Abstract:
A method of accessing a hollow anatomical structure (HAS) of a patient includes puncturing the patient&#39;s skin with a needle, upon which is disposed a cannula. A tip portion of the needle is inserted into the HAS. A distal portion of the cannula is advanced distally along the needle, until the distal portion of the cannula is in the HAS. The needle is removed from the HAS while the distal portion of the cannula remains in the HAS. A guide wire is inserted into the HAS via the cannula. The cannula is removed from the HAS while at least a portion of the guide wire remains in the HAS.

Description:
BACKGROUND 
       [0001]    Generally, access devices are used to provide fluid communication with a patient&#39;s internal anatomy. For example, a catheter may be used to deliver fluid to the patient&#39;s vasculature or to withdraw fluid from the patient&#39;s vasculature. Currently, a clinician must perform a series of preliminary steps in order to place the catheter in communication with the patient&#39;s vasculature. For instance, an initial access step is performed by puncturing the patient&#39;s skin with a micro-access needle. A micro guide wire is then inserted into the micro-access needle and into the patient&#39;s vasculature. The micro-access needle is withdrawn over the micro guide wire leaving the micro guide wire in place. Next, a rigid dilator is advanced over the micro guide wire to expand the access pathway. The micro guide wire is removed and a larger size guide wire is inserted into the dilator. The dilator can then be removed leaving the larger guide wire for use by the clinician to advance a catheter into the patient&#39;s vasculature. Once the desired device is in place in the patient&#39;s vasculature, the larger guide wire can be removed. One problem with this conventional vascular access procedure, however, is that the use of the rigid dilator can cause significant patient trauma. 
       SUMMARY 
       [0002]    The present disclosure is directed to a method and kit for accessing a hollow anatomical structure of a patient with reduced patient trauma, as compared to conventional vascular access procedures that use dilators. 
         [0003]    In one aspect, a method of accessing a hollow anatomical structure (HAS) of a patient includes puncturing the patient&#39;s skin with a needle, upon which is disposed a cannula. A tip portion of the needle is inserted into the HAS. A distal portion of the cannula is advanced distally along the needle, until the distal portion of the cannula is in the HAS. The needle is removed from the HAS while the distal portion of the cannula remains in the HAS. A guide wire is inserted into the HAS via the cannula. The cannula is removed from the HAS while at least a portion of the guide wire remains in the HAS. 
         [0004]    In some embodiments, a catheter is advanced over the guide wire and into the HAS. 
         [0005]    In other embodiments, the needle defines a needle longitudinal axis and the cannula defines a cannula longitudinal axis. The cannula is disposed on the needle such that the cannula longitudinal axis is coaxially aligned with the needle longitudinal axis. 
         [0006]    In some embodiments, the distal portion of the cannula is advanced along the needle longitudinal axis and the needle is moved in a proximal direction along the cannula longitudinal axis. 
         [0007]    In other embodiments, the guide wire is moved in a distal direction along the cannula longitudinal axis. 
         [0008]    In some embodiments, the cannula comprises a port. The needle and guide wire are moved through the port. 
         [0009]    In other embodiments, the cannula longitudinal axis intersects the port. 
         [0010]    In some embodiments, the port is a hemostatic valve. 
         [0011]    In other embodiments, the hemostatic valve maintains the position of the guide wire in the HAS. 
         [0012]    In some embodiments, the cannula is less rigid than the needle. 
         [0013]    In other embodiments, the tip portion of the needle extends distally of the distal portion of the cannula while the needle punctures the patient&#39;s skin and while the tip portion of the needle is inserted into the HAS. 
         [0014]    In some embodiments, the cannula defines a lumen having an inner diameter greater than an outer diameter of the needle and the lumen of the cannula is moved along the outer diameter of the needle. 
         [0015]    In other embodiments, the guide wire is moved through the lumen of the cannula. 
         [0016]    In another aspect, a kit includes a needle, a flexible cannula, a guide wire, and a package containing the needle, cannula, and guide wire. The flexible cannula includes a distal portion and a proximal portion. The cannula defines a lumen extending from the proximal portion to the distal portion. The needle is disposed in the lumen. The needle includes a tip portion extending distally beyond the distal portion of the cannula. The needle is movable in a proximal direction for removal from the cannula at the proximal portion of the lumen. The guide wire is movable through the lumen from the proximal portion to the distal portion of the cannula. 
         [0017]    In some embodiments, the needle defines a needle longitudinal axis and the lumen of the cannula defines a cannula longitudinal axis. The needle longitudinal axis is coaxially aligned with the cannula longitudinal axis when the needle is disposed in the lumen. 
         [0018]    In other embodiments, the cannula includes a port disposed along the proximal portion of the cannula. The needle is movable through the port for removal from the cannula at the proximal portion of the lumen. 
         [0019]    In some embodiments, the guide wire is movable through the port and into the lumen of the cannula. 
         [0020]    In other embodiments, the cannula longitudinal axis intersects the port. 
         [0021]    In some embodiments, the port is a hemostatic valve. 
         [0022]    Embodiments can include one or more of the following advantages. 
         [0023]    In some embodiments, access to an anatomical structure of a patient is achieved with significantly less trauma to the patient. Additionally, access is achieved without the use of a dilator. 
         [0024]    In other embodiments, access to an anatomical structure of a patient is achieved through minimal access steps. 
         [0025]    In some embodiments, access to an anatomical structure of a patient is achieved with a single access device and a guide wire. 
         [0026]    Other aspects, features, and advantages will be apparent from the description and drawings, and from the claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0027]      FIG. 1  is a side elevation of an access device. 
           [0028]      FIG. 2  is the side elevation of the access device of  FIG. 1  with a needle and needle hub removed. 
           [0029]      FIG. 3  is a side elevation of the needle and needle hub with a needle-stick prevention mechanism disposed over the needle. 
           [0030]      FIG. 4  is the side elevation of  FIG. 2  with a valve of the access device removed. 
           [0031]      FIG. 5  is a horizontal cross section of the valve. 
           [0032]      FIG. 6  is an illustration of the needle in an unprotected configuration. 
           [0033]      FIG. 7  is an illustration of the needle in a protected configuration. 
           [0034]      FIG. 8  is an illustration of a guide wire inserted in the access device. 
           [0035]      FIGS. 9-13  are schematic illustrations of a process of using the access device to access a patient&#39;s hollow anatomical structure. 
           [0036]      FIG. 14  is an illustration of the access device and guide wire in a package. 
       
    
    
     DETAILED DESCRIPTION 
       [0037]    Referring to  FIGS. 1-4 , an access device  1  includes a needle hub  3  and a needle shaft  5  fixedly attached to the needle hub at a proximal end of the needle shaft. A plug  7  is disposed in a proximal end of the needle hub  3 . The needle shaft  5  extends distally from the needle hub to a sharp distal tip. When the access device  1  is in a pre-use configuration, a cannula  8  including a cannula hub  9  and a flexible tube  11 , extending distally from the cannula hub, surrounds at least a portion of the needle shaft  5 . At least a portion of the sharp distal tip of the needle shaft  5  extends past a distal end of the cannula  8  so that the sharp distal tip can be used to puncture a subject&#39;s skin during use. The needle shaft  5  defines a needle longitudinal axis LA 2  ( FIG. 3 ), and the cannula  8  defines a cannula longitudinal axis LA 2  ( FIG. 2 ). In certain embodiments, the cannula  8  is disposed on the needle shaft  5  such that the cannula longitudinal axis LA 2  is coaxially aligned with the needle longitudinal axis LA 1 . The cannula  8  defines a lumen extending from a proximal portion of the cannula to a distal portion of the cannula. The lumen of the cannula  8  has an inner diameter that is greater than an outer diameter of the needle shaft  5 . Therefore, the cannula  8  can move (e.g., longitudinally and/or rotationally) along an outer surface of the needle shaft  5  as will be explained in greater detail below. A guide wire  13  is insertable into the access device  1  ( FIG. 8 ). The access device  1  and guide wire  13  are used to gain access to a hollow anatomical structure (HAS) of a patient such as a vein V to provide a guide for inserting a catheter C ( FIG. 13 ) into the vein. 
         [0038]    The needle shaft  5  and cannula  8  facilitate access of a patient&#39;s vein or other HAS with minimal stress to the patient&#39;s tissue. In particular, the access device  1 , including the needle shaft  5  and cannula  8 , provides a single access assembly which can be used, with the guide wire  13 , to gain access to the patient&#39;s HAS thereby limiting the number of devices and steps needed to access the patient&#39;s HAS. Additionally, the access device  1  provides access to the patient&#39;s HAS without the use of a rigid dilator which can be stressful on the patient&#39;s tissue causing significant trauma to the patient. As a result, the access device  1  facilitates access to the patient&#39;s HAS with less resulting trauma to the patient. 
         [0039]    Referring to  FIGS. 2, 4, and 5 , a hemostatic valve  15  is removably attached to a proximal end of the cannula hub  9 . The valve  15  defines a port of the cannula  8  when attached to the cannula hub  9 . The valve  15  includes a housing  19  including threads  21  that mate with threads  23  on the cannula hub  9 . For example, the threads  21  of the housing and the threads on the cannula  9  can be mating portions of a Luer lock connection. 
         [0040]    The access device  1  has an axial alignment such that the longitudinal axis LA 2  of the cannula  8 , and the longitudinal axis LA 1  of the needle shaft  5  when the needle shaft is received in the cannula  8 , extend through the port and through the valve  15 . A valve member  25  is hemostatic and prevents a backflow of blood out of the port of the cannula  8  when the valve is attached to the port. The valve member  25  also seals around the needle shaft  5 . Therefore, as the needle shaft  5  is moved with respect to the cannula  8 , fluid is prevented from escaping the access device  1  around an outer surface of the needle shaft. In some embodiments, the valve  15  comprises a “gummy” valve. In certain embodiments, the valve  15  positions the needle shaft  5  as the needle is moved with respect to the cannula hub  9  and flexible tube  11 . For instance, the valve  15  may yieldably resist movement of the needle shaft  5  along the longitudinal axis LA 2  of the cannula  8 . 
         [0041]    Referring to  FIGS. 6 and 7 , a needle-stick prevention mechanism  31  is releasably secured to the housing  19  of the valve  15 . The needle-stick prevention mechanism  31  comprises a main body  33  having a proximal portion and a distal portion. A needle passage  35  ( FIG. 7 ) extends through the proximal and distal portions of the main body  33 . A retaining ring  37  is disposed in the needle passage in the proximal portion of the main body  33 . The distal portion of the main body  33  at least partially houses a blocking arm  39  biased by a spring  41  and movable in a transverse passage  43  in the distal portion of the main body. In the pre-use configuration, the needle shaft  5  passes entirely through the needle passage  35  in the main body  33  of the needle-stick prevention mechanism  31 . In this configuration, the needle shaft  5  holds the blocking arm  39 , against the bias of the spring  41 , to one side of the distal portion of the main body  33  ( FIG. 6 ). As a result, an end of the blocking arm  39  extends out of the transverse passage  43 . 
         [0042]    The distal portion of the main body  33  of the needle-stick prevention mechanism  31  is received in an open end  45  of the housing  19  of the valve  15  in the pre-use configuration ( FIGS. 1 and 5 ). In particular, the end of the blocking arm  39  that extends out of the transverse passage  43  is received in a recess  47  in the housing  19  of the valve  15 . A diameter of the end of the blocking arm  39  is sized larger than a narrow section of the recess  47  so that the needle-stick prevention mechanism  31  is prevented from being pulled out of the valve housing  19 . 
         [0043]    The needle hub  3  and needle shaft  5  are movable relative to the cannula  8 , hemostatic valve  15 , and needle-stick prevention mechanism  31  to withdraw the needle shaft  5  from the cannula and valve after the subject&#39;s skin has been punctured and the cannula has been placed in communication with the subject&#39;s HAS. If the sharp distal tip of the needle shaft  5  is withdrawn proximally of the blocking arm  39  of the needle-stick prevention mechanism  31 , the bias of the spring  41  causes the blocking arm to move along the transverse passage  43 , across the needle passage  35 , blocking the needle passage. This movement also moves the end of the blocking arm  39  out of the recess  47  in the valve  15  allowing the needle-stick prevention mechanism  31  to be separated from the valve ( FIG. 7 ). Thus, the blocking arm  39  prevents the sharp distal tip of the needle shaft  5  from being moved distally out of the main body  33  of the needle-stick prevention mechanism  31 . A crimp  51  on the needle shaft  5  is engageble with the retaining ring  37  in the proximal portion of the main body  33  of the needle-stick prevention mechanism  31 . Therefore, the retaining ring  37  prevents the sharp distal tip of the needle shaft  5  from being moved proximally out of the main body  33  of the needle-stick prevention mechanism  31 . Accordingly, the sharp distal tip of the needle shaft  5  is enclosed in the main body  33  of the needle-stick prevention mechanism  31  preventing the chance of an accidental stick by the needle once it has been pulled out of the cannula  8  and hemostatic valve  15 . 
         [0044]    In use, referring to  FIGS. 9-13 , the access device  1  is positioned near the patient&#39;s skin at a location of the HAS that is to be accessed. The patient&#39;s skin is then punctured with the sharp distal tip of the needle shaft  5  at the location of the HAS. The distal tip of the needle shaft  5 , along with the cannula  8  disposed on the needle shaft, is inserted into the patient&#39;s HAS ( FIG. 9 ). In the illustrated embodiment, the HAS is a vein V. The lumen of the cannula  8  is moved along the outer diameter of the needle shaft to advance the flexible tube  11  of the cannula  8  distally along the needle shaft  5 . More particularly, in order to place the flexible tube  11  in the patient&#39;s vein V, the cannula  8  is moved distally along the needle shaft  5  shaft such that a distal end of the flexible tube is moved over the distal tip of the needle shaft and into the patient&#39;s vein V ( FIG. 10 ). In some embodiments, the cannula  8  is moved distally along the longitudinal axis LA 1  of the needle shaft  5 . Next, the needle shaft  5  is moved proximally with respect to the cannula  8  to withdraw the needle shaft from the patient&#39;s vein V and to withdraw the needle shaft from the cannula ( FIG. 11 ). With the needle removed, the valve  15  prevents a backflow of blood out of the cannula  8 . In certain embodiments, the needle shaft  5  is moved proximally along the cannula longitudinal axis LA 2 . In some embodiments, the needle shaft  5  is withdrawn from the port of the cannula  8 . 
         [0045]    Referring to  FIG. 12 , the guide wire  13  is then inserted through the valve  15  at the port and into the cannula  8 . Continued insertion of the guide wire  13  passes the guide wire through the cannula hub  9 , through the flexible tube  11 , and into the patient&#39;s vein V. The valve  15  functions to maintain a position of the guide wire  13 . For instance, the valve  15  holds the guide wire  13  in place in the patient&#39;s vein V. The flexible tube  11  can be removed from the patient&#39;s vein V once the guide wire  13  is in place in the patient&#39;s vein. Movement of the flexible  11  and cannula hub  9 , proximally away from the patient&#39;s vein V will remove the cannula  8  from the guide wire  13  completely ( FIG. 13 ). The guide wire  13  is then in position for guiding a medical device into the patient&#39;s vein V. For instance, a catheter C can be advanced over the guide wire  13  and into the patient&#39;s vein V. 
         [0046]    This process facilitates access to the patient&#39;s HAS using only the access device  1  and the guide wire  13 . Thus, the process for facilitating access to the HAS is simplified and uses less components. As a result, the trauma to the patient&#39;s body is lessened. 
         [0047]    In some embodiments, the needle shaft  5  is made from a rigid material such as stainless steel. In other embodiments, the needle shaft  5  is a 19 gauge needle. In some embodiments, the needle shaft is a 21 gauge needle. 
         [0048]    In other embodiments, the flexible tube  11  of the cannula  8  is made from a flexible material, such as polypropylene, which is less rigid than the needle shaft  5 . In some embodiment, the flexible tube  11  is a 17 gauge cannula. In other embodiments, the flexible tube  11  is a 19 gauge cannula. Use of the flexible tube  11  to place the guide wire  13  in the patient&#39;s HAS is believed to lessen the trauma to the patient as compared to the use of a rigid dilator. 
         [0049]    In other embodiments, a ratio of an outer diameter of the flexible tube  11  of the cannula  8  to an outer diameter of the needle shaft  5  is between about 1.6 to 1 and about 1.2 to 1. In some embodiments, the outer diameter of the flexible tube  11  is about 0.056 inches (1.422 mm). It is believed that the ratio of outer diameters of the flexible tube  11  and needle shaft  5  is relatively small so that the transition between inserting the needle into the patient&#39;s HAS and then moving the cannula over the needle and into the patient&#39;s HAS provides minimal stress on the patient&#39;s tissue resulting in a less traumatic access process. 
         [0050]    In some embodiments, the guide wire  13  has an outer diameter of about 0.018 in. (0.457 mm). 
         [0051]    In certain embodiments, the access device  1  and guide wire  13  come pre-packaged in a package P to facilitate use of the access device ( FIG. 14 ). In the package P, the access device  1  is configured in its pre-use configuration where the needle shaft  5  is disposed within the lumen of the cannula  8  such that the sharp distal tip of the needle shaft extends distally of the distal end of the cannula. The guide wire  13  is packaged with the access device  1  but is not inserted into the cannula  8  within the package. However, the guide wire  13  is configured for movement through the lumen of the cannula  8  during use of the access device  1 . 
         [0052]    While certain embodiments have been described, other embodiments are additionally or alternatively possible. 
         [0053]    A number of embodiments have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the disclosure. Accordingly, other embodiments are within the scope of the following claims.