Patent Publication Number: US-2015065804-A1

Title: Cannula - obturator structure

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of and priority to U.S. Provisional Patent Application No. 61/871,020, filed Aug. 28, 2013, the entire disclosure of which is incorporated by reference herein. 
    
    
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to surgical instruments. More particularly, the present disclosure relates to a cannula including an obturator structure incorporated therein in a pre-assembled manner. 
     2. Background of the Related Art 
     Access systems have been of particular advantage in facilitating less invasive surgery across a body wall and within a body cavity. This is particularly true in the case of abdominal surgery where access systems have provided working channels across the abdominal wall to facilitate the use of instruments within the abdominal cavity. 
     The access systems of the past typically include a cannula, which defines the working channel, and an obturator which is used to place the cannula across the abdominal wall. The obturator is inserted into the working channel of the cannula and then pushed through the abdominal wall with a penetration force of sufficient magnitude to result in penetration of the abdominal wall. Once the cannula is in place, the obturator can be removed. 
     In the past, obturators have been developed with an intent to provide a reduction in the force required for penetration. Sharp blades have typically been used to enable the obturator to cut its way through the abdominal wall. 
     In some cases, shields have been provided with the obturators in order to sense penetration of the abdominal wall and immediately shield the sharp blades. 
     SUMMARY 
     The following presents a simplified summary of the claimed subject matter in order to provide a basic understanding of some aspects of the claimed subject matter. This summary is not an extensive overview of the claimed subject matter. It is intended to neither identify key or critical elements of the claimed subject matter nor delineate the scope of the claimed subject matter. Its sole purpose is to present some concepts of the claimed subject matter in a simplified form as a prelude to the more detailed description that is presented later. 
     A cannula assembly in accordance with an embodiment of the present disclosure includes a cannula having a plurality of circumferential openings at a distal end thereof and an obturator having a proximal end and a distal end, and a plurality of circumferential tabs that lockingly engage the plurality of circumferential openings of the cannula. 
     In an exemplary embodiment, the distal end of the obturator includes a tip and the proximal end of the obturator includes a plurality of leg structures. Each of the plurality of leg structures of the obturator is configured to interlock with at least one latching mechanism of a retractor for disengaging the plurality of circumferential tabs of the obturator from the plurality of circumferential openings of the cannula. 
     In another exemplary embodiment, each of the plurality of leg structures of the obturator includes a snap profile for engaging the at least one latching mechanism of a retractor. 
     In yet another exemplary embodiment, the obturator is pre-assembled to interlock with the cannula. 
     In an exemplary embodiment, the obturator, in its entirety, is positioned at the distal end of the cannula, such that the obturator and cannula move together as one unit. 
     In another exemplary embodiment, the cannula has a first length and the obturator has a second length, the second length being less than half of the first length. 
     An obturator in accordance with an embodiment of the present disclosure includes a tip at a distal end thereof, a plurality of leg extensions at a proximal end thereof and a plurality of circumferential tabs positioned between the proximal and distal ends of the obturator. 
     In an exemplary embodiment, the plurality of circumferential tabs is adapted and dimensioned to engage a plurality of circumferential openings of a distal end of a cannula. 
     In another exemplary embodiment, the plurality of leg extensions is adapted and dimensioned to engage a plurality of collet fingers of a retractor for removing the obturator from a cannula. Each of the plurality of leg extensions includes a snap profile for engaging the plurality of collet fingers of a retractor. 
     In yet another exemplary embodiment, the obturator is configured to be pre-assembled, in a releasable manner, into an inner portion of a cannula. 
     A cannula in accordance with an embodiment of the present disclosure includes a head portion, a body portion having a proximal end and a distal end, a plurality of circumferential openings at the distal end of the body portion and a removable tip incorporated at the distal end of the body portion, the removable tip having a plurality of circumferential tabs for releasably interlocking with the plurality of circumferential openings. 
     In an exemplary embodiment, the removable tip is pre-assembled to interlock within an inner portion at the distal end of the body portion. 
     A method in accordance with an embodiment of the present disclosure includes the step of inserting a cannula assembly through a body wall of a patient, the cannula assembly including a cannula having a proximal end and a distal end and a plurality of circumferential openings at a distal end thereof and an obturator having a proximal end and a distal end, a plurality of circumferential tabs that engage the plurality of circumferential openings of the cannula and a plurality of leg extensions at a proximal end thereof, wherein the cannula has a first length and the obturator has a second length, the second length being less than half of the first length. The method also includes the steps of removing the obturator from the cannula by inserting a retractor into the proximal end of the cannula, the retractor including at least one latching mechanism that interlocks with the plurality of leg structures of the obturator and disengages the plurality of circumferential tabs of the obturator from the plurality of circumferential openings of the cannula and using the cannula as an access port for passage of surgical instruments through a body wall of a patient. 
     Further scope of applicability of the present disclosure will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating specific embodiments of the present disclosure, are given by way of illustration only, since various changes and modifications within the spirit and scope of the present disclosure will become apparent to those skilled in the art from this detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects, features, and advantages of the present disclosure will become more apparent in light of the following detailed description when taken in conjunction with the accompanying drawings in which: 
         FIGS. 1A-1C  are perspective views of a removable obturator, having a plurality of circumferential tabs thereon, according to an embodiment of the present disclosure; 
         FIGS. 2A-2C  are perspective views of a cannula illustrating a plurality of openings at a distal end thereof, according to an embodiment of the present disclosure; 
         FIGS. 3A-3C  are perspective views of pre-assembling the obturator of  FIGS. 1A-1C  to the cannula of  FIGS. 2A-2C , according to an embodiment of the present disclosure; 
         FIGS. 4A-4C  are perspective views of a retractor, according to an embodiment of the present disclosure; 
         FIG. 4D  is a cross-sectional view of the retractor of  FIGS. 4A-4C , according to an embodiment of the present disclosure; 
         FIGS. 5A-5D  are cross-sectional views of the retractor entering the cannula, connecting to the obturator, and removing the obturator from the cannula, according to an embodiment of the present disclosure; 
         FIGS. 5E-5H  are perspective views of the retractor entering the cannula, connecting to the obturator, and removing the obturator from the cannula, according to an embodiment of the present disclosure; and 
         FIGS. 6A-6C  illustrate different obturator tips, in accordance with various embodiments of the present disclosure. 
     
    
    
     The figures depict specific embodiments of the present disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following discussion that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the present disclosure described herein. 
     DETAILED DESCRIPTION 
     Particular embodiments of the present disclosure are described hereinbelow with reference to the accompanying drawings; however, it is to be understood that the disclosed embodiments are merely exemplary of the disclosure and may be embodied in various forms. Well-known functions or constructions are not described in detail to avoid obscuring the present disclosure in unnecessary detail. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present disclosure in virtually any appropriately detailed structure. 
     Like reference numerals may refer to similar or identical elements throughout the description of the figures. As shown in the drawings and described throughout the following description, as is traditional when referring to relative positioning on a surgical instrument, the term “proximal” refers to the end of the apparatus which is closer to the user and the term “distal” refers to the end of the apparatus which is farther away from the user. The term “clinician” refers to any medical professional (i.e., doctor, surgeon, nurse, or the like) performing a medical procedure involving the use of embodiments described herein. 
     The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments. The word “example” may be used interchangeably with the term “exemplary.” 
     Reference will now be made in detail to embodiments of the present disclosure. While certain embodiments of the present disclosure will be described, it will be understood that it is not intended to limit the embodiments of the present disclosure to those described embodiments. To the contrary, reference to embodiments of the present disclosure is intended to cover alternatives, modifications, and equivalents as may be included within the spirit and scope of the embodiments of the present disclosure as defined by the appended claims. 
       FIGS. 1A-1C  present various views of a removable obturator  100 , having a plurality of circumferential tabs  18  thereon, according to an embodiment of the present disclosure. 
     In  FIGS. 1A-1C , the obturator  100  includes an obturator tip  12  at a distal end  13  of the obturator body  10 . The obturator  100  further includes a plurality of leg structures  14  at a proximal end  11  of the obturator body  10 . The leg structures  14  may be referred to as leg extensions. The plurality of leg structures  14  is configured to engage latching mechanisms  417  of a retractor  400  (discussed below with reference to  FIGS. 4A-4D ) via a plurality of snap profiles  16 . The obturator  100  also includes a plurality of circumferential tabs  18  equally spaced apart from each other (or equidistant). Each tab  18  includes an angled or chamfered portion  19 . The plurality of circumferential tabs  18  is configured to interlock with a plurality of openings  214  of a cannula  200  (discussed below with reference to  FIGS. 2A-2C ). The angled or chamfered portion  19  of each tab  18  facilitates removal of the tab  18  from the corresponding opening  214  as described below in connection with  FIGS. 5D and 5H . 
     The plurality of circumferential tabs  18  may include eight separate and distinct tabs. However, in another exemplary embodiment the plurality of circumferential tabs  18  may include four separate and distinct tabs. One skilled in the art may contemplate any number of tabs  18  for connecting to a cannula  200  (discussed below). Additionally, the tabs  18  may be referred to as pins, projections, locking detents, or latches. Moreover, the plurality of circumferential tabs  18  may be positioned substantially adjacent a distal end of the plurality of leg structures  14 . 
       FIGS. 2A-2C  present various views of a cannula  200  illustrating a plurality of openings  214  at a distal end thereof, according to an embodiment of the present disclosure. 
     In  FIGS. 2A-2C , cannula  200  includes a cannula head  212  at a proximal end  211  and a plurality of circumferential openings  214  at a distal end  213 . The cannula head  212  is connected to a cannula body  210 . The plurality of circumferential openings  214  is positioned at a distal end of the cannula body  210 . Moreover, the distal end  213  of cannula  200  includes an opening  220  (see  FIG. 2C ). 
     The plurality of circumferential openings  214  may include eight openings. However, in another exemplary embodiment the plurality of circumferential openings  214  may include four openings. One skilled in the art may contemplate any number of openings  214  for connecting to the obturator  100  (discussed above). The number of openings  214  in cannula  200  may, but does not necessarily correspond to the number of tabs  18  on obturator  100 . 
     In use or operation, the obturator  100  is configured to engage an inner surface of the cannula  200 . The plurality of circumferential tabs  18  is configured to lockingly engage the plurality of circumferential openings  214  of the cannula  200 . Thus, a secure connection is created between the obturator  100  and the cannula  200 . In other words, the obturator  100  is configured to interlockingly engage the inner surface of the cannula  200  during insertion of the cannula  200  within an incision in tissue. Therefore, during an initial stage of insertion of a cannula into the body of a patient, the obturator  100  is connected to the cannula  200  and such components move together as one unit. Thus, the obturator  100  and the cannula  200  are pre-assembled to form a single unit, as described below with reference to  FIGS. 5A-5D . Stated differently, the cannula  200  is pre-assembled to include an obturator  100  secured therein (e.g., at a distal end of the cannula  200 ). 
     Additionally, it is noted that the obturator  100  is much smaller than conventional obturator assemblies in order to securely attach or connect to the inner surface of the cannula  200 . The length of the obturator  100  is less than the length of the cannula  200 . For example, the obturator  100  may be less than half the length of the cannula  200 . In most configurations, it is contemplated that the obturator  100  occupies a small portion of the distal end of the cannula  200 . Therefore, manufacturing costs may be reduced because the obturator  100  does not include any exterior housing or sleeves. Instead, the cannula  200  is manufactured to include a penetrating tip, such as the obturator  100 , pre-assembled thereon. Thus, the obturator  100  is part of the cannula  200  itself. Moreover, the obturator  100  may have a first diameter and the cannula  200  may have a second diameter, where the first diameter is smaller than the second diameter, such that obturator  100  snugly fits within the distal end of the cannula  200 . 
     Moreover, regarding the cannula  200 , a seal (not shown) or a seal structure or seal assembly may be positioned at the proximal end  211  in order to prevent insufflation gasses from escaping when, for example, the cannula  200  is inserted through tissue. One skilled in the art may contemplate a plurality of different seals capable of sealing the proximal end  211  of cannula  200 . 
       FIGS. 3A-3C  present various views  300  of pre-assembling the obturator  100  of  FIGS. 1A-1C  to the cannula  200  of  FIGS. 2A-2C , according to an embodiment of the present disclosure. 
     In  FIG. 3A , the obturator  100  is shown separated from the cannula  200 . In  FIG. 3B , the obturator  100  is shown slowly inserted into the opening  220  of the cannula  200 . The plurality of leg structures  14  is first inserted into the opening  220  of the cannula  200 . In  FIG. 3C , the obturator  100  is fully inserted into the distal end of the cannula  200 . In the fully inserted position, each of the plurality of circumferential tabs  18  of the obturator  100  is inserted through one of the plurality of circumferential openings  214  of the cannula  200 . Therefore, the obturator  100  securely interlocks with the cannula  200  at a distal end thereof. In the fully inserted position, only the tip  12  of the obturator  100  is exposed at the distal end of the cannula  200 . The obturator body  10 , as well as the plurality of leg structures  14  are fully inserted into the interior of the cannula  200 . 
       FIGS. 4A-4D  present various views of a retractor  400 , according to an embodiment of the present disclosure. 
     In  FIGS. 4A-4D , the retractor  400  includes a retractor body  410  having a retractor head  412  at a proximal end and a plurality of latching mechanisms  417  at a distal end. The back surface  415  of the plurality of latching mechanisms  417  extends the length of the retractor  400 . The plurality of latching mechanisms  417  may be referred to as a plurality of collet fingers. The retractor  400  also includes openings  420  (see  FIGS. 4B and 4C ) at a distal end thereof, the openings  420  separating the plurality of latching mechanisms  417  from each other. The cross-sectional view of the retractor  400  illustrated in  FIG. 4D , depicts the latching mechanisms  417  and the openings  420 . Each of the plurality of latching mechanisms  417  includes an undercut portion  419  for connecting to the plurality of leg structures  14  of the obturator  100  (described below with reference to  FIGS. 5A-5D ). 
       FIGS. 5A-5H  present various views  500 A- 500 H of the retractor  400  entering the cannula  200 , connecting to the obturator  100 , and removing the obturator  100  from the cannula  200 , according to an embodiment of the present disclosure. 
     In  FIGS. 5A and 5E , in a first configuration  500 A, the obturator  100  is pre-assembled to the cannula  200  at a distal end  501  of the cannula  200 . The retractor  400  is shown positioned outside of the cannula  200  at a proximal end  503  of the cannula  200 . 
     In  FIGS. 5B and 5F , in a second configuration  500 B, the retractor  400  is inserted at the proximal end  503  of the cannula  200 . The refractor  400  moves in a direction “A” through channel  510  of cannula  200  to connect to the obturator  100 . As shown, the body  410  of the retractor does not engage the interior surface  401  of the cannula  200 . 
     It is noted that the plurality of leg extensions  14  is outwardly deflected with reference to axis “c-c,” whereas the plurality of latching mechanisms  417  is inwardly deflected with respect to axis “c-c.” 
     In  FIGS. 5C and 5G , in a third configuration  500 C, the distal end of the retractor  400  connects to the proximal end of the obturator  100 . In particular, the plurality of leg structures  14  of the obturator  100  connect to the plurality of latching mechanisms  417  of the retractor  400 . Stated differently, the snap profiles  16  of the plurality of leg structures  14  securely interconnect or interlock with the undercut portions  419  of the plurality of latching mechanisms  417  (see  FIGS. 5A-5B ). The undercut portions  419  sit directly below the snap profiles  16  to form the secure connection. In other words, the leg structures  14  are compressed or deflected when they come into contact with the latching mechanisms  417  during distal movement of the retractor  400 . The latching mechanisms  417  inwardly deflect the leg structures  14  in order to enable a secure connection therebetween. In such an instance, the undercut portions  419  are directly adjacent the snap profiles  16 . The undercut portions  419  may also be referred to as first surfaces and the snap profiles may be referred to as second surfaces, where the first and second surfaces engage each other to provide for the secure connection between the latching mechanisms  417  and the leg structures  14 . The first and second surfaces are substantially parallel to each other when the secure connection between the latching mechanisms  417  and the leg structures  14  is enabled. 
     In  FIGS. 5D and 5H , once the connection has been established between the retractor  400  and the obturator  100 , the retractor  400  is moved in a direction “B,” in order to remove the obturator  100  from the cannula  200 . In other words, the obturator  100  is temporarily or removably attached to the cannula  200 . In use or operation, after the cannula  200  is inserted through an incision in tissue, the obturator  100  needs to be removed from the surgical site. The obturator  100  is removed to allow cannula  200  to act as an access port for surgical instruments. The retractor  400  is tasked with this responsibility.  FIG. 5D  illustrates how the obturator  100  is removed from the cannula  200 . Upon movement of retractor  400  in direction “B”, the plurality of circumferential tabs  18  disengage from the plurality of circumferential openings  214 , which disengagement is facilitated by the presence of angled or chamfered portion  19  on each tab  18 . The plurality of circumferential tabs  18  may slidably engage the interior surface  401  of the cannula  200  during removal of the obturator  100  from the cannula  200 . 
     Therefore, each of the plurality of leg structures  14  of the obturator  100  is configured to interlock with at least one latching mechanism  417  of the retractor  400  for disengaging the plurality of circumferential tabs  18  of the obturator  100  from the plurality of circumferential openings  214  of the cannula  200 . Each of the plurality of leg structures  14  of the obturator  100  includes a snap profile  16  for engaging the at least one latching mechanism  417  of the retractor  400 . Thus, in summary, the obturator  100  is pre-assembled to interlock the cannula  200 , and the obturator  100 , in its entirety, is positioned at a distal end of the cannula  200 , such that the obturator  100  and the cannula  200  move together as a single unit. Stated differently, the obturator  100  is configured to be pre-assembled, in a releasable manner, into an inner portion  401  of the cannula  200 . The retractor  400  is inserted into the cannula  200  to connect to the obturator  100 , and then detach and fully remove the obturator  100  from the cannula  200 . 
     With reference to  FIGS. 6A-6C , different obturators are presented, in accordance with embodiments of the present disclosure. 
       FIG. 6A  illustrates an obturator  600   a  having a substantially circular tip  610 . 
       FIG. 6B  illustrates an obturator  600   b  having a off-center, substantially sharp tip  620 . 
       FIG. 6C  illustrates an obturator  600   c  having a truncated, substantially conical tip  630 . 
     It is contemplated that any of these obturator tips  600   a,    600   b,    600   c  could be incorporated into the exemplary embodiments described with reference to  FIGS. 1A-5H . 
     In summary, it is proposed to incorporate or embed a small obturator within or onto an interior surface of a cannula. The obturator includes a plurality of tabs that cooperate with a plurality of openings at a distal end of a cannula in order to provide a secure connection therebetween. The obturator and the cannula are considered a single unit and are constructed or formed in such a manner so as to move together or in tandem. Stated differently, the obturator and cannula form a single, unitary structure, where the two components are removably attached or connected to each other. The obturator may be removed from the cannula via, for example, a retractor including a plurality of finger collets that engagingly interlock with a plurality of leg extensions of the obturator to properly remove the obturator from the cannula. 
     While several embodiments of the disclosure have been shown in the drawings, it is not intended that the disclosure be limited thereto, as it is intended that the disclosure be as broad in scope as the art will allow and that the specification be read likewise. Therefore, the above description should not be construed as limiting, but merely as exemplifications of presently disclosed embodiments. Thus the scope of the embodiments should be determined by the appended claims and their legal equivalents, rather than by the examples given. 
     Persons skilled in the art will understand that the devices and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments. The features illustrated or described in connection with one exemplary embodiment may be combined with the features of other embodiments. Such modifications and variations are intended to be included within the scope of the present disclosure. As well, one skilled in the art will appreciate further features and advantages of the present disclosure based on the above-described embodiments. Accordingly, the present disclosure is not to be limited by what has been particularly shown and described, except as indicated by the appended claims. 
     It should be understood that the foregoing description is only illustrative of the present disclosure. Various alternatives and modifications can be devised by those skilled in the art without departing from the disclosure. Accordingly, the present disclosure is intended to embrace all such alternatives, modifications and variances. The embodiments described with reference to the attached drawing figs. are presented only to demonstrate certain examples of the disclosure. Other elements, steps, methods and techniques that are insubstantially different from those described above and/or in the appended claims are also intended to be within the scope of the disclosure.