated with radiopaque material or comprise a separate radiopaque marker.

According to an advantageous embodiment, the stent has at a proximal or distal stent end two holding elements, which are arranged in an angular distance of at least approximately 180 ° measured in the circumferential direction of the stent. This allows a particularly reliable mounting of the stent. The stent may also have two additional stent markers with a radiopaque material on the other one of the proximal and distal ends, which are likewise arranged in an angular distance of at least approximately 180 ° measured in the circumferential direction of the stent. The holding elements and the stent markers can be arranged offset relative to one another in the circumferential direction of the stent in such a way that in each case a holding element and a stent marker form a circumferential stent. measure angular distance of at least approximately 90 °. This ensures good radiological observability of the stent from every angle. Another object of the invention is a method for producing a stent according to the invention as described herein. The advantageous embodiments and advantages described above in relation to the production apply accordingly. The method comprises forming two coupling sections and one loop section of a wire for a base body of the stent, two sections of the wire being inserted into a groove of a retaining element or being guided through an opening of the retaining element so as to form a coupling section formed between the two coupling sections wire portion forms a loop portion.

Another object of the invention is a Einführkatheter with a stent. The introducer catheter comprises a stent according to the invention as described herein, an internal stylet, an outer sheath into which the stylet can be inserted together with the stent, and a positioning element which is immovably connected to the stylet and in particular for coupling the stent to the stylet. which has at least one recess into which the holding element of the stent is inserted in the compressed stent state, wherein a wall of the positioning element bounding the recess forms an effective undercut in the axial direction of the stent with the inserted holding element.

Due to the axial undercut between the positioning and the holding element inserted therein an axial movement of the stent is prevented or at least limited and thus jumping of the Stents prevented until the outer shell releases the retaining element. At the same time, the stent can be repositioned by retracting it or by pushing the outer sheath back onto the stent, even after it has been partially withdrawn.

The stylet has an elongated shape and may be, for example, wire-shaped or tubular, i. as Vollmandrin or as Hohlmandrin be formed. A hollow mandrin may preferably be used in a preloaded delivery catheter system. The Hohlmandrin forms with the stent and the outer sheath a Einführkatheter that can be inserted directly into a hollow organ of a body. For this purpose, the introduction catheter with the lumen formed by the cavity of the hollow mandrin can be placed on a guide wire introduced in advance into the hollow organ and then pushed over the guide wire ('over-the-wire') into the hollow organ.

A wire stylet may preferably be used in a non-preloaded catheter system. The stylet with the attached stent and the outer shell thereby form an insertion cartridge, which is connected to a proximal lock of a pre-e.g. can be attached by means of a guide wire - inserted into the hollow organ catheter. The stylet with the stent can then be inserted from its outer shell via the proximal sheath into the catheter already in the hollow organ and advanced in the distal direction to the desired location in the hollow organ.

A Hohlmandrin can with at least a part of its length with

Be cut to increase the flexibility of the stylet targeted and To facilitate the introduction of the mandrin into the hollow organ, especially in highly tortuous areas of the hollow organ and thereby avoid injury to the hollow organ. A wire-shaped mandrin may for this purpose have a substantially helical spring-shaped distal end region. The positioning element is preferably connected to the stylet in the distal end region of the stylet.

The positioning element can in principle be connected to the stylet by at least one of the joining techniques of laser welding, soldering, gluing, shrinking presses or a snap connection. The positioning element preferably has a radiopaque material and thus simultaneously forms a radiopaque marker of the stylet.

The holding member of the stent may preferably comprise a material selected from the group consisting of platinum, a platinum-iridium alloy, stainless steel, a cobalt-chromium alloy, tantalum, tungsten, and a shape memory metal such as nitinol. The positioning element of the delivery catheter may also comprise a material as described above.

The wire of the stent advantageously comprises a shape memory metal such as Nitinol and is preferably electropolished.

The stylet may advantageously comprise a material selected from the group consisting of stainless steel, a shape memory metal such as nitinol, a cobalt-chromium alloy, a polyimide, a polyamide, a polyether amide, a polysulfone, a polyether ether ketone and an acrylonitrile butadiene styrene. Hereinafter, the present invention will be described purely by way of example with reference to an advantageous embodiment with reference to the accompanying drawings. 1 shows a lateral view of a stent in the expanded state

State according to an embodiment of the invention;

Fig. 2 is an enlarged view of the area A of Fig. 1; Fig. 3 is a view on the plane B-B of Fig. 1;

Fig. 4 is an enlarged view of the detail C of Fig. 3;

Fig. 5 is a view on the plane D-D of Fig. 1;

Fig. 6 is a perspective view of the proximal end portion of the stent shown in Figs. 1-5;

7 is a perspective view of the holding element of

Stents of Figures 1 to 6;

Fig. 8 is a plan view of the holding member of Fig. 7;

FIG. 9 is a view taken along line E-E of FIG. 8 of the retaining element of FIGS. 7 and 8; FIG.

10 shows a perspective view of a holding element according to a further embodiment of the invention; Fig. 1 1 is a plan view of the holding element of Fig. 10; a front view of the holding member of Fig. 10 and Fig. 1 1; an enlarged view of the section Y of Fig. 12; a perspective view of a holding element according to another embodiment of the invention; a plan view of the retaining element of Fig. 14; a front view of the holding member of Fig. 14 and Fig. 15; a perspective view of a proximal end portion of the stent of Figures 1 to 6 inserted into an associated positioning element of a delivery catheter. a plan view of the arrangement shown in Fig. 17; a side view of the arrangement shown in Figures 17 and 18; a view of the arrangement shown in Figures 17 to 19 viewed from a distal side. a view of the arrangement shown in Figures 17 to 20 viewed from a proximal side. a perspective view of the positioning shown in Figure 17 to 21 without inserted stent. an enlarged view of the section F of Fig. 22; a side view of a portion of a delivery catheter according to an embodiment of the invention; an enlarged view of the section X of Fig. 24; a view cut along the line GG of Figure 25 of the insertion catheter of Fig. 25; a view on the plane HH of Fig. 25; a side view of a portion of a delivery catheter according to an embodiment of the invention; an enlarged view of the section I of Fig. 28; a view on the plane JJ of Fig. 29; a length portion of a tubular body of the mandrin of Figures 28 to 30 in the unrolled state. a side view of a delivery catheter according to an embodiment of the invention;

30 33 is an enlarged view of the detail K of FIG.

32;

FIG. 34 is a sectional view taken along line L-L of FIG. 32. FIG

View of the delivery catheter of Fig. 32;

FIG. 35 is a sectional view taken along line M-M of FIG. 32. FIG

View of the delivery catheter of Fig. 32; FIG. 36 is an enlarged view of the detail N of FIG.

33;

Fig. 37 is a sectional view taken along the line O-O of Fig. 29

View of the detail shown in Fig. 36;

FIG. 38 is a perspective view of the insertion catheter of FIG

FIGS. 32 to 37.

Fig. 1 shows a stent 10 suitable for transluminal implantation into a hollow organ, e.g. a vessel of a human body is formed, in its expanded state. The stent 10 has a braided wire 12 forming a substantially tubular body 14 of the stent 10. The braided wire 12 defines the cylindrical wall formed by the base body 14 in approximately diamond-shaped cells 15.

At the proximal end 16 of the stent 10, two holding elements 18 are fixed, which are designed for coupling the stent 10 with a positioning element (see, for example, FIG. 10). In principle, another number of proximal shafts distributed along the circumference of the stent 10 could also be used. be provided te elements, for example, 3, 4 or more holding elements.

As seen in the enlarged view in Fig. 2, the wire 12 in the region of a holding member 18 each have two coupling portions 20 and a loop of the wire 12 forming loop portion 22, wherein the coupling portions 20, starting from the base body 14 of the stent 10 through corresponding openings 30 (see FIG. 4) of the holding element 18 extend therethrough and are connected to one another at their ends remote from the base body 14 via the loop portion 22. In Fig. 2, the fixing holes 25 of the holding member 18 can be seen, which are used for fixing the coupling portion 20 of the wire 12 to the holding member 18, for example by welding.

The loop portion 22 limits movement of the holding member 18 in the proximal direction, whereby a reliable support of the holding member 18 is secured to the stent 10, even if the cohesive connection between the holding member 18 and the wire 12 should solve. As shown in FIG. 2, the two coupling sections 20 each comprise a substantially straight connecting section 24 arranged between the main body 14 and the retaining element 18, wherein the two connecting sections 24 extend substantially parallel to one another in the axial stent direction and, for example, have a length h of approximately 2 mm may have. The main body 14 may e.g. have a length between 10 mm and 45 mm or more than 45 mm.

The holding elements 18 in the present embodiment consist of a radiopaque material and thus ensure an improved radiographic visibility of the proximal end 16 of the stent 10, thereby facilitating proper positioning of the stent 10 in the hollow organ for the user. As shown in Figure 1, the stent 10 additionally includes two distal markers 26 at the distal end 28 of the stent 10, which also comprise a radiopaque material.

As shown in FIG. 3, the two holding elements 18 and the two distal markers 26 are each arranged opposite to one another with respect to the central longitudinal axis of the stent 10 and thus have an angular distance wi or W2 of approximately 180 ° measured in the circumferential direction of the stent 10 on. The holding elements 18 are offset relative to the distal markers 26 in the circumferential direction of the stent 10 such that a holding element 18 and a marker 26 each have an angular distance of 90 ° measured in the circumferential direction. By this measure, a good radiological observability of the stent 10 is ensured from every angle.

4 shows an enlarged view of the detail C of FIG. 3. The holding element 18 has a plurality of openings 30 for threading through the wire 12, whereby the coupling portions 20 and the loop portion 22 are defined.

As can be seen in FIG. 4, the holding element 18 has only a small extent in the radial direction of the stent 10, so that it does not provide any substantial additional space requirement in this direction. This allows a substantial miniaturization of the stent 10. For example, a diameter di (see FIG. 3) of the stent 10 in the expanded state may be less than or equal to 10 mm, preferably less than or equal to 5 mm and preferably less than or equal to 4 mm. In the compressed th state, the stent 10 may have a diameter of less than 1 mm.

As can be seen from FIGS. 4 and 5, each holding element 18 has a concave curvature directed toward the longitudinal axis of the stent 10. More specifically, the holding member 18 has substantially the shape of an inwardly curved plate.

The perspective view of the proximal end region of the stent 10 shown in FIG. 6 illustrates how the threading through of the wire 12 forming the base body 14 ensures a fixation of the retaining element 18 on the wire 12, which is dependent on interruptions of the wire 12 in the region of the retaining element 18 dispensed with and thus avoids resulting sharp edges and possible injury to the hollow organ.

Fig. 7 shows the holding member 18 having provided for threading through the wire 12 openings 30, which are formed as shown in FIG. 8 through and separated from each other so that the wire 12 does not pass from one opening 30 into the other opening 30 and the loop 22 can not be pulled through the support member 18. As can be seen in the cross-sectional view in FIG. 9, the fixing openings 25, which are arranged approximately in the middle of the holding element 18, allow access to the openings 30 from the outside, so that in the openings 30 inserted coupling portions 20, these through the fixing openings 25th can be welded through to the holding element 18.

The holding element 18 has approximately the shape of a cylinder jacket segment with a substantially constant thickness, wherein the radius at least approximately corresponds to the radius of the cylinder defined by the base body 1 of the stent 10 in the compressed state.

FIGS. 10 to 13 show a further embodiment of a holding element 18, which differs substantially from the holding element shown in FIGS. 1 to 9 only in that two grooves 23 are provided instead of two through openings which are separate from each other are formed for receiving a coupling portion 20. In FIG. 12, only the contour of the right-hand coupling section 20 is partially shown. Each groove 23 extends as shown in Fig. 1 1 in the

Substantially in the longitudinal direction of the stent and has seen in its cross section on an undercut profile, wherein in each case a web-like portion 27 with the received in the groove 23 coupling portion 20 (Fig. 12) forms an effective in the radial direction of the stent undercut.

As can be readily seen in Fig. 13, a portion 29 of the retainer 18 which restricts a respective groove 23 in the stent circumferential direction defines a substantially circular segmental cross-sectional portion of the groove 23 whose diameter O 2 (Fig. 12) is substantially equal to the diameter of the coupling portion 20 forming wire 12 corresponds. The wire 12 is biased so that the two coupling portions 20 are each pressed in the stent circumferential direction outwardly against the respective portion 29 of the support member 18.

The two grooves 23 are separated by a projecting between the grooves 23 in the radial direction, web-like portion 31 of the support member 18. The section 31 thus cooperates with a loop section 22 (see FIGS. 1 to 9) of the wire 12 such that a movement tion of the holding member 18 is limited relative to the wire 12 in the longitudinal direction of the stent 12.

A coupling section 20 is preferably welded to the retaining element 18 via a plurality of spot welds in the region of the groove 23.

FIGS. 14 to 15 show a further holding element 18 which comprises an opening 30 as shown in FIGS. 1 to 9 for receiving a coupling section of the stent and a groove 23 as shown in FIGS. 10 to 13 for receiving the other coupling section of the stent stents.

The holding elements 18 shown in FIGS. 10 to 16 can in principle be used in the same way in a stent and an insertion catheter as shown in FIGS. 1 to 9 and FIGS. 17 to 38 for the holding elements shown there.

FIG. 17 shows a positioning element 32 of a delivery catheter not shown, which is designed for coupling to a stent 10 as shown in FIGS. 1 to 9. The holding elements 18 of the stent 10 are inserted into recesses 34 of the positioning element 32 designed as openings in such a way that they form effective undercuts with the positioning element 32 in the axial direction. The positioning element 32 is annular and has a substantially cylindrical cross-section. The recesses 34 have a connection region 36 which, starting from a distal end face 38 of the positioning element 32, extends into the positioning element 32 in the axial direction and merges into a holding region 40 of the recess 34 widened in relation to the connection region 36. The holding regions 40 are designed to be complementary to the holding elements 18 and, in the present exemplary embodiment, are shown in FIG. Longer direction opposite to the support members 18 extended to form a receiving space for the loop portion 22 of the wire 12.

As shown in FIGS. 18 and 19, two projections 42 bounding a connecting portion 36 in the circumferential direction on both sides form undercuts with the holding member 18, which restrict movement of the stent 10 in the axial direction, whereby in cooperation with an outer shell a delivery catheter prevents premature dislodgement or protrusion of the stent 10 relative to the positioning member 32 and a repositioning of the stent 10 can be ensured.

As can be seen in the front view in FIG. 20, the connecting regions 36 extend in the circumferential direction over an angular range W3 of approximately 75 °, whereas the holding regions 40 enclose on both sides a slightly larger angular range in order to form the undercuts , In principle, it is preferred if the holding regions 40 and / or the holding elements 18 include an angle range between 75 and 130 °. As shown in FIG. 20, the retaining elements 18 inserted into the positioning element 32 supplement the substantially annular cross-section of the positioning element 32 and in this case project in the radial direction not at all or only minimally outward beyond the circular outer cross-section predetermined by the positioning element 32. Radially inwardly the retaining elements 18 are only slightly above the predetermined by the positioning member 32 circular inner cross section. In the interior of the positioning element 32 there thus remains a continuous clearance 44 with an approximately circular cross-section, through which, as explained below, a wire-shaped stylet of the insertion catheter or a guide wire can extend, for example. It is also clear from the rear view shown in FIG. 21 that the essentially circular cross section of the arrangement formed by positioning element 32 and stent 10 is widened only insignificantly in the radial direction by retaining elements 18.

Fig. 22 shows the positioning element 32 in isolation. The positioning element 32 can be produced, for example, by a cutting process, in particular a laser cutting process, wherein a tubular body, for example made of metal, can be used as the starting body.

FIG. 23 shows an enlarged view of the detail F of FIG. 22. A protrusion 42 can be seen which, as described above, forms an axial undercut with an inserted holding element 18. Of the

Projection 42 has a circumferentially measured length k of less than 2 mm, specifically about 0.07 mm. This length b is already sufficient to achieve a reliable fixing effect. Fig. 24 shows a part of an insertion catheter according to an embodiment of the invention. Shown is an internal wire-formed stylet 46 having a distal end portion 48 to which is attached a positioning member 32 as shown in FIGS. 17-23. The wire-shaped stylet 46 and a stent 10 attached thereto can thus be loaded proximally into a marketable microcatheter and guided through the complete microcatheter to the desired location of the hollow organ.

The distal end region 48 of the mandrel 46, shown enlarged in FIG. 25, comprises an elongated helical spring-shaped section 50, which forms the inlet. lead the mandrin 46 into a hollow organ facilitated. The helical spring-shaped section 50, which has increased flexibility, is widened in relation to a wire-shaped main body 52 of the mandrel 46 and fastened thereto, eg by welding or gluing. As can be seen in the cross-sectional view in FIG. 26, the base body 52 can continue inside the spiral-spring-shaped section 50. The helical spring-shaped portion 50 may be made, for example, by laser cutting a substantially tubular body or by winding a wire-shaped body.

The distal end portion 48 of the stylet 46 with the helical spring-shaped portion 50 extends through the positioning member 32, wherein the area distal to the positioning member 32 forms a support body for a stent, which can be placed on the stylet 46 in the compressed state. The positioning element 32 is connected in a cohesive manner on its radially inner side to the stylet 46 or, more precisely, to the helical spring-shaped section 50, for example by welding. Due to the fact that the projections of the holding element 18 and the projections 42 of the positioning element 32 protrude substantially only in the circumferential direction, an arrangement of positioning element 32 and holding element 18 which is very flat in the radial direction is created, as shown in FIGS. 25 to 27.

Figs. 28 to 30 show an embodiment of a tubular

Mandrins 46, in which a positioning member 32 is welded at an axial end face 54 with the tubular mandril 46. In this case, the axial end face 54 forms the distal end of the stylet 46. In principle, it would also be possible for a configuration as shown in FIGS. 28 to 30 that an extension of the stylet 46 extends through the positioning member 32 to form a support body for a stent coupled to the stylet 46. The stylet 46 includes a tubular body 52 (see FIG. 31) that includes a metal material and is provided with at least a portion of its length with multiple laser cuts 53 to achieve a desired flexibility. The metallic base body 52 is surrounded by a protective tube 55 having a plastic material, eg PET, which serves to prevent damage to an outer sheath or a vessel wall of the hollow organ surrounding the stylet 46 by sharp edges in the area of the cuts 53.

Fig. 31 shows a longitudinal portion of the stylet 46 of Fig. 28 to 30 in the unrolled state. As shown in FIG. 31, the cuts 53 are elongated and inclined to a longitudinal axis of the mandrel 46. The cuts 53 extend around the longitudinal axis of the mandrel 46 substantially along a helical path and are along this path by webs 57 of the main body 52 separated from each other. The flexibility of the base body 52 can be selectively adjusted by suitable choice of a measured in the longitudinal direction of the spiral path between two successive turns of the spiral or by appropriate choice of the circumferential direction of the spiral

Mandrin 46 measured angle, which is covered by one of the cuts 53 and a web 57 of the main body 52 each. For example, a section 53 in FIG. 31 extends over an angle of approximately 185 °, while a web 57 covers an angle of approximately 10 °. Preferably, the distance U, the angle covered by a cut 53 and / or the angle covered by a web 57 are varied over the length of the stylet 46 such that the flexibility of the stylet 46 is at least about a part of the length of the mandrin viewed - increases from proximal to distal. For example, the distance U between two cuts 53 in the distal direction may increase substantially linearly. FIG. 32 shows a complete insertion catheter 56 with a stent 10, whose base body 14 has already been expanded. The holding elements of the stent 10 are still arranged within an outer shell 62, which is mounted on the stylet 46 and the positioning element. In Fig. 32 and 38, the outer sheath 62 is shown interrupted in the distal region. The elongated region of the insertion catheter 56 with outer sheath 62 and stylet 46 provided for insertion into the hollow organ is in reality significantly longer than shown in FIGS. 32 and 38 and may, for example, have a length in the range of 1 to 2 m or more ,

The delivery catheter 56 includes a front handle 58 and a rear handle 60 which are longitudinally slidable relative to one another with the rear handle 60 slidably connected to the stylet 46 and the front handle 58 slidably connected to the outer cover 62 such that by moving the two handles 58, 60, the outer shell 62 and stylet 46 are longitudinally displaceable relative to each other.

33 shows an enlarged view of the almost completely released stent 10, which is still received in the outer sheath 62 only in the area of the retaining elements and is thereby held on the insertion catheter 56. In addition, a radiopaque marker 64 attached to the distal end of the outer sheath 62 is shown. FIG. 36 shows an enlarged view of the detail N from FIG. 33, from which the almost complete suspension of the stent 10 can be seen.

In this position, the outer sheath 62 only has to be pushed back in the proximal direction by approximately the length of a retaining element 18 as shown in FIG. 37, so that the stent 10 is completely exposed and also the retaining elements 18 extend radially outward from the positioning element 32, which causes the complete release of the stent 10. Although only one retaining element 18 is shown in FIG. 37, the use of a stent with two or more retaining elements is also possible.

Fig. 34 shows a cross section along the line L-L of Fig. 32, from which the coupling between stylet 46 and rear handle 60 can be seen. As shown in Fig. 34, the stylet 46 may be formed hollow in principle to allow additional implementation of a guidewire, not shown.

Fig. 35 shows a cross-section along the line MM of Fig. 32. As shown therein, the outer sheath 62 extends in the proximal direction to the front handle 58 and is there fixedly connected to the front handle 58. The stylet 46 received in the outer sheath 62, on the other hand, extends through the front handle 58 to the rear handle 60, the distance between the front handle 58 and the rear handle 60 being at least equal to the length of the stent 10, such that the introducer catheter is longitudinally displaced the handles 58, 60 can be moved relative to one another between a position in which the stent 10 is completely received in the outer sheath 62 and a position in which the stent 10 is completely released. FIG. 38 shows the insertion catheter 56 shown in FIG. 32 in a perspective view. Such a catheter 56 can be used as a completely pre-assembled and preloaded catheter with stent 10 inserted. During pre-assembly, the stent is then preferably placed on the stylet 46 from the distal end of the outer shell 62 and inserted into the outer shell 62. It is also possible to insert a wire-like stylet 46 with a positioning element and an attached stent into the microcatheter from a proximal end of a microcatheter by means of an introducer cartridge and push it through the microcatheter to its distal end, whereupon a as described above insertion of the stent can be done in a hollow organ.

LIST OF REFERENCE NUMBERS

10 stents

12 wires

14 basic body

15 cell

16 proximal end

18 holding element

20 coupling section

22 loop section

23 groove

24 connecting section

25 fixing opening

26 markers

27 section

28 distal end

29 section

30 opening

31 section

32 positioning element

34 recess

36 connection area

38 front side

40 holding area

42 lead

44 free space

46 Mandrin

48 distal end region

50 spiral section

52 basic body 53 section

54 front side

55 protective hose

56 introducer catheter

57 footbridge

58 front handle

60 rear handle

62 outer shell

64 markers

di stent diameter d ₂ diameter h,, b, U length

Wl, W2 angular distance

W3 angular range

Claims

claims

Stent for transluminal implantation in hollow organs, comprising a substantially tubular base body (1) comprising at least one wire (12), which can be converted from a compressed state with a minimum cross-sectional diameter to an expanded state with an enlarged cross-sectional diameter (di), and at least a holding member (18) secured to the wire (12) at a proximal or distal end (16, 28) of the stent (10) adapted to couple the stent (10) to a positioning member (32) of a delivery catheter (56) .

By doing so, that is

the wire (12) has at least two coupling sections (20) and a loop section (22) forming a loop of the wire (12) in the region of the retaining element (18), the coupling sections (20) starting from the main body (14) of the stent (10) extend through the holding element (18) and are connected to each other at their ends remote from the base body (14) via the loop portion (22).

Stent according to claim 1,

By doing so, that is

at least one of the coupling sections (20) is received in a groove (23) of the retaining element (18) extending through the retaining element (18), the groove (23) extending in particular at least approximately in the axial direction of the stent (10).

Stent according to claim 2,

characterized in that

the groove (23) of the holding element (18) viewed in its cross section has an undercut profile.

Stent according to claim 2 or 3,

characterized in that

the at least one coupling section (20) accommodated in the groove (23) rests against a section (29) of the retaining element (18) delimiting the groove (23) in the circumferential direction of the stent (10) under a prestress acting in the circumferential direction of the stent (10) ,

Stent according to at least one of claims 2 to 4,

characterized in that

the two coupling portions (20) are respectively received in one of two grooves (23) of the holding member (18), wherein the two grooves (23) of the holding member (18) are defined by a protruding portion (31) of the one between the grooves (23) Retaining element (18) are separated from each other.

Stent according to at least one of the preceding claims, characterized in that

at least one of the coupling sections (20) extends through a through opening (30) of the retaining element (18), wherein the opening (30) extends in particular at least approximately in the axial direction of the stent (10).

Stent according to at least one of the preceding claims, characterized in that

the holding element (18) has at least one in particular lateral fixing opening (25) through which one of the coupling sections (20), in particular for welding the coupling section (20) to the holding element (18), is accessible from the outside.

Stent according to at least one of the preceding claims, characterized in that

the loop portion (22) of the wire (12) is formed by an at least approximately semicircular bent wire section.

Stent according to at least one of the preceding claims, characterized in that

the two coupling sections (20) each comprise a substantially straight connecting section (24) of the wire (12) arranged between the base body (14) and the retaining element (18), in particular wherein the two connecting sections (24) are at least approximately in the axial direction of the stent (10).

Stent according to at least one of the preceding claims, characterized in that

the holding element (18) defines a projection or a plurality of projections of the stent (10), wherein a projection is formed in order to form an undercut in the axial direction of the stent with a positioning element (32) of an insertion catheter (56) in order to prevent stent movement in the stent restrict axial direction.

11. stent according to claim 6,

characterized in that

the holding element (18) in particular defines two protrusions (42) of the stent (10) that project preferably in the circumferential direction of the stent (10).

12. Stent according to at least one of the preceding claims,

characterized in that

the holding element (18) both in the compressed and in the expanded stent state in the region of the outer diameter of the

Basic body (14) is arranged.

13. Stent according to at least one of the preceding claims,

characterized in that

an outer contour and / or an inner contour of the retaining element

(18), which limits the cross section of the holding element (18) radially outward or radially inward, in the compressed stent state at least partially and has approximately the shape of a about the central longitudinal axis of the stent (10) extending arc segment, in particular wherein the Angle of the arc segment between 60 and 90 degrees, in particular about 75 degrees.

14. Stent according to at least one of the preceding claims,

characterized in that

the cross-section of the holding element (18) in the circumferential direction of the stent (10) is limited by side surfaces which are designed to form a radially effective undercut with corresponding side walls of a positioning element (32).

Stent according to at least one of the preceding claims, characterized in that

the stent (10) has at the proximal or distal end (16, 28) two holding elements (18) which are arranged at an angular distance (wi) of at least approximately 180 degrees from one another in the circumferential direction of the stent (10), and the Stent (10) at the other of the proximal and distal ends (16, 28) has two additional stent markers (26), which are also arranged in an in the circumferential direction of the stent (10) measured angular distance (W2) of at least approximately 180 degrees from each other, wherein the holding elements (18) and the stent markers (26) in the circumferential direction of the stent (10) are arranged offset from each other so that in each case a holding element (18) and a stent marker (26) in the circumferential direction of the stent (10) measured angular distance of at least approximately 90 degrees.

Method for producing a stent (10) according to at least one of the preceding claims,

By doing so, that is

two coupling portions (20) and a loop portion (22) of a wire (12) of a base body (14) of the stent (10) are formed, wherein two portions of the wire (12) each for forming a coupling portion (20) in a groove (23 ) of a Hal ^¬ teelements (18) are inserted or passed through an opening (30) of the holding element (18), such that between the two coupling portions (20) formed wire section forms a loop portion (22).

17. introducer catheter with a stent (10) according to at least one of claims 1 to 15, with an inner mandrin (46) and with an outer sheath (62) into which the stylet (46) can be inserted together with the stent (10), and a non-displaceably connected to the stylet (46), in particular annular, positioning member (32) for coupling the stent (10) with the stylet (46) having at least one recess (34) into which the holding element (18) of the stent (10) is inserted in the compressed stent state, wherein a recess (34) bounding wall of the positioning element (32) forms with the inserted holding element (18) in the axial direction of the stent (10) effective undercut.

18. introducer catheter according to claim 17,

characterized in that

the stylet (46) is designed as a tubular stylet or as a wire-shaped stylet.

19. introducer catheter according to claim 17 or 18,

characterized in that

the stylet (46) has a distal end region (48) provided with cuts (53) and / or the stylet (46) has a substantially helical spring-shaped distal end region (48).

20. Einführkatheter according to at least one of claims 17 to 19, characterized in that

the positioning element (32) is connected to the stylet (46) by at least one of the joining techniques of laser welding, soldering, gluing, shrinking presses or a snap connection.

21. Einführkatheter according to at least one of claims 17 to 20, characterized g e k e n e z e c h e n e, that

the holding element (18) of the stent (10) and / or the positioning element (32) of the insertion catheter (56) comprises a material which consists of the group consisting of platinum, a platinum-iridium

Alloy, stainless steel, a cobalt-chromium alloy, tantalum, tungsten and a shape memory metal such as e.g. Nitinol is selected, and / or

the wire (12) of the stent (10) comprises a shape memory metal, in particular nitinol, and / or

in that the stylet (46) comprises a material selected from the group consisting of stainless steel, nitinol, a cobalt-chromium alloy, a polyimide, a polyamide, a polyether amide, a polysulfone, a polyether ether ketone and an acrylonitrile-butadiene - Styrene is selected.