Patent Document

RELATED APPLICATIONS 
       [0001]    This application is a divisional application of U.S. patent application Ser. No. 10/664,134 filed Sep. 17, 2003. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates generally to the field of intravascular devices. More specifically, the present invention pertains to embolectomy devices for aspirating foreign bodies within a body lumen. 
       BACKGROUND OF THE INVENTION 
       [0003]    There are a number of situations in the practice of medicine where it is desirable to remove an embolus from a patient&#39;s vasculature. If an embolus is not removed it may travel to the neural vasculature, for example, and cause severe trauma. Many prior art embolectomy devices require a retrieval portion to be placed downstream or distal the embolus. This is not always practical or desirable. Other prior art embolectomy devices may require the use of a significant vacuum to remove the embolectomy. This may cause the collapse of a portion of the vasculature and result in trauma. 
       SUMMARY OF THE INVENTION 
       [0004]    In one embodiment of an embolectomy device, a first catheter having an expandable tip may be disposed inside of a second catheter which constrains the tip. The proximal end of either the first or second catheters may be fluidly attached to a vacuum source. The tip may be expanded by moving the first catheter distally relative the second catheter. An embolus may then be urged into the tip by operating the vacuum source. 
         [0005]    In another embodiment of an embolectomy device, a first catheter having an expandable tip may be disposed inside of a second catheter which constrains the tip. A clot pulling device may be disposed within the second catheter. The tip may be expanded by moving the first catheter distally relative the second catheter. The clot pulling device may be operated to urge an embolus into the expanded tip. 
         [0006]    In another embodiment, a clot unclogging or fragmenting device may be disposed in a catheter, which may be fluidly connected to a vacuum source. The unclogging or fragmenting device may be connected to a motion control apparatus by a wire disposed in a lumen of the catheter. The unclogging or fragmenting device may be operated to open the tip of a catheter blocked by the clot burden or to fragment an embolus, which may then be drawn into a catheter lumen by operation of the vacuum source. The catheter may have a lumen connected to an irrigation source. 
         [0007]    The above summary of some embodiments is not intended to describe each disclosed embodiment or every implementation of the present invention. The figures and detailed description which follow more particularly exemplify these embodiments. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    The invention may be more completely understood in consideration of the following detailed description of various embodiments of the invention in connection with the accompanying drawings in which: 
           [0009]      FIG. 1   a  depicts an embolectomy device  300  disposed in a body lumen. 
           [0010]      FIG. 1   b  depicts an embolectomy device  400  disposed in a body lumen. 
           [0011]      FIG. 1   c  depicts an embolectomy device  500  disposed in a body lumen. 
           [0012]      FIG. 2   a  depicts a retrieval catheter  204  of embolectomy device  200 . 
           [0013]      FIG. 2   b  depicts a guide catheter  206  of embolectomy device  200 . 
           [0014]      FIG. 2   c  depicts embolectomy device  200 . 
           [0015]      FIG. 2   d  depicts embolectomy device  200 . 
           [0016]      FIG. 3  depicts an embolectomy device  100  disposed in a vascular lumen. 
       
    
    
     DETAILED DESCRIPTION 
       [0017]    The following detailed description should be read with reference to the drawings, in which like elements in different drawings are numbered identically. The drawings which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of the invention. 
         [0018]      FIG. 1   a  depicts an embolectomy device  300  disposed in a body lumen. Device  300  includes catheter  302  and distal device  304 . Distal device  304  may be used to unclog the aspiration lumen or to fragment an embolus for aspiration. Catheter  302  may have a manifold  306  attached proximally including a first port  308  and a second port  310 . Distal device  304  has a proximal end  312  attached to an elongate member  314  disposed in a lumen of catheter  302 . Distal device  304  may have an arcuate shape, or may be formed into a loop, coil, paddle, whisk, zigzag, helical or other shape suitable for fragmenting an embolus. The proximal end of elongate member  314  may be free or may be attached to a motion control apparatus  340  able to impart motion along the axis of elongate member  314 . The motion control apparatus  340  may impart longitudinal or radial motion or vibration to the distal end of elongate member  314 . Catheter  302  may also be fluidly attached to a vacuum source. 
         [0019]    The motion control apparatus  340  may impart a motion to distal device  304  at between 1 Hz and 150 Hz. Of course, motion at higher or lower frequencies than this are envisioned. As an example, it may be advantageous to move distal device  304  at selective intervals lower than 1 Hz only when a lumen is clogged. In addition, it may be preferable to impart a motion at up to 20 kHz. The motion control apparatus  340  may have any advantageous range of motion. One example range of motion is 17 mm. This may be done by configuring the motion control apparatus  340  to move distal device  2  mm proximally and 15 mm distal from a starting position. Another example range of motion is 120 mm, with the motion control apparatus  340  configured to move distal device  304  20 mm proximally and 100 mm distally. 
         [0020]      FIG. 1   b  depicts an embolectomy device  400 . Device  400  is similar to device  300  and includes a catheter  402  having an angled distal end  418 . 
         [0021]      FIG. 1   c  depicts an embolectomy device  500 . Device  500  is similar to device  300  and includes a first lumen  520  and a second lumen  522 . Elongate member  314  is disposed in first lumen  520  and the vacuum source is fluidly connected to second lumen  522 . In use, embolectomy device  500  may be positioned proximate an embolus and the vacuum source may be operated. Distal device  304  may be operated, either by hand or through a motion control apparatus to unclog an aspiration or other lumen or to fragment an embolus. Distal device  304  may thereby fragment the embolus and the embolus or one or more fragments thereof is drawn into second lumen  522 . Distal device  304  may alter the shape of an embolus and unclog a lumen or fragment the embolus through vibrations or pulses at the distal end of elongate member  314 . In an alternative use, fluid may be irrigated through first lumen  520  or through an additional lumen. Distal device  304  may alternatively or additionally be used to unclog an embolus from a lumen by removing the embolus burden and thereby creating an open channel for more effective aspiration 
         [0022]      FIG. 2   c  depicts embolectomy device  200 , which includes retrieval sheath  204  and guide catheter  206 . As depicted in  FIG. 2   a , retrieval sheath  204  may include an expandable elongate shaft or elongate shaft  208  and expandable tip portion  210 . Expandable tip portion may be formed from a shape memory polyurethane, a nitinol coiled sheet catheter, an expanding nitinol mesh or braid or other suitable material. A coiled sheet catheter may be fashioned from a flat ribbon of nitinol or other suitable material by coiling the ribbon so that proximal coils overlap and thereby constrain distal coils. When unconstrained, expandable tip portion  210  has an expanded profile and an expanded distal lumen. As shown in  FIG. 2   b , expandable tip portion  210  may also be constrained to fit within guide catheter  206 . Embolectomy device  200  may include a clot pulling device  212 , comprising an elongate member  214  and wire mesh  216  or other suitable embolus capturing device. Clot pulling device  212  may include and be disposed in a microcatheter  218 . In one contemplated method, retrieval sheath  204  may be disposed in guide catheter  206  so that the distal ends are approximately even and are located proximate an embolus. Clot pulling device  212  then may be inserted through sheath  204  to capture or retain the embolus. Catheter  206  then may be moved proximally so that tip portion  210  is distally disposed of guide catheter  206  and expands as shown in  FIG. 2   d . Alternatively, retrieval sheath  204  may be moved distally relative guide catheter  206  to expand tip portion  210 . Clot pulling device  212  may then be moved to position the embolus into the expanded tip portion  210 . Retrieval sheath  204 , and clot pulling device  212  may then be removed proximally from guide catheter  206 . If desired, the embolic material may be removed from retrieval sheath  204  and clot pulling device  212  and these devices may be reintroduced into guide catheter  206 . Of course other methods are contemplated. For instance, retrieval sheath  204  may be urged distally to cause tip portion  210  to expand and then clot pulling device  212  is inserted distally through retrieval sheath  204 . 
         [0023]      FIG. 3  depicts an embolectomy device  100  in use in a vascular lumen  102 . Device  100  includes a retrieval catheter  104  and a sheath catheter  106 . Retrieval catheter  104  includes lumen  118  and may have an unconstrained state where its profile has a greater cross sectional area than the profile of sheath catheter  106  or may have a tip portion  108  having an unconstrained profile having a greater cross sectional area than the profile of sheath catheter  106 . Retrieval catheter  104  also has a constrained state where it may be disposed within sheath catheter  106 . Retrieval catheter  104  may be fluidly coupled to a vacuum source  116  and may include a proximally positioned manifold  110  for this purpose. Manifold may include one or more axially or radially located ports  112 . Retrieval catheter includes an expandable material such as a shape memory polyurethane, nitinol coiled sheet catheter, or other suitable material. In use, retrieval catheter  104  is disposed in the lumen of sheath catheter  106  and is positioned proximate an embolus  120 . Retrieval catheter  104  may be extended distally or sheath catheter  106  may be retracted proximally until a desired distal portion of retrieval catheter  104 , which may include tip portion  108 , is in an expanded state. Vacuum source  116  may be operated to urge embolus  120  into lumen  118 . Alternatively, retrieval catheter  104  having an expanded distal portion may be positioned to capture embolus  120  in lumen  118  and vacuum source  116  may be operated to secure the embolus. Once the embolus is capture, it may be removed. This may be accomplished by retracting retrieval catheter  104  proximally into sheath catheter  106  or by extending sheath catheter  106  distally. Tip portion  108  may be fully or partially disposed within sheath catheter  106 . Embolectomy device  100  may then be removed from vascular lumen  102 . Alternatively, retrieval catheter  104  alone may be removed distally from sheath catheter  106 . In another alternative, vacuum source  116  may be operated to remove embolus  120  distally from retrieval catheter  104 . In another alternative an irrigation catheter may be used to provide fluid. 
         [0024]    Numerous advantages of the invention covered by this document have been set forth in the foregoing description. It will be understood, however, that this disclosure is, in many respects, only illustrative. Changes may be made in details, particularly in matters of shape, size, and arrangement of parts or order of steps without exceeding the scope of the invention. The invention&#39;s scope is, of course, defined in the language in which the appended claims are expressed.

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