MXPA98007376A - Tool for folding type boqui - Google Patents

Abstract

The present invention relates to a tool for folding an endoprosthesis onto a catheter, characterized in that it comprises: a cylindrical body having a clamping end and a collar end, wherein the cylindrical body at the end of the collar transits to a plurality of segmented jaws that are flared outwardly, external threads disposed in the cylindrical body between the collar end and the clamping end, a collar rotatably mounted on the cylindrical body, wherein an internal threaded opening engages the external threads on the body and a The inner inner diameter of the internal threaded opening engages the plurality of segmented jaws, wherein advancing the collar on the threads transfers the front inner diameter over the segmented jaws to converge the segmented jaws in a closed state, and a groove formed over a length of each segmented jaw, where when the plurality of segmented jaws and The slots collectively form a cylindrical cavity leading to an opening in the collar end of the cylindrical body, wherein when closing the segmented jaws on the stent mounted on the catheter, when the stent and the catheter are placed within the cavity, fold the stent over the catheter

Description

TOOL FOR FOLDING TYPE NOZZLE BACKGROUND OF THE INVENTION The present invention relates to an apparatus for loading a tubular graft, such as a stent, on the distal end of a catheter structure of the type employed, for example in percutaneous transluminal coronary angioplasty procedures. (PTCA), percutaneous transluminal angioplasty (PTA) procedures, atherectomies and the like. In typical PTCA procedures, a catheter 10 is inserted percutaneously into a patient's cardiovascular system through the brachial or femoral arteries and advanced through the vasculature until the distant end of the glider catheter is in the aorta of the aorta that leads to the coronary arteries. A guidewire and a dilatation catheter having a balloon at the distal end are introduced through the guide catheter, with the guidewire sliding within the dilatation catheter. The guide wire is first advanced outside the guiding catheter in the patient's coronary vasculature and the dilatation catheter is advanced over the previously advanced glide wire until the dilatation balloon is properly placed through the arterial lesion. Once in position through the lesion, a flexible and expandable balloon is inflated to a pre-terminated size with a radio-opaque liquid at relatively high pressures, to radially compress the atherosclerotic plaque of the lesion against the interior of the arterial wall and thus dilates the lumen of the artery.The balloon then deflates to a small profile, so that the dilatation catheter can be removed from the vasculature of the patient and resume blood flow through the dilated artery As will be appreciated by those skilled in the art, while the procedure described above is typical, it is not the only method used in angioplasty.In angioplasty procedures of the type previously discussed, restenosis of the artery may arise in or near the artery. treatment area, which may require another angioplasty procedure, a surgical bypass operation or some other method to repair In order to reduce the likelihood of the development of restenosis and reinforce the area, a doctor can implant an intravascular prosthesis to maintain the vascular opening, commonly known as a stent within the artery of the treated area. The stent is transported in its delivery diameter through the vasculature. At the deployment site, the stent expands to a larger diameter, often by inflating the portion of the catheter balloon. The stent may also be of the self-expanding type. Because the catheter and stent travel through the patient's vasculature and typically through the coronary arteries, the stent should have a small delivery diameter and be firmly connected to the catheter until the doctor is ready to implant it. In this way, the stent can be loaded into the catheter in a manner that does not interfere with delivery, and should not be dislodged from the catheter until it is implanted In procedures where the stent is placed over the balloon portion of the catheter, it is necessary Folding the stent over the portion of the balloon to reduce its diameter and prevent it from slipping out of the catheter, when the catheter is advanced through the patient's vasculature.A non-uniform folding can result in sharp edges that can form on the surface now non-homogenous stent graft.In addition, non-uniform stent folding may not achieve the minimum profile desired for the stent and catheter structure. When the stent is not reliably folded over the catheter, the stent can slip out of the catheter and into the patient's vasculature prematurely as a loose foreign body, possibly causing blood clots in the vasculature, including thrombosis. Therefore, it is important to ensure the proper folding of a stent over a catheter in a uniform and reliable manner. This folding is often done by hand, which may not be satisfactory due to non-uniform application of force resulting in non-uniform folds. In addition, it is difficult to judge visually when a uniform and reliable folding has been applied. Some self-expanding stents are difficult to load by hand onto a delivery device such as a catheter. In addition, the more the stent is handled, the greater the likelihood of human error that can result in an improperly folded endoprosthesis. Accordingly, there is a need for the specialty for a device that reliably folds a stent over a catheter. There have been attempts to design a tool for folding a stent over a balloon delivery catheter. An example of this tool comprises a series of plates that substantially have flat, parallel surfaces that move in a rectilinear fashion with each other. A stent-carrying catheter is disposed between those surfaces, these surfaces fold the stent onto the outside of the catheter by reason of relative movement and applied pressure. The plates have multiple degrees of freedom and may have force-indicating transducers to measure and indicate the • force applied to the catheter during stent folding. Another tool design for stent loading comprises a tubular member that houses a bladder. The tubular member and the bladder are constructed to hold a stent that is to be folded over a balloon catheter structure. By placing the stent over the balloon portion of the catheter, a valve is activated in the loading tool to inflate the bladder. The bladder compresses the stent radially inward to a reduced diameter over the portion of the catheter balloon to achieve a snug fit. In this way, the endoprosthesis is folded over the distal end of a balloon catheter, with a minimum of human handling. Folding tools for anterior endoprostheses are described, for example, in U.S. Pat. of assignment and common property Nos. 5,437,083 and 5,546,646 granted to Williams et al. However, another stent-folding tool is known in the art and manufactured under the trademark "BARD XT" by C. R. Bard Inc. of Boston Massachusetts, the tool in fact is a stent loader. It is constructed of a tubular body with a ball at one end that is connected to a plurality of long, thin strips that pass through the tubular-rigid body. An unfolded stent is placed over the plurality of long, thin strips, and the strips hold the stent in an expanded state. The balloon portion of a catheter is inserted into the cylindrical space formed by the plurality of strips. When the user pulls the ball while holding the tubular body against the stent, the strips slide under the stent and the stent is transferred onto the balloon portion. Yet another conventional stent folding tool is manufactured by Johnson & Johnson Company and resembles a hinge nutcracker. Specifically, the tool comprises two hand operated levers that are hinged at one end. The levers are designed to be held in the palm of a user's hand at the opposite end. A cylindrical opening is provided which maintains a folding tube through the middle portion of the tool to receive a loaded stent over a balloon catheter. The folding operation is performed when the user compresses the levers thus pressing the folding tube which upon contracting rotates contracts the stent onto the balloon catheter.

While the prior art devices are suitable for folding stent over balloon catheters, these devices have problems - such as non-uniform bending forces, which result in non-uniform bends and thus these devices are unsuitable for use by physicians in a catheterization laboratory, who wish to fold the stent over the balloon catheter. SUMMARY OF THE INVENTION The present invention is directed to a method and apparatus for folding an intravascular stent over the distal end of a catheter. The apparatus is constituted by a cylindrical body having a clamping end and a collar end and the clamping end. A collar is rotatably mounted on the cylindrical body and has an internally threaded opening that couples the threads on the body. The front inner diameter of the threaded opening internally engages the plurality of segmented jaws, wherein advancing in collar on the threads transfers the inner front diameter on the segmented flared jaws to converge the jaws in a closed state. In a preferred embodiment, a groove is formed over the length of each jaw, such that when the plurality of segmented jaws are in a closed state, the grooves collectively form a cylindrical cavity leading to an opening in the collar end of the cylindrical body. In this way, closing • the segmented jaws on the endoprosthesis mounted on the portion of the catheter balloonWhen the stent and catheter are positioned within the cavity, fold the stent over the catheter. In the preferred embodiment, a folding apparatus according to the invention has four segmented jaws and each segmented jaw includes a generally quarter-circle cross-sectional shape. The segmented jaws can be modified with a liner, various coatings, foam plates or a floating head. These modifications are aimed at holding and maintaining the endoprosthesis without damaging the part. Furthermore, when the segmented jaws converging in the closed state are lined, the lining material ensures that the resulting fold is characterized by a fold of constant diameter. The diameter can be adjusted by changing the thicknesses or shapes of the lining material. In the preferred embodiment of the present invention, the tool is designed for use in a catheterization laboratory for folding intravascular stents over balloon catheters, by forcing the stent to compress from four points around its circumference onto the outer diameter of the balloon.

The balloon with the unfolded stent mounted in the correct position is placed inside the flared collar end of the cylindrical body, with the collar threaded in half towards the flared collar end. The balloon and stent are held in position by a person other than the one doing the folding or by a table or other support. While the balloon and the stent are held, another person may twist the collar to advance it over the length of the threads, thereby forcing the segmented jaws at the collar end to converge and close down on the stent. This closing action reaches the stent on the balloon. As previously mentioned, grooves are formed on the length of each jaw, such that when the jaws are in their closed state, the grooves collectively form a cylindrical cavity, the dimensions and shape of which correspond to the folded stent. The cylindrical cavity contains the folded endoprosthesis and the catheter balloon when the segmented jaws have completely converged. The grooves can be profiled to vary the diameter of the cavity and the contours over the length of the folded stent. It is normal to find some resistance in the compression process. The endoprosthesis and catheter balloon can be released from the tool by unscrewing the collar from the cylindrical body, releasing - this way the external pressure and the segmented jaws converge and allow the jaws to open. If the folding process is not satisfactory, the process can be repeated as many times as the user deems necessary. The tool and its operation are extremely simple and repeatable. Undoubtedly, by virtue of the rotary movement of the collar on the cylindrical body, it is possible to mark the tool by the precise distance that the collar is advanced on the threads of the cylindrical body, in order to accurately fold the endoprosthesis by the convergent segmented jaws. The present invention in this manner provides the end user with a precise and repeatable method of folding a stent over a balloon catheter. To achieve accuracy, the present invention can be modified to be provided with an optional micrometer, strain gauges or the like for narrow control. In contrast, many conventional processes are unreliable and achieve inconsistent and non-uniform folds. Additional embodiments of the folding tool of the present invention can be used with any stent that is designed to be released without a delivery system. The folding tool can be sold with or without a stent as a component. Finally, the tool of the present invention solves a common problem with conventional tools where folding by reducing to a certain diameter with precision is difficult. These and other advantages of the present invention will become more apparent from the following detailed description, when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is an elevation view, partially in section, of an intravascular stent that is mounted on a supply balloon catheter and disposed within a vessel. Figure 2 is a perspective view of a preferred embodiment of a folding tool according to the invention, showing the segmented jaws in the open state. Figures 3a and 3b illustrate a view in side elevation and front respectively, the cylindrical body of a preferred embodiment of a folding tool according to the invention, has a clamping end and a flared end of the collar, with the jaws segmented in the open, flared state.

Figures 4a and 4b illustrate a view in lateral and frontal elevation, respectively, of the collar of a folding tool according to the invention, which has internal threads, a leading edge and a knurled exterior. Figure 5 is a side elevational view of one embodiment of a folding tool according to the invention, wherein a catheter-and-stent structure has been loaded at the collar end just prior to the folding operation. Figure 6 is a side elevational view of the embodiment of a folding tool illustrated in Figure 5, wherein the folding operation has occurred and the segmented jaws have converged on the stent-and-catheter structure due to the advancement of the collar on the cylindrical body of the folding tool. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Figure 1 illustrates an intravascular stent 10 which is mounted on a delivery catheter 11. The stent 10 generally comprises a plurality of radially expandable cylindrical elements 12, arranged generally coaxially and interconnected by the members 13 that are they disposed between adjacent cylindrical elements 12. The delivery catheter 12 has an expandable portion or balloon 14 for expanding the endoprosthesis 10 within artery 15 or another vessel. An artery 15 as illustrated in Figure 1 has a dissected liner 16 that has occluded a portion of the passage - arterial. The delivery catheter 11 on which the stent 10 is mounted, can essentially be the same type of balloon dilatation catheter that is conventionally employed for angioplasty procedures. The balloon 14 may be formed of suitable materials such as polyethylene, polyvinyl chloride, polyethylene terephthalate and other similar polymers. In order for the stent 10 to remain in place in the balloon 14 during delivery to the damage site within the artery 15, the stent 10 is compressed on the balloon 14. This compression step is referred to as folding. An optional retaintable protective supply liner or sleeve 20, may be provided to further ensure that the stent 10 remains in place in the balloon 14 of the delivery catheter 10, and to prevent abrasion of the body lumen by the open surface of the stent 10 during delivery to the desired artery location. Other means for securing the endoprosthesis 10 on the balloon 14 can also be employed, such as providing collars or ridges at the ends of the working portion, ie the cylindrical portion of the balloon 14. The catheter-and-endoprosthesis structure can be introduced. to the vasculature of the patient through processes that are known in the art, generally immediately after PTCA, PTA or arterectomy procedures. Briefly, a guidewire 18 is disposed through the treated arterial section, referred to as the target area 16 and the catheter-and-stent structure is advanced over the guidewire 18 within the artery 15, until the stent 10 is directly under the target area 16. Prior to inflation of the balloon 14, the delivery sleeve 20 is retracted to expose the stent 10. The balloon 14 of the delivery catheter 11 is then expanded using an inflation fluid. The expansion of balloon 14 in turn expands stent 10 into contact with artery 15. Next, balloon 14 deflates and catheter 11 is removed, leaving stent 10 to support target area 16. As mentioned above, In order to ensure proper seating of the stent 10 on the balloon 14 and to ensure proper deployment of the stent 10 in the target area 16 within the artery 15, the procedure of stent folding is critical.

In order to implant the endoprosthesis 10 in a vessel, it is first mounted on the inflation balloon 14 at the distal end of the delivery catheter 11. The endoprosthesis 10 is folded down onto the balloon 14 to ensure a low profile. The present invention encompasses this folding process. Figure 2 provides a perspective view of a preferred embodiment of the stent-folding tool 22, according to the invention. In the preferred embodiment as illustrated, the stent-folding tool 22 is constituted by a cylindrical body 25 having a clamping end 26 opposite a collar end 28. The collar end 28 is constituted by a plurality of clamping jaws. flared open segment 30 which is formed by separating the collar end 28 into discrete branches. The cylindrical body 25 further includes external threads 32 disposed between the clamping end 26 and the collar end 28. The stent folding tool 22 further includes a rotating cylindrical collar 34 having internal threads that engage the external threads 32 of the cylindrical body 25. The cylindrical collar 34 also includes a leading edge 36 which is designed to engage the segmented jaws, as the collar 34 advances forward in the direction of the collar end 28. As this engagement progresses, the leading edge 36 forces the segmented jaws. 30 from the flared open state to a closed state, wherein all the segmented jaws 30 converge towards a theoretical axial center line of the cylindrical body 25. Figure 2 further illustrates an optional slot 38, preferably formed in each segmented jaw 30 extending the length of each jaw 30. As best seen in Figures 3a and 3b, which respectively provide a side elevation view and a front view of the cylindrical body 25 of a tool of folding according to the preferred embodiment of the invention, the slot 38 transits to a confluence point 40 in a bore 42 extending over a length of the cylindrical body 25. The holding end 26 can optionally be knurled 46 to provide a better clamping surface. Other finishing methods known in the art can be used to improve friction at this point, as well. The cylindrical body 25 is preferably approximately 9.53 cm (3.75") long however this length may vary depending on the application The suction end 26 is characterized by a chamfered edge 44 and as mentioned above, a knurled surface 46 can be provided just beyond the chamfering edge 44 to allow a better grip Just outside the knurled portion 46 there are external threads 32 which in the preferred embodiment are a coarse thread of 5. The external threads 32 are wound approximately 6.35 cm (2.5") upwardly of the arrow of the cylindrical body 25. Then, the profile of the cylindrical body 25 flares out from its central axis, preferably at an angle of 4o, and transits within the collar end 28. The collar end not only flares out but also divides the arrow approximately 6.35 cm (2.5") where the threads begin, roughly coinciding with the the confluence point 40. The preferred spacing is a 4th taper that begins at the 6.35 cm (2.5") mark from the clamping end 26 and expands 4o (relative to the central axis) relative to the collar end 28, creating an approximate space of 0.48 cm (.189") between the ends of the cylindrical body 25. In this embodiment, the collar end 28 is preferably divided into four discrete segmented jaws 30 and each segmented jaw 30 is flared outwardly to a 4 ° angle approximate to the axial center line of the cylindrical body 25. Segmented jaws 30 are preferably formed from sections of a quarter pipe which are defined by a small inner radius of 1.78 mm (.007"). In the flared open state, the outer diameter of the open segmented jaws 30 is approximately 3.06 cm (1.105") in contrast to the preferred diameter of 2.54 cm (1") of the non-flared section of the cylindrical body 25. The slot 38 formed in each segmented jaw 30 is best seen in the front view of the cylindrical body 25 in Figure 3. Figures 4a and 4b provide a side elevational view and a front view, respectively of the cylindrical collar 34 that is rotatably mounted in the cylindrical body 25. In the preferred embodiment illustrated in Figures 4a and 4b, the cylindrical collar 34 has a general cylindrical shape with a first diameter, and a leading edge 36 with a smaller second diameter. Therefore, as noted in the elevation view of Figure 4a, the cylindrical collar 34 preferably has a stepped diameter in descending form. The cylindrical collar 34 in this manner is a two-stage cylinder which in the preferred embodiment is approximately 3.81 cm (1.5") long with a maximum diameter of 5.08 cm (2"). The inner diameter is a constant at 2.54 cm (1") and is terminated with a thick internal thread of 5 °, 50, to correspond with the external threads 32 in the cylindrical body 25. The large diameter section of the cylindrical collar 34 of it is 2.54 cm (1") long and has a diameter of 5.08 cm (2"), and it is also chamfered on both edges, which section also has a knurled surface 52 to facilitate a better grip on the piece. 38 has a length of 1.27 cm (.5") and is cut in a reduced form in diameter preferably to 3.81 cm (1.5"). The leading edge 36 is significant for forcing the segmented jaws outwardly flared 30, from the open state to the closed state, wherein each segmented jaw 30 converges towards the axial centerline of the cylindrical body 25. Figures 5 and 6 are side elevation views of a preferred embodiment of a stent-folding tool 22, of according to the invention. In Figure 5, the segmented jaws 30 are flared open to receive the balloon catheter 11 with the stent 10 loaded onto the balloon 14. The balloon stent-and-catheter structure is illustrated in Figure 5 located within a space or cavity 58, which is formed by the segmented jaws 30 in the flared open state. As mentioned above, a stent-folding tool 22 according to the invention is designed to be used in a catheterization laboratory to bend stent over the catheter balloon portions, by compressing the stent over the balloon, preferably at four points around the outer circumference of the catheter. Therefore, as seen in Figure 5, the balloon 14 with the unfolded stent mounted in the correct position is placed inside the collar end 28 of the cylindrical body 25. In this step, the cylindrical collar 34 has already been threaded in half towards the collar end 28 preferably 3.81 cm (1.5") as measured from the trailing end of the clamping end 28. The stent-and-catheter structure can be advanced by any method until it is aligned at the ends. collar segments In the catheterization laboratory, ideally, the stent-and-catheter structure is held in place by a person other than that using the bending tool or by a table or other support known in the art. the stent-and-catheter structure is supported, the user of the bending tool can twist the cylindrical collar 34, thereby advancing the collar 34 on the cylindrical body 25 in the direction of the arrow 54. By this movement the leading edge 36 moves in engagement with the segmented jaw 30. The preferably smooth inner diameter 56 of the cylindrical collar 34 slides over the segmented, open, flared jaws 30. As the cylindrical collar 34 advances further into the direction of the arrow 54, the inner diameter 56 engages and forces the segmented jaws 30 from the open state to converge toward an axial centerline of the cylindrical body 25 to the closed state. The convergence of the segmented jaws 30 in the stent-and-catheter structure compresses the stent 10 over the balloon 14. The cavity 58 is formed when the segmented jaws 30 converge and fully engage the stent-and-catheter structure. The cavity 58 is partially formed by the collective convergence of the slots 38. Figure 6 shows the condition in which the segmented jaws 30 have acquired the closed state and the cylindrical collar 34 has advanced completely forward in the cylindrical body 25. As seen in Figure 6, perforation 42 is required to accommodate longer catheters where the balloon rests as far back as possible. The stent-and-catheter structure can be released by unscrewing the cylindrical collar 34 from the cylindrical body 25. This action releases the leading edge 36 from contact with the segmented jaws 30, which are preferably derived to flare outwards. The segmented jaws 30 then return to the flared open state, thus releasing the endoprosthesis-and-catheter structure and allowing its removal. If the folding is not satisfactory, the folding process can be repeated as many times as necessary to achieve a tight uniform fold. As seen here, the operation of the stent tool of the stent 22 is simple, repeatable and can be controlled accurately. In fact, with the rotary movement of the cylindrical collar 34, it is possible to mark the cylindrical body 25 to indicate the amount of forward movement that moves to the amount of convergence in the segmented jaws 30., thus accurately folding the stent 10. To ensure accuracy, and as illustrated in Figure 6, an optional indicia 60 can be provided to assist the user in controlling the advance amount of the cylindrical collar 34 and the associated amount of convergence of the segmented jaws 30 during the folding operation. As will be appreciated by those skilled in the art, a folding tool 22 according to the present invention is designed for both simple applications in a catheterization laboratory by a physician, or for multiple use applications in a sterile environment of a high-volume manufacturing facility. In this manufacturing version where sterile conditions exist, the stent-folding tool 22 can be repeatedly used to bend stent over balloon catheters until the mechanism wears. In this manner, repeated uses of the present invention are contemplated for controlled sterile environments, although simple use applications are required when used by catheterization laboratory personnel. Modes of a stent-folding tool according to the invention can be employed with any stent that is released without a delivery system. The folding tool can also be sold alone, because its design is robust enough to be put to many uses. The folding tool 22 can be used to fold any expandable stent over any catheter, and is particularly suitable for stent-grafts implanted in the coronary arteries, arteries, veins and other body lumens. The tool is also suitable for folding grafts of saphenous veins. In a preferred embodiment, all parts of the stent-folding tool 22 are made from machined polymers. Alternatively, the present invention is also suitable for processing from surgical steel, aluminum or other metals, such that it can be used and reused. In an alternate embodiment, the groove of the segmented jaws and the jaws can be coated with rubber or other resilient materials. In addition, in other alternate embodiments, the slots and / or the segmented jaws may include floating heads, foam plates or a liner, in order to affect a desired outside diameter or a specific profile for the stent. For the same purpose, a liner can also be used to cover the endoprosthesis-and-catheter before folding. The division of the cylindrical body 25 at the collar end 28 can be achieved by using a band saw or rotary blade type tool, wherein the natural reaction of the polymer base material is to derive the segmented jaws outward in a flared configuration. It is also possible, through processes known in the art, to heat-train the polymer to create the outward shunting of the flared segmented jaws. Other modifications may be made to the present invention, without departing from its scope. The specific dimensions, process steps and construction materials are given as examples and the ducts are easily contemplated that do not depart from the invention.

Claims (20)

1. CLAIMS 1.- A tool for folding a stent onto a catheter, characterized in that it comprises: a cylindrical body having a clamping end and a collar end, wherein the cylindrical body at the end of the collar transits to a plurality of segmented clamps that are flared out; external threads disposed in the cylindrical body between the collar end and the clamping end; a collar rotatably mounted on the cylindrical body, wherein an internal threaded opening engages the external threads on the body and a front inner diameter of the internal threaded opening couples the plurality of segmented jaws; wherein advancing the collar on the threads transfers the inner front diameter on the segmented jaws to converge the segmented jaws in a closed state; and a groove formed over a length of each segmented jaw, wherein when the plurality of segmented jaws are closed, the grooves collectively form a cylindrical cavity leading to an opening in the collar end of the cylindrical body; wherein when closing the segmented jaws on the endoprosthesis mounted on the catheter, when the endoprosthesis and the catheter are placed inside the cavity, the stent is folded over the catheter.
2. 2. - The tool according to claim 1, characterized in that the tool includes four segmented jaws and each segmented jaw includes a shape of. general cross section of a tubular wall room.
3. 3. - The tool according to claim 1, characterized in that the groove formed on each segmented jaw is lined.
4. 4. - The tool according to claim 1, characterized in that the collar includes a shape in annular cross section.
5. 5. - The tool according to claim 1, characterized in that the collar includes a segment having a smooth inner diameter.
6. 6. - The tool according to claim 1, characterized in that the cylindrical body includes a metallic material.
7. 7. - The tool according to claim 1, characterized in that the end of the strainer is rounded.
8. 8. - The tool according to claim 1, characterized in that the segmented jaws include a coating of the material at least in a portion thereof.
9. 9. - The tool according to claim 1, characterized in that the apparatus includes a polymer.
10. 10. - A tool for folding a stent over a catheter, characterized in that it comprises: a cylindrical body having a clamping end and a collar end, wherein the collar end includes a plurality of segmented clamps having a flared open state and a converged closed state; an opening in the collar end leading to a cavity collectively formed by the plurality of segmented jaws in the converged closed state; external threads arranged in the cylindrical body; a collar having an internal opening with internal threads, wherein the collar is rotatably disposed in the body with the internal threads that engage the external threads in the body; wherein the segmented jaws are derived to flare outward toward the open state and the collar overcomes the shunt when advancing on the x-threads to partially engage the segmented jaws and converge the segmented jaws together to the closed state; and with which the segmented jaws converge in the endoprosthesis placed in the catheter located within the cavity, fold the endoprosthesis over the catheter.
11. 11. - The tool according to claim 10, characterized in that the cavity has a cylindrical shape, and the cavity extends over an axial length of the cylindrical body.
12. 12. - The tool according to claim 10, characterized in that at least one of the segmented jaws includes a coating at least in one portion.
13. 13. - The tool according to claim 10, characterized in that the collar end includes a tubular cross-sectional shape.
14. 14. - The tool according to claim 10, characterized in that each segmented jaw in the flared open state defines at least an angle of four degrees from a longitudinal axis of the cylindrical body.
15. 15. - The tool according to claim 10, characterized in that the collar includes a cylindrical shape having a total diameter with a descending stepped profile defining a leading edge with a diameter smaller than the total diameter of the collar, and where the leading edge is next to and engages the segmented jaws to converge the segmented jaws in the closed state, as the collar is advanced over the external threads of the body.
16. 16. - The tool according to claim 10, characterized in that the cavity is configured to receive a balloon portion of a catheter.
17. 17. Method for folding an endoprosthesis onto a catheter, characterized in that it comprises the steps of: providing a cylindrical body having a clamping end and a collar end, wherein the collar end includes a plurality of segmented jaws having a flared open state and a converged closed state; providing an opening in the collar end leading to a cavity formed collectively by the plurality of segmented jaws in the converged closed state; adding external threads on the cylindrical body, - providing a collar having an internal opening with internal threads, advancing the collar on the body, wherein the internal threads engage the external threads on the body; derive the segmented jaws to flare out toward the open state; place the stent coaxially and superimposing the catheter; insert the endoprosthesis and catheter into the cavity; and rotating the strainer on the external threads to partially couple the segmented jaws to overcome the derivation, in order to converge the jaws segmented to each other to the closed state; with which the convergence of the segmented jaws in the stent folds the stent over the catheter.
18. 18. - The method according to claim 17, characterized the cavity has a cylindrical shape.
19. 19. - The method according to claim 17, characterized the step of deriving segmented jaws include deforming each segmented jaw out.
20. 20. The method according to claim 17, characterized in that the step of providing the cylindrical body has a clamping end and the collar end further comprises the step of dividing the cylindrical body at the end of the collar to form the segmented clamps.