Abstract:
A needle assembly according to an exemplary aspect of the present disclosure includes, among other things, a cannula, a trocar insertable through the cannula, the trocar including a shaft extending longitudinally between a proximal portion and a tip portion and a groove formed in the shaft and extending from near the tip portion at least partially toward the proximal portion.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    This disclosure relates to a surgical device. More particularly, this disclosure is directed to a bone marrow aspiration needle assembly for collecting a bone marrow sample for analysis. 
         [0002]    Bone marrow is the soft tissue located inside bones that helps form blood cells. Bone marrow is typically located in the hollow parts of most bones. Bone marrow examination is useful for diagnosing a variety of diseases and conditions. A sample of the bone marrow must be first extracted from the bone marrow space before it can be examined. 
         [0003]    In one known bone marrow aspiration or biopsy procedure, a needle assembly is inserted into a bone, such as into the posterior iliac crest of the pelvic bone. After the needle assembly penetrates the bone, a trocar or stylet is removed from the needle assembly. Fluid from the bone marrow cavity can then be aspirated through the needle assembly to collect a bone marrow sample, which can then be appropriately analysed. The process of removing the bone marrow sample from bone is often a relatively painful procedure. 
       SUMMARY OF THE INVENTION 
       [0004]    A needle assembly according to an exemplary aspect of the present disclosure includes, among other things, a cannula, a trocar insertable through the cannula, the trocar including a shaft extending longitudinally between a proximal portion and a tip portion and a groove formed in the shaft and extending from near the tip portion at least partially toward the proximal portion. 
         [0005]    In a further non-limiting embodiment of the foregoing assembly, the groove extends across an entire length of the trocar. 
         [0006]    In a further non-limiting embodiment of either of the foregoing assemblies, the groove extends from the tip portion to the proximal portion. 
         [0007]    In a further non-limiting embodiment of any of the foregoing assemblies, the tip portion includes a pointed tip. 
         [0008]    In a further non-limiting embodiment of any of the foregoing assemblies, the cannula is removably connected to a handle. 
         [0009]    In a further non-limiting embodiment of any of the foregoing assemblies, the trocar includes a central lumen that accommodates a wire. 
         [0010]    In a further non-limiting embodiment of any of the foregoing assemblies, the cannula includes a plurality of depth markings and a plurality of side ports. 
         [0011]    In a further non-limiting embodiment of any of the foregoing assemblies, the cannula includes a distal portion having a forked tip. 
         [0012]    In a further non-limiting embodiment of any of the foregoing assemblies, the trocar includes a cap and the shaft is connected to the cap. 
         [0013]    In a further non-limiting embodiment of any of the foregoing assemblies, an adaptor is disposed on the cap and configured to receive an insertion tool. 
         [0014]    A bone marrow aspiration needle assembly according to another exemplary aspect of the present disclosure includes, among other things, a handle, a cannula removably connected to the handle and a trocar insertable into the cannula, the trocar including a groove that extends along a shaft and a cap that includes an adaptor configured to accommodate an insertion tool. 
         [0015]    In a further non-limiting embodiment of the foregoing assembly, the cannula is connected to the handle by a coupling assembly. 
         [0016]    In a further non-limiting embodiment of either of the foregoing assemblies, the groove extends an entire length between a tip portion and a proximal portion of the trocar. 
         [0017]    In a further non-limiting embodiment of any of the foregoing assemblies, the adaptor includes a plurality of pin openings. 
         [0018]    In a further non-limiting embodiment of any of the foregoing assemblies, the adaptor includes a recessed opening having a hexagonal shape. 
         [0019]    A surgical method according to another exemplary aspect of the present disclosure includes, among other things, inserting a needle assembly into a bone marrow space inside a bone, the needle assembly including a cannula and a grooved trocar received through the cannula, and equalizing a pressure gradient between the bone marrow space and an ambient space outside of the bone with the grooved trocar as the grooved trocar is removed from the cannula. 
         [0020]    In a further non-limiting embodiment of the foregoing surgical method, the inserting step includes connecting an insertion tool to an adaptor of the grooved trocar and drilling the needle assembly into the bone marrow space. 
         [0021]    In a further non-limiting embodiment of either of the foregoing surgical methods, the method includes disconnecting a cap of the grooved trocar from a handle of the needle assembly prior to removing the grooved trocar from the cannula. 
         [0022]    In a further non-limiting embodiment of any of the foregoing surgical methods, the method includes inserting an extraction tool into the cannula after removing the grooved trocar. 
         [0023]    In a further non-limiting embodiment of any of the foregoing surgical methods, the inserting step includes positioning the needle assembly over a wire via a central lumen that extends through the grooved trocar. 
         [0024]    The embodiments, examples and alternatives of the preceding paragraphs, the claims, or the following description and drawings, including any of their various aspects or respective individual features, may be taken independently or in any combination. Features described in connection with one embodiment are applicable to all embodiments, unless such features are incompatible. 
         [0025]    The various features and advantages of this disclosure will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]      FIG. 1  illustrates a bone marrow aspiration needle assembly. 
           [0027]      FIG. 2  illustrates a cannula of a bone marrow aspiration needle assembly. 
           [0028]      FIGS. 3A and 3B  illustrate exemplary distal portions of a cannula of a bone marrow aspiration needle assembly. 
           [0029]      FIG. 4  illustrates a trocar of a bone marrow aspiration needle assembly. 
           [0030]      FIG. 5  illustrates another trocar. 
           [0031]      FIGS. 6A and 6B  illustrate exemplary adapters of a trocar cap of a bone marrow aspiration needle assembly. 
           [0032]      FIGS. 7A ,  7 B,  7 C and  7 D schematically illustrate a method of harvesting a bone marrow sample using a bone marrow aspiration needle assembly. 
           [0033]      FIG. 8  illustrates a bone marrow needle assembly according to another embodiment of this disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0034]    This disclosure details a bone marrow aspiration needle assembly that can be utilized to obtain a bone marrow sample. In some embodiments, the needle assembly includes a trocar having a shaft and a groove extending longitudinally along the shaft. In other embodiments, the needle assembly includes a trocar having a cap that includes an adapter configured to accommodate an insertion tool, such as a drill. In still other embodiments, the needle assembly includes a handle and a cannula removably connected to the handle. These and other features are described in greater detail in the paragraphs that follow. 
         [0035]      FIG. 1  illustrates a bone marrow aspiration needle assembly  10 . The needle assembly  10  may be employed to harvest a bone marrow sample from a bone marrow space  11  inside a bone  12 . The exemplary needle assembly  10  may be used to perform biopsies of soft tissue or bone. In one non-limiting embodiment, the bone  12  is a pelvic bone, and the needle assembly  10  may be inserted into the posterior iliac crest of the pelvic bone. However, the needle assembly  10  could be used to aspirate bone marrow samples from other locations of a patient&#39;s body, including the breast bone, sternum, tibia and/or any other bone. 
         [0036]    The needle assembly  10  may include a handle  14 , a cannula  16  connected to the handle  14 , and a trocar  18  insertable through the cannula  16 . The trocar  18  may be received through an internal bore  20  of the cannula  16  and may extend beyond a distal portion  30  of the cannula  16 . In one embodiment, the cannula  16  is removably connected to the handle  14  via a coupling assembly  22 . The coupling assembly  22  may include an actuator  24  that can be actuated to release the cannula  16  from the handle  14 . 
         [0037]    In another embodiment, the trocar  18  is removably connected to the handle  14 . The trocar  18  may be connected to the handle  14  using a luer-type coupling  15 . The luer-type coupling  15  may include a tab  17  and an L-shaped notch  19  for receiving the tab  17 . In one embodiment, the tab  17  is part of the handle  14  and the notch  19  is part of a cap  44  of the trocar  18 . An opposite configuration is also contemplated in which the tab  17  is part of the cap  44  and the notch  19  is part of the handle  14 . The cap  44  of the trocar  18  may be twisted in a first direction D 1  to connect the trocar  18  to the handle  14 , and may be twisted in a second, opposite direction D 2  to disengage the trocar  18  from the handle  14 , in one non-limiting embodiment. 
         [0038]      FIG. 2  illustrates a cannula  16  of the bone marrow aspiration needle assembly  10  of  FIG. 1 . The cannula  16  includes a tube  26  that extends between a proximal portion  28  and a distal portion  30 . The proximal portion  28  includes a hub  32  configured to connect to the coupling assembly  22  of the handle  14  (see  FIG. 1 ). A plurality of depth markings  34  may be disposed along a length of the tube  26 . The depth markings  34  can be used to control a depth of insertion of the needle assembly  10  into the bone  12  (see  FIG. 1 ). 
         [0039]    The cannula  16  may additionally include multiple side ports  36  that extend through the tube  26 . In one embodiment, the side ports  36  are disposed along a length of the tube  26  between the distal portion  30  and the depth markings  34 . The side ports  36  may embody a variety of sizes and shapes. The side ports  36  open into the internal bore  20  of the cannula  16  and may reduce pressure during a bone marrow aspiration process. This may reduce inefficient bone marrow flow through the internal bore  20  and damage to the bone marrow as it is aspirated through the needle assembly  10 . 
         [0040]      FIG. 3A  illustrates a first embodiment of a distal portion  30  of the cannula  16 . In this embodiment, the distal portion  30  includes a forked tip  31  having at least one V-shaped notch  38 . In another embodiment, shown in  FIG. 3B , the distal portion  30  includes a forked tip  31  that includes a plurality of indents  40 . The indents  40  may form serrated edges  42 . The serrated edges  42  facilitate the insertion of the needle assembly  10  into bone  12 . 
         [0041]      FIG. 4  illustrates a trocar  18  of a bone marrow aspiration needle assembly  10 . The trocar  18  includes a cap  44  and a shaft  46  connected to the cap  44 . The shaft  46  extends between a proximal portion  48  and a tip portion  50 . The proximal portion  48  may be connected to the cap  44 , and the tip portion  50  may be pointed to facilitate penetrating bone. 
         [0042]    The shaft  46  of the trocar  18  may include a groove  52  that extends longitudinally across a length L of the shaft  46 . The groove  52  may be formed in an outer surface  47  of the shaft  46 . In one embodiment, the groove  52  extends radially into the shaft  46 . 
         [0043]    In one non-limiting embodiment, the length L of the groove  52  spans the entire distance from the tip portion  50  to the proximal portion  48 . In another embodiment, the length L of the groove  52  spans only a portion of the distance between the tip portion  50  and the proximal portion  48  (see  FIG. 5 ). In both of these embodiments, the groove  52  is not localized at the tip portion  50  but extends at least partially into a central body of the shaft  46  that is between the proximal portion  48  and the tip portion  50 . As discussed in greater detail below, the groove  52  equalizes pressure gradients that may occur between a bone marrow space inside of bone and an ambient space outside of bone to alleviate pain associated with a bone marrow aspiration procedure. For example, pain is often associated with removing the trocar  18  from the cannula  16  of the needle assembly  10  (see, e.g.,  FIG. 1  and  FIG. 7B ). 
         [0044]    Referring to  FIGS. 6A and 6B , the cap  44  of the trocar  18  may include an adapter  54 . The adaptor  54  may be located on a top face  66  of the cap  44  and accommodates an insertion tool, such as a drill or other insertion tool. In one embodiment, the adaptor  54  includes a plurality of pin openings  60  for connecting to an insertion tool (see  FIG. 6A ). In another embodiment, the adaptor  54  includes a recessed opening  64  for accepting an insertion tool. The recessed opening  64  may include a hexagonal shape, in one non-limiting embodiment. Other shapes are also contemplated within the scope of this disclosure. 
         [0045]      FIGS. 7A-7D , with continued reference to  FIGS. 1-6B , schematically illustrate an exemplary method for aspirating a bone marrow sample from a bone. The bone marrow aspiration needle assembly  10  may be used to aspirate bone marrow from any bone. However, the following exemplary method is illustrated and described with reference to a human pelvic bone. In addition, the exemplary method is not limited to the exact order described below, and a person of ordinary skill in the art would recognize that additional or fewer steps may be necessary to obtain a bone marrow sample from the bone. 
         [0046]    Referring to  FIG. 7A , once an insertion location is selected and the site is prepared for the extraction process (measurements, markings, anesthetics, etc.), the needle assembly  10  is inserted into a bone marrow space  11  inside a bone  12 . The needle assembly  10  may be pushed-in by hand, hammered in, or drilled into the bone marrow space  11  using an insertion tool T. In one non-limiting embodiment, if an insertion tool T is used for insertion, the handle  14  (see  FIG. 1 ) may first be removed from the needle assembly  10  prior to attaching the insertion tool T to the adaptor  54  of the cap  44  of the trocar  18 . The distal portion  30  of the cannula  16  and the tip portion  50  of the trocar  18  facilitate insertion of the needle assembly  10  into the bone marrow space  11 . 
         [0047]    Next, as illustrated by  FIG. 7B , the trocar  18  of the needle assembly  10  is removed from the cannula  16 . The cap  44  of the trocar  18  may need disconnected from the handle  14  of the needle assembly  10  (see  FIG. 1 ) prior to removing the trocar  18 . The cannula  16  remains inserted inside the bone marrow space  11 . During removal of the trocar  18 , the groove  52  of the shaft  46  of the trocar  18  equalizes a pressure gradient between the bone marrow space  11  and an ambient space  70  outside of the bone  12 . This reduces the amount of pain experienced by the patient during the bone marrow biopsy, particularly during removal of the trocar  18 . 
         [0048]    An extraction device  80 , such as a syringe, may next be inserted through the cannula  16  as shown in  FIG. 7C . The extraction device  80  can then be employed to draw a bone marrow sample  90  into the extraction device (see  FIG. 7D ). The bone marrow sample  90  may then be removed and analyzed as desired. 
         [0049]      FIG. 8  illustrates another bone marrow aspiration needle assembly  110 . In this disclosure, like reference numbers designate like elements where appropriate and reference numerals with the addition of  100  or multiples thereof designate modified elements that are understood to incorporate the same features and benefits of the corresponding original elements. 
         [0050]    The needle assembly  110  is similar to the needle assembly  10  of  FIG. 1  and includes a handle  114 , a cannula  116  connected to the handle  114 , and a trocar  118  that can be inserted through the cannula  116 . The trocar  118  may also be grooved. However, in this embodiment, the trocar  118  includes a central lumen  125  that extends through the trocar  118 . The needle assembly  110  may be inserted over a wire  127 , such as a k-wire, via the central lumen  125  to provide targeted insertion of the needle assembly  110  into a bone marrow space  11  of a bone  12 . 
         [0051]    Although the different non-limiting embodiments are illustrated as having specific components, the embodiments of this disclosure are not limited to those particular combinations. It is possible to use some of the components or features from any of the non-limiting embodiments in combination with features or components from any of the other non-limiting embodiments. 
         [0052]    It should be understood that like reference numerals identify corresponding or similar elements throughout the several drawings. It should also be understood that although a particular component arrangement is disclosed and illustrated in these exemplary embodiments, other arrangements could also benefit from the teachings of this disclosure. 
         [0053]    The foregoing description shall be interpreted as illustrative and not in any limiting sense. A worker of ordinary skill in the art would understand that certain modifications could come within the scope of this disclosure. For these reasons, the following claims should be studied to determine the true scope and content of this disclosure.