Abstract:
The present invention includes a thrombus disrupting device. The device comprises a main body that defines a lumen comprising a distal end portion. A wire is positioned within the lumen and extends from the lumen. The wire comprises a distal end. The device also comprises a main body segment defining the lumen, the main body segment positioned over the wire, proximal to the distal end of the wire and distal to the main body. The wire has a first arc conformation wherein the main body segment is separated from the main body and a second arc-free conformation wherein the main body segment contacts the main body.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a catheter or to a microcatheter or to a guidewire for macerating a thrombus and to a method for thrombus maceration with the catheter or the microcatheter or the guidewire. 
     Guidewires have had use in procedures such as percutaneous transluminal coronary angioplasty (PTCA), and as mechanisms for advancing a catheter to a treatment site within a blood vessel. In one type of procedure, a guiding catheter is introduced into a patient&#39;s arterial system and is advanced to an ostium of the patient&#39;s diseased artery. A guidewire has been used with the guiding catheter in over-the-wire procedures wherein the guidewire is preloaded with an inner lumen of a dilatation catheter. Both the dilatation catheter and the guidewire are advanced through the guiding catheter to a distal end of the guiding catheter. The guidewire is advanced out of the distal end of the guiding catheter into the artery. 
     A physician may shape the distal end of the guidewire to facilitate guiding it through coronary anatomy to a diseased region. When the guidewire is in a desired position, the dilatation catheter is advanced out of the guiding catheter over the guidewire where it may be activated when properly positioned. 
     Guidewires may be fixed or may be built in to a steerable catheter. Guidewires typically include an elongated core member with a flexible helical coil secured to a distal extremity of the core member. The core member can extend to the distal end of the coil and can be secured thereto. Alternately, the distal extension of the core element can terminate short of the distal end of the coil and a shaping ribbon can extend to the distal end of the coil and can be secured by its distal end thereto. The ribbon may be secured by soldering or brazing to the core element. 
     The Kotula et al. Pat. U.S. No. 5,569,275, issuing Oct. 29, 1996, describes a thrombus macerating device that includes an elongate, flexible shaft which can be guided along a vascular path. A rotor or impeller with blades is affixed to the shaft adjacent to its distal end. A drive mechanism is provided for rotating the shaft and the rotator which is attached to the shaft. The rotor is retained within a rotor housing and rotates within the housing. The rotor housing includes a cylindrical wall that surrounds the rotor and that has at least three ports spaced angularly about the circumference of the housing. As the rotor is rotated, it will tend to draw blood into the housing in a proximal direction and expel the blood out through the ports. The blood then tends to be drawn back into the distal end of the housing and through the rotor again. This movement sets up a recirculating vortex which repeatedly passes the blood across the blades. 
     When the blood is ejected through the ports in the housing within a vascular channel, the blood will act against the wall of the channel. This action maintains the housing in a position which is faced away from the surrounding vascular wall. By spacing the ports angularly about the circumference of the housing, the force exerted by the ejected blood tends to maintain the housing and rotor carried within the housing in a position that is centered within a vascular channel. 
     The Kotula et al. Pat. U.S. No. 5,284,486, issuing Feb. 8, 1994, describes a mechanism for breaking down a thrombus with rotating blades. The thrombus is broken down into particles which are fine enough to be left in the vascular system without a significant risk of forming additional thrombi. The mechanism also includes another mechanism to ensure that rotating blades of the mechanism do not directly contact walls of a vessel, but remain centered within the vessel. The mechanism includes an elongate, flexible shaft with a rotor or impeller having blades affixed to the shaft adjacent its distal end. A drive mechanism is provided for rapidly rotating the shaft and the rotor attached to the shaft. The rotor is retained within a rotor housing and rotates within the housing. The rotor housing includes a generally cylindrical wall that is substantially surrounding the rotor and that has at least three ports spaced angularly about the circumference of the housing. As the rotor is rotated, it will tend to draw blood into the housing in a proximal direction and expel the blood out through the ports. The blood then tends to be drawn back into the distal end of the housing and through the rotor again. This activity sets up a recirculating vortex which repeatedly passes the blood across the blades. 
     The thrombus may also be dissolved because the thrombus is comprised of components that can be dissolved or “lysed” with drugs such as TPA and Urokinase. In conventional stroke therapy, TPA is administered via a systemic intravenous (I.V.) Administration. The drugs are infused throughout the entire circuitry system so that only a very diluted concentration of drug actually contacts the thrombus. 
     SUMMARY OF THE INVENTION 
     One embodiment of the present invention includes a thrombus disrupting device. The device comprises a main body. The main body defines a lumen that comprises a distal end portion. A wire is positioned within the lumen and extends from the lumen. The wire comprises a distal end. The device also includes a main body segment that defines the lumen. The main body segment is positioned over the wire, proximal to the distal end of the wire and distal to the main body. The wire has a first arc conformation wherein the main body segment is separated from the main body and a second arc-free conformation wherein the main body segment contacts the main body. 
     Another embodiment of the present invention includes a thrombus disrupting device. The thrombus disrupting device comprises an elongated tubular main body and a wire positioned within the tubular main body. The wire, in one position, defines an arc. The arc is proximal to the distal end of the wire. 
     Another embodiment of the present invention includes a guidewire. The guidewire comprises an elongated wire-based main body with a distal end and a proximal end. The main body comprises an endcap at its distal end and is memory shaped proximal to its distal end to form at least one arc. A cover segment is positioned over the main body and is positioned adjacent the endcap and the arc. 
     Another embodiment of the present invention includes a method for disrupting a thrombus. The method comprises providing a wire with a first arc shape and a second straight shape. The wire is positioned within a thrombus when the wire has the arc shape. The wire is transversely moved so that the arc moves back-and-forth within the thrombus, or rotated within the thrombus. 
     One other embodiment of the present invention includes a core wire. The core wire comprises a proximal wire portion and a distal memory-shaped portion. The distal memory-shaped portion is memory shaped to have at least one arc. The distal memory-shaped portion has a second, straightened arc-free symmetry. In another embodiment, the core wire includes a stop mechanism. 
     Another embodiment of the present invention includes a catheter assembly. The catheter assembly includes a main body that defines a lumen and a thrombus disrupting device positioned within the lumen. The thrombus disrupting device comprises an elongated tubular main body with a distal end and a wire positioned within the tubular main body. The wire, in one position, defines an arc. The arc is proximal to the distal end. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 illustrates a side view of one embodiment of the thrombus macerator of the present invention with a macerator component in an expanded, activated position. 
     FIG. 2 illustrates a side view of the thrombus macerator of the present invention with the macerator component in an unexpanded, inactive position. 
     FIGS. 3 a  and  3   b  illustrate a side view of the thrombus macerator illustrating, with particularity, a stop mechanism. 
     FIG. 4 illustrates an axial cross-sectional view of the macerator component of FIG. 1, in an activated position. 
     FIG. 5 illustrates a side view of one embodiment of an end hole infusion catheter with the macerating component of the present invention. 
     FIG. 5 a  illustrates a side view of one embodiment of an infusion catheter with the macerating component of the present invention. 
     FIG. 5 b  illustrates a side view of one embodiment of an infusion catheter with another embodiment of the macerating component of the present invention. 
     FIG. 5 c  illustrates a cross-sectional view of one embodiment of a single lumen EHIC catheter. 
     FIG. 5 d   1  illustrates a cross-sectional view of one embodiment of a duel lumen EHIC catheter. 
     FIG. 5 d   2  illustrates a cross-sectional view of one other embodiment of a duel lumen EHIC catheter. 
     FIG. 6 a  illustrates a side view of one embodiment of a guidewire that comprises an arc for maceration of a thrombus wherein the arc is straightened. 
     FIG. 6 b  illustrates a side view of one embodiment of the guidewire that comprises the arc for maceration of a thrombus. 
     FIG. 7 illustrates a side view of one embodiment of the core wire wherein the core wire distally comprises a first arc shape. 
     FIG. 8 illustrates a side view of one embodiment of the core wire wherein the core wire distally comprises two arc shapes. 
     FIG. 9 illustrates a side view of one embodiment of a conventional guidewire of the present invention. 
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     One embodiment of the thrombus macerator catheter of the present invention, illustrated generally at  10  in FIG. 1, comprises a catheter body illustrated as comprising proximal portion  14  and distal portion  16  in FIG. 1 and a core wire  12  that is slidably positioned within the catheter portion  14  attached to  16 , as shown in FIG.  1 . The proximal main body portion  14  is comprised of a plurality of coiled segments  18   a, b, c,  and  d.  The distal main body portion  16  is comprised of coiled segments  20   a, b, c, d,  and  e.  While coiled segments  18   a, b, c  and  d  are shown, it is understood that coiled segments  18  extend to a proximal end of the catheter  10 . The coiled segments  18  are, in one embodiment, covered with a flexible sleeve  19 . While coiled segments are shown, it is understood that other conventional flexible coverings are suitable for use in the present invention. 
     The distal catheter portion  16  terminates at an endcap  24  defined by the core wire  12 . Distal segment  16  is made of radiopaque materials and has a radiopaque coating or covering. 
     The coiled segments  18   a-d  and  20   a-e  are made, in one embodiment, of wire or filament. The wire may be flat, square, round, half-round or triangular in cross-section. The wire or filament may be made from biocompatible materials such as platinum, palladium, rhodium, gold, silver, tungsten, iridium, nickel-titanium alloys, Elgiloy, various stainless steels as well as materials coated with a biocompatible coating. Suitable biocompatible polymers for use as wire or filament in the coils include polyethylene, polyurethane, polyester, and polypropylene. It is also believed that polymers such as nylon, Teflon and inorganic materials such as fibrous carbon are also suitable for use as coil material. 
     In an activated position shown in FIG. 1, the core wire  12  has an arc such as is shown at  26 . The core wire  12  is preformed to have the arc  26 . The arc  26  acts as a macerator or clot disrupter when positioned and moved within a thrombus. In one embodiment, the macerating arc  26  is positioned within a thrombus and is moved so that the arc  26  is rotated such as is shown in cross-section in FIG.  4 . By rotating the arc  26  over a radial distance of up to 360 degrees, the thrombus is scraped and disrupted within a blood vessel. The arc  26  may also be moved transversely through a clot. In one other embodiment, the arc  26  is moved radially and transversely in order to more completely disrupt the thrombus. One purpose of the scraping and disruption is to increase the surface area of the thrombus that is subsequently or concurrently exposed to lytic drugs. The lytic drugs are, in one embodiment, administered through an EHIC catheter  50 , illustrated in FIG. 5 a  or  110 , illustrated in FIG. 5 or  100  in FIG. 5 b.    
     While a single arc  26  is shown, it is contemplated that the core wire  12  may preformed into multiple arcs such as is shown at  80  in FIG.  8 . The amplitude of the arc  26  is preformed to be compatible to dimensions of a thrombus. 
     In one embodiment, the core wire  12  is made of an elastic material such as a super elastic Nitinol. Other materials with a degree of stiffening that permits their passage through a blood vessel, particularly biocompatible materials which have a memory and which are capable of returning to a first arc shape after having been straightened, are suitable for use as the core wire  12 . 
     The core wire  12  is retractable within  14  to an inactive, arc-free shape by pulling the core wire  12  at a proximal end of the wire to change the symmetry from the arc  26  to a straightened segment such as is shown in FIG.  2 . As the core wire  12  is straightened, the catheter portions  14  and  16  come together. 
     In one other core wire embodiment, illustrated at  30  in FIG. 3 a,  a stop mechanism  36  is formed integrally with a core wire portion  26 . The core wire  26  is positioned within the proximal catheter portion  14  and the distal catheter portion  16 . The core wire portion  26  terminates at distal end  27  in an endcap  24 . The distal catheter portion  16  encloses the core wire portion  26  and is adhered to the endcap  24  at coil  20   f.  The distal catheter portion  16  is also attachable to the stop mechanism  36  at coil  20   a.  The coil  20   a  is fused or is otherwise adhered to the stop mechanism  36  that is integral with the core wire  26 . 
     The stop mechanism  36  comprises a main body  37  that defines a stopping surface  38 . The main body  37  has a larger diameter than the diameter of the core wire portion  26 . The stop mechanism  36  also includes a pair of opposing tapering surfaces  39   a  and  39   b,  respectively, that are positioned between the stopping surface  38  and the core wire portion  26 . 
     With this embodiment, as the core wire portion  26  is retracted, thereby straightening the wire portion  26 , the retraction stop  36  seats or wedges into a lumen  40  of the distal catheter body portion  14  at the stopping surface  38 , which is illustrated in FIG. 3 b.  The presence of the stop  36  facilitates transmission of torque between the distal catheter body portion  16  and the proximal catheter body portion  14  as the two independent coiled segments  18   a-d  and  20   a-e  are locked together. The locking occurs when the coil wire segments  18   a  and  20   a  are both seated on the same stop  36 . 
     In one embodiment illustrated in FIG. 5, the catheter  10  is passed through a lumen  13  and endhole  15 , defined by the distal portion  114  of an endhole infusion catheter, EHIC,  110 . The catheter  10  is passed by manually pushing the core wire  12  through the catheter  110  at a proximal end of the catheter  10 , wherein the proximal end is not shown and out by way of the endhole  15 . 
     In another embodiment illustrated in FIG. 5 a , the catheter  10  is passed through a lumen  52  and endhole  55  of an end hole infusion catheter  50  that also defines sideholes  56   a,    56   b,    56   c,    56   d,    56   c  and  56   f  for drug delivery. A core wire such as the core wire  12  may also be pushed through the catheter  50 . A marker band may be applied on the distal endcap  24 . The marker band is used for positioning and confirming movement of the core wire  12 . The marker band is comprised of a radiopaque material such as gold, tungsten, tantalum and the like. 
     The EHIC catheters  50  and  110  may be of varying size, including a microcatheter size. The EHIC catheters  50  and  110  may be duel lumen catheters, shown in cross-section in FIGS. 5 d   1  and  5   d   2 , with lumens  19  and  21 . The EHIC catheters  50  and  110  may also be single lumen catheters, as shown at  23  in FIG. 5 c.    
     Thrombi are most effectively lysed when the drug actually comes into contact with the largest possible surface area of a thrombus. It is believed that the EHIC catheters, acting in concert with the thrombus macerating microcatheter of the present invention, produces a synergistic effect by the combined action of local drug delivery and mechanical thrombus disruption. 
     In one embodiment illustrated in FIG. 5 b,  the catheter  10  is transported to a treatment site within a catheter such as the catheter  110 . In one other embodiment, such as is illustrated for catheter  100 , a proximal main body portion  38  is attached to the catheter  100 . The distal main body portion  34  is positioned over the wire  26 . The wire  26  defines the stop mechanism  36 . 
     One other embodiment of the present invention is illustrated generally at  60  in FIGS. 6 a  and  6   b.  The guidewire  60  includes an elongate tubular shaft  70  formed of a material such as stainless steel or Nitinol hypodermic tubing. A distal end  72  is formed of coil segments  74  and  76 . The coiled segment  74  is attached to the tubular shaft  70 . The coiled segment  76  is attached to a cap  66  of a core wire  61 . The core wire  61  extends through the elongate tubular shaft  70 . The core wire  61  is, in one embodiment, made of an elastic material such as Nitinol. The core wire  61  and the core wire  12  may be coated with a material such as TEFLON, or may be coated with an anti-thrombic material or hydrophilic coatings. 
     The core wire  61  as shown in FIG. 6 b,  forms an arc  62 . The arc  62  may be positioned within a thrombus in order to treat the thrombus as described above. The core wire  61  terminates in the cap  66 . In one embodiment, the core wire also includes the stop mechanism  36 . 
     In a guidewire embodiment, illustrated generally at  90  in FIG. 9, the steerable guidewire  90  includes a proximal wire portion  92 , a distal wire arc portion  94  formed within distal coil segment  96 . The guidewire  90  terminates distally in an endcap  98 . The wire acts within a catheter to cover and straighten the arc portion  94  during advancement. As the distal end of the wire exits the catheter, the wire arc portion  94  is allowed to expand. 
     Those skilled in the art will further appreciate that the present invention may be embodied in other specific forms without departing from the spirit or central attributes thereof. In that the foregoing description of the present invention discloses only exemplary embodiments thereof, it is to be understood that other variations are contemplated as being within the scope of the preset invention. Accordingly, the present invention is not limited in the particular embodiments which have been described and detailed therein. Rather, reference should be made to the appended claims as indicative of the scope and content of the present invention.