MXPA97002425A - System for supply of endoprotesis auto-expans - Google Patents

Abstract

The present invention relates to a catheter assembly, characterized in that it comprises: an elongated catheter having a proximal end and a distal end, the catheter has an inner member and an outer member extending on a longitudinal axis, the inner member and the outer member has a coaxial configuration and are dimensioned for relative axial movement, means for providing relative axial movement between the inner member and the outer member, a self-expanding stent having an open network structure configured to be directed from a delivery configuration that has a reduced cross section and a predetermined length to an open configuration with an enlarged cross section and being positioned within a distal end of the outer member in the delivery configuration, and a plurality of connection projections at a distal end of the inner member spaced apart along the the endoprosthesis a distance of at least as large as the predetermined length to facilitate the removably connecting the stent to the distant end of the limb.

Description

SYSTEM FOR SUPPLYING AUTO-EXPANDED ENDOPROTESIS BACKGROUND OF THE INVENTION The invention relates to self-expanding stent delivery systems with systems that are used to implant a stent within a patient's body lumen to maintain the opening of the lumen. The endoprosthesis delivery system is useful in the treatment and repair of body lumens that are damaged or affected by disease, including coronary arteries, renal arteries, carotid arteries, and other body lumens. Stents in general are cylindrically shaped devices that function to keep open and sometimes to expand a segment of a blood vessel or other body lumen. They are particularly suitable for use in supporting and retaining a dissected arterial lining that can occlude the passage of fluid. Stents are also useful in maintaining the opening of a body lumen, such as a coronary artery, after a percutaneous transluminal coronary angioplasty (PTCA) procedure or an atherectomy procedure to open a stenosed area of the artery. A variety of devices for use as stents are known in the art and include coiled wires in a variety of patterns that expand after being intraluminally placed by a balloon catheter; coil springs helically wound, made from an expandable thermo-sensitive material such as nickel-titanium; and self-expanding endoprosthetics that are introduced into the body lumen in a compressed state and form in a zig-zag pattern. Commonly, prior art stents are delivered intraluminally through a percutaneous incision made in a femoral or renal artery. A stent is mounted at a distal or distal end of the elongated catheter, typically in the balloon portion of a catheter, and the catheter and stent is advanced intraluminally to the site where the stent is to be implanted. With expandable stents, the balloon portion of the catheter is inflated to expand the stent radially outwardly in contact with the arterial wall, whereby the stent is subjected to plastic deformation and remains in an expanded state to keep the artery open and supportable. With respect to self-expanding stents, it has been known to provide a retractable liner that is placed over the self-expanding stent mounted at the distal end of a catheter. When the catheter has advanced intraluminally to the site where the stent is to be implanted, the liner is removed, allowing the self-expanding stent to expand radially outward in contact with the arterial wall, thereby keeping it open and supporting the artery One of the problems associated with prior art stents and catheter delivery systems is with the means by which the stent is removably connected to the distal end or balloon portion of a catheter. Frequently, the means employed are insufficient to prevent the stent from detaching or moving axially over the catheter or balloon, a movement that compromises the physician's ability to accurately and reliably deploy the endoprosthesis at the desired site in the body lumen. What has been required and to date is not available is a reliable catheter delivery system in which the endoprosthesis can be mounted and connected reorably, so that it does not move axially in the catheter either during delivery and advance through of the vascular system, or during implantation of the endoprosthesis. The present invention satisfies this need. SUMMARY OF THE INVENTION The present invention is directed to a self-expanding stent delivery system, wherein a self-expanding stent is removably connected to a catheter, such that the stent remains in position in the catheter until it is implant Unlike the stents of the prior art, which have a tendency to detach from the distal end of the catheter or move axially in the catheter shaft, when a protective liner is removed or when the catheter is advanced through a tortuous vasculature, the present invention provides means to removably connect the catheter. stent to the catheter, in such a way that it is prevented from moving axially on the catheter shaft. A catheter assembly for removably connecting an intravascular stent is provided wherein an elongate catheter has an inner member and an outer member, both extending about a longitudinal axis, wherein the inner member and the outer member have a coaxial configuration and are dimensioned such that they are free to move axially with each other. A self-expanding stent having an open network structure, and which is directed toward an open configuration, is mounted within the outer member. The inner member is slidably positioned within the lumen of the stent and then the inner member is heated until it fits and fills the open network structure of the stent with connection projections. The present invention includes an inner member that is naturally collapsible and deformable or alternating, that is thermodemable, and is formed from a polymeric material that when heated, will fill the open network structure of the stent with connection projections . The inner member can be formed from polymeric materials selected from the group consisting of polyurethanes, polyethylenes, polyethylene terephthalates and nylon. In another embodiment of the invention, an elastomeric sleeve is connected to the distal end of the inner member. This stent is mounted at the distal end of the outer member and is directed outwardly against the outer member. The distal end of the inner member and its sleeve are placed within the stent and the sleeve is heated until it fills and forms the connection projections in the open network structure of the stent. The invention also relates to the method of mounting the self-expanding stent in the delivery catheter. The delivery catheter includes an outer member and an inner member that can move axially with each other and that have control handles to induce this relative axial movement between the members. The self-expanding stent is positioned within the inner lumen of the outer member and the control handles are manipulated to slide the distal end of the inner member axially into the interior lumen of the self-expanding stent. Subsequently, heat is applied to the distal end of the inner member, such that the open network structure of the self-expanding stent is adapted and filled with connecting projections, thereby releasably connecting the self-expanding stent to the distal end of the stent. inner member and avoiding axial movement of the endoprosthesis. The self-expanding stent remains radially directed to the outside and prevents it from expanding until expansion is desired by the outer member. The invention further includes a method for implanting a self-expanding stent, using the catheter delivery system described above. By using the catheter delivery system, the stent is advanced through the vascular system of a patient until it is soldered at the site where the stent is to be implanted. The sontrol handles are manipulated to move the inner member axially in a distal direction and to simultaneously move the outer member axially in a proximal direction. As the stent is exposed and is not further restricted by the outer member, the stent will deploy when self-expanding radially up to the body lumen. The endoprosthesis will not move axially in the catheter shaft since the inner member and the outer member move axially to each other, because the stent is removably connected to the inner member by the connection projects. After deployment, the satter delivery system is removed from the patient, leaving the stent behind to perform its intended function of maintaining the opening of the fluid passage in the sorption lumen.

One feature of the present invention was to allow the breech to deploy the stent partially and if it proves to have been inappropriately pulled, the outer member can move axially to recapture the stent deployed parsially such that the stent can be stented at the discarded site. For example, the sontrol handles can be manipulated to move the inner member axially in the distal direction and to simultaneously move the outer member, axially in a proximal direction to begin to unfold the stent. Subsequently, if it is determined that the stent is implanted in the wrong site in an artery, the sontrol handles can be manipulated to move the inner member axially in a proximal direction and to simultaneously move the outer member, axially in a distal direction to resapture the stent deployed, so that it can be resolved at the adesuado site in the artery. The stent is then implanted as it was previously disintegrated. Other sarasteristises and advantages of the present invention will be more apparent from the following detailed breakdown of the invention, suando are taken in sonjunto are the accompanying exemplary drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1-4 depict views of stent lift of prior art and satin delivery systems, where the stent is self-expanding either because the stent is directed radially outwardly or is formed of a thermosensitive material such as nickel-titanium. Figure 5 is a schematic view of the catheter delivery system of the invention, wherein the self-expanding stent is colossal within the inner lumen of the outer member before the stent is mounted on the inner member. Figure 6 is a schematic view illustrating the inner member set within the inner lumen of the self-expanding stent, and a tapered mandrel inserted into the inner member for purposes of heat-stacking to form the connection processes. Figure 7 is a schematic view illustrating an alternate embodiment of the invention, wherein an elastomeric segment is attached at the distal end of the inner member and is used to adapt and fill the open network strut of the self-expanding stent with projections of connection. Figure 8 is a schematic view of an over-the-wire catheter delivery system, wherein the stent is placed in a narrow position in the vessel wall. Figure 9 is a schematic view illustrating the over-the-wire catheter delivery system of Figure 8, wherein the outer member is removed proximally, so that the stent can self-expand radially outwardly in contact with the wall of the glass. Figure 10 is a schematic view illustrating the stent of Figures 8 and 9 implanted and contacting the vessel wall. Figure 11 is a schematic view illustrating a rapid intermesh catheter delivery system, wherein the guidewire extends through a gate on the catheter side, such that the catheter can quickly be exchanged upon removal of the patient . Figure 12 is a schematic view illustrating the satin delivery system of Figure 11, wherein the stent self-expands, the external member being axially withdrawn in the proximal direction. Figure 13 is a schematic view illustrating the fast intermesh satin delivery system, wherein the self-expanding stent has been implanted and put into sontaste are the vessel wall, and the fast interstitial satter is ready to be removed from the vessel. vassular system of the passenger. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to a satin delivery system in which a self-expanding stent is delivered intraluminally into the body lumen of a human patient, such as a coronary artery, carotid artery, the renal arteries or arteries or peripheral and similar veins.

The invention provides a stent delivery assembly and a method for its use, during which a stent is implanted in a patient. As can be seen in Figures 1-4, there are numerous prior tetanus stents that are adapted for use in the present invention. The stents 10 illustrated in Figures 1-4 are all self-expanding stents and will expand from a sonored sonde, ie, the sonde where the stents are sred in the catheter assembly, to an expanded squeeze where the stent is makes that enter in contasto are the sorporal lumen. The stents are self-expanding, which can be achieved by several means. As illustrated in Figures 1-4, the prior art 10 stent stents are formed from stainless steel material and are designed to branch radially outward, intended to expand as they withdraw any restriction preventing expansion. The stents illustrated in Figures 1-4 can also be formed of a thermo-sensitive material, such as nickel-titanium, this material before application of a transformation temperature will self-expand radially outwardly. These endoprostheses of the prior art are representative of a great sanctity of stents that can be adapted for use with the present invention.

In a preferred embodiment of the invention, as illustrated in Figures 5-6, the catheter assembly 20 is provided to deliver and implant a stent. The catheter assembly 20 incorporates an elongate catheter body 21 having a proximal end 22 and a distal end 23. The inner member 24 and an outer member 25 are arranged in coaxial alignment. The inner member 24 collapses slidably within the outer member 25 and relative axial movement between the two members is made possible by a handgrip handle of the inner member 26 and a handgrip handle of the outer member 27. The handles 26, 27 can be take many forms, but are illustrated schematically for ease of illustration. As an example, however, the control handles 26, 27 may take the form of a thumb-switch assembly, a rotating screw-type assembly or a ratchet assembly. These sontrol handle mounts are well known in prior art catheter delivery systems. A self-expanding stent 28 having an open net scaff29 is mounted on the distal end 23 of the satin assembly 20. The self-expanding stent 28 can virtually take any configuration having an open network constraint 29, such as can be seen in the examples of prior art stents illustrated in Figures 1-4.

Following the invention, the self-expanding stent 28 is inserted into the inner lumen 31 of the outer member 25, and positioned at the distal end 23 of the outer member. In those applications where the self-expanding stent 28 is made of stainless steel or a similar material that is directed outwardly, the stent 28 will be compressed and inserted into the inner lumen 31 prior to delivery to the deployment site. Subsequently, the distal end 32 of the inner member 24 collapses within the inner lumen of the stent 34, such that the outer surface 33 of the inner member 24 can enter the sontaste are the inner lumen of stent 34. Following are the preferred embodiment , the distal end 32 of the inner member 24 is made from a polymer material that is already soft by design, or that will soften when salting is applied. The intention is to removably remove the self-expanding stent 28 from the outer surface 33 of the inner member 24 of the elongate catheter body. The outer surface 33 of the inner member 24 will partially fill the open wheel housing 29 of the stent 28 to form connecting projections 30 such that the stent can not move in an axial direction on the outer surface 33 of the inner member 24.

In the preferred embodiment, the self-expanding stent 28 is mounted on the outer surface 33 at the distal end 32 of the inner member 24 and the open network structure 29 is filled by connection projections 30. Due to the coaxial arrangement between the inner member 24 and the outer member 25, the inner lumen 31 of the outer member 25 under the self-expanding stent 28 and aid in retaining the stent on the outer surface 33 of the inner member 24. In order to adapt the outer surface 33 in such a way that adapt or fill the open net strut 29 of the self-expanding stent are connection projects 30, salting can be stacked by various methods. For example, a tapered mandrel 35 is illustrated in Figure 6, it can be inserted at the distal end 32 of the inner member 24 in the region of the stent. Thereafter, salver is piled to the outer member 25 by well-known means for which they are dexterity in the relevant teasin, such as using a salted tube of sapura (not shown) that sirs the outer member 25. The catheter tube can be formed from the material manufactured under the "TEFLON" porr by EI DuPont de Nemours, Co., glass or similar and generally heated using heated air. As the outer member 25 heats up, the inner member 24 is inserted into the inner lumen 31 of the outer member 25, thereby allowing connection portions 30 to sire and form around the endoprosthesis 28. In another preferred embodiment, it is illustrated in Figure 7, an elastomide segment 40 is connected to the outer surface 33 of the inner member 24 of the elongate catheter body 21 at the distal end 32 of the inner member 24. The elastomeric segment 40 is formed from a sensitive material to heat, or designed to be relatively soft in comparison are the inner member 24, such that the endoprosthesis 28 can be removably removed in the elastomeric segment 40, this segment will adapt and fill the open network stricture 29 of the endoprosthesis. Sinexion projeess 30. The elastomer segment can be salted by the methods mentioned above or if it is formed of a material That which is relatively soft, will naturally adapt and fill the open net shrinkage 29 are connection projects 30 without salting. In the preferred method of use, the catheter assembly 20 is used to implant the self-expanding stent in a body lumen, using an over-the-saber catheter or a quick-interbody configuration. In a preferred embodiment, as shown in Figures 8-10, the over-the-wire catheter 50 has a guidewire lumen 51 that extends through the catheter and is configured to receive the guide wire 52. In order of implanting the self-expanding stent 28, the guidewire 52 is soldered in the sorporal lumen of a patient, at a point on the vessel wall 55 and typically the guidewire 52 extends beyond a stenotic region 56. The end Distant 54 of the over-the-wire satin 50 is threaded onto the proximal end of the guide wire that is outside the lead (not shown) and the satter 50 is advanced over the guide wire until the distal end 54 of the satter 50 is soldered within of the stenosed region 56. As illustrated in Figures 9 and 10, the self-expanding stent 28 is implanted in the stenosed region 56 by moving the outer member 25 of the elongate satin body 21 in a proximal direction while moving if simultaneously the inner member 24 in a distal direction. The endoprosthesis 28 will not slide or move axially on the outer surface 33 because the open net structure 29 is filled with connection projections 30. Since the portions of the self-expanding stent 28 are no longer contained by the outer member 25. , will expand radially outwardly in contaste are the vessel wall 55 in the area of the stenosed region 56. When deployed and implanted completely, it is illustrated in Figure 10., the stent 28 will support and hold open the stenosed region 56, such that the fluid flow is not restricted. The connection projections 30 do not inhibit stent 28 against radially outward self-expansion, but rather the connection processes 30 only prevent axial movement of the stent. With self-expanding endoprostheses, there is a tendency for the stent to be somewhat attached to the expander. When the stent is shortened, the doctor may find that the stent has unacceptably solved in the stenosed region, 56 if the previously-treated efestos had not been taken in consideration. In accordance with this, it may be necessary to previously move the inner member 24 distantly in order to sompensar the asortamiento of the endoprosthesis before expansion of the endoprosthesis. It is also possible, due to a stent design, that the self-expanding stent is not apportiably associated with expansion. If this were the case, it may be unnecessary to move the inner member 24, distally while simultaneously moving the outer member 25 proximally in order to release the self-expanding stent 28 in the body lumen. With a stent configuration that does not abruptly attach during expansion, the outer member 25 moves axially while the inner member 24 remains stationary, as the self-expanding stent 28 expands radially outward in contrast to the vessel wall 55. After the endoprosthesis 28 is implanted and contacts the stenosed region 56, the over-the-wire satin 50 is removed from the patient's vassal system. A typical over-the-wire catheter design is described in U.S. Pat. No. 4,323,071. In another preferred method of implanting a stent as illustrated in Figures 11-13, a fast interspersed satter 6 is provided. The fast interstitial satellites are sonosed in the shade and the details of sonorusses and use are set forth in the patents of the USA Nos. 5,458,613; 5,346,505; and 5,300,085. In general, rapid exchange catheters include a guidewire lumen 61 that extends into the distal portion of the catheter from a lateral port 63 to the distal end of the catheter. The guidewire 62 is inserted through the lateral port 63 and extends outwardly from the distal end of the catheter 60, such that the distal end of the guidewire is positioned beyond the stenosed region 56. The method of deployment of the self-expanding stent 28 using the rapid exchange catheter 60, is similar to that dessrito to use the over-the-wire satin 50. One of the differences between the two systems of satter supply, it includes a slot 64 in the satin of rapid interfit 60 extending from lateral port 63 to approximately just proximal to the area where stent 28 is mounted. After the stent 28 is implanted in the stenosed region 56, the quick exchange catheter 60 is removed from the vascular system of the foot and the guidewire 62 will be shed through the slot 64, the inter-assembly of one satter by another a simple prose. Typically, a reinforcing mandrel 65 is insorporated in the proximal region of the fast interspersed satter 60, to improve the thrust sapaty of the catheter through the vassal system of the catheter, and to improve the catheter tracking sausage in comparison with the wire guide. The endoprostheses herein can be formed from any sanctity of materials, including metals, metal alloys and polymer materials. More suitably, stents are formed from alloys of metals such as stainless steel, tantalum or heat-sensitive metal alloys such as nickel-titanium (NiTi). Endoprostheses formed from stainless steel or similar aleasions, are typically designed as in a helioidal coil or the like, so that the stent is spring-loaded to the outside. With respect to endoprostheses formed from aleasions are shape memory, such as nickel-titanium (NiTi) alloy, the stent will remain passive in its martensitic state until it is maintained at a temperature below the transition temperature. In this case, the transition temperature will be below the normal body temperature, at or below 37 * C (98.6 ° F). When the NiTi stent is exposed to a normal body temperature, it will immediately attempt to return to its austenitic state and rapidly expand radially outward to achieve its preformed state. Details concerning the properties of devices made from nickel-titanium, can be found in "Shape-Memory Alloys" (Alloys with Memory of Form), Scientific American. Vol. 281, pages 74-82 (Nov. 1979). With respect to all the embodiments described above, the inner member 24 and for that reason the outer member 25, can be formed of polymeric materials, including polyurethanes, polyethylenes, polyethylene terephthalate and nylon. Similarly, the elastomeric segment 40 can be formed from polyurethane, elastomeric polyesters and the like. Generally speaking, the closest portions of the inner member 24 and the outer member 25 will be formed of a polymeric material that is stiffer than the distal section, such that the next session has sufficient thrust capability to advance through the vascular system of the patient. On the other hand, the more distant portions of the inner member 24 and the outer member 25 can be formed of a more flexible material, such that the distal portion of the catheter remains flexible and more easily tracked over the guide wire. Other modifications and improvements can be made without departing from the price of the investment. For example, the various drawing figures illustrate various configurations of the stent including various sizes, which can be modified to fit a particular application without departing from the spirit and scope of the invention. In addition, the configuration of the satin assembly is a soaxial set between the inner member and the outer member, which can be modified to other configurations without departing from the preferred invention.

Claims (13)

1. CLAIMS 1. A satter assembly to removably mount an intravascular stent to a delivery catheter, sarasterized because it comprises: an elongate catheter having a proximal end and a distal end; the catheter has an inner member and an outer member, which extends over a longitudinal axis, the inner member and the outer member have a coaxial configuration and dimensioned for relative axial movement; means for providing relative axial movement between the inner member and the outer member; a self-expanding stent having an open network scaffold, the stent is directed to an open configuration and colossus within a distal end of the outer member; and means for adapting a distal end of the inner member to removably pry the stent to the distal end of the inner member.
2. 2. The assembly of the sonicity satellites are claim 1, which is sarasterized because the means for adapting the distal end of the inner member to remove the stent removably includes a plurality of connection projections formed from the inner member having a thermoformable polymeric material. .
3. 3. The catheter assembly according to claim 2, characterized in that the polymer material at the distal end of the inner member is taken from the group of polimerisoe materials comprising polyurethanes, polyethylenes, polyethylene terephtalates and nylon.
4. 4. The assembly of the sonic satellites are claim 1, characterized in that the means for providing relative axial movement between the inner member and the outer member includes a colossal control handle at the proximal end of the elongated catheter.
5. 5. The catheter assembly according to claim 1, characterized in that the self-expanding stent is formed from a metal alloy that is taken from the group of metal alloys including stainless steel, titanium-nickel and tantalum.
6. 6. The catheter assembly according to claim 1, sarasterized in that the inner member of the elongate satter has a through lumen to support a guidewire, such that the elongated catheter can collapse into a lumen as it advances over the wire guide.
7. 7. The satelliteship assembly is claim 1, which is sarasterized because the inner member of the elongated satellite has a side port to accommodate a guide wire, the side port is positioned such that the catheter can be swapped quickly.
8. 8. The sonication catheter assembly is claim 1, sarasterized because the distal end of the elongated catheter includes a polymer sleeve conested to the distal end, the polymer sleeve is adapted to fit and fill the network structure of the self-expanding stent, with a plurality of connection projects.
9. 9. A method for mounting an intravascular stent in a supply satter, the method is characterized in that it comprises: providing a supply satter having an elongated satin body and a proximal end and a distal end, the catheter has an inner member and an outer member extending over the longitudinal axis, the inner member and the outer member have a soaxial and dimensioned configuration for relative axial movement and the handles to provide relative axial movement between the inner member and the outer member; releasing a self-expanding stent within an inner lumen of the outer member; manipulating the sontrol handles to slide the distal end of the inner member into the inner lumen of the self-expanding stent; and discharging the distal end of the inner member, such that the open network strut of the self-expanding stent is adapted and filled, is a plurality of connection projections., thereby releasably connecting the self-expanding stent to the distal end of the inner member.
10. 10. A method for implanting a self-expanding stent in a body lumen, the method is rendered expensive because it provides: providing an elongated satter having a proximal end and a distal end, the satter has an inner member and an outer member extending on a longitudinal axis, the inner member and the outer member have a soaxial and sized configuration for relative axial movement, control handles to provide relative axial movement between the inner member and the outer member and a self-expanding stent mounted at a distant end of the inner member, with the distal end of the outer member forming a lining around the self-expanding stent; manipulating the control handles to simultaneously move the inner member axially in a distal direction and the outer member axially in a proximal direction; deploying the stent by allowing it to self-expand radially outwardly in contrast to the body lumen while preventing axial movement of the stent in the catheter by providing a plurality of connection projections; and remove the catheter from the body lumen.
11. 11. The method for implanting a stent according to claim 10, the method is further characterized in that it comprises: placing the distal end of the catheter in place to implant the stent; manipulating the control handles to simultaneously move the inner member axially in a distal direction and the outer member axially in a proximal direction to begin implanting the stent; manipulating the control handles to simultaneously move the inner member axially in a proximal direction and the outer member axially in a distal direction to recover the endoprosthesis and to loosen the endoprosthesis at the distal end of the inner member; re-routing the distal end of the satter to implant the stent; manipulating the sontrol handles to simultaneously move the inner member axially in a distal direction, and the outer member axially in a proximal direction to release the self-expanding stent in the sorporal lumen; and remove the catheter from the body lumen.
12. 12. A method for implanting a self-expanding stent in a body lumen, the method is characterized in that it comprises: providing an elongated catheter having a proximal end and a distal end, the catheter has an inner member and an outer member extending on a longitudinal axis, the inner member and the outer member have a soaxial and dirasional configuration for relative axial movement, handles to provide relative axial movement between the inner member and the outer member, and a self-expanding stent mounted at one end distant from the inner member, with the distal end of the outer member forming a liner around the self-expanding stent; manipulating the control handle to move the outer member axially in a proximal direction while keeping the inner member stationary; unfolding the endoprosthesis by allowing it to radially self-expand to the outside in sontaste are the sorporal lumen; and removing the satter from the sorporal lumen.
13. 13. The method for implanting a stent-graft is claim 12, further characterized in that it comprises: collating the distal end of the satter at the site to implant the stent; manipulating the sontrol handles to simultaneously move the inner member axially in a proximal direction and the outer member axially in a distal direction to recover the endoprosthesis; re-routing the distal end of the satter to implant the stent; manipulating the sontrol handles to move the outer member axially in the proximal direction to release the self-expanding stent in the sorporal lumen, while the inner member is simultaneously held stationary; and removing the satter from the sorporal lumen.