Abstract:
The present invention provides, in certain aspects, devices and methods for protecting the body from downstream embolization. In one embodiment, a distal protection device comprises a shaft and a jacket with the shaft being received within the jacket. The device also includes a filter, which is supported by a wire cone that has one end attached to the jacket and an opposite end attached to the shaft. The shaft is rotatable relative to the jacket to reduce the size of the cone for capturing embolic debris within the wire cone. The invention also provides such devices in combination with instruments (e.g., balloon stent catheters) for treating stenosis and other similar conditions.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The present invention relates to an emboli capturing method and device.  
         [0002]     Various procedures are used to treat stenosis in the vascular system including balloon angioplasty, and ablation procedures such as thrombectomy, and atherectomy. Stenotic debris can be created by such treatments which can move with the blood flow in the vascular system causing significant problems. Such debris may also occur when treating stenotic vein grafts (CABG), renal stenting and carotid artery interventions. Improved methods and devices are needed for preventing emboli from causing damage to the vascular system and similar areas where there is risk of downstream embolism.  
       SUMMARY OF INVENTION  
       [0003]     One embodiment of the invention might involve a distal protection device comprising a shaft and a jacket with the shaft being received within the jacket. A filter is supported by a wire cone which has one end attached to the jacket and an opposite end attached to the shaft. The shaft is rotatable relative to the jacket to reduce the size of the cone for capturing embolic debris within the wire cone.  
         [0004]     Another embodiment of the invention includes a method of capturing and disposing of emboli by providing a distal protection device including a jacket and a shaft received within the jacket. A coiled cone of wire has one end attached to the jacket and an opposite end attached to the shaft. Mesh is mounted on the cone. The device is inserted in a body lumen downstream of a stenosed region of the lumen. The coiled cone is expanded by rotating the shaft relative to the jacket. The stenosed region is treated to correct the stenosis resulting in emboli moving downstream into the mesh on the cone. The coiled cone is reduced by rotating the shaft relative to the jacket and the distal protection device is withdrawn from the body lumen.  
         [0005]     Further objects, embodiments, forms, benefits, aspects, features and advantages of the present invention may be obtained from the description, drawings, and claims provided herein.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]      FIG. 1  is a side elevation partially in section of the distal protection device in open position.  
         [0007]      FIG. 2  is a side elevation similar to  FIG. 1  showing the device partially closed.  
         [0008]      FIG. 3  is a elevation partially in section showing the device in closed position.  
         [0009]      FIG. 4  is an end elevation showing the device in the same position as  FIG. 1 .  
         [0010]      FIG. 5  is an end elevation showing another distal protection device of the invention.  
         [0011]      FIG. 6  is a schematic vessel showing one example of the use of the distal protection device.  
         [0012]      FIG. 7  is a schematic vessel showing another example of the use of the distal protection device.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0013]     For the purposes of promoting understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is hereby intended and alterations and modifications in the illustrated device, and further applications of the principles of the present invention as illustrated herein being contemplated as would normally occur to one skilled in the art to which the invention relates.  
         [0014]      FIG. 1  shows the device  9  in open position. The device is designed to be inserted in the vascular system or in other similar areas where there is risk of downstream embolization. The device includes a coiled cone  10  formed of wire which is connected at one end  11  to an outer jacket  12  and it is connected at the other end  15  to a shaft  16 . The wire of the coiled cone  10  is woven through a mesh  17  so that the coil can move freely to allow expansion and contraction of the coiled cone.  FIG. 2  shows the device partially closed and  FIG. 3  shows the device entirely closed. The closure is accomplished by rotating the shaft  16  relative to the jacket  12 . The mesh  17  is porous, preferably having pores in the range of 80 to 110 microns and the coiled cone wire is smaller in cross sectional size (to the 80 to 110 microns) in order to allow weaving through the pores of the mesh. The shaft  16  is preferably formed of an alloy of nickel and titanium known as Nitinol and the wire of the cone  10  is formed preferably of a shape memory polymer or metal.  
         [0015]     The device of  FIGS. 1-4  may be inserted into the vascular system or other body lumen independently of the instrument selected to perform treatment of the stenosis or, alternatively the outer jacket  12  may function as a wire guide for the instrument used to perform the treatment of the stenosis. In either event, the treatment of the stenosis occurs upstream of the coiled cone  10  and accompanying mesh  17  so that the mesh functions to allow the blood or fluid to pass through the coiled cone but also functions to trap the stenotic particles in the coiled cone upstream of the mesh. The distal protection device of  FIGS. 1-4  is positioned in the open position of  FIG. 1  when it is being used to perform the filtering.  
         [0016]     After the treatment of the stenosis has been completed and the risk of further emboli creation is no longer present, the coiled cone  10  is reduced in size to the configuration of  FIG. 2  and further to the configuration of  FIG. 1 . The reduction in size is accomplished by rotating the shaft  16  relative to the jacket  12 . The rotation may be accomplished manually or by means of a motor. The emboli captured within the cone and mesh are then removed from the body lumen by withdrawing the distal protection device from the body lumen.  
         [0017]     Additionally, an inventive device can incorporate one or more adaptations to enhance movement of the coiled cone. Illustratively and referring now to  FIG. 5 , one or more rails  30  or other similar elongate members can extend along successive coils of the cone (e.g., in a generally longitudinal fashion, and perpendicular relative to the coils as shown). Adaptations of this sort can be formed with a variety of materials (e.g., metals, synthetic polymeric materials, etc.), and may be rigid, semi-flexible, or flexible. Also, such adaptations need not be fixed to the coil wire. In some instances, a rail is retained in association with the coiled cone, yet the two are able to translate along one another as the cone changes shape. Those skilled in the art will recognize other suitable means for facilitating desirable expansion and contraction of the coiled cone, and therefore, they are encompassed by the present invention.  
         [0018]      FIG. 6  shows one method of use in the distal protection device. In  FIG. 6 , the body lumen  20  is shown as having plaque or stenosis  21  which is restricting the flow of blood. This stenosis may be treated by means of a balloon stent catheter  22  which is inserted into the stenosis and expanded to open up the size of the passageway in a manner well known to those skilled in the art. The catheter includes a stent  25  which is plastically deformed holding the lumen open and facilitating blood flow. The balloon catheter is then removed from the lumen. This procedure can produce emboli which moves downstream in the direction of the arrow  26 .  
         [0019]     Prior to the introduction of the balloon stent and the expanding of the stent to open up the body lumen, the distal protection device is inserted into the body lumen  20  downstream of the stenosis  21 . The insertion is accomplished by means of an introducer sheath  27 . When the distal protection device  9  is inserted through the introducer sheath, it is in the closed position of  FIG. 3 , but without emboli received within the mesh  17 . After insertion, it is opened to the position of  FIG. 1  and  FIG. 6  in contact with the wall of the lumen  20  wherein device  9  filters the blood flow moving downstream from the stenting procedure. After the catheter  22  has been removed and the risk of further emboli moving downstream from the stenting procedure is over, the distal protection device is manipulated by rotating the shaft  16  relative to the jacket  12  so that the emboli are captured in the mesh  17  of the coiled cone  10  and the coiled cone is reduced in size to the configuration of  FIG. 3 . The distal protection device is then removed from the body lumen by withdrawal through the introducer sheath  27 .  
         [0020]     The mesh is porous preferably in the range of 80 to 110 microns. The structure of the mesh  17  may be made from numerous base materials, such as polymers including bioabsorbable or biostable polymers; nonmetallic biocompatible materials including polyamides, polyolefins (e.g., polypropylene or polyethylene), nonabsorbable polyesters (e.g., polyethylene terephthalate) or bioabsorbable aliphatic polyesters (e.g. homopolymers or copolymers of lactic acid, glycolic acid, lactide, glycolide, paradioxanone, trimethylene carbonate or .episolon.-caprolactone); polymeric materials (e.g., poly-L-lactic acid, polycarbonate, polyethylene terephthalate or engineering plastics such as thermotropic liquid crystal polymers (LCPs)); biocompatible polymeric materials (e.g., cellulose acetate, cellulose nitrate, silicone, polyethylene terephthalate, polyurethane, polyamide, polyester, polyorthoester, polyanhydride, polyether sulfone, polycarbonate, polypropylene, high molecular weight polyethylene or polytetrafluoroethylene); degradable or biodegradable polymers, plastics, natural (e.g., animal, plant or microbial) or recombinant material (e.g., polylactic acid, polyglycolic acid, polyanhydride, polycarprolactone, polyhydroxybutyrate valerate, polydepsipeptides, nylon copolymides, conventional poly(amino acid) synthetic polymers, pseudo-poly(amino acids) or aliphatic polyesters (e.g., polyglycolic acid (PGA), polylactic acid (PLA), polyalkylene succinates, polyhydroxybutyrate (PHB), polybutylene diglycolate, poly epsilon-caprolactone (PCL), polydihydropyrans, polyphosphazenes, polyortho esters, polycyanoacrylates, polyanhydrides, polyketals, polyacetals, poly(.alpha.-hydroxy-esters), poly(carbonates), poly(imino-carbonates), poly(.beta.-hydroxy-esters) or polypeptides)); polyethylene terephthalate (e.g., dacron or mylar); expanded fluoropolymers (e.g., polytetrafluoroethylene (PTFE)); fluorinated ethylene propylene (FEP); copolymers of tetrafluoroethylene (TFE) and per fluoro(propyl vinyl ether) (PFA)); homopolymers of polychlorotrifluoroethylene (PCTFE) and copolymers with TFE; ethylene-chorotrifluoroethylene (ECTFE); copolymers of ethylene-tetrafluoroethylene (ETFE); polyvinylidene fluoride (PVDF); polyvinyfluoride (PVF); polyaramids (e.g., kevlar); polyfluorocarbons including polytetrafluoroethylene with and without copolymerized hexafluoropropylene (e.g., Teflon or goretex); expanded fluorocarbon polymers; polyglycolides; polylactides; polyglycerol sebacate; polyethylene oxide; polybutylene terepthalate; polydioxanones; proteoglycans; glycosaminoglycans; poly(alkylene oxalates); polyalkanotes; polyamides; polyaspartimic acid; polyglutarunic acid polymer; poly-p-diaxanone (e.g., PDS); polyphosphazene; polyurethane including porous or nonporous polyurethanes; poly(glycolide-trimethylene carbonate); terpolymer (copolymers of glycolide, lactide or dimethyltrimethylene carbonate); polyhydroxyalkanoates (PHA); polyhydroxybutyrate (PHB) or poly(hydroxybutyrate-co-valerate) (PHB-co-HV); poly(epsilon-caprolactone((e.g., lactide or glycolide); poly(episilon-caprolactone-dimethyltrimethylene carbonate); polyglycolic acid (PGA); poly-L and poly-D(lactic acid) (e.g., calcium phosphate glass); lactic acid/ethylene glycol copolymers; polyarylates (L-tyrosine-derived) or free acid polyarylates; polycarbonates (tyrosine or L-tyosine-derived); poly(esteramides); poly(propylene fumarate-co-ethylene glycol) copolymer (e.g., fumarate anhydrides); polyanhydride esters; polyanhydrides; polyorthoesters; prolastin or silk-elastin polymers (SELP); calcium phosphate (bioglass); compositions of PLA, PCL, PGA ester; polyphosphazenes; polyamino acids; polysaccharides; polyhydroxyalkanoate polymers; various plastic materials; teflon; nylon; block polymers or copolymers; Leica RM2165; Leica RM2155; organic fabrics; biologic agents (e.g., protein, extracellular matrix component, collagen, fibrin); small intestinal submucosa (SIS) (e.g., vacuum formed SIS); collagen or collagen matrices with growth modulators; aliginate; cellulose and ester; dextran; elastin; fibrin; gelatin; hyaluronic acid; hydroxyapatite; polypeptides; proteins; ceramics (e.g., silicon nitride, silicon carbide, zirconia or alumina); bioactive silica-based materials; carbon or carbon fiber; cotton; silk; spider silk; chitin; chitosan (NOCC or NOOC-G); urethanes; glass; silica; sapphire; composites; any mixture, blend, alloy, copolymer or combination of any of these; or various other materials not limited by these examples.  
         [0021]     Illustratively, a mesh useful in the invention such as mesh  17  may be formed with a metallic material. Suitable metallic materials include but are not limited to stainless steel, titanium, cobalt, tantalum, gold, platinum, nickel, iron, copper and the like, as well as alloys of these metals (e.g., cobalt alloys, such as Elgiloy®, a cobalt-chromium-nickel alloy, MP35N, a nickel-cobalt-chromium-molybdenum alloy, and Nitinol®, a nickel-titanium alloy). These and other suitable materials (e.g., synthetic polymers such as polyester, polypropylene, nylon and polytetrafluoroethylene) can be provided in filament form and employed as either monofilaments or multi-strand filaments. A filament or strand can have circular, square, rectangular, or irregular cross-sectional shapes. Additionally, a suitable mesh may be constructed in a variety of manners including some that involve braiding, knitting and weaving material. These meshes can have any suitable porosity for a given use, for example, for allowing perfusing blood flow while capturing emboli. These and other suitable materials for providing filtration will be recognized by the skilled artisan, therefore, are encompassed by the present invention.  
         [0022]     In some embodiments, a distal protection device works directly with an instrument that is configured to provide upstream treatment of a stenosed region, and in this regard, the invention provides, in certain aspects, apparatuses that include a distal protection device in combination with such an instrument. Those skilled in the art will recognize the large variety of instruments available for treating stenosis and other similar conditions, and will be able to combine these instruments with the distal protection devices described herein without undue experimentation.  
         [0023]     In certain forms, a treatment instrument (e.g., a balloon catheter) incorporates a distal protection device directly as a component that extends distally from other parts of the instrument (or can be extended distally in the body lumen from the area of treatment). Although not necessary to broader aspects of the invention, in some instances, the proximal end  11  of the coiled cone wire can be connected to a distal portion of the treatment instrument, thus potentially obviating the need for the outer jacket  12 . In other embodiments, a distal protection device is not necessarily attached to the treatment instrument but is extendable through the instrument (e.g., through an instrument lumen) to enable the coiled cone  10  and accompanying mesh  17  to be placed downstream of the stenosed region. Cooperation between the distal protection device and the treatment instrument will, in certain embodiments, be in a controlled fashion; e.g. wherein portions of the distal protection device and treatment instrument engage and potentially translate along one another in a fashion that is predictably controlled by engaged surface features of the two objects.  
         [0024]     With reference now to  FIG. 7 , shown is another method of use in the distal protection device, which is similar to that of  FIG. 6  except that the distal protection device  9  extends through the balloon stent catheter  22 . Prior to expanding the stent to open up the body lumen, the distal protection device is positioned in the body lumen  20  downstream of the stenosis  21 . It is then opened to the position of  FIG. 1  in contact with the wall of the lumen  20  wherein device  9  filters the blood flow moving downstream from the stenosed region. The balloon catheter  22  is then operated to expand the stent. Once the risk of further emboli moving downstream from the stenting procedure is over, the distal protection device is manipulated by rotating the shaft  16  relative to the jacket  12  so that the emboli are captured in the mesh  17  of the coiled cone  10  and the coiled cone is reduced in size to the configuration of  FIG. 3 . The distal protection device is then removed from the body lumen along with or after removal of the balloon catheter  22 .  
         [0025]     While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment have been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected. The articles “a”, “an”, “said” and “the” are not limited to a singular element, and include one or more such elements.