Patent Publication Number: US-8986248-B2

Title: Cutting balloon and process

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 10/879,894, now U.S. Pat. No. 7,976,557, filed on Jun. 23, 2004, the entire disclosure of which is incorporated herein by reference. 
    
    
     BACKGROUND 
     Arterial blockages, which are also called stenoses, are typically caused by the build-up of atherosclerotic plaque on the inside wall of an artery. In fact, several such stenoses may occur contiguously within a single artery. This can result in a partial, or even complete, blockage of the artery. As a result of the danger associated with such a blockage, several methods and procedures have been developed to treat stenoses. One such method is an angioplasty procedure which uses an inflatable balloon to dilate the blocked artery. A typical inflatable angioplasty device, for example, is disclosed in U.S. Pat. No. 4,896,669. 
     Angioplasty balloons have enjoyed widespread acceptance in the treatment of stenoses. Recent studies, however, have indicated that the efficacy of the dilation of a stenosis is enhanced by first, or simultaneously, incising the material that is creating the stenosis. Consequently, recent developments have been made to equip angioplasty balloons with cutting edges, or atherotomes, which are intended to incise a stenosis during the dilation procedure. For example, U.S. Pat. No. 5,196,024; U.S. Pat. No. 5,616,149 and U.S. Pat. No. 5,797,935 respectively describe an inflatable angioplasty balloon having a number of atherotomes mounted longitudinally on the surface of the balloon. Upon inflation of the balloon, the atherotomes induce a series of longitudinal cuts into the surface of the stenotic material as the balloon expands to dilate the stenosis. As a result of such cuts, the stenosis is more easily dilated, and the likelihood of damaging the artery during dilation is reduced. 
     In manufacturing a balloon having one or more atherotomes or blades, typically the balloon is inflated and one or more blades are bonded to the balloon while it remains inflated. The necessity of inflating the balloon in order to position the blades thereon is time consuming and can lead to additional manufacturing complications as it may be difficult to position the blades with sufficient accuracy so as maintain a reduced balloon profile and to minimize interference of the blades with the folds of the balloon when it is uninflated and loaded onto a catheter for use. 
     In light of the above it would be desirable to provide a balloon and method of manufacturing the same, which presents a balloon having one or more blades wherein a blade is placed on the balloon body without the necessity of having to first inflate the balloon. 
     All US patents and 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 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 
     The present invention is directed to several embodiments. In at least one embodiment the invention is directed to a medical balloon for use with a catheter or similar device, wherein the medical balloon is equipped with at least one cutting blade. 
     In some embodiments, the balloon may be configured for use in conjunction with an implantable medical prosthesis such a stent, graft, stent-graft, vena cava filter, or other similar device hereinafter collectively referred to as stents. 
     In at least one embodiment at least one blade is positioned on the outer surface of the balloon. In some embodiments, when the balloon is expanded the at least one blade defines a substantially spiral-like path about the balloon body. In some embodiments, when the balloon is deflated the at least one blade defines a substantially straight path along the balloon body. In some embodiments, when the balloon is folded into a reduced profile configuration for passage into a lumen, the at least one blade is substantially parallel to the longitudinal axis of the catheter. 
     In at least one embodiment the invention is directed to a method of manufacturing a medical balloon having at least one blade positioned thereon, wherein the at least one blade is positioned on the balloon without having to inflate the balloon. 
     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 view of an embodiment of the invention wherein the balloon is shown in an unexpanded state. 
         FIG. 2  is a perspective view of the embodiment shown in  FIG. 1  wherein the balloon is shown in a folded configuration. 
         FIG. 3  is a perspective view of the embodiment shown in  FIG. 2  wherein the balloon is shown in an expanded state. 
         FIGS. 4A and 4B  are detailed perspective views of the blade shown in  FIGS. 1-3 . 
     
    
    
     DETAILED DESCRIPTION 
     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. 
     As indicated above, the present invention is embodied in a variety of forms. In at least one embodiment, an example of which is illustrated in  FIGS. 1-3 , the invention is directed to a balloon  10  for use with a catheter  14 , wherein the balloon  10  is equipped with at least one atherotome, cutting member or blade  12 . In the embodiment shown, a blade  12  is positioned on the exterior surface  16  of the balloon body  18  so that when the balloon  10  is expanded, such as in the manner shown in  FIG. 3 , the blade  12  defines a substantially spiral-like or helical path about the circumference of the balloon body  18 . A blade  12  is engaged to the balloon  10  when the balloon  10  is in a deflated, flattened out state, such as is depicted in  FIG. 1 . 
     While there are many ways to engage a blade to a balloon body, such as the prior art method discussed above, which requires that the balloon body be expanded in order to position the blade thereon, in at least one embodiment of the present invention, the invention is directed to a method wherein a blade  12  is engaged to the exterior surface  16  of the balloon body  18 , while the balloon body is in an unexpanded, flattened out state. Not only does this new method save time and money, it provides a more simplified mechanism for engaging a blade  12  to the balloon body  18 . 
     In at least one embodiment, after the balloon body  18  has been formed such as by extrusion, molding, etc., one or more blades  12 , is engaged to the exterior surface  16  of the balloon  10  using any engagement method desired. For example, in some embodiments a blade  12  may by engaged to the balloon body  18  such as by adhesive engagement, mechanical engagement, etc. In at least one embodiment the blade  12  may be mechanically engaged to the balloon body  18  such as by providing the blade  12  and the exterior surface  16  of the balloon body  18  with one or more interlocking surface features for mutual securement. In at least one embodiment a chemical adhesive is applied to one or both of the balloon body  18  and the blade  12  to adhesively engage one to the other. Other mechanisms for engaging blade  12  to the balloon body  18  may also be utilized. 
     The balloon body  18  may be made of any suitable balloon material including compliant and non-compliant materials and combinations thereof. Some examples of suitable materials for constructing the balloon body  18  include but are not limited to: low pressure, relatively soft or flexible polymeric materials, such as thermoplastic polymers, thermoplastic elastomers, polyethylene (high density, low density, intermediate density, linear low density), various co-polymers and blends of polyethylene, ionomers, polyesters, polyurethanes, polycarbonates, polyamides, poly-vinyl chloride, acrylonitrile-butadiene-styrene copolymers, polyether-polyester copolymers, and polyetherpolyamide copolymers; copolymer polyolefin material available from E.I. DuPont de Nemours and Co. (Wilmington, Del.), under the trade name Surlyn™; ionomer and a polyether block amide available under the trade name PEBAX™; high pressure polymeric materials, such as thermoplastic polymers and thermoset polymeric materials, polyethylene terephthalate) (commonly referred to as PET), polyimide, thermoplastic polyamide, polyamides, polyesters, polycarbonates, polyphenylene sulfides, polypropylene and rigid polyurethane; one or more liquid crystal polymers; and combinations of one or more of any of the above. 
     Blade  12  may be constructed from one or more metals, polymers, combinations of one or more metals and/or polymers, and/or other desired material(s). In at least one embodiment, blade  12  is at least partially constructed of a shape memory material, such as nitinol and/or a shape memory polymer. The blade  12  may comprise a plurality of separate blade segments or may be a single continuous structure as desired. 
     As may be seen in  FIG. 1 , a convenient aspect of affixing blade  12  to balloon body  18  in the unexpanded state is that the blade  12  may be engaged to the balloon body  18  while the blade  12  is in a substantially linear configuration and the balloon  10  is substantially flattened out or “pancaked”. In at least one embodiment, the blade  12  is substantially straight when it is engaged to the exterior surface  16  of the flattened balloon body  18 . That is to say, it is not necessary to provide the blade  12  with one or more bends or curves (such as would be necessary when affixing a blade to a balloon in the expanded state) when the blade  12  is engaged to the exterior surface  16  of the balloon body  18 , unless such features are desired. 
     In at least one embodiment, when the balloon body  18  is in the unexpanded “flattened” state the exterior surface  16  of the balloon body  18  comprises four corner regions. This is true even in the case of a substantially cylindrical shaped balloon when it is flattened in the unexpanded state. The corner regions may be described by their respective orientation such as: a proximal top corner  20 , a proximal bottom corner  22 , a distal top corner  24  and a distal bottom corner  26 . 
     In order to provide the balloon  10  with a blade  12  having a substantially spiral-like configuration in the expanded state, such as is shown in  FIG. 3 , the blade  12  is engaged to the balloon body  18  in the unexpanded state so that the ends  30  and  32  of the blade  12  are positioned in opposite corner regions such as in the manner shown in  FIG. 1 . For example, an end of the blade  12  may be positioned in the proximal top corner  20  while the other end is positioned in the distal bottom corner  26  of the unexpanded balloon body  18 . In some embodiments a blade end is be positioned in the proximal bottom corner  22  and the other blade end is positioned in the distal top corner  24 . 
     If desired, the blade  12  may be positioned in any manner desired upon the balloon body  18 . The opposing corner to corner, substantially linear configuration of the balloon  10  shown in  FIG. 1  is an embodiment which will provide the substantially spiral-like blade orientation shown in  FIG. 3 . It is recognized that other configurations may be desired, such as for example, a blade  12  may be engaged to the balloon body  18  so that in the expanded state the balloon  10  is provided with a blade or blades  12  that are substantially longitudinally disposed, radially disposed or otherwise positioned or disposed about the balloon body  18 . As such, a blade  12  may be engaged to the balloon body  18  in the unexpanded state with any orientation in order to provide the balloon  10  in the expanded state with a blade  12  that has any configuration desired. 
     Where the balloon  10  is produced separately from the shaft  13  of the catheter  14 , the blade  12  may be engaged to the balloon body  18  before or after the balloon  10  is affixed to the catheter shaft  13 . 
     Once blade  12  is engaged to the balloon body  18 , and the balloon  10  is engaged to the catheter shaft  13 , the unexpanded balloon  10  is folded and/or wrapped, such as in the manner shown in  FIG. 2  in order to attain a reduced profile configuration suitable for advancement within a body lumen or vessel. 
     In some embodiments the catheter  14  may be configured to deliver one or more therapeutic agents to a stenosis, aneurysm or lesion within a body lumen. In some embodiments at least a portion of the blade  12  is configured to include one or more holes  30 , notches  32 , or other surface features for use in delivering one or more therapeutic agents  34  to a lesion, as seen in  FIGS. 4A and 4B , for example. A therapeutic agent may be placed on the blade  12  and/or the exterior surface  16  of the balloon body  18  in the form of one or more coatings. In at least one embodiment the coating includes at least one therapeutic agent and at least one polymer. 
     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 polymer agent may be a polystyrene-polyisobutylene-polystyrene triblock copolymer (SIBS), polyethylene oxide, silicone rubber and/or any other suitable substrate. 
     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.