Title of Invention

'DEVICE FORMING AN ENDOPROSTHESIS HAVING TAPERED ENDS'

Abstract

The invention relates to an endoprosthesis-forming device comprising a proximal end and a distal end, and including passage-facilitating means for facilitating passing the device through an obstacle. The invention relates mainly to an endoprosthesis-forming device (10) comprising a distal end (lOa) and a proximal end (lOb), and including at least one passage-facilitating means (11) facilitating passing the device in a duct, such as a blood vessel or a guide catheter, in particular past an obstacle, e.g. a stenosis or the end of a guide catheter. The invention is particularly suitable for use in the field of cardiological intervention and vascular radiology.

Full Text

-FORMI-NG AH-EMDOPRQ3THESIS HAVING TAPERED ENDS The invention relates essentially to an endoprosthesis-forming device having a proximal end and a distal end, and including means for facilitating passing the device through an obstacle. STATE OF THE ART Endoprosthesis devices, commonly called "stents", serve to treat the narrowing of various ducts in human anatomy, such as an artery, and to keep them open. Various types of stent are in existence, and they are described in numerous patents. Nevertheless, when putting such an endoprosthesis-forming device into place, e.g. while performing angioplasty, it is necessary to make use of a guide catheter and also of a flexible guide. The guide catheter is placed upstream from the stenosis, e.g. upstream from an artery suffering from stenosis, with the flexible guide passing through the stenosis and extending downstream therefrom. Before being put into its final position, the endoprosthesis-forming device is in a position in which it is retracted relative to the stenosis. Various techniques exist for expanding such endoprosthesis-forming devices, for the purpose of putting them into place, such as in particular self-expansion, or expansion by means of balloons. Nevertheless, when the duct in which the endoprosthesis-forming device is to be placed is too narrow, in particular when it is reduced to a diameter that is smaller than the outside diameter of the endoprosthesis-forming device, the operator cannot put the device into place. The operator then has to withdraw the endoprosthesis-forming device assembly from the body of the patient. The operator can then encounter a difficulty that lies in the fact that the proximal portion of the endoprosthesis-forming device comes up against the inlet to the guide catheter, which can lead to the endoprosthesis-forming device becoming partially or completely released. Furthermore, while the endoprosthesis-forming device is being inserted into a stenosis-forming lesion, it can also happen that the operator causes the endoprosthesis-forming device to come into abutment against the calcified portion. OBJECTS OP THE INVENTION A main object of the present invention is to solve the above-specified novel technical problems. An object of the invention is to solve the novel technical problem that occurs during withdrawal from the body of the patient of the assembly constituted by the device for facilitating placement of the endoprosthesis-forming device and that consists in finding a solution that improves the operation of withdrawing said assembly into the guide catheter.Another object of the present invention is to solve the novel technical problem consisting in facilitating passing the endoprosthesis-forming device through a stenosis.Another object of the present invention is to solve the various above-specified technical problems in association with all existing forms of endoprosthesis-forming devices or stents, such as, in particular, devices forming endoprostheses that are tubular, single-wire, braided mesh, or knitted. In addition, an object of the present invention is to be associated with all expansion techniques, such as those used in particular by endoprosthesis-forming devices that are self-expandable, or that are expandable by means of balloons.Another object of the present invention is to be usable in all fields that require it, such as in particular cardiological intervention and vascular radiology.An object of the invention is to provide a solution to the above-specified technical problems by a design that is particularly simple, relatively inexpensive, and suitable for use on a medical and on an industrial scale. SUMMARY OF THE INVENTIONThus, in a first aspect, the present invention provides an endoprosthesis-forming device including a proximal end and a distal end, and characterized in that it includes at least one passage-facilitating means for facilitating passing the device into a duct, such as a blood vessel or a guide catheter, in particular past an obstacle, e.g. a stenosis or the end of a guide catheter.The proximal end may comprise a plurality of proximal end edges and the distal end may comprise a plurality of distal end edges.In an advantageous embodiment of the invention, the passage-facilitating means is located on at least some of the edges of said proximal or distal end, preferably at both of the proximal and distal ends, respectively.In an advantageous embodiment, the passage-facilitating means has a tapering cross-section, at at least one of the distal or proximal ends.In an advantageous embodiment, the tapering cross-section comprises at least one chamfered portion made in at least one or some of the distal or proximal end edges.In an advantageous embodiment, the endoprosthesis-forming device including a distal end and a proximal end is formed by one or more zigzag-wound metal wires defining bends or edges, at least one of bends or edges presenting said passage-facilitating means at the proximal and/or distal end. In an advantageous embodiment, the passage-facilitating means is made mechanically in the material of the device, e.g. by crimping, or by flattening, or by machining, by removing shavings.In an advantageous embodiment, the passage-facilitating means comprises an endpiece secured to at least one of the proximal or distal end edges (12 or 14) of the device.In general, the proximal and/or distal ends comprise a plurality of end edges. In the context of an endoprosthesis-forming device made up of one or more zigzag-wound metal wires defining bends or edges, the end edges are formed in particular by some of the edges present at the ends of the device.Advantageously, the endoprosthesis-forming device comprises a plurality of means for facilitating passing the device.Advantageously, the passage-facilitating means comprises a chamfer, optionally including a flat, on at least one of the end edges, and in particular on an end of at least one of the above-mentioned edges. The flat preferably extends over at least 0.025 millimeters (mm). The flat makes it possible to obtain an end edge that is less dangerous, in particular by ensuring the point presents at least the thickness represented by said end edge, and by constituting a surface that slopes towards the axis of the device for facilitating sliding of the end in order to penetrate either into the narrow passage of the stenosis or into the guide catheter in order to be withdrawn.Advantageously, the chamfer presents an angle alpha (a) defining the chamfer angle, said angle preferably lying in the range 1° to 89°, and more preferably in the range 5° to 55°.Advantageously, the chamfer extends over a length that lies in the range 0.01 mm to the entire length ofthe device. Thus, in a variant, at least one wire used for making the device or stent is chamfered.A particularly advantageous embodiment is found by selecting an angle a lying in the range 20° to 40°, and preferably when the angle a is equal to about 30°.The invention can be performed by presenting means for facilitating passing the device on only some of the end edges at the proximal and/or distal end.Naturally the inventors find that an advantageous embodiment lies in an endoprosthesis-forming device having all of the end edges at the proximal or distal ends provided with means for facilitating passing the device.The invention can be implemented by providing one of its embodiments on one of the proximal or distal end edges, and advantageously the invention is implemented on all of the proximal or distal end edges, and even more advantageously on all of the proximal and distal end edges. As a result, in this highly advantageous embodiment of the invention, the proximal end and the distal end present end edges each including means for facilitating passing the device into a duct.The endoprosthesis-forming device may be made of metal wire, e.g. of a stainless steel such as 316L stainless steel, or of other metals such as tantalum, or mixtures of metals such as nitinol, for example. This wire substrate may be coated in an inorganic layer e.g. in carbon, silicon carbide, titanium oxide nitride, titanium, chromium-cobalt, platinum, silicones, polymers. The substrate may also be coated in a layer suitable for releasing drugs presenting antimitotic, anti-inflammatory, or immunosuppressant properties. The diameter of the wire may vary over a wide range well known to the person skilled in the art, generally from 0.05 mm to 0.20 mm. DETAILED DESCRIPTION OF THE INVENTION By way of example, the invention can be used while performing an angioplasty and a surgical operation for repairing a stenosis that requires a stent to be put into place, or more generally that requires an endoprosthetic device to be put into place.In particular, in this type of operation, the operator needs to place in a duct, e.g. formed by an artery or possibly a vein, a set comprising: a guide catheter; a generally flexible guide; and a balloon-carrier catheter for carrying at least one endoprosthesis-forming device disposed at least externally around the balloon while in the deflated state.As is well known to the person skilled in the art, the guide catheter is initially advanced upstream of the stenosis. Thereafter, the flexible metal guide is inserted through the stenosis to a position downstream therefrom. Finally, the carrier catheter together with its endoprosthesis-forming device is inserted in the guide catheter, sliding on the guide. At this stage, it can happen that the endoprosthesis-forming device cannot penetrate through the passage defined by the stenosis. The present invention provides means of the kind described above for facilitating the passage of the endoprosthesis-forming device into a stenosis presenting a hollow bottom portion. The inventors use the "hollow bottom portion" to designate the small passage left by the stenosis to allow a fluid such as blood to flow within a duct such as an artery or a vein.Nevertheless, if the endoprosthesis-forming device of the invention or of the prior art does not pass through the stenosis, then the operator is obliged to withdraw the assembly comprising the endoprosthesis-forming device and the balloon-carrier catheter from the body of the patient. To do this, the operator needs to reposition the assembly comprising the endoprosthesis-forming device and the balloon catheter back inside the guide catheter. However, during this withdrawal, it can happen that the endoprosthesis-forming device comes into abutment against the inlet of the guide catheter and that the endoprosthesis-forming device becomes partially or completely released from the carrier catheter. The present invention provides the above-described means to enable the assembly comprising the endoprosthesis-forming device and its carrier catheter to be reinserted into the guide catheter. Other objects, characteristics, and advantages of the invention appear clearly in the light of the following description made with reference to the accompanying drawings, showing various presently-preferred embodiments of the invention given purely by way of illustration and thus not serving in any way to limit the scope of the invention.In the figures: Figure 1 shows a first presently-preferred embodiment of an endoprosthesis-forming device (10) of the present invention in which the means (11) facilitating the passage of the endoprosthesis-forming device in the duct is a chamfer (400);Figure 2 is a detail view of an end edge such as adistal end edge (14) and/or a proximal end edge (12) ofthe Figure 1 device; Figure 3 shows another embodiment of the means (11) of the present invention shown as a detail view of an end edge such as a distal end edge (14) and/or a proximal end edge (12) of the device; Figure 4 shows another embodiment of the means of the invention as a detail view of an end edge, such as a distal end edge (14) and/or a proximal end edge of the device; Figure 5 shows an embodiment in which the means (11) is a fitted endpiece (500) serving to reduce the section of at least one of the proximal or distal ends; Figure 6 shows an embodiment in which the means (11) is a proximal and/or distal end edge (12 and/or 14) presenting sufficient flexibility to enable the terminal outside diameter (34) to be reduced thus making it possible to pass an obstacle by taking up a position for defining a new terminal outside diameter (34'); Figure 7 shows a prior art endoprosthesis-forming device (50) with plane end edges; Figure 8 shows a prior art endoprosthesis-forming device (50) in abutment against an obstacle (100), in this example constituted by a guide catheter, while withdrawing the endoprosthesis-forming device (50) from the body of a patient, for example; Figure 9 shows a device constituting an embodiment of the means (11) of the present invention, in particular an endoprosthesis-forming device (10) having at least its proximal end edges (12) chamfered, in abutment against an obstacle while the device is being withdrawn, thereby facilitating the passage of the device through the obstacle (100), formed in this example by the guide catheter, thus enabling the device to penetrate back into the inside of the guide catheter; ' Figure 10 shows a prior art device (50) in abutment against an obstacle (200) while the device is being put into place, e.g. during an intervention on a stenosis; and • Figure 11 shows a device constituting an embodiment of the means (11) of the present invention, e.g. an endoprosthesis-forming device (10) presenting at least one of its distal end edges (14) chamfered, in abutment against an obstacle (200) while the device is being put into place, thus making it easier to put the device into place through the obstacle (200). Figure 1 shows a presently-preferred first embodiment of an endoprosthesis-forming device of the present invention given overall reference numeral (10) . This endoprosthesis-forming device comprises a proximal end (lOa) defined by a set of proximal end edges (12) and a distal end (lOb) defined by a set of distal end edges (14), and interconnected by a central portion (16) forming the body of the device. In this particular embodiment, the means (11) is a chamfer (400) .The proximal and distal end edges (12 and 14) present a chamfer, e.g. presenting a chamfer angle a with a value lying in the range 1° to 89°, but preferably lying in the range 5° to 55°, and in a particular embodiment being about 30°, and preferably equal to 27°. The proximal and distal end edges (12 and 14) also present a flat (21) of length (20) lying in the range 0.01 mm and the thickness (18) of the endoprosthesis-forming device. This endoprosthesis-forming device advantageously has a thickness (18) equivalent to that of the endoprosthesis-forming devices known to the person skilled in the art which generally lies in the range 0.05 mm to 0.20 mm.In an advantageous embodiment, the thickness (18) corresponds to the thickness of one or more metal wires (17) wound in a zigzag configuration in order to form the endoprosthesis-forming device.The central portion or body (16) of the device serves to define an outside diameter (30) and an inside diameter (32), and also a terminal outside diameter (34) and a terminal inside diameter (36) . As its general object, the invention seeks to obtain a terminal diameter(34 and/or 36) that is less than the outside diameter(30) .This structure serves to facilitate passing through an obstacle that presents a hollow portion in which theendoprosthesis-forming device is to be inserted, such as in particular through a stenosis or a guide catheter.Figure 2 shows a detail of the chamfer (400) at the proximal or distal end edges (12 or 14) of the Figure 1 embodiment. This figure also shows a plan view of such an end, e.g. of an endoprosthesis-forming device having rounded ends possessing a chamfer. This figure shows the thickness (18) and the thickness (20) given by the flat (21), when such a flat is present. Similarly, the length (15) represents the length of the chamfer (400) along the outside surface in this embodiment. The chamfer may extend over a length (15) lying in the range 0.01 mm to the entire length of the device. In particular, an angle a can be identified representing the angle of the chamfer, said angle possibly lying in the range 1° to 89°, but preferably lying in the range 5° to 55°, and in a particular embodiment being about 30°, and preferably being 27°. Figure 3 shows another embodiment of the means (11), and in particular shows the angle a defined by the chamfer angle and the angle β defined by the half-angle at the apex inside the truncated cone formed in three dimensions by the set of proximal or distal end edges (12 or 14) when the set of end edges presents means (11) for facilitating passing the device. Figure 4 shows another embodiment of the means (11) of the present invention, in which the endoprosthesis-forming device (10) comprises a device body (16) having an outside diameter (30) and an inside diameter (32). The proximal or distal end edges (12 or 14) together form a terminal outside diameter (34) and a terminal inside diameter (36), which diameters are smaller than the outside and inside diameters (30 and 32) respectively. In this embodiment, the thickness (18) is conserved, but the intermediate portion (40) could present a different thickness. Similarly, the end edge (12 or 14)could present a thickness (20) that is identical or different.In an advantageous embodiment, the end edge (12 or 14) in this particular embodiment may present a chamfered shape as shown in Figure 2.Figures 5A and 5B show a chamfered endpiece (500) secured to an endoprosthesis-forming device so as to facilitate passing the device in a duct. The endpiece (500) is shown in an embodiment that corresponds to Figure 2. Nevertheless, endpieces can correspond to any of the embodiments of the invention and in particular to the embodiments shown in Figures 3, 4, and 6.Figures 5A and 5B thus show two different embodiments of a fitted chamfered endpiece (500), but without the shape of the endpiece being limited thereto.Figures 5A and 5B show a proximal and/or distal end edge (12 and/or 14) presenting an endpiece (500) secured to the end of a prior art endoprosthesis-forming device, for example. The fitted endpiece (500) is put into place on the end of an endoprosthesis-forming device presenting the prior drawback and not solving the problem posed and solved by the present invention. The fitted endpiece (500) can take on the various shapes provided for by the invention in its generality. The fitted endpiece (500) may be in the form of an endpiece that is secured to one of the proximal or distal end edges (12 or 14), or of a set of end edges for securing to the proximal or distal end (12 or 14).Figure 6 shows an endoprosthesis-forming device presenting an embodiment in which the proximal and/or distal end edges (12 and/or 14) comprise a flexible portion. This enables the endoprosthesis-forming devices (10) to pass from a terminal outside diameter formed by the set of proximal or distal end edges (12 or 14) to a new terminal outside diameter formed by the proximal or distal end edges (12 or 14), the new diameter (34') being smaller than the old diameter (34) and facilitating passing the endoprosthesis-forming device (10) through an obstacle.Figure 7 shows a prior art endoprosthesis-forming device (50). This device is plane in shape at its ends, and in particular it presents a thickness (20") at its end that is identical to the thickness (18") of its central portion.Figure 8 shows a prior art endoprosthesis-forming device (50) in abutment against an obstacle (100) . This Figure shows in particular the contact made between at least one prior art proximal end edge (12') and the obstacle (100) while the device is being withdrawn into a duct (101); this obstacle may be the edge of a guide catheter while the device (10) is being withdrawn into the catheter. Figure 9 shows an endoprosthesis-forming device (10) of the invention, e.g. constituting one of its embodiments as shown in Figure 1 or Figure 2, coming into abutment against an obstacle (100). This figure shows how passing the endoprosthesis-forming device (10) through an obstacle (100) is facilitated by having proximal end edges (12) provided with passage-facilitating means (11), in this case a chamfer, while an endoprosthesis-forming device is being withdrawn into a duct (101), e.g. a guide catheter.Figure 10 shows a prior art endoprosthesis-forming device (50) in abutment against an obstacle (200), e.g. formed by a stenosis. This figure shows in particular how at least one distal end edge (14') of the prior art comes into contact against the obstacle (200) which may be constituted by a stenosis, for example, while the device (50) is being put into place. This figure also shows a duct (300) that does not impede passage of the endoprosthesis-forming device, where the duct (300) may be constituted by an artery, for example.This figure also shows the guide catheter (70), the balloon-carrying catheter (80) on which the prior artendoprosthesis-forming device (50) is mounted, and with X-ray markers (61) being shown for enabling the endoprosthesis-forming device to be positioned properly prior to being expanded. This figure shows clearly the difficulty represented by passing the device (50) through the obstacle (200) . Figure 11 shows an endoprosthesis-forming device (10) of the invention, e.g. in one of its embodiments as shown in Figure 1 or Figure 2, coming into abutment against an obstacle (200), e.g. formed by a stenosis. This figure shows clearly how passage of the endoprosthesis-forming device (10) through an obstacle (200) is facilitated by the distal end edges (14), e.g. while the endoprosthesis-forming device (10) is being put into place through the obstacle (200) . The references in the figures are identical for all of the Figures 1 to 11, and the Applicant deems it unnecessary to repeat the description of all of the references for each of the figures. It will be understood that the invention can be embodied in various ways and that it covers all means constituting means that are technical equivalents of the means described and shown. Figures 1 to 11 form an integral portion of the present invention and thus of the present description. The invention also covers any characteristic that can be seen to be novel from the description and the drawings themselves, compared with the state of the art and on this account as general means. It would also be understood that the variant embodiments and implementations can be combined with one another. For example, it is possible to combine restricting the diameter of the outside section of a distal or proximal end with fitting on an endpiece that also has a restriction in the diameter of its outside section. Other advantageous characteristics and objects of the invention appear clearly to the person skilled in theart from the description below of an embodiment given by way of illustration and that does not limit the scope of the invention in any way. EXAMPLE 1 A prior art endoprosthesis-forming device, e.g. an LIC7 chamfered heli.stent (manufacturer: Hexacath) , was machined by removing shavings so as to present a set of proximal and distal terminal ends (12 and 14). (The references are given relative to the references in the figures.) The ends were machined so as to make a chamfer having a chamfer angle of 27°. The end of the chamfer had a flat of about 0.025 mm. The machined portion extended over a length of about 0.12 mm from one end. WE CLAIM: An endoprosthesis-forming device (10) including a distal end (lOa) and a proximal end (lOb), the device being characterized in that it includes at least one passage-facilitating means (11) for facilitating passing the device into a duct, such as a blood vessel or a guide catheter, in particular in the presence of an obstacle, e.g. a stenosis or the end of a guide catheter, said passage-facilitating means (11) comprising a chamfer- forming chamfered portion (400) formed on at least one or some of the proximal end edge (12) and/or distal end edge (14) . An endoprosthesis-forming device (10) according to claim 1, in which the proximal end (lOa) comprises a plurality of proximal end edges (12) and the distal end (lOb) comprises a plurality of distal edges (14), the device being characterized in that said passage- facilitating means (11) is placed at at least one of the proximal end edge (12) or distal end edge (14), and preferably at both proximal and distal ends. An endoprosthesis-forming device (10) according to any preceding claim, comprising a distal end (lOb) and a proximal end (lOa), formed by one or more zigzag-wound metal wires (17), defining bends or edges, the device being characterized in that at least one of said bends or edges present at the proximal end (lOa) and/or distal end (lOb) includes said passage-facilitating means (11). An endoprosthesis-forming device (10) according to any preceding claim, characterized in that the passage- facilitating means (11) is made mechanically in the material of the device, e.g. by crimping, or by flattening, or by machining to remove shavings.An endoprosthesis-forming device (10) according to any preceding claim, characterized in that the passage- facilitating means (11) is an endpiece (500) secured to at least one of the proximal end edge (12) or distal end edge (14) of the device.An endoprosthesis-forming device (10) according to anypreceding claim, characterized inthat it includes aplurality of means (11) for facilitating passing thedevice. An endoprosthesis-forming device (10) according to any preceding claim, characterized in that the passage- facilitating means (11) comprises a chamfer (400) presenting a flat (21) on at least one of the proximal end (lOa) and distal end (lOb), preferably a flat (21) of at least 0.025 mm. An endoprosthesis-forming device (10) according to any preceding claim, characterized in that at least one of the proximal end edge (12) and/or distal end edge (14) presents an angle (a) defining the chamfer angle, said angle preferably lying in the range 1° to 89°, and more preferably in the range 5° to 55°. An endoprosthesis-forming device (10) according to claim 8, characterized in that the angle (a) lies in the range 20° to 40°, and is preferably about 30°. 10. An endoprosthesis-forming device (10) according to any preceding claim, characterized in that the passage- facilitating means (11) comprises a chamfer extending over about 0.12 mm at each proximal end edge (12) or distal end edge (14) of the endoprosthesis-forming device. 11. An endoprosthesis-forming device (10) comprising a distal end (lOa) and a proximal end (10b), the device comprising at least one passage-facilitating means (11) for facilitating passing the device in a duct (101; 300) such as a blood vessel or a guide catheter, in particular in the presence of an obstacle (100; 200), e.g. a stenosis or the end of a guide catheter, the endoprosthesis-forming device being formed by one or more zigzag-wound metal wires (17) defining bends or edges, at least one of said bends or edges present at the proximal and/or distal end (lOa and/or lOb) including said passage-facilitating means (11), said passage- facilitating means (11) being a chamfer (400) made in at least one of said bends present at the proximal and/or distal ends, for which the angle alpha (a) defining the chamfer angle is about 27°, the end of the chamfer presenting a flat (21) of about 0.025 mm, the chamfer being made over a length (15) of about 0.12 mm. 12. An endoprosthesis-forming device substantially as herein described with reference to accompanying drawings.

Documents:

3078-delnp-2006-abstract.pdf

3078-delnp-2006-Claims-(06-05-2014).pdf

3078-delnp-2006-Claims-(29-04-2014).pdf

3078-DELNP-2006-Claims-161214.pdf

3078-delnp-2006-claims.pdf

3078-delnp-2006-Correspondence Others-(01-10-2013).pdf

3078-delnp-2006-Correspondence Others-(02-12-2014).pdf

3078-delnp-2006-Correspondence Others-(06-05-2014).pdf

3078-delnp-2006-Correspondence Others-(11-07-2014).pdf

3078-delnp-2006-Correspondence Others-(11-08-2014).pdf

3078-delnp-2006-Correspondence Others-(12-08-2014).pdf

3078-delnp-2006-Correspondence Others-(19-02-2013).pdf

3078-delnp-2006-Correspondence Others-(29-04-2014).pdf

3078-DELNP-2006-Correspondence-161214.pdf

3078-delnp-2006-Correspondence-Others-(30-07-2013).pdf

3078-delnp-2006-correspondence-others-1.pdf

3078-delnp-2006-correspondence-others.pdf

3078-delnp-2006-descrption (complete).pdf

3078-delnp-2006-drawings.pdf

3078-delnp-2006-Form-1-(01-10-2013).pdf

3078-delnp-2006-form-1.pdf

3078-delnp-2006-Form-13-(06-05-2014).pdf

3078-delnp-2006-form-18.pdf

3078-delnp-2006-form-2.pdf

3078-delnp-2006-Form-24-(11-08-2014).pdf

3078-delnp-2006-form-26.pdf

3078-delnp-2006-Form-3-(02-12-2014).pdf

3078-delnp-2006-Form-3-(30-07-2013).pdf

3078-delnp-2006-form-3.pdf

3078-delnp-2006-form-5.pdf

3078-delnp-2006-GPA-(12-08-2014).pdf

3078-delnp-2006-GPA-(30-07-2013).pdf

3078-DELNP-2006-OTHERS-161214.pdf