Abstract:
A device is provided for performing intra myocardial injections. The device comprises a needle, a catheter formed with a lumen, and an inflatable abutment member. The abutment member is movable between a first configuration, wherein it is substantially tube-like and is deflated, and a second configuration, wherein it inflates beyond the distal end of the catheter and extends radially. Before the needle is advanced to perform an injection, the abutment member is moved to its second configuration to prevent contact between the catheter and the myocardial tissue during the injection.

Description:
[0001]    This application is a continuation-in-part of application Ser. No. 11/422,307 filed Jun. 5, 2006 which is currently pending. The contents of application Ser. No. 11/422,307 are incorporated herein by reference. 
       FIELD OF THE INVENTION 
       [0002]    The present invention pertains generally to devices and methods for delivering medicaments to a patient. More specifically, the present invention pertains to devices and methods for performing intra myocardial injections. The present invention is particularly, but not exclusively, useful as a device and method for advancing a needle from a catheter to perform an intra myocardial injection while protecting the myocardial tissue from contact with the catheter. 
       BACKGROUND OF THE INVENTION 
       [0003]    Intravascular catheters are used in a wide variety of medical procedures by inserting the catheter into the vascular system of the patient at an easily accessible location. Thereafter, the tip of the catheter is advanced through the vasculature to a desired target site. In this manner, virtually any target site in the patient&#39;s vascular system may be remotely accessed. Of particular interest here are those medical procedures that require the use of injection catheters to inject therapeutic or diagnostic agents into various target tissues within the human body. When so used, an advantage of injection catheters is that the target tissue may be accessed by minimally invasive surgical techniques. 
         [0004]    In many applications the target tissue is within a wall of an organ, such as the heart. For instance, therapeutic or diagnostic agents such as genes, proteins, stem cells, or drugs may be injected directly into the heart. When the target tissue is within the wall of an organ, however, it is often desirable to inject the therapeutic or diagnostic agent into the tissue at a specific site in the organ wall. In these applications, if the needle of the injection catheter inadvertently passes through the wall, the therapeutic or diagnostic agents that are dispensed from the distal end of the needle will not be effectively delivered to the target tissue. Further, because the injection procedure often requires the thrust of a needle in the distal direction, the required motion can cause the catheter itself to contact and perforate or otherwise injure the wall of the organ, resulting in a life threatening situation. 
         [0005]    In light of the above, it is an object of the present invention to provide a device and method that protects the myocardial wall from injury and perforation during an intra myocardial injection. Another object of the invention is to provide a device and method for controlling the depth of an intra myocardial injection. Still another object of the invention is to provide a device and method for performing an intra myocardial injection from a catheter in which a removable barrier prevents contact between the catheter and the myocardial tissue and allows the physician to advance the needle with confidence and without fear of perforating the myocardial tissue with the catheter. Yet another object of the present invention is to provide a device and method for performing intra myocardial injections which is easy to implement, simple to perform, and cost effective. 
       SUMMARY OF THE INVENTION 
       [0006]    In accordance with the present invention, an injector is provided to perform intra myocardial injections while preventing unnecessary trauma to the myocardial tissue. Structurally, the injector includes a catheter having a proximal end and a distal end. Further, the catheter is formed with a lumen that extends from the proximal end to the distal end and defines a longitudinal axis. The injector also includes a needle that is mounted within the lumen of the catheter for axial movement therein. 
         [0007]    An important aspect of the injector of the present invention is an inflatable abutment member that is mounted to the catheter. For purposes of the present invention, this inflatable abutment member is tube-shaped and is movable between a first configuration and a second configuration. In the first configuration, the abutment member is deflated and is held alongside the catheter. In the second configuration, the abutment member is inflated and extends radially from and beyond the distal end of the catheter. Further, in the second configuration, the abutment member maintains a central void for passage of the needle tip through the central void. 
         [0008]    Also, the inflatable abutment member includes a port that is in fluid communication with a fluid source, such as a reservoir of saline with iodinated contrast. Specifically, the injector includes a tube that connects the port on the abutment member with the saline reservoir. 
         [0009]    For the operation of the present invention, saline with iodinated contrast is transferred between the saline reservoir and the abutment member to move the abutment member between the first configuration and the second configuration. In the first configuration, as mentioned above, the abutment member is substantially tube-like. In the second configuration, the abutment member extends radially from and beyond the distal end of the catheter. 
         [0010]    In order to perform an intra myocardial injection, the injector is placed at a desired position near or adjacent myocardial tissue. During this placement, the abutment member is in its first configuration. Thereafter, saline or contrast or a mixture of both is transferred from the saline reservoir to the abutment member to expand the abutment member in the distal direction through the distal end of the catheter until the abutment member reaches the second configuration. In the second configuration, the distal portion of the abutment member flares radially. Because the abutment member extends distally from the catheter, the abutment member provides a barrier between the catheter and the myocardial tissue. Therefore, when the needle is advanced (through the central void in the abutment member) and the needle tip penetrates the myocardial tissue to perform the injection, the abutment member limits or minimizes contact between the catheter and the myocardial tissue, preventing unwanted advancement of the catheter. As a result, the surgeon may confidently advance the needle without risk of damaging the myocardial tissue with the catheter. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    The novel features of this invention, as well as the invention itself, both as to its structure and its operation, will be best understood from the accompanying drawings, taken in conjunction with the accompanying description, in which similar reference characters refer to similar parts, and in which: 
           [0012]      FIG. 1  is a perspective view of the intra myocardial injector in accordance with the present invention; 
           [0013]      FIG. 2  is a perspective view of an embodiment of the intra myocardial injector of  FIG. 1  shown with the abutment member in its second configuration in accordance with the present invention; 
           [0014]      FIG. 3A  is a cross sectional view of the injector of  FIG. 2  shown with the abutment member in its first configuration in accordance with the present invention; 
           [0015]      FIG. 3B  is a cross sectional view of the injector of  FIG. 2  shown with the abutment member in its second configuration in accordance with the present invention; 
           [0016]      FIG. 3C  is a cross sectional view of the injector of  FIG. 2  shown with the abutment member in its second configuration and with the needle advanced and penetrating myocardial tissue in accordance with the present invention; 
           [0017]      FIG. 4  is a perspective view of another embodiment of the intra myocardial injector of  FIG. 1  shown with the abutment member in its extended (second) configuration in accordance with the present invention; 
           [0018]      FIG. 5A  is a cross sectional view of an embodiment of the injector of  FIG. 4  shown with the abutment member in its first configuration in accordance with the present invention; 
           [0019]      FIG. 5B  is a cross sectional view of the injector shown in  FIG. 5A  shown with the abutment member in its second configuration in accordance with the present invention; 
           [0020]      FIG. 5C  is a cross sectional view of the injector shown in  FIG. 5B  with the needle advanced and penetrating myocardial tissue in accordance with the present invention; 
           [0021]      FIG. 6A  is a cross sectional view of an alternate embodiment of the injector of  FIG. 4  shown with the abutment member in its first configuration in accordance with the present invention; 
           [0022]      FIG. 6B  is a cross sectional view of the injector shown in  FIG. 6A  shown with the abutment member in its second configuration in accordance with the present invention; and 
           [0023]      FIG. 6C  is a cross sectional view of the injector shown in  FIG. 6B  with the needle advanced and penetrating myocardial tissue in accordance with the present invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0024]    Referring initially to  FIG. 1 , an intra myocardial injector in accordance with the present invention is shown, and is generally designated  10 . As shown in  FIG. 1 , the injector  10  includes a catheter  12  that extends along an axis  14  from a proximal end  15  to a distal end  16 . As is shown, the proximal end  15  of the catheter  12  is connected to tubing  13 . For purposes of the present invention, the tubing  13  is in fluid communication with a vessel  17  for holding medicament or other fluid for medical treatment. As is further shown, the tubing  13  also includes a port  19  that provides access for manipulation of internal components of the catheter  12 . For instance, the port  19  may connect to a fluid reservoir  11 . 
         [0025]    Referring now to  FIG. 2 , the injector  10  is shown to include a needle  18  that terminates at a needle tip  20 . As shown in  FIG. 2 , the needle  18  has been advanced so that the needle tip  20  extends beyond the distal end  16  of the catheter  12 . Further, the injector  10  is shown to include an abutment member  22 . As shown, the abutment member  22  is formed from a plurality of loops  24  of wire  26 . Specifically, the abutment member  22  is formed with overlapping loops  24  that are biased to radially extend from the axis  14 . Further, the abutment member  22  may include a webbing  25  that interconnects adjacent loops  24 . Such a webbing  25  can comprise a high-friction material. For the present invention, the abutment member  22  may include engagement elements  28  such as tines that extend from exemplary loops  24   a ,  24   b , or a high friction surface. 
         [0026]    Turning now to  FIG. 3A , the internal features of the injector  10  may be understood. As shown in  FIG. 3A , the catheter  12  forms a lumen  30  that extends along the axis  14  to the distal end  16 . Unlike in  FIG. 2 , the abutment member  22 ′ is positioned completely within the lumen  30 , i.e., in its first configuration. As shown, when in its first configuration, the abutment member  22 ′ is substantially tube-like. Specifically, the abutment member  22 ′ includes a proximal portion  32  and a distal portion  34  that are substantially cylindrical. 
         [0027]    In  FIG. 3A , it is further shown that the injector  10  includes a pusher rod  36  that includes a distal end  38 . As shown, the pusher rod  36  is received within the lumen  30  and is axially movable with respect to the catheter  12 . For purposes of the present invention, the distal end  38  of the pusher rod  36  engages the proximal portion  32  of the abutment member  22 ′ to cause movement of the abutment member  22 ′. In certain embodiments, the rod  36  and the abutment member  22  may be a single piece. 
         [0028]    Still referring to  FIG. 3A , the needle  18  is shown positioned entirely within the lumen  30 , with the end  16  of the catheter  12  distal of the needle tip  20 . Structurally, the needle  18  may be mounted to a needle hub (not shown) for movement with respect to the lumen  30  of the catheter  12 . 
         [0029]    Referring now to  FIG. 3B , the abutment member  22 ″ is shown in its second configuration. Specifically, as shown, the distal portion  34  of the abutment member  22 ″ is shown extended from the distal end  16  of the catheter  12 . Because it is radially biased, the distal portion  34  of the abutment member  22 ″ flares radially when extended beyond the distal end  16  of the catheter  12  and takes a fan shape. As shown in  FIG. 3B , the needle  18  is still retracted within the catheter  12 . 
         [0030]    Referring now to  FIG. 3C , it can be seen that the needle  18  has been advanced to extend the needle tip  20  beyond the distal end  16  of the catheter  12  and the abutment member  22 ″. Preferably, the needle tip  20  extends between 3 and 7 millimeters beyond the distal portion  34  of the abutment member  22 ″. 
         [0031]    Referring now to  FIGS. 3A-3C  collectively, the operation of the present invention may be understood. Initially, the injector  10  is configured as in  FIG. 3A  with the abutment member  22 ′ in its first configuration. When an intra myocardial injection is desired, the injector  10  is placed adjacent myocardial tissue  42 . Next, as shown in  FIG. 3B , the pusher rod  36  is advanced and the distal end  38  of the rod  36  forces the abutment member  22  in the distal direction. The abutment member  22  is moved distally until it reaches its second configuration. In the second configuration, the distal portion  34  of the abutment member  22 ″ flares radially and provides a barrier between the distal end  16  of the catheter  12  and the myocardial tissue  42 . When the injector  10  is moved toward the myocardial tissue  42 , the abutment member  22  abuts the tissue  42  and prevents further movement of the catheter  12  in the distal direction. Further, the engagement elements  28  (shown in  FIG. 2 ) on the abutment member  22  may pierce or contact and engage the myocardial tissue  42  to anchor the injector  10  in position. 
         [0032]    With the abutment member  22 ″ in its second configuration, the needle  18  may be advanced to extend the needle tip  20  as shown in  FIG. 3C . Advancement of the needle  18  may be accomplished by pushing the needle hub (not shown) relative to the catheter  12 , or otherwise pushing the needle  18  relative to the catheter  12  as known in the art. As a result of its advancement, the needle tip  20  extends beyond the distal end  16  of the catheter  12  and beyond the distal portion  34  of the abutment member  22 ″ to penetrate the myocardial tissue  42  to an approximate depth of between 3 and 7 millimeters. When the myocardial tissue  42  has been penetrated by the needle tip  20  at the appropriate depth, a medicament or other treatment fluid may be injected through the needle tip  20  as is well known in the art. 
         [0033]    After the injection has been performed, the needle  18  is retracted within the lumen  30 , as illustrated in  FIG. 3B . Then the abutment member  22 ″ is withdrawn into the lumen  30  by the pusher rod  36 , as illustrated in  FIG. 3A . Thereafter, the injector  10  is removed from the patient&#39;s vasculature. 
         [0034]    Referring now to  FIG. 4 , the injector  10  is again shown to include a needle  18  that terminates at a needle tip  20 . Similar to the injector  10  shown in  FIG. 2 , the needle  18  has been advanced so that the needle tip  20  extends beyond the distal end  16  of the catheter  12 . Further, the injector  10  is shown to include an inflatable abutment member  44 . As shown, the abutment member  44  is formed from a flexible bladder such as a balloon. For purposes of the present invention, the abutment member  44  may be round, flat, elliptical, or any desired shape. As shown, the abutment member  44  has a proximal portion  46  mounted to the catheter  12 . For the present invention, the abutment member  44  may include a high friction surface  50 . 
         [0035]    Turning now to  FIG. 5A , the internal features of the injector  10  may be understood. As shown in  FIG. 5A , the catheter  12  forms a lumen  30  that extends along the axis  14  to the distal end  16 . Unlike in  FIG. 4 , the abutment member  44 ′ is deflated and positioned completely within the lumen  30 , i.e., in its first configuration. As shown, when in its first configuration, the abutment member  44 ′ is substantially tube-like. Specifically, the proximal portion  46  and the distal portion  48  of the abutment member  44 ′ are substantially cylindrical. For purposes of the present invention, the proximal portion  46  of the abutment member  44  may be mounted to the catheter  12 . 
         [0036]    In  FIG. 5A , it is further shown that the abutment member  44  includes a port  52  that is in fluid communication with a tube  54 . For purposes of the present invention, the tube  54  is connected to the fluid reservoir  11  (shown in  FIG. 1 ) to transfer fluid between the reservoir  11  and the abutment member  44 ′ to cause movement of the abutment member  44 ′. In certain embodiments, the abutment member  44 ′ and the tube  54  may be a single piece. 
         [0037]    Still referring to  FIG. 5A , the needle  18  is shown positioned entirely within the lumen  30 , with the end  16  of the catheter  12  distal of the needle tip  20 . Structurally, the needle  18  may be mounted to a needle hub (not shown) for movement with respect to the lumen  30  of the catheter  12 . 
         [0038]    Referring now to  FIG. 5B , the abutment member  44 ″ is shown in its second configuration. Specifically, as shown, the distal portion  48  of the abutment member  44 ″ is shown extended from the distal end  16  of the catheter  12 . Due to its preformed pancake shape, the distal portion  48  of the pancake shaped abutment member  44 ″ flares radially when inflated beyond the distal end  16  of the catheter  12 . As shown in  FIG. 5B , the needle  18  is still retracted within the catheter  12 . 
         [0039]    Referring now to  FIG. 5C , it can be seen that the needle  18  has been advanced to extend the needle tip  20  beyond the distal end  16  of the catheter  12  and the abutment member  44 ″. Preferably, the needle tip  20  extends between 3 and 7 millimeters beyond the surface  50  of the abutment member  44 ″. 
         [0040]    Referring now to  FIGS. 5A-5C  collectively, the operation of the present invention may be understood. Initially, the injector  10  is configured as in  FIG. 5A  with the abutment member  44 ′ in its first configuration. When an intra myocardial injection is desired, the injector  10  is placed adjacent myocardial tissue  42 . Next, as shown in  FIG. 5B , fluid such as iodinated saline is transferred from the reservoir  11  to the abutment member  44  and the distal portion  48  of the abutment member  44  expands in the distal direction. The abutment member  44  expands until it reaches its second configuration. In the second configuration, the distal portion  48  of the abutment member  44 ″ flares radially and provides a barrier between the distal end  16  of the catheter  12  and the myocardial tissue  42 . When the injector  10  is moved toward the myocardial tissue  42 , the surface  50  of the abutment member  44  abuts the tissue  42  and prevents further movement of the catheter  12  in the distal direction. Further, the surface  50  may contact and engage the myocardial tissue  42  to anchor the injector  10  in position. 
         [0041]    With the abutment member  44 ″ in its second configuration, the needle  18  may be advanced to extend the needle tip  20  as shown in  FIG. 5C . Advancement of the needle  18  may be accomplished by pushing the needle hub (not shown) relative to the catheter  12 , or otherwise pushing the needle  18  relative to the catheter  12  as known in the art. As a result of its advancement, the needle tip  20  extends beyond the distal end  16  of the catheter  12  and beyond the surface  50  of the abutment member  44 ″ to penetrate the myocardial tissue  42  to an approximate depth of between 3 and 7 millimeters. When the myocardial tissue  42  has been penetrated by the needle tip  20  at the appropriate depth, a medicament or other treatment fluid may be injected through the needle tip  20  as is well known in the art. 
         [0042]    After the injection has been performed, the needle  18  is retracted within the lumen  30 , as illustrated in  FIG. 5B . Then the abutment member  44 ′ is deflated by transferring fluid from the abutment member  44  to the fluid reservoir  11 , as illustrated in  FIG. 5A . Thereafter, the injector  10  is removed from the patient&#39;s vasculature. 
         [0043]    Turning now to  FIG. 6A , the internal features of another embodiment of the injector  10  may be understood. As shown in  FIG. 6A , the catheter  12  forms a lumen  30  that extends along the axis  14  to the distal end  16 . Unlike in  FIG. 4 , the abutment member  44 ′ is deflated and positioned substantially alongside the catheter  12 , i.e., in its first configuration. As shown, when in its first configuration, the abutment member  44 ′ is substantially tube-like. Specifically, the proximal portion  46  and the distal portion  48  of the abutment member  44 ′ are substantially cylindrical. For purposes of the present invention, the proximal portion  46  of the abutment member  44  may be mounted to the catheter  12 . 
         [0044]    In  FIG. 6A , it is further shown that the abutment member  44  includes a port  52  that is in fluid communication with a tube  54 . For purposes of the present invention, the tube  54  is connected to the fluid reservoir  11  (shown in  FIG. 1 ) to transfer fluid between the reservoir  11  and the abutment member  44 ′ to cause movement of the abutment member  44 ′. In certain embodiments, the abutment member  44 ′ and the tube  54  may be a single piece. Further, while the tube  54  is positioned within the lumen  30  in  FIG. 6A , it may be positioned outside of the catheter  12  as shown in  FIG. 5A . 
         [0045]    Still referring to  FIG. 6A , the needle  18  is shown positioned entirely within the lumen  30 , with the end  16  of the catheter  12  distal of the needle tip  20 . Structurally, the needle  18  may be mounted to a needle hub (not shown) for movement with respect to the lumen  30  of the catheter  12 . 
         [0046]    Referring now to  FIG. 6B , the abutment member  44 ″ is shown in its second configuration. Specifically, as shown, the distal portion  48  of the abutment member  44 ″ is shown extended from the distal end  16  of the catheter  12 . Due to its preformed shape, the abutment member  44 ″ flares radially when inflated beyond the distal end  16  of the catheter  12 . As shown in  FIG. 6B , the needle  18  is still retracted within the catheter  12 . 
         [0047]    Referring now to  FIG. 6C , it can be seen that the needle  18  has been advanced to extend the needle tip  20  beyond the distal end  16  of the catheter  12  and the abutment member  44 ″. Preferably, the needle tip  20  extends between 3 and 7 millimeters beyond the surface  50  of the abutment member  44 ″. 
         [0048]    Referring now to  FIGS. 6A-6C  collectively, the operation of the present invention may be understood. Initially, the injector  10  is configured as in  FIG. 6A  with the abutment member  44 ′ in its first configuration. When an intra myocardial injection is desired, the injector  10  is placed adjacent myocardial tissue  42 . Next, as shown in  FIG. 6B , fluid is transferred from the reservoir  11  to the abutment member  44  and the distal portion  48  of the abutment member  44  expands radially outward and in the distal direction. The abutment member  44  expands until it reaches its second configuration. In the second configuration, the distal portion  48  of the abutment member  44 ″ provides a barrier between the distal end  16  of the catheter  12  and the myocardial tissue  42 . When the injector  10  is moved toward the myocardial tissue  42 , the surface  50  of the abutment member  44  abuts the tissue  42  and prevents further movement of the catheter  12  in the distal direction. Further, the surface  50  may contact and engage the myocardial tissue  42  to anchor the injector  10  in position. 
         [0049]    With the abutment member  44 ″ in its second configuration, the needle  18  may be advanced to extend the needle tip  20  as shown in  FIG. 6C . Advancement of the needle  18  may be accomplished by pushing the needle hub (not shown) relative to the catheter  12 , or otherwise pushing the needle  18  relative to the catheter  12  as known in the art. As a result of its advancement, the needle tip  20  extends beyond the distal end  16  of the catheter  12  and beyond the surface  50  of the abutment member  44 ″ to penetrate the myocardial tissue  42  to an approximate depth of between 3 and 7 millimeters. When the myocardial tissue  42  has been penetrated by the needle tip  20  at the appropriate depth, a medicament or other treatment fluid may be injected through the needle tip  20  as is well known in the art. 
         [0050]    After the injection has been performed, the needle  18  is retracted within the lumen  30 , as illustrated in  FIG. 6B . Then the abutment member  44 ″ is deflated by transferring fluid from the abutment member  44  to the fluid reservoir  11 , as illustrated in  FIG. 6A . Thereafter, the injector  10  is removed from the patient&#39;s vasculature. 
         [0051]    While the particular Myocardial Injector With Balloon Abutment as herein shown and disclosed in detail is fully capable of obtaining the objects and providing the advantages herein before stated, it is to be understood that it is merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended to the details of construction or design herein shown other than as described in the appended claims.