Abstract:
A dual lumen aspiration catheter system with an aspiration catheter, a hub and a flexible strain relief, and a suction assembly. The aspiration catheter includes multiple successively connected flexible tubular components each increasing in relative flexibility in the distal direction, the most proximal tubular component connectingly extending from the hub and through the flexible strain relief. The tubular components of the aspiration catheter include, in order proximally to distally, a composite tube, an intermediate tube, a dual lumen tube, and a flexible tip tube. The dual lumen tube includes eccentrically co-located large and small tubular portions forming eccentrically co-located large and small lumens to provide a minimum cross section. The distal end of the dual lumen tube includes a convex beveled edge. The convex beveled edge and the flexible tip tube singly or jointly inflict minimal traumatic contact with a vessel wall when urged along a tortuous vascular path.

Description:
CROSS REFERENCES TO RELATED APPLICATIONS  
       [0001]     None.  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to the field of catheters, and more directly relates to an aspiration catheter system having a dual lumen tube, wherein a small lumen is co-located eccentric to and within a large lumen, and wherein a convex beveled edge and a flexible tip tube are located at the distal end of the dual lumen tube.  
         [0004]     2. Description of the Prior Art  
         [0005]     Prior art systems or devices have provided aspiration catheters incorporating more than one lumen. Generally, the location of a small lumen, usually used for passage over a guidewire, was attachingly located exteriorly to a large lumen. Such an arrangement added to the overall cross sectional profile of the catheter device, thereby restricting passage of the device along smaller sized blood vessels. Additional material, incorporated to form adjacent large and small lumen one-piece extrusions, added to the bulk of the device, thereby detrimentally limiting the flexibility of the aspiration catheter, especially at the distal tip portion.  
         [0006]     Other systems incorporated tubular sections having the same flexibility along the length, thereby limiting the flexibility within a tortuous path. Often, the shape at the distal portion of a dual lumen catheter was not conducive to easy and minimum trauma passage along a blood vessel or vein and often abrasive passage occurred. The present invention overcomes the difficulties encountered by the use of prior art aspiration catheters or aspiration catheter systems.  
       SUMMARY OF THE INVENTION  
       [0007]     The general purpose of the present invention is to provide a dual lumen aspiration catheter system.  
         [0008]     According to one embodiment of the present invention, there is provided a dual lumen aspiration catheter system including a hub and a flexible strain relief, an aspiration catheter, and a suction assembly which attaches to and is in communication with the aspiration catheter. The aspiration catheter includes multiple successively connected flexible tubular components each increasing in relative flexibility in the distal direction, the most proximal tubular component connectingly extending from the hub and through the flexible strain relief. The tubular components of the aspiration catheter include, in order proximally to distally, a composite tube, an intermediate tube, a dual lumen tube, and a flexible tip tube, each tubular component having one or more lumens associated therewith. The dual lumen tube includes a large radius tubular portion and a small radius tubular portion being eccentrically co-located to delineate a large lumen and a small lumen, respectively, where the small lumen is eccentric to and located substantially within the general profile of the large lumen. The dual lumen tube includes a distal end having a convex beveled edge. The convex beveled edge and the flexible tip tube singly or in combination facilitate ease of passage of the aspiration catheter along a tortuous path of a blood vessel, vein or the like. The flexible tip tube secures to the small radius tubular portion of the dual lumen tube at a position adjacent to and partially encompassed by the convex beveled edge to communicate with the small lumen. The small lumen includes a proximally located exit end. The flexible tip tube and the small lumen form a path for accommodation of a guidewire, whereby a guidewire can enter the flexible tip tube lumen at the distal end and exit the small lumen at the proximally located exit end. The large lumen of the large radius tubular portion is used to evacuate loose material from a blood vessel, vein or the like in cooperation with the suction assembly. A fluoroscopic ring or marker band is located about the distal end of the small radius tubular portion. The suction assembly includes a syringe, a stopcock, an extension tube, and connectors to provide for a low pressure source for evacuation of debris, thrombi, emboli and the like through the hub and aspiration catheter.  
         [0009]     One significant aspect and feature of the present invention is a dual lumen aspiration catheter system having a suction assembly, a hub and strain relief, and an aspiration catheter.  
         [0010]     Another significant aspect and feature of the present invention is an aspiration catheter which is increasingly flexible along portions of the length thereof from the proximal end to the distal end.  
         [0011]     Yet another significant aspect and feature of the present invention is the use of an aspiration catheter having a large radius tubular portion and an intersecting small radius tubular portion commonly and eccentrically co-located, thereby delineating a large lumen and a small lumen.  
         [0012]     Still another significant aspect and feature of the present invention is the use of an aspiration catheter having large and small lumens commonly and eccentrically co-located, wherein the small lumen is eccentric to and located substantially within the general profile of the large lumen.  
         [0013]     A further significant aspect and feature of the present invention is the use of eccentrically co-located large and small tubular portions to provide a minimum cross section aspiration catheter.  
         [0014]     Another further significant aspect and feature of the present invention is a dual lumen tube having a convex beveled edge distal tip conducive to easy and minimum trauma passage along a tortuous path blood vessel or vein.  
         [0015]     Another further significant aspect and feature of the present invention is the use of a flexible tip tube secured over and about a small radius tubular portion at the distal portion of a dual lumen tube at a position adjacent to and partially encompassed by a convex beveled edge to communicate with the small lumen of a small radius tubular portion.  
         [0016]     Another further significant aspect and feature of the present invention is the use of a small radius tubular portion and connected flexible tip tube for accommodation and passage of a guidewire.  
         [0017]     Another further significant aspect and feature of the present invention is the use of a proximal flared section of dual lumen tube to accommodate the distal end of an intermediate tube.  
         [0018]     Having thus briefly described an embodiment of the present invention and having mentioned some significant aspects and features of the present invention, it is the principal object of the present invention to provide a dual lumen aspiration catheter system.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0019]     Other objects of the present invention and many of the attendant advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, in which like reference numerals designate like parts throughout the figures thereof and wherein:  
         [0020]      FIG. 1  is a plan view of a dual lumen aspiration catheter system, the present invention;  
         [0021]      FIG. 2  is an exploded isometric view of the aspiration catheter, the hub, and the strain relief of the dual lumen aspiration catheter system;  
         [0022]      FIG. 3  is an exploded cross section view of the hub and the strain relief of the dual lumen aspiration catheter system;  
         [0023]      FIG. 4  is an assembled cross section view of the hub and the strain relief of the dual lumen aspiration catheter system;  
         [0024]      FIG. 5  is an exploded isometric view of the distal end of the dual lumen tube and associated components combined later into use therewith;  
         [0025]      FIG. 6  is a cross section view of the dual lumen tube distal end along line  6 - 6  of  FIG. 1 ;  
         [0026]      FIG. 7  is an expanded cross section view along line  7 - 7  of  FIG. 1 ;  
         [0027]      FIG. 8  is a cross section view of the dual lumen tube along line  8 - 8  of  FIG. 7 ;  
         [0028]      FIG. 9  is a cross section view of the intermediate tube along line  9 - 9  of  FIG. 7 ;  
         [0029]      FIG. 10  is an assembled cross section view of the components of  FIG. 7 ;  
         [0030]      FIG. 11  shows the routing of a guidewire through the dual lumen tube; and,  
         [0031]      FIG. 12  shows a blood vessel having a tortuous path and the flexible tip tube and the convex beveled edge at the distal portion of the dual lumen tube at the site of excess debris, thrombi, emboli and the like.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0032]      FIG. 1  is a plan view of a dual lumen aspiration catheter system  10 , the present invention, including a hub  12 , a strain relief  14 , an aspiration catheter  16 , and a suction assembly  18 . The aspiration catheter  16  is comprised of a composite tube  20 ,an intermediate tube  22  of a thermoplastic such as Pebax or other suitable material, a flexible dual lumen tube  24  preferably of a thermoplastic such as Pebax or other suitable flexible material, and a flexible tip tube  26 . The proximal end of the composite tube  20  extends through the strain relief  14  and secures to the hub  12 , and the distal end of the composite tube  20  connects to and suitably communicates with the proximal end of the intermediate tube  22 . The composite tube  20  can be made of polyimide layers with stainless steel flat braid wires in between the layers and is designed to have a thin wall or largest lumen to maximize the evacuation power of an evacuation syringe. The composite tube  20  incorporates braided construction for strength and torqueability, but can be effectively formed in other ways, for example, by using reinforcing components such as fibers, wound strands, rings, wraps or combinations thereof. The proximal end of the dual lumen tube  24  includes a flared section  28  for the accommodation of the distal end of the intermediate tube  22 . The distal portion of the dual lumen tube  24  includes a distal end which connects to and partially communicates with the flexible tip tube  26 . The distal portion of the dual lumen tube  24  also includes a convex beveled edge  32 . The suction assembly  18 , which provides a low pressure for evacuation of debris, thrombi, emboli and the like through the aspiration catheter  16 , includes a syringe  34  which can be lockable, a stopcock  36  connected to one end of the syringe  34 , a connector  38  connecting one end of an extension tube  40  to the stopcock  36 , and a connector  42  connecting one end of the extension tube  40  to the proximal end of the hub  12 .  
         [0033]     Different stiffness and flexibilities are incorporated into the design of the aspiration catheter  16 , wherein the components become more flexible in a distal direction. For purpose of example and illustration, the composite tube  20  can be 80-120 centimeters in length and is the stiffest component of the aspiration catheter  16 . The intermediate tube  22  can be in a range of 15-25 centimeters in length and can be comprised of 72 durometer Pebax and is more flexible than the composite tube  20 . The dual lumen tube  24  can be 25 centimeters in length and can be comprised of 63 durometer Pebax and is more flexible than the intermediate tube  22 . The flexible tip tube  26  can be of a softer 25-55 durometer Pebax, wherein trauma is reduced when accessing the target lesion.  
         [0034]      FIG. 2  is an exploded isometric view of the aspiration catheter  16 , the hub  12 , and the strain relief  14  of the dual lumen aspiration catheter system  10 ; and  FIG. 3  is an exploded cross section view of the hub  12  and the strain relief  14  of the dual lumen aspiration catheter system  10 . The hub  12  and the strain relief  14 , shown in  FIGS. 2 and 3 , are now described. The hub  12  is generally cylindrical in shape, fashioned preferably of plastic or other suitable material, and includes a tapered extension  44  extending from a main body  46 . A lumen  48  extends along the centerline of the hub  12  through the tapered extension  44  and through the main body  46  to intersect and communicate with a cavity  50 , which can be tapered, at the opposite end of the hub  12  where the cavity  50  also extends along the centerline of the hub  12 . A connection flange  52  is located at one end of the main body  46  of the hub  12 . An orifice  54  extends through the tapered extension  44  to intersect the lumen  48  of the hub  12  in order to provide a path for passage and/or for inclusion of adhesive therethrough and/or therein to contact and secure the proximal end of the composite tube  20 , which also extends through a lumen  56  of the strain relief  14 , to and partially within the lumen  48  of the hub  12 , as shown in  FIG. 4 . The strain relief  14  comprised of a flexible plastic or other suitable material includes the lumen  56  extending along the centerline of the strain relief  14  to intersect a tapered extension receptor  58  also extending along the centerline of the strain relief  14 . The shape of the tapered extension receptor  58  is complementary to the shape of the tapered extension  44  of the hub  12  to ensure a proper mutual fit, as shown in  FIG. 4 . An adhesive or other suitable method of affixing the tapered extension  44  of the hub  12  within the tapered extension receptor  58  can be used. Grasping tabs  60  and  62  extend outwardly from the periphery of the hub main body  46  to assist in maneuvering of the aspiration catheter  16 .  
         [0035]      FIG. 4  is an assembled cross section view of the hub  12  and the strain relief  14  of the dual lumen aspiration catheter system  10 . Shown in particular is the relationship of the composite tube  20  to the assembled hub  12  and strain relief  14 .  
         [0036]      FIG. 5  is an exploded isometric view of the distal end of the dual lumen tube  24  and associated components combined later into use therewith. The dual lumen tube  24 , preferably an extruded structure, includes a large radius tubular portion  64  and an intersecting small radius tubular portion  66 . The tubular portions  64  and  66  are commonly and eccentrically co-located, thereby delineating a large lumen  68  and a small lumen  70 , respectively. The small radius tubular portion  66  forms the small lumen  70  which is circular in shape. The wall of the large radius tubular portion  64  intersects the wall of the small radius tubular portion  66  to have structure in common where the combination of a greater portion of the interior surface of the large radius tubular portion  64  and a greater portion of the exterior surface of the small radius tubular portion  66  forms the structure delineating the large lumen  68 . The large radius tubular portion  64  and the small radius tubular portion  66  are truncated at the distal end of each. The cross section size of the large lumen  68  is the difference between the inner surface of the large radius tubular portion  64  and the outer surface of the small radius tubular portion  66 . The small lumen  70  is eccentric to and located substantially within the general profile of the large lumen  68 . A cross section view of the dual lumen tube  24  is shown in  FIG. 8 . The distal end portion of the dual lumen tube  24 , specifically the large radius tubular portion  64 , includes the convex beveled edge  32  for facilitating ease of passage along a blood vessel, vein or the like having a tortuous path. The flexible tip tube  26 , which includes a lumen  72 , secures over and about the small radius tubular portion  66  at the distal portion of the dual lumen tube  24  at a position adjacent to and partially encompassed by the convex beveled edge  32  to communicate with the small lumen  70  of the small radius tubular portion  66 . Longitudinally oriented slits  74  and  76  are made between the outer surface of the small radius tubular portion  66  and the inner surface of the large radius tubular portion  64  in order to accommodate a radiopaque marker band  78  and the flexible tip tube  26  over and about the small radius tubular portion  66 .  
         [0037]      FIG. 6  is a cross section view along line  6 - 6  of  FIG. 1  showing the relationship of the flexible tip tube  26  and the radiopaque marker band  78  to the distal portion of the small radius tubular portion  66 . The radiopaque marker band  78  aligns and secures over and about the small radius tubular portion  66 . The flexible tip tube  26  aligns and secures over and about both the radiopaque marker band  78  and the distal portion of the small radius tubular portion  66 , thereby providing communication of the lumen  72  of the flexible tip tube  26  with the small lumen  70  of the small radius tubular portion  66 , thus forming a convenient conduit for the passage of a guidewire therethrough. Also shown is the profile of the convex beveled edge  32  of the large radius tubular portion  64  at the distal end of the dual lumen tube  24 . The convex beveled edge  32  includes convex beveled edge portions  32   a  and  32   b  ( FIG. 5 ) located to either side of an imaginary plane extending vertically along and through the longitudinal axis of the dual lumen tube  24 . The extreme distal end of the small radius tubular portion  66  preferably includes a convex beveled edge portion  32   c  preferably complying with and being equal to the curvature, i.e, the radius of the bevel of the convex beveled edge portions  32   a  and  32   b  of the convex beveled edge  32 . The convex beveled edge portions  32   a  and  32   b  of the dual lumen tube  24  promote minimum trauma passage of the distal tip of the dual lumen tube  24  through the vasculature due to the convex structure. The convex beveled edge portion  32   c  of the small radius tubular portion  66  also assists in entry of a guidewire through the initial point of overlap commonality between the distal end of the small radius wall  66  and the flexible tip tube  26 .  
         [0038]      FIG. 7  is an expanded cross section view along line  7 - 7  of  FIG. 1  showing the flared section  28  at the proximal end of the dual lumen tube  24  and the distal end of the intermediate tube  22 . The flared section  28  at the proximal end of the dual lumen tube  24  accommodates the distal end of the intermediate tube  22 .  
         [0039]      FIG. 8  is a cross section view of the dual lumen tube  24  along line  8 - 8  of  FIG. 7  showing the relationship of the small radius tubular portion  66  forming the small lumen  70  and the large radius tubular portion  64  forming the large lumen  68 .  
         [0040]      FIG. 9  is a cross section view of the intermediate tube  22  along line  9 - 9  of  FIG. 7 .  
         [0041]      FIG. 10  is an assembled cross section view of the components of  FIG. 7  where the distal end of the intermediate tube  22  is accommodated by the flared section  28  of the dual lumen tube  24 . For purposes of example and illustration, a guidewire  82  is shown extending through and exiting from the small lumen  70  of the small radius tubular portion  66 .  
         [0042]      FIG. 11  shows the routing of a guidewire  82  through the dual lumen tube  24 , wherein the guidewire  82  passes through the lumen  72  of the flexible tip tube  26  and through the small lumen  70  of the small radius tubular portion  66  of the dual lumen tube  24  to exit the proximal portion thereof in close proximity to the intermediate tube  22 , as shown in larger scale in  FIG. 10 .  
         [0043]      FIG. 12  shows the flexible tip tube  26  and the convex beveled edge  32  at the distal portion of the dual lumen tube  24  flexibly engaging a torturous path along the interior of a blood vessel  84  in close proximity to the site of excess debris, thrombi, emboli and the like, such as represented by particles  86 . Also shown in outline profile form is an outline of the distal ends of obtrusive prior art suction catheter devices having a simple beveled end  88  or a straight cut end  90 . Such obtrusive geometry can cause contacting of the walls of the blood vessel  84  by the geometry of such devices just referenced and unfortunately can cause abrasive and traumatic impingement with the walls of the blood vessel  84 .  
       Mode of Operation  
       [0044]     With reference specifically to  FIGS. 10, 11  and  12 , and to all the figures in general, the mode of operation of the present invention is now described.  
         [0045]     A suitably sized guidewire, such as the guidewire  82 , is inserted through incorporation of a conventional introducer into the vasculature, such as represented by blood vessel  84 , and suitably advanced to or beyond the region of debris, thrombi, emboli and the like, such as represented by particles  86 . The aspiration catheter  16  by itself or the aspiration catheter  16  with the suction assembly  18  connected thereto, along with the use of a conventional introducer, is maneuvered to cause engagement with the proximal end of the guidewire  82 , whereby the proximal end of the guidewire  82  enters and is accommodated by the lumen  72  of the flexible tip tube  26 , wherein the flexible tip tube  26  passes over and about the guidewire  82 . The proximal end of the guidewire  82  is then accommodated by the connected small lumen  70  of the small radius tubular portion  66 . The guidewire  82  is accommodated directly by the small radius tubular portion  66  of the dual lumen tube  24  and indirectly by the interior of the dual lumen tube  24  owing to the location of the small radius tubular portion  66  substantially within the large radius tubular portion  64  of the dual lumen tube  24 . As the aspiration catheter  16 , including the dual lumen tube  24 , the intermediate tube  22 , and the composite tube  20 , is urged distally, the proximal end of the guidewire  82  exits the proximal end of the small radius tubular portion  66  in close proximity to the distal end of the intermediate tube  22 . As the aspiration catheter  16  is urged distally along a tortuous path within the blood vessel  84  incorporating the guidance of the small radius tubular portion  66  of the dual lumen tube  24  along the guidewire  82 , the soft and small profile flexible tip tube  26  gently and flexibly and with minimum trauma can contact the wall of the tortuous path blood vessel  84 . The convex beveled edge portions  32   a  and  32   b  of the convex beveled edge  32  of the dual lumen tube  24  gently and with minimum trauma can contact the wall of the tortuous path blood vessel  84 .  
         [0046]     The combination of the flexible tip tube  26  and the streamlined convex beveled edge  32  of the dual lumen tube  24  provides for minimum trauma passage of the distal end of the dual lumen tube  24  through a blood vessel  84  having a tortuous path. Such association with the compact profile of the dual lumen tube  24  provides a highly flexible and maneuverable aspiration device.  
         [0047]     The syringe  34  and the stopcock  36 , as well as the other components of the suction assembly  18 , are incorporated to provide controlled vacuum to the hub  12  and the aspiration catheter  16  to remove debris, thrombi, emboli and the like from a vascular site.  
         [0048]     Various modifications can be made to the present invention without departing from the apparent scope thereof.