Abstract:
A method of delivering graft material to a surgical site includes positioning graft material in a tube of a delivery device. The tube defines an open end and a bend along its length. A plunger within the tube is advanced to dispense the graft material through the open end.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of U.S. application Ser. No. 13/871,743, filed Apr. 26, 2013, entitled “Delivery Device for Graft Material”; the entire teachings of which are incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    Concepts presented herein relate to delivery of graft material to a target site. 
         [0003]    Example applications that utilize graft material include rhinologic functional endoscopic sinus surgery (FESS), spinal, orthopedic and arthroscopic procedures. Regardless of the exact procedure, various instruments for delivery of graft material are currently employed. In some procedures to delivery material to a target site, surrounding structures can be sensitive and thus contact between these structures and the instruments should be avoided. As such, current procedures can be overtly time consuming and require that the instruments pass sensitive structures multiple times to perform the delivery of material. This situation increases the chance of damage to sensitive structures adjacent the target site. 
       SUMMARY 
       [0004]    A method of delivering graft material to a surgical site includes positioning graft material in a tube of a delivery device. The tube defines an open end and a bend portion along its length. A plunger within the tube is advanced to dispense the graft material through the open end. 
         [0005]    A delivery device for delivering graft material to a target site includes a hand piece maintaining an actuator mechanism. A tube that defines a lumen, an open end and a bent portion along its length is coupled to the hand piece. A plunger is positioned within the lumen of the tube and coupled to the actuator mechanism. The actuator mechanism is configured to move the plunger within the lumen from a loading position to an extended position. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  is a side view of a delivery device according to a first embodiment. 
           [0007]      FIG. 2  is a side view of a delivery device according to a second embodiment. 
           [0008]      FIG. 3  is a side view of a distal end of a delivery device. 
           [0009]      FIG. 4  is a side view of an alternative plunger of a delivery device. 
           [0010]      FIGS. 5 and 6  are schematic views of steps in using a delivery tube to deliver graft material to a cavity. 
       
    
    
     DETAILED DESCRIPTION 
       [0011]      FIG. 1  is a side view of a first embodiment of a delivery device  10 . Device  10  includes a delivery tube  12 , a plunger  14  positioned within the delivery tube  12  and a hand piece  16  coupled with the tube  12  and plunger  14 . Hand piece  16  maintains an actuator mechanism  18  configured to move plunger  14  with respect to tube  12 . In one embodiment, the actuator mechanism  18  can move plunger  14  in a controlled, metered manner as desired. In the illustrated embodiment, actuator mechanism  18  includes a first handle  20 , a second handle  22  and a ratcheting mechanism generally indicated at  24 . As a user squeezes handles  20  and  22  together, ratcheting mechanism  24  moves to operate and advance plunger  14  along the tube  12 . Advancement of the plunger  14  can be controlled to advance a predetermined distance each time the actuation mechanism  18  is actuated. This predetermined distance corresponds to a volume of material within the tube that will be dispersed. In a further embodiment, tube  12  can include markings to denote an amount of material positioned with the tube  12 . 
         [0012]    Hand piece  16  can also include a release mechanism  26  that releases plunger  14  from engagement with the ratchet mechanism  24 . In particular, in order to move plunger  14  manually with respect to tube  12 , a user can depress the release mechanism  26  and operate a handle  28  to move the plunger  14  to a desired position along tube  12 . 
         [0013]    Details of the tube  12  are discussed below. In general, however, tube  12  can include a suitable connection mechanism  30  that engages a corresponding receiving mechanism  31  on the hand piece  16  so as to secure the tube  12  to the hand piece  16  during operation of the device  10 . Tube  12  includes a first, proximal end  32  and a distal, open end  34 . The tube  12  further defines a lumen  36  configured to transport graft material therein. The tube  12  further includes a bend portion  38  positioned between the proximal end  32  and the proximal end  34  and the distal end  34 . In one embodiment, a distance from the distal end  34  to the bend portion  38  is approximately in a range from 1.0 to 1.5 inches. Furthermore, the bend portion  38  is defined as having approximately a 4.0 inch radius. 
         [0014]    In any event, plunger  14  in  FIG. 1  is illustrated in a retracted or loading position that allows graft material to be inserted through distal end  34  and into lumen  36 . Once the material is loaded into lumen, plunger  14  can be advanced toward the distal end  34  (i.e., to an extended or delivery position) in order to advance material within the lumen  36  along the tube  12 . Ultimately, the material exits the distal end  34 . 
         [0015]      FIG. 2  is a side view of a second embodiment of a delivery device  50  that includes the delivery tube  12  and plunger  14  as discussed above with respect to  FIG. 1 . As opposed to the hand operated mechanism  18  of device  10 , device  50  includes a motorized actuator mechanism  52  that includes a motor to deliver powered rotational movement to a rod  54 . A translation mechanism  56  translates the rotational movement of the rod  54  to linear movement so as to move plunger  14  relative to tube  12 . In particular, hand piece  52  includes a trigger mechanism  58  that, when depressed, provides rotational power to the rod  54 . 
         [0016]    Regardless of a particular actuator mechanism used to position plunger  14  with respect to tube  12 ,  FIG. 3  is a close up view of the tube  12  and plunger  14 . As compared with  FIG. 1 , plunger  14  is illustrated in  FIG. 3  in an extended or delivery position, wherein the plunger  14  extends to the distal end  34  of the tube  12 . Tube  12  includes a proximal portion  60  and a distal portion  62 . The proximal portion  60  extends from the connection mechanism  30  and narrows at a tapered portion  64  to connect with the distal portion  62 . Distal portion  62  defines a constant diameter from the tapered portion  64  to the open distal end  34 . In one embodiment, an outer diameter of the distal portion is in a range of approximately 5.0-7.0 millimeters. The tapered portion  64  can assist in preventing material from being compacted within the lumen  36 . 
         [0017]    As illustrated, plunger  14  includes a proximal rod  70 , a flexible distal portion  72  and a distal tip  74 . In one embodiment, the plunger  14  is formed of stainless steel or polyether ether ketone (PEEK). Other materials can be used to form the plunger  14 . Prior to use, the plunger  14  can be sterilized. Rod  70  is directly coupled to an actuator mechanism (e.g., mechanism  18  or  52 ) to move plunger  14  along the tube  12 . Flexible distal portion  72  includes a plurality of cuts  76  that impart flexibility within the distal portion  72 . In the embodiment illustrated, cuts  76  are dovetail shaped. In alternative embodiments, the cuts  76  can be spiral shaped, double spiral shaped and/or other shapes as desired. For example,  FIG. 4  illustrates an alternative plunger  80  that includes double spiral cuts  82  positioned along a length of the plunger  82 . Independent of the shape of cuts  76 , the cuts  76  impart flexibility on the distal portion  72  so as to allow plunger  14  to move along bend portion  38 . Distal tip  74  can be formed of silicon or other surgically safe material as desired. 
         [0018]    To secure tube  12  to hand piece  18 , the connection mechanism  30  defines a flange  84  positioned at the proximal end  32 . Flange  84  is positioned within recesses  86  (one of which is shown) in receiving mechanism  31  of the hand piece  16 . To connect connection mechanism  30  to receiving mechanism  31 , flange  84  is inserted into receiving mechanism  31  and rotated a quarter turn to position flange  84  within recesses  86 . 
         [0019]      FIGS. 5 and 6  illustrate delivery of material to a cavity at a target site. In the embodiment illustrated, the target site is an intervertebral disc  100 . Delivery tube  12  can be modified as desired for delivery of graft material to alternative target sites. For example, bend portion  38  can be positioned at different distances from distal end  34  and/or define a different radius of curvature. By way of reference, the intervertebral disc  100  generally includes a nucleus  102  forming a cavity surrounded by an annulus  104 . The tube  12  is employed to deliver graft material  110  positioned within lumen  36  to the nucleus  102 . In particular, the plunger  14  is in a loading position (i.e., retracted from distal end  34 ) and graft material  110  has been positioned within lumen  36 . Once the material  110  is loaded, tube  12  approaches the intervertebral disc  100 . In one embodiment, the tube  12  is deployed using a transforaminal approach, for example during a transforaminal lumbar interbody fusion (TLIF) procedure. Alternative approaches to the disc  100  are also acceptable and include a posterior approach, posterior-lateral approach, anterior approach, left or right lateral approach, etc. 
         [0020]    Regardless of the approach, the tube  12  is positioned through an opening  106  formed in the annulus  104 . The opening  106  can be a naturally-occurring tear or similar passage. Alternatively, the opening  106  can be surgically cut or otherwise created in the annulus  104 . In  FIG. 5 , the open distal end  34  of the tube  12  is positioned within the nucleus  102  for delivery of graft material therein. In particular, the plunger  14  is in a retracted position, allowing graft material  110  to be positioned within the lumen  36  distal the tip  74 . The distal end  34  is advanced into the nucleus  102  to a desired position. Once positioned within the nucleus  102 , as illustrated in  FIG. 6 , the plunger  14  is distally advanced to an extended position to dispense graft material  110  out the distal end  34  of the delivery tube  12 . 
         [0021]    Although the present disclosure has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes can be made in form and detail without departing from the spirit and scope of the present disclosure.