Abstract:
A suturing device for grasping soft tissue and placing stitches in soft tissue during endoscopic procedures is described. An elongate housing with a stationary jaw and a movable jaw disposed at the distal end are configured for grasping and releasing soft tissue. A movable needle disposed within the housing is actuated to engage a length of suture and drive the suture into and through the grasped soft tissue. A suture capture member is disposed on the movable jaw and is configured to allow passage of the needle therethrough while securing a portion of the stitched length of suture.

Description:
FIELD OF THE DISCLOSURE 
     The present invention relates to a method and apparatus for placing sutures in soft tissue. More particularly, the present invention relates to apparatus and methods improve the ability to place a stitch or suture deeper within tissue when compared to conventional methods. Although methods and devices described herein make reference to arthroscopic repair of torn rotator cuffs, the principles of the devices and methods may be applied to any soft tissue application. 
     BACKGROUND 
     Traditional suturing of body tissues is a time consuming aspect of most surgical procedures. Many surgical procedures are currently being performed where it is necessary to make a large opening to expose the area of, for instance, the human body that requires surgical repair. In recent practice, endoscopes are used to allow the viewing of certain areas of the body through a small puncture wound without exposing the entire body cavity. Endoscopes can be used in conjunction with specialized surgical instrumentation to detect, diagnose, and repair areas of the body that were previously only able to be repaired using traditional “open” surgery. In conjunction with the advances in endoscopic surgery, there have been many attempts to simplify the task of driving a needle carrying suture through body tissues to approximate, ligate and fixate them. Many prior disclosures, such as described in U.S. Pat. No. 919,138 to Drake et al., employs a hollow needle driven through the tissue with the suture material passing through the hollow center lumen. The needle is withdrawn, leaving the suture material in place, and the suture is tied, completing the approximation. A limitation of these types of devices is that they are particularly adapted for use in open surgical procedures where there is ample room for the surgeon to manipulate the instrument. 
     Others have attempted to devise suturing instruments that resemble traditional forceps, such as U.S. Pat. No. 3,946,740 to Bassett. These devices pinch tissue between opposing jaws and pass a needle from one jaw through the tissue to the other jaw. Graspers then pull the needle and suture material through the tissue. A limitation of these designs is that they also are adapted primarily for open surgery, in that they require exposure of the tissues to be sutured in order that the tissue may be grasped or pinched between the jaws of the instrument. This is a severe limitation in the case of endoscopic surgery. 
     Less invasive arthroscopic techniques are beginning to be developed in an effort to address the shortcomings of open surgical repair. Access to the operative site using endosurgical or minimally invasive techniques is accomplished by inserting small tubes, known as trocars, into a body cavity. These trocars have a diameter of, for example, between 3 mm and 30 mm and a length of about 150 mm (6 inches). Working through small trocar portals that minimize disruption of the deltoid muscle, surgeons have been able to reattach the rotator cuff using various bone anchor and suture configurations. The rotator cuff is sutured intracorporeally using instruments and techniques such as those previously described. The repair is completed by tying the cuff down against bone using the anchor and suture that is knotted to secure the tissue in proximity to the bone. 
     The suture knots in the tissue can be bulky and create a painful impingement of the tendon on the bone. This is because the knots end up on top of the cuff, in the sub-acromial space, and have the opportunity to rub on the acromion as the arm is raised. Because non-absorbable suture materials are used for these types of repairs, the suture and associated knots are not absorbed into the body, and hence provide a constant, painful reminder of their presence. Accordingly, devices configured to place, retrieve, and secure sutures in tissue without reliance on tying knots are desirable. Additionally, devices configured to grasp and secure tissue to effect the placement of suture in a particular location of the tissue provide an advantageous utility that is valued by practitioners during the practice of endoscopic tissue repair. 
     SUMMARY 
     The present device and methods include an instrument that combines the function of both grasping the tissue and passing sutures through the tissue to form a stitch. In a general sense, the instrument includes a pair of grasping jaws that oppose each other along a line substantially perpendicular to the long axis of the instrument. The distal end of the instrument incorporates the fixed jaw, and proximal to that jaw is a moveable jaw that is controlled by the user via a lever on the handgrip. 
     In a preferred embodiment the instrument is inserted through a portal known as a trocar cannula. The portal is created by first making an incision in the skin, and then inserting a cannula through the incision to the repair site. The distal end of the instrument is inserted through the cannula under direct visualization from a second trocar cannula that has been previously inserted. The visualization is accomplished via an endoscope, of a type well known in the art. The instrument is inserted until the jaws reach, for example, torn rotator cuff tissue. In operation, the distal end of the grasper aspect of the instrument is positioned at the repair site underneath the tissue to be grasped. The moveable jaw is movable toward the stationary jaw by squeezing the handle lever. The handle lever moves inward by pivoting about a pivot pin. 
     Once the surgeon is satisfied with the placement of the grasper on the grasped tissue, the surgeon can then deploy a suture needle to create a stitch in the tissue, for example, the above-mentioned torn rotator cuff. In operation, the suture needle may be advanced through the grasped tissues by actuating a second lever. In order to create the suture, at least one needle advances to engage a suture disposed in the stationary jaw. The needle comprises a distal point, a proximal shaft, and a hook defining a suture holding area. The suture needle is actuated such that the tip of the suture needle engages a portion of suture housed in a more distal portion of the stationary jaw, and begins to penetrate through the bottom of the grasped tissue and advances upward toward the movable jaw. Thereby, the device includes features to allow the needle engage and capture the suture and then to penetrate tissue and draw the suture through the tissue. 
     The movable jaw may incorporate a suture capture member disposed at a distal end of the device. In certain embodiments, the suture capture member may comprise a cartridge removably disposed on one of the jaws at the distal end of the distal. The suture capture member may be characterized by apertures coaxial to the longitudinal axis of the suturing device designed to allow the suture needle engaged with suture to pass therethrough. The suture capture member comprises components designed to spring away from the aperture in order to allow passage of the suture needle and suture through the aperture on the upstroke of the needle through the tissue. The aperture may be further characterized by opposed serrated edges, fingers or teeth to assist in securing the portion of suture as the needle begins a down stroke through the aperture and the tissue. 
     The instrument can be retracted back through the portal via the trocar cannula. As the instrument is removed from the suture site, the free ends of the suture are retrieved as well. This causes the suture form a looped stitch in the tissue. 
     Thus, the disclosed embodiments comprise a combination of features and characteristics which are directed to allow it to overcome various shortcomings of prior devices. The various characteristics described above, as well as other features, will be readily apparent to those skilled in the art upon reading the following detailed description of the preferred embodiments of the invention, and by referring to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a perspective view of a suturing device in accordance with at least some embodiments. 
         FIG. 2A  illustrates a perspective view of a suture capture member in accordance with at least some embodiments. 
         FIG. 2B  illustrates a cross-sectional view of the suture capture member in accordance with at least some embodiments. 
         FIG. 3  illustrates a perspective view of a suture capture cartridge in accordance with at least some embodiments. 
         FIG. 4A  illustrates a perspective view of a suturing device in accordance with at least some embodiments. 
         FIG. 4B  illustrates a perspective view of a suturing device in accordance with at least some embodiments. 
         FIG. 4C  illustrates a perspective view of a suturing device in accordance with at least some embodiments. 
         FIG. 4D  illustrates a perspective view of a suturing device in accordance with at least some embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     The present invention relates to a method and apparatus for suturing of soft tissue at a surgical repair site. In one variation the invention uses a device that is a combination tissue grasper and suture placement device. Although the present invention is described primarily in conjunction with the repair of a torn rotator cuff, the apparatus and method could also be used in arthroscopic repair at other sites, such as the knee, elbow, hip surgery, and for other surgical techniques for securing suture in the soft tissues of the body. 
     One embodiment of a suture passer instrument having a suture capture mechanism is shown in the perspective view of  FIG. 1 . Suturing device  100  includes lower jaw member  102  and upper jaw member  104  disposed at a distal end of the device. Jaws  102  and  104  are connected to an elongate housing  108  comprising a hollow tube. In certain embodiments, upper jaw  104  may be further characterized by opening  105  at the distal end of device  100 . Lower jaw  102  may have a suture recess  106  oriented in a generally perpendicular direction to the longitudinal axis of device  100  for engaging and accommodating a length of suture  300  with free ends  320 ,  330  in preparation for stitching the length of suture  300  through the soft tissue and subsequently capturing the length of suture  300 . The distal portion of device  100  between jaws  102 ,  104  defines a tissue receiving area  150 . 
     In certain embodiments, upper jaw  104  includes suture capture member  200  disposed at the distal end of device  100 . Suture capture member  200  may in some embodiments comprise a suture capture cartridge  201  removably disposed within opening  105  of upper jaw  104 . Referring now to  FIGS. 2A and 3 , suture capture member  200  comprises elongate aperture  202  formed by edges  204 ,  206  on each opposed side. Edges  204 ,  206  may further comprise suture capture surface  208  in certain embodiments. Suture capture surface  208  may be configured as opposed serrated edges, a plurality of interdigitating teeth, a plurality of opposed notches, or other similar opposed edge features. Suture capture cartridge  200  further comprises deflecting portions  210 ,  212  (i.e., arms  210 ,  212 ) which extend from edges  204 ,  206  respectively, and may be formed in a curved or arcuate shape. Referring now to  FIG. 2B , suture capture member  200  is disposed relative to upper jaw  104  such that gaps  214 ,  216  are created between arms  210 ,  212  and the respective inner surfaces within upper jaw  104 . In certain embodiments, cartridge  201  and/or the components of suture capture member  200  are preferably comprised of high temper spring steel material. 
     Suturing device  100  is inserted through a trocar cannula until jaws  102 ,  104  reach the tissue to be treated. Upper jaw  104  may be actuated into the open configuration and soft tissue  400  is introduced into the space between the upper jaw  104  and the lower jaw  102 . Referring now to  FIG. 4A , by means of a mechanism not discussed or shown herein, but of a type well known to those skilled in the art, the upper jaw  104  is movable relative to lower jaw  102 , causing upper jaw  104  to clamp or grasp the soft tissue  400  and immobilize it between the upper jaw  104  and the lower jaw  102 . In certain embodiments, upper jaw  104  may be pivoted about a generally perpendicular axis relative to housing  108 , or alternatively the connection between lower jaw  102  and upper jaw  104  may be a reciprocating or cam system wherein upper jaw  104  is movable relative to lower jaw  102 . With upper jaw  104  positioned in proximity to lower jaw  102 , jaws  102 ,  104  are thereby positioned in the closed configuration. 
     In certain embodiments, lower jaw  102  is stationary while upper jaw  104  is movable relative to lower jaw  102  or pivotable about a fixed point coupled to the distal end of housing  108 . The movable nature of upper jaw  104  allows jaws  102 ,  104  to be actuated between an open configuration for receiving tissue and a closed configuration for grasping tissue. Referring now to  FIG. 4B , suture needle  110  is movably disposed within housing  108 , and comprises shaft  112 , point  114 , and suture capture area  116 . Needle  110  is axially movable within and extendable from housing  108 , such that needle point  114  may be positioned in a retracted position withdrawn from tissue receiving area  150  or in an extended position displaced through upper jaw  104 . According to the embodiments described herein, needle  110  is configured such that it is generally directable upward from its retracted position away from tissue receiving area  150  to its extended position displaced through upper jaw  104  and soft tissue  400 . For example, it is contemplated that needle  110  may be ramped generally upward off a surface in lower jaw  102  as it is displaced from the retracted position to the extended position. In certain embodiments, needle  110  is comprised of a super-elastic material such as nitinol, has a generally circular cross-section, and is preformed to include a bend or curved region  118  at the distal end portion of needle  110 . The super-elastic nature of the material comprising needle  110  in these embodiments allows that needle  110  may be disposed in a generally linear configuration while placed in the retracted position, and then returns to the preformed curved configuration during the displacement of needle  110  from the retracted to extended position. 
     The housing  108  is coupled to a handle portion (not shown) having a similar or the same design as those typically used in conventional suturing devices as discussed above. For example, such a handle portion in accordance with the embodiments discussed herein may have a stationary grip with a moveable needle deployment lever to actuate axial movement of the needle. The handle portions further include a deployment member or trigger to effectuate closing of the jaws  102 ,  104  to grasp and secure the tissue therebetween. 
     With the position of the soft tissue  400  grasped between jaws  102 ,  104  and within the tissue receiving area  150  device  100  deemed satisfactory, needle  110  may be deployed by actuation of needle deployment member or trigger in the handle portion of device  100  to the extended position, as depicted in  FIG. 4B . Needle  110  is advanced axially toward the distal end of device  100  such that suture capture area  116  engages suture  300  accommodated in suture recess  106  of lower jaw  102  (as previously described and depicted in  FIG. 1 ). As described above, in certain embodiments needle  110  comprises a super-elastic material and is preformed to include a bend or curved region  118 . The preformed curved region  118  of needle  110  allows that as needle  110  is advanced in a generally distal direction needle point  114  is urged toward upper jaw  104  and needle point  114  thereby penetrates and enters the underside of soft tissue  400  grasped between jaws  102 ,  104 . In addition to needle point  114  penetrating and entering soft tissue  400 , the advancement of needle  110  also results in passing suture capture area  116  and the length of suture  300  engaged within suture capture area  116  through soft tissue  400 . The tissue receiving area  150  may be defined by protrusions or teeth  103  to assist in retaining the tissue within the tissue receiving area  150  as needle  110  advances through the soft tissue  400 . 
     With needle point  114 , suture capture area  116 , and suture  300  drawn through soft tissue  400 , the actuation of needle  110  continues until needle  110  advances into and through opening  105  in upper jaw  104 . Concurrently, needle  110  and length of suture  300  are also directed through aperture  202  of suture capture member  200 . Referring concurrently to  FIGS. 2B and 4 , as needle  110  passes through aperture  202 , needle  110  contacts edges  204 ,  206  such that each of arms  210 ,  212  are deflected away from needle  110  and into a portion of gaps  214 ,  216 . The deflection of arms  210 ,  212  is designed to be elastic such that arms  210 ,  212  respectively return to or spring back into a pre-deflected position upon the subsequent withdrawal of needle  110  through aperture  202 . In the fully extended position of needle  110 , the length of suture  300  that has been drawn through soft tissue  400  forms a suture portion  310  which protrudes from and is disposed above upper jaw  104  and suture capture member  200 . In certain embodiments, suture portion  310  may form a looped configuration. 
     With the suture portion  310  protruding through suture capture member  200 , needle  110  may be withdrawn through aperture  202  and returned to a retracted position, as depicted in  FIG. 4C . As needle  110  is withdrawn through suture capture member  200 , arms  210 ,  212  spring back to a non-deflected position such that aperture  202  and suture capture surface  208  are allowed to close around suture portion  310  of suture  300 . Aperture  202  is large enough and the spring deflection of arms  210 ,  212  is great enough that these characteristics of suture capture member  200  do not restrict the movement of needle  110  during displacement to the extended position. However, arms  210 ,  212  are configured such that arms  210 ,  212  can only be deflected in an outward direction, away from the top outer surface of upper jaw  104 , as needle  110  is moved through aperture  202  during displacement to the extended position. In addition, aperture  202  is sufficiently small when arms  210 ,  212  are in the non-deflected configuration so that suture portion  310  is not allowed to pass back through suture capture member  200 . Further, suture capture surface  208  engages and captures suture portion  310 , and further secures suture portion  310  of suture  300  as needle  110  is withdrawn through aperture  202  and returned to the retracted position. Thereby, suture portion  310  is trapped in suture capture member  200  on upper jaw  104  with a portion of suture  300  simultaneously stitched through soft tissue  400 . Thereafter, jaws  102 ,  104  of device  100  are opened to release soft tissue  400  from the grasp of device  100 . 
     Referring now to  FIG. 4D , with jaws  102 ,  104  of device  100  fully actuated into the open configuration and needle  110  displaced to the fully retracted position (not shown), device  100  is pulled away from the repair site and retracted through the trocar cannula, thereby leaving a portion of suture  300  stitched through a portion of soft tissue  400 . Concurrently, suture portion  310  of suture  300  may be pulled away from the repair site and withdrawn from the trocar cannula. Suture portion  310  is manually removed from suture capture member  200  creating suture free ends  320 ,  330  that may be utilized to secure soft tissue  400  to a desired location using soft tissue attachment methods or bone anchors otherwise known in the art. 
     While preferred embodiments of this invention have been shown and described, modifications thereof can be made by one skilled in the art without departing from the scope or teaching herein. The embodiments described herein are exemplary only and are not limiting. Because many varying and different embodiments may be made within the scope of the present teachings, including equivalent structures or materials hereafter thought of, and because many modifications may be made in the embodiments herein detailed in accordance with the descriptive requirements of the law, it is to be understood that the details herein are to be interpreted as illustrative and not in a limiting sense.