Abstract:
A medical device having a catheter shaft having a distal portion and a proximal portion, a medical balloon co-axially mounted on the distal portion of the catheter shaft and a tubular mesh wrapped around the balloon, wherein the mesh strengthens and reinforced the balloon and may be manipulation to dictate the shape of the balloon and to squeeze the balloon down onto the catheter shaft during deflation of the balloon.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to the field of balloon catheters. More specifically, the invention relates to catheter balloon and fiber mesh combinations and their methods of use. 
     2. Description of the Related Art 
     Percutaneous transluminal angioplasty (PTA) is a procedure, including ercutaneous transluminal coronary angioplasty (PTCA), which is well established for the treatment of blockages, lesions, stenosis, thrombus, etc. present in body lumens, such as the coronary arteries and/or other vessels. 
     Percutaneous angioplasty makes use of a dilatation balloon catheter, which is introduced into and advanced through a lumen or body vessel until the distal end thereof is at a desired location in the vasculature. Once in position across an afflicted site, the expandable portion of the catheter, or balloon, is inflated to a predetermined size with a fluid at relatively high pressures. By doing so the vessel is dilated, thereby radially compressing the atherosclerotic plaque of any lesion present against the inside of the artery wall, and/or otherwise treating the afflicted area of the vessel. The balloon is then deflated to a small profile so that the dilatation catheter may be withdrawn from the patient&#39;s vasculature and blood flow resumed through the dilated artery. 
     In angioplasty procedures of the kind described above, there may be restenosis of the artery, which either necessitates another angioplasty procedure, a surgical by-pass operation, or some method of repairing or strengthening the area. To reduce restenosis and strengthen the area, a physician can implant an intravascular prosthesis for maintaining vascular patency, such as a stent, inside the artery at the lesion. 
     Catheter balloons are exposed to large amounts of pressure. Additionally, the profile of balloons must be small in order to be introduced into blood vessels and other small areas of the body. Therefore, materials with high strength relative to film thickness are chosen. These balloons require the requisite strength to withstand the pressure used for transit in a blood vessel and expansion to open an occluded vessel and the ability not to expand beyond a predetermined size and to maintain substantially a profile so as not to rupture or dissect the vessel as the balloon expands. 
     The requirements for the strength and size of the balloon vary widely depending on the balloon&#39;s intended use and the vessel size into which the catheter is inserted. 
     Areas of concern in balloon and balloon catheter development include hoop strength, molecular orientation, material selection, thermal processing, profile, burst strength, pressure capabilities, catheter trackability and pushability and plastic deformation, as well as others. These and other issues are addressed by the present invention to enhance product performance and to minimize the possibility of patient trauma and recovery. 
     All US patents, applications and all other published documents mentioned anywhere in this application are incorporated herein by reference in their entirety. 
     Without limiting the scope of the invention a brief summary of some of the claimed embodiments of the invention is set forth below. Additional details of the summarized embodiments of the invention and/or additional embodiments of the invention may be found in the Detailed Description of the Invention below. 
     A brief abstract of the technical disclosure in the specification is provided as well only for the purposes of complying with 37 C.F.R. 1.72. The abstract is not intended to be used for interpreting the scope of the claims. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention is directed to a variety of embodiments. For example, in at least one embodiment the invention is directed to a balloon catheter, wherein a mesh is wrapped about at least part of the balloon. In one particular embodiment, one end of the mesh is fixed in place relative to the catheter shaft, while the other end is connected to an elastic restraining mechanism. As the balloon is expanded, the mesh and elastic restraining mechanism resist the radial expansion of the balloon. After the internal pressure is relieved, the mesh, under the pulling force of the elastic restraining mechanism, draws the balloon down to a reduced profile. 
     In a further embodiment, the mesh may be proximately restrained via a loadable spring. In this particular embodiment, the proximal end of the mesh is connected to the distal end of a spring, which is coaxially mounted on the catheter shaft. As the balloon is expanded, a load is built up in the spring. Upon reduction of balloon pressure, the spring pulls the mesh proximally, thus drawing the mesh down over the balloon. 
     In at least one embodiment, a restraining strip longitudinally extends across the balloon and may be embedded in or attached to the mesh. The strip is connected to proximal and distal retaining rings, which are mounted on the catheter shaft on either side of the balloon. As the balloon is expanded, lobes are created as the balloon expands on either side of the strip. Upon the reduction of balloon pressure, the balloon is drawn down under the restraining force of the mesh/strip combination. 
     In a further embodiment, a manual restraining mechanism is configured such that the user may apply a pulling force on the mesh from the manifold. Upon the reduction of balloon pressure, the user may draw the mesh proximally via pull wire, thus reducing the profile of the balloon. 
     In at least one embodiment, the mesh, which is mounted about the balloon, has a plurality of crossing strands forming the mesh. Pre-selected crossing strands are fused or bonded together, such that they remain fixed relative to one another at the point of the bond. The remaining crossing strands are allowed to move freely across one another with the movement of the balloon and mesh combination. By pre-selecting a specific pattern of bonded strands, one may control and create a specific expansion shape of the balloon. In particular, fusing the junctures that, when the balloon is inflated, lie in annular regions at or near to the transition from balloon waist-to-cone or cone-to-body, while leaving the major proportion of the junctures over at least the body region unfused, facilitates proper alignment of the mesh over the balloon during inflation and allows a highly efficient collapse of the mesh and balloon to a reduced profile after inflation. 
     These and other embodiments, which characterize the invention, are pointed out with particularity in the claims annexed hereto and forming a part hereof. However, for a better understanding of the invention, its advantages and objectives obtained by its use, reference should be made to the drawings which form a further part hereof and the accompanying descriptive matter, in which there is illustrated and described embodiments of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) 
       A detailed description of the invention is hereafter described with specific reference being made to the drawings. 
         FIG. 1  is a side perspective view of the distal portion of an embodiment of the invention. 
         FIG. 2  is a side perspective view of the distal portion of an embodiment of the invention. 
         FIG. 3  is a side perspective view of the distal portion of an embodiment of the invention. 
         FIG. 4  is a side perspective view of the distal portion of an embodiment of the invention. 
         FIG. 5  is a partial side perspective view of the distal portion of an embodiment of the invention. 
         FIG. 6  is a cross-sectional view of the embodiment shown in  FIG. 5  along lines  5 - 5 . 
         FIG. 7  is a side perspective view of the distal portion of an embodiment of the invention. 
         FIG. 8  is a side perspective view of the distal portion of an embodiment of the invention. 
         FIG. 9  is a side perspective view of a spring used in an embodiment of the invention. 
         FIG. 10  is a side perspective view of the distal portion of an embodiment of the invention. 
         FIG. 11  is a side perspective view of the distal portion of an embodiment of the invention. 
         FIG. 12  is a cross-sectional view of the embodiment shown in  FIG. 11  along lines  12 - 12 . 
         FIG. 13  is a side perspective view and partial cut-away of the distal portion of an embodiment of the invention. 
         FIG. 14  is a side perspective view of the proximal portion of an embodiment of the invention. 
         FIG. 15  is a cross-sectional view of the embodiment shown in  FIG. 14  along lines  15 - 15 . 
         FIG. 16  is a side view of an embodiment of the mesh of the present invention mounted on a balloon. 
         FIG. 17  is a side view of an embodiment of the mesh of the present invention mounted on a balloon. 
         FIG. 18  is a side view of an embodiment of the mesh of the present invention mounted on a balloon. 
         FIG. 19  is a side view of an embodiment of the mesh of the present invention mounted on a balloon. 
         FIG. 20  is a side view of an embodiment of the mesh of the present invention mounted on a balloon with a cross-sectional view of a medical device mounted thereon. 
         FIG. 21  is a perspective view of the distal portion of a membrane. 
         FIG. 22  is a side view of the distal portion of an embodiment of the invention, partially shown in phantom. 
         FIG. 23  is a side view of an embodiment of the mesh of the present invention mounted on a balloon. 
         FIG. 24  is a side view of an embodiment of the mesh of the present invention mounted on a balloon. 
         FIG. 25  is a cross-sectional view of a strand of an embodiment of the mesh of the present invention. 
         FIG. 26  is a cross-sectional view of a strand of an embodiment of the mesh of the present invention. 
         FIG. 27  is a side view of an embodiment of the mesh of the present invention mounted on a balloon. 
         FIG. 28  is a side view of an embodiment of the mesh of the present invention mounted on a balloon. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     While this invention may be embodied in many different forms, there are described in detail herein specific preferred embodiments of the invention. This description is an exemplification of the principles of the invention and is not intended to limit the invention to the particular embodiments illustrated. 
     For the purposes of this disclosure, like reference numerals in the figures shall refer to like features unless otherwise indicated. 
     In at least one embodiment, an example of which is shown in  FIGS. 1-2 , the distal end of a catheter system  10  is depicted, which includes a catheter shaft  20  and a balloon  12  mounted thereon. The balloon  12  has a proximal waist  14  and a distal waist  16 , both of which are connected to the catheter shaft  20 . The balloon  12  may be expandable via conventional means.  FIG. 1  illustrates the balloon  12  in its contracted state and  FIG. 2  illustrates the balloon  12  in its expanded state. 
     The embodiment further includes a mesh  18 , which is positioned about the balloon  12 . The mesh  18  is in tubular form and is free-floating over the outer surface of the balloon  12 , which means that it is not embedded in the balloon material and the mesh  18  and balloon  12  can move relative to each other as the balloon is inflated and deflated. The mesh  18  may be placed over the entire balloon or over part of it. In the particular embodiment shown in  FIGS. 1-2 , the distal end  22  of the mesh  18  is fixed in place relative to the catheter shaft  20 . This may be achieved in any conventional manner. In the embodiment shown, the distal end  22  of the mesh  18  is held down on the catheter shaft  20  via a ring  24 . The ring  24  may be positioned over the distal waist  16  of the balloon  12  or at a position distal to the distal waist  16 . It should be understood that the mesh  18  may extend to the distal end  28  of the catheter. 
     As shown in  FIGS. 1-2 , in at least one embodiment, the proximal end  30  of the mesh  18  is attached to a tube  32 , the proximal end  56  of which is connected to the catheter shaft  20  at point  34 , via conventional methods, such as, but not limited to, adhesion and welding, etc. The tube  32  acts as a loadable restraining mechanism. In the embodiment shown, the tube  32  is an elastic tube, whereby a longitudinal pulling or biasing tension is applied to the mesh  18  in a direction shown by arrow  36 . Suitable materials for the elastic tube include, but are not limited to, a rubber-like material, such as silicon rubber, latex, polyurethane, PVC, etc. 
     As the balloon is expanded, as shown in  FIG. 2 , the expansion forces of the inflated balloon axially pull the elastic tube  32 , thus stretching it distally. Due to the greater diameter of the balloon  12  as it expands and contracts from an expanded state, a slight radial force is also created. When the pressure used in expanding the balloon  12  is reduced, the mesh  18  is drawn proximally by the elastic tension of the tube  32 . 
     In at least a further embodiment, as shown in  FIGS. 3-4 , the mesh  18  may have a shorter length and cover less of the balloon  12 .  FIG. 3  illustrates the balloon  12  in its contracted state and  FIG. 4  illustrates the balloon  12  in its expanded state. The distal end  22  of the mesh  18  is fixed in place relative to the catheter shaft  20  via a plurality of strands  42 . The proximal ends  44  of the strands  42  are connected to the distal end  22  of the mesh  18 . The distal ends  46  of the strands  42  are in turn connected to ring  24 . The ring  24  may be positioned over the distal waist  16  of the balloon  12  or at a position distal to the distal waist  16 . It should be understood that the strands  42  may also be directly connected to the balloon waist  16  or the catheter shaft  20 . It should also be understood that strands  42 , as well as strands  48  discussed below, may be a continuation of the mesh material, i.e., unwoven tails of the mesh. 
     As shown in  FIGS. 3-4 , in at least one embodiment, the proximal end  30  of the mesh  18  is connected to a second set of strands  48 . The distal ends  50  of the strands  48  are connected to the proximal end  30  of the mesh  18 . The proximal ends  52  of the strands  48  are in turn connected to tube  32 , which is connected to the catheter shaft  20  at point  34 . 
     As mentioned above, the tube  32  may be elastic, such that a pulling tension is applied to the strands  48 , and thus the mesh  18 , in a direction shown by arrow  36 . As the balloon is expanded, as shown in  FIG. 4 , the expansion forces of the inflated balloon longitudinally overpower the elastic tube  32 , thus stretching it distally. When the fluid pressure used in expanding the balloon is reduced, the mesh  18  is drawn proximally by the elastic tension of the tube  32 , thus reducing the profile of the balloon  12 . The invention also contemplates the embodiments discussed herein without a restraining mechanism, such as the tube  32 , spring  58 , etc., wherein the proximal end of the mesh  18  is secured directly to the catheter shaft  20 . 
     As shown in  FIG. 5 , which is a partial perspective view, the proximal end  56  of the tube  32  may be held in place relative to the catheter shaft  20  by a crimping ring  54 .  FIG. 6  illustrates a cross-section view of  FIG. 5  along lines  6 - 6 . 
       FIGS. 7-9  illustrate a further embodiment of the invention. In this particular embodiment, the loadable restraining mechanism is a spring  58 .  FIG. 8  illustrates the balloon  12  in its contracted state and  FIG. 7  illustrates the balloon  12  in its expanded state. The distal end  22  of the mesh  18  is fixed in place relative to the catheter shaft  20  via a plurality of strands  42 . The proximal ends  44  of the strands  42  are connected to the distal end  22  of the mesh  18 . The distal ends  46  of the strands  42  are in turn connected to ring  24 . The ring  24  may be positioned over the distal waist  16  of the balloon  12  or at a position distal to the distal waist  16 . It should be understood that the strands  42  may also be directly connected to the balloon waist  16  or the catheter shaft  20 . 
     As shown in  FIGS. 7-8 , in at least one embodiment, the proximal end  30  of the mesh  18  is connected to a second set of strands  48 . The distal ends  50  of the strands  48  are connected to the proximal end  30  of the mesh  18 . The proximal ends  52  of the strands  48  are in turn connected to spring  58 , which is connected to the catheter shaft  20 . It should be understood that the spring  58  may be directly connected to the mesh  18 . 
     As mentioned above, the spring  58  may be loaded, such that a pulling tension is applied to the strands  48 , and thus the mesh  18 , in a direction shown by arrow  36 . As the balloon is expanded, as shown in  FIG. 7 , the expansion forces of the inflated balloon longitudinally overpower the spring  58 , thus stretching it distally. When the pressure used in expanding the balloon is reduced, the mesh  18  is drawn proximally by the elastic tension of the spring  58 . 
     Spring  58  may be made by any conventional means, including, but not limited to, shaping a coil from a piece of suitable material or mechanical or laser cutting  62  a coiled shape into a tube of suitable material, as shown in  FIG. 9 . Other patterns which allow elongation of the spring  58  upon application of a pulling force may be used, including, but not limited to, horizontal “S” shape cuts along the axis. The spring  58  may be made from suitable materials, such as, but not limited to, plastic, stainless steel, nitinol and titanium. 
     The proximal end  60  of the spring  58  may be held in place relative to the catheter shaft  20  by suitable means, such as, but not limited to, adhesion, welding or by a restraining ring, etc. The distal end  64  is allowed slide over the catheter shaft  20  as the balloon  12  expands and contracts. 
       FIGS. 10-12  illustrate a further embodiment of the invention. In this particular embodiment, the loadable restraining mechanism is a strip  66  longitudinally extending across the mesh  18  and balloon  12 . The strip  66  is connected to, or integral with, proximal ring  68  and distal ring  70 , which are both connected to the catheter shaft  20 . The strip  66  may also be embedded in or connected to the mesh  18 . In this particular embodiment, lobes  72  are formed due to the restraint created by the strip  66 .  FIG. 11  illustrates the balloon  12  in its contracted state and  FIG. 10  illustrates the balloon  12  in its expanded state.  FIG. 12  illustrates a cross-section of the embodiment shown in  FIG. 11  along lines  12 - 12 . 
     The distal ring  70  and proximal ring  68  shown in  FIGS. 10-11  are connected to the catheter shaft  20 . It should be understood that rings  68  and  70  may take the form of a partial rings and may be fixed in place relative to the catheter shaft  20  or may be slidably connected to the catheter shaft  20 . 
     The proximal end  74  of the strip  66  is connected to the proximal ring  68  and the distal end  76  of the strip  66  is connected to the distal ring  70 . The strip  66  may be integral with the rings  68 ,  70 , or may be a separate piece which is connected to the rings  68 ,  70 , by suitable means, such as, but not limited to, adhesion or welding. The strip  66  may have elastic characteristics, such that, when the balloon is expanded, it stretches under force of the expanding balloon  12 . The tension created by the strip  66  causes the formation of lobes  72  in the balloon  12 . When the pressure is relieved, the strip  66  draws the mesh  18  down, which in turn draws the balloon  12  down to reduce the profile of the catheter. 
     In one particular embodiment, the strands of the mesh  48 ,  42 , are connected to ring  68  and ring  70 , respectively. It should also be understood that the ends of the mesh  30 ,  22 , may also be directly connected to the rings  68 ,  70 . One or both of the rings  68 ,  70 , are slidable along the catheter shaft  20 . As the balloon  12  expands, the strip  66  bends and the rings  68 ,  70 , slide closer together, allowing the mesh  18  under the strip  66  to foreshorten. When the pressure is released, the strip  66  straightens, forcing the rings  68 ,  70 , apart, which, in turn, draws the mesh  18  down to reduce the profile of the balloon  12 . In this particular embodiment, the strip  66  is thin enough to be flexible so that is may bend with the balloon  12 , but inelastic enough to push the rings  68 ,  70 , apart during depressurizing. The strip  66  may be made from suitable materials, such as, but not limited to, plastic, stainless steel, nitinol and titanium. 
     It should be understood that the invention contemplates two or more strips  66  spaced circumferentially around the balloon  12 . When the balloon expands, lobes are created as the balloon expands between the strips  66 . It also contemplates combining the embodiments with FLEXINOL™ actuator wires, which are available from Dynalloy, Inc., for bifurcation applications. 
       FIGS. 13-15  illustrate a further embodiment of the invention. In this particular embodiment, a mesh restraining mechanism is used which may be controlled by the user via a catheter manifold  80 , which is at the proximal end of the catheter system, as shown in  FIG. 14 . 
     In this particular embodiment, the proximal strands  48 , which are connected to the distal end  30  of the mesh  18 , are also connected to a sliding ring  82 , which is slidable along the catheter shaft  20 . The distal ends  84  of pull wires  86 , one of which is partially shown in phantom, are also connected to the sliding ring  82 . The pull wires  86  extend proximally to the manifold  80  and are connected to a retracting mechanism  88 , which allows for manual retraction to apply a pulling force on the mesh  18  in order to draw the balloon  12  down after inflation. 
     As shown in  FIGS. 14-15 , in one particular embodiment, the retracting mechanism  88 , shown on the catheter shaft  20  and adjacent to a hub  100 , includes a sliding ring  90 , a threaded portion  92  and a screw  94 . The proximal end  96  of the pull wires  86  are connected to the sliding ring  82 . As shown in  FIG. 15 , which a cross-section of the invention shown in  FIG. 14  along lines  15 - 15 , channels  98  are formed in the threaded portion  92  to provide space for the pull wires  86  to travel through between it and the screw  94 . A longitudinal pulling force may be applied to the mesh  18  by winding the screw  94  proximately, thereby forcing the sliding ring  90  and pull wires  86  proximately. The reverse action may be taken to relieve the tension on the mesh  18  to allow the balloon  12  to be expanded. 
     The pull wires  86  may be embedded or attached to a tubular membrane  102 .  FIG. 13  shows a partial-cut away of the pull wire  86  and tubular membrane  102  combination. The tubular membrane  102  is a thin, flexible membrane, which keeps the pull wires  86  close to the catheter shaft  20  and prevents tangling. The distal end  104  of the tubular membrane  102  may be connected to the sliding ring  82  and extend proximally to a point near the manifold  80 . The membrane  102  may act as part of the pull wires  86  and may extend further in the proximal direction than shown to the screw  94  and distally may be connected directly to the mesh  18 . The membrane  102  may be made of any non-compliant material, including, but not limited to, nylons, PET, HDPE, etc. 
     As shown in  FIGS. 21-22 , the membrane  102  may be integral with the mesh  18  by cutting a diamond pattern  150  in the distal portion  152  of the membrane. The diamond pattern  150  is placed over the balloon  12  to form the mesh  18 . The diameter  154  of the membrane  102  is just large enough to slidably fit over the catheter shaft  20  and balloon  12 , when the balloon  12  is in its contracted state. The diamond pattern  150  is cut into the membrane  102  when the membrane  102  is in its relaxed state. When the balloon  12  is inflated to its expanded state, the diamonds in the diamond pattern  150  change shape to accommodate the increase in diameter, as shown in  FIG. 22 . When pressure to the balloon  12  is reduced, the membrane  102  is drawn proximally, as described above, effectually drawing the balloon  12  down to its contracted state. Since the distal end  156  of the membrane  102  is not expanded with the balloon  12 , it functions as an anchor during the drawing process. 
     In the embodiments shown, the mesh  18  is positioned about the balloon  12 , but it is not connected to the balloon  12 . However, as mentioned above, one end of the mesh  18  may be anchored to one of the waists  14 ,  16 , of the balloon  12 . The mesh controls and/or limits the expansion (diameter and length) of the balloon  12 . It may cover a portion of the balloon  12  or part of it. 
       FIGS. 16-19  illustrate particular placements and configurations of the mesh  18  on the balloon  12 . As such, only the balloon  12  and mesh  18  are shown. The strands of the mesh  18  may be arranged to create the mesh  18  by known processes, such as, but not limited to, braiding, weaving, crocheting, etc. The distances between adjacent strands  112  may vary. The invention also contemplates a tight weave, wherein adjacent strands come in direct contact with one another. The mesh  18  may also take the form of, but not limited to, a coil as shown in  FIG. 17 , a coil, wherein adjacent strand portions  120  are joined, as shown in  FIG. 18 , or any random orientation, an example of which is shown in  FIG. 19 . 
     The present invention also contemplates using a mesh  18 , as shown in  FIG. 19 , which is of one-piece construction. Multi-piece constructions are also contemplated. In this particular embodiment, a particular design or strand pattern is cut from a tube of material, or from a sheet of material, which is then rolled into a tube, using such techniques as found in implantable medical device making. Strands  42 ,  48 , may be connected to the ends of the mesh  18  so as to control the extension of the one-piece mesh  18 . When the balloon expands, mesh  18  expands with the balloon, foreshortening the length of the mesh. When the balloon expansion pressure is released, the mesh elongates as it is drawn down by axial pulling, as described above, collapsing the balloon. A mesh of this type can otherwise be used in the same manner as described in the other embodiments. 
     The mesh  18  of the various embodiments may take the shape of the expanded balloon  12  on which it is to be placed. In order to control the resulting shape of an expanded balloon, specific nodes  110 , as shown in  FIG. 16 , are created. These nodes  110  are points where strands  112  of the mesh  18  cross each other and are connected to each other in a fixed manner. This may be achieved by adhesion, welding, or by some kind of mechanical mechanism, etc. The at least two strands  112  which make up each node  110  are fixed relative to one another at the point of the node  110 . The remaining strands are allowed to move relative to one another as the mesh  18  is longitudinally and axially manipulated. It should be understood that the present invention is not limited to node  110  formations shown in the figures. The present invention contemplates any number of nodes  110  from zero nodes  110  to a node  110  at each strand cross-over point, both generally and specifically. 
     Linking specific cross-over-points to create nodes allows for the creation of specific features, such as waist  14 ,  16 , to cone  114 ,  116 , transitions or cone  114 ,  116 , to body  118  transitions, wherein there is a decrease or increase in nodes from the waist(s)  14 ,  16 , to the cone(s)  114 ,  116 , and/or from the cone(s)  114 ,  116 , to the body  118 . Upon inflation of the balloon, the balloon comes in contact with the mesh. As expansion continues, the balloon portions, which come in contact with the pre-selected portions of the mesh  18  which have nodes  110 , will have their movement and expansion restricted. Whereas, the balloon portions, which come in contact with the mesh  18  in places where nodes  110  are lacking and the strands of the mesh are allowed to move freely relative to each other, will have their movement and expansion less restricted. By pre-selecting the number and arrangement of the nodes  110 , one may control the shape of the resulting expanded balloon  12 . In this manner, the user may control the resulting diameter, both generally and regionally, and length of the expanded balloon. 
     As shown in  FIG. 23 , the mesh  18  may have a tapered shape, tapering either distally or proximally. 
     As shown in  FIG. 24 , a mesh bulge  160  may be incorporated into the mesh  18  to accommodate a bifurcation balloon. 
     The mesh in the various embodiments may be made from strands that comprise high-strength inelastic fibers. By “inelastic”, as used herein and in the appended claims, is meant that the fibers have very minimal elasticity or stretch under the stresses imposed during delivery, use and withdrawal of the device. In some embodiments the strands will have elongations of less than 10%, for instance 0.1 to 3% under these use conditions. High strength inelastic fibers useful in the present invention include, but are not limited to, high strength and/or ultra high molecular weight polyethylene, such as Spectra® or Dyneema® fibers; carbon fibers, ceramic fibers, such as Nextel™ fibers from 3M™; metal fibers, such as stainless steel fibers, i.e., Bekinox® VN continuous 1 micrometer diameter metal fibers from BEKAERT; aramid fibers for instance Kevlar®; fibers of liquid crystal polymers such as Vectan®; polyester fibers, for instance Dacron®, Terlon (PBT), Zylon (PBO), polyimide (PIM), etc. The fibers may be string-like or ribbon-like; that is, they have a flattened to a rectangular shape. The strands of the mesh may be composites of such fibers in a resin matrix or a mixture of different types of fibers in a single strand. 
     The present invention also contemplates a mesh having a predetermined arrangement of nodes mounted on a balloon, wherein the mesh is not attached to the balloon or catheter, but is free flowing over the balloon. The predetermined node arrangement allows the balloon to expand into a predetermined shape. In this particular embodiment, the mesh may have elastic characteristics to encourage the contraction of the balloon. 
     In some embodiments, the strands of the mesh  18  may be made of two or more types of material. As shown in  FIGS. 25 and 26 , the strands  162  may be a combination of plastic deforming strands (PDS)  164  and elastic strands (ES)  166 . The strands  162  may be multi-layered, as shown in  FIG. 26 , which shows a longitudinal strand  166  cross-section, or one material may be enclosed within the other, as shown in  FIG. 25 , which is a circumferential cross-section of a strand  166 . The elastic strand  166  may also be within the plastic deforming strand  164 . 
       FIGS. 27-28  illustrate a mesh  18  made from the PDS/ES combination strands  162  about a balloon  12  having a bifurcation balloon branch  168 . As shown in  FIG. 27 , the elastic nature of the strands  162  holds the branch  168  down to allow for insertion of the catheter into the body. Upon activation of the balloon branch  168 , the applied force stretches the strands  162 . Afterwards, the balloon branch  168  is pulled back into place by the elastic strands  166 . 
     In some embodiments, the mesh  18  may have a coating of light curable ceramics and be cured to varying levels down the length of the shaft of the catheter. This would allow for an elastic shaft over the entire length and allow for balloon expansion via non-coated-cured section(s). Braid pitch of the mesh  18  and the level of cure can control pushability and trackability. Portions of the catheters and other medical devices may thereby be selectively stiffened, as desired, to alter the pushability and trackability. For examples selective portions of the catheter shaft may be coated and cured to different extents. Curable coating methods and materials may be found in U.S. Patent Application Publication No. 20050033407 A1, which is incorporated herein by reference in its entirety. 
     The embodiments of the present invention may also, as mentioned above, be incorporated into bifurcated catheter assemblies. Examples of systems that address vessel bifurcation are shown and described in: 
     U.S. patent application Ser. No. 10/375,689, filed Feb. 27, 2003 and U.S. patent application Ser. No. 10/657,472, filed Sep. 8, 2003 both of which are entitled Rotating Balloon Expandable Sheath Bifurcation Delivery; U.S. patent application Ser. No. 10/747,546, filed Dec. 29, 2003 and entitled Rotating Balloon Expandable Sheath Bifurcation Delivery System; U.S. patent application Ser. No. 10/757,646, filed Jan. 13, 2004 and entitled Bifurcated Stent Delivery System; and U.S. patent application Ser. No. 10/784,337, filed Feb. 23, 2004 and entitled Apparatus and Method for Crimping a Stent Assembly; the entire content of each of which are incorporated herein by reference. 
     Embodiments of the present invention can be incorporated into those shown and described in the various references cited above. Likewise, embodiments of the inventions shown and described therein can be incorporated herein. 
     In some embodiments the mesh  18  may include one or more therapeutic and/or lubricious coatings applied thereto. In some embodiments the agent is placed on the mesh in the form of a coating. In at least one embodiment the coating includes at least one therapeutic agent and at least one polymer agent. A therapeutic agent may be a drug or other pharmaceutical product such as non-genetic agents, genetic agents, cellular material, etc. Some examples of suitable non-genetic therapeutic agents include but are not limited to: anti-thrombogenic agents such as heparin, heparin derivatives, vascular cell growth promoters, growth factor inhibitors, Paclitaxel, etc. Where an agent includes a genetic therapeutic agent, such a genetic agent may include but is not limited to: DNA, RNA and their respective derivatives and/or components; hedgehog proteins, etc. Where a therapeutic agent includes cellular material, the cellular material may include but is not limited to: cells of human origin and/or non-human origin as well as their respective components and/or derivatives thereof. Where the therapeutic agent includes a polymer agent, the agent may be a polystyrene-polyisobutylene-polystyrene triblock copolymer (SIBS), polyethylene oxide, silicone rubber and/or any other suitable substrate. 
     The balloon  12  may be a compliant or non-compliant balloon and may be made from suitable materials used in the art, such as, but not limited to, conventional polymers and copolymers used in medical balloon construction, such as, but not limited to, polyethylene, polyethylene terephthalate (PET), polycaprolactam, polyesters, polyethers, polyamides, polyurethanes, polyimides, ABS copolymers, polyester/polyether block copolymers, ionomer resins, liquid crystal polymers, and rigid rod polymers. 
     The invention also contemplates that a medical device  122  may be carried on the balloon for delivery to a target site in the body. Contemplated medical devices included, but are not limited to, stents, grafts, stent-grafts, vena cava filters, vascular implants, and similar implantable medical devices. These medical devices are radially expandable endoprostheses which are typically intravascular implants capable of being implanted transluminally and enlarged radially after being introduced percutaneously. Stents may be implanted in a variety of body lumens or vessels such as within the vascular system, urinary tracts, bile ducts, etc. Stents may be used to reinforce body vessels and to prevent restenosis following angioplasty in the vascular system. They may be self-expanding, such as a nitinol shape memory stent, mechanically expandable, such as a balloon expandable stent, or hybrid expandable. In the particular embodiments described above, the medical device  122  would be mounted on the balloon, such that the mesh  18  is between the medical device  122  and the balloon  12 . 
     The above disclosure is intended to be illustrative and not exhaustive. This description will suggest many variations and alternatives to one of ordinary skill in this art. All these alternatives and variations are intended to be included within the scope of the claims where the term “comprising” means “including, but not limited to”. Those familiar with the art may recognize other equivalents to the specific embodiments described herein which equivalents are also intended to be encompassed by the claims. 
     Further, the particular features presented in the dependent claims can be combined with each other in other manners within the scope of the invention such that the invention should be recognized as also specifically directed to other embodiments having any other possible combination of the features of the dependent claims. For instance, for purposes of claim publication, any dependent claim which follows should be taken as alternatively written in a multiple dependent form from all prior claims which possess all antecedents referenced in such dependent claim if such multiple dependent format is an accepted format within the jurisdiction (e.g. each claim depending directly from claim  1  should be alternatively taken as depending from all previous claims). In jurisdictions where multiple dependent claim formats are restricted, the following dependent claims should each be also taken as alternatively written in each singly dependent claim format which creates a dependency from a prior antecedent-possessing claim other than the specific claim listed in such dependent claim below. 
     This completes the description of the preferred and alternate embodiments of the invention. Those skilled in the art may recognize other equivalents to the specific embodiment described herein which equivalents are intended to be encompassed by the claims attached hereto.