Patent Publication Number: US-2021186479-A1

Title: Surgical retractor system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of U.S. patent application Ser. No. 15/980,880, filed May 16, 2018 (published as U.S. Pat. Pub. No. 2018/0263616), which is a continuation of U.S. patent application Ser. No. 15/483,489, filed Apr. 10, 2017, now U.S. Pat. No. 9,993,239, which is a continuation application of U.S. patent application Ser. No. 14/630,085, filed on Feb. 24, 2015, now U.S. Pat. No. 9,649,101, which is a continuation application of U.S. patent application Ser. No. 13/070,033, filed Mar. 23, 2011, now U.S. Pat. No. 8,992,425, which is a continuation of U.S. patent application Ser. No. 11/422,511, filed Jun. 6, 2006, now U.S. Pat. No. 7,935,053. Each of the references cited herein is hereby incorporated by reference in its entirety for all purposes. 
    
    
     FIELD OF THE INVENTION 
     The invention generally relates to devices and methods that improve surgical procedures by, for example, providing a working space for the procedure and improving the surgical conditions for the practitioner of a procedure. 
     BACKGROUND OF THE INVENTION 
     In surgical procedures generally, surgeons try to keep incisions as small as possible to minimize or reduce trauma to the patient and damage to tissue. However, it is usually necessary that the surgeon have a clear view of the operating field. Also, an opening may need to be enlarged to accommodate the passing of medical implants therethrough. 
     In the field of spine surgery, there is an increasing interest in developing minimally invasive methods, as opposed to conventional “open” spine surgery. The goals of these less invasive alternatives are to avoid the surgical exposure, dissection, and retraction of muscles and tissues that is necessary with “open” surgery. In general, a minimally invasive spine surgery system should be able to perform the same procedure as the traditional open technique, but through smaller incisions. As a result, some physicians feel that using a minimally invasive spine surgery system generally causes less soft tissue damage, reduces blood loss and reduces recovery time. In addition, patients generally prefer the smaller scars that are left using a minimally invasive approach. 
     A variety of retractors are available for use in surgical operations to reposition muscular tissue, vessels, nerves, and other tissue with the aid of retractor blades, thereby providing access to the site of the operation. Surgical retractors are particularly important in performing surgical procedures that involve the spinal column, where access to the surgical site can be obtained through a posterior, anterior, lateral, or combined approach. 
     Many current retractors have several shortcomings. For example, most currently available retractors are large and cumbersome, requiring a long incision length that traumatizes the patient&#39;s muscles and tissue. Also, some current retractors provide so much variability and adjustability that they are unwieldy, fiddly, and/or difficult to adjust or maneuver and are simply impractical for use in a typical surgical environment. However, other retractors may not provide sufficient adjustability. For example, some retractors do not allow independent pivoting of an individual retractor blade, while others may only provide for retraction of coupled pairs of blades as opposed to independent retraction, and still others may only allow for finite adjustment constrained to a rack and pinion system or a predefined arc for pivoting. 
     Therefore a need exists for a retractor system that overcomes or minimizes these and other problems. 
     SUMMARY OF THE INVENTION 
     Embodiments of the invention are generally directed toward a surgical retractor system having a frame and a plurality of arms connected thereto. In one embodiment, at least one arm is moveable relative to the frame and the relative movement is generally constrained to a direction along the longitudinal axis of the arm. At least one retractor blade is removably connected to each of the plurality of arms. In one embodiment, each blade is fixably rotatable about an axis normal to the longitudinal axis of the arm to which it is connected. 
     In one embodiment, the system includes at least four arms and at least one arm is fixed relative to the frame. In another embodiment, a plurality of arms are moveable relative to the frame, and wherein the relative movement of each moveable arm is constrained to a direction along the longitudinal axis of the arm, and wherein each moveable arm is independently moveable relative to the frame. 
     According to another embodiment, a bar clamp mechanism is connected to the frame and associated with at least one moveable arm to releasably clamp the moveable arm in a fixed position relative to the frame. In one embodiment, each moveable arm is non-threadedly connected to the frame and is actuatable by a manual retraction tool. In another embodiment, the longitudinal axes of the arms are coplanar. In another embodiment, the longitudinal axes do not rotate about frame. 
     According to one embodiment, the frame has a generally polygonal shape. In another embodiment, each of the moveable arms is selectably slidable with respect to the frame. According to another embodiment, the system comprises at least four retractor blades. In another embodiment, the blades comprise an elongate body having an inner face and an outer face and a longitudinal axis extending from a proximal end to a distal end, the inner face being generally concave and the outer face being generally convex. In another embodiment, a flexible sleeve at least partially surrounds the retractor blades. In an alternative embodiment, the flexible sleeve is made from a polyurethane rubber material 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be more readily understood with reference to the embodiments thereof illustrated in the attached figures, in which: 
         FIG. 1  is a perspective view of one embodiment of a retractor system according to the present invention positioned adjacent a bone model by a surgical arm; 
         FIG. 2  is a top perspective view of one embodiment of a retractor system according to the present invention shown in a first position; 
         FIG. 3  is a bottom perspective view of the retractor system of  FIG. 2 ; 
         FIG. 4  is a top perspective view of another embodiment of a retractor system according to the present invention shown without retractor blades; 
         FIG. 5  is a bottom perspective view of the retractor system of  FIG. 4 ; 
         FIG. 6  is a perspective view of various embodiments of retractor blades according to the present invention; 
         FIGS. 7-8  are partial cross-sectional views of a retractor system according to the invention showing a sleeve member assembled on the retractor blades; 
         FIG. 9  is a top perspective view of one embodiment of a retractor system according to the present invention shown in a second position; 
         FIG. 10  is a bottom perspective view of the retractor system of  FIG. 9 ; 
         FIGS. 11-12  are perspective views of one embodiment of a retraction tool in operation with a retractor system according to the present invention; 
         FIG. 13  is a top perspective view of one embodiment of a retractor system according to the present invention shown in a third position; 
         FIG. 14  is a bottom perspective view of the retractor system of  FIG. 13 ; 
         FIG. 15  is a perspective view of one embodiment of an arm assembly according to the invention shown in a first position; 
         FIG. 15A  is a cross-sectional view of  FIG. 15  taken along line  15 A; 
         FIG. 16  is a perspective view of one embodiment of an arm assembly according to the invention shown in a second position; 
         FIG. 16A  is a cross-sectional view of  FIG. 16  taken along line  16 A; 
         FIG. 17  is an enlarged sectional view of a portion of one embodiment of an arm assembly according to the invention; and 
         FIG. 18  is an exploded view of another embodiment of a surgical retractor system according to the present invention 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Embodiments of the invention will now be described. The following detailed description of the invention is not intended to be illustrative of all embodiments. In describing embodiments of the present invention, specific terminology is employed for the sake of clarity. However, the invention is not intended to be limited to the specific terminology so selected. It is to be understood that each specific element includes all technical equivalents that operate in a similar manner to accomplish a similar purpose. 
     The terms “first position,” “second position,” and “third position,” as used herein, merely refer to dissimilar positions and are not meant to imply that all embodiments can only be adjusted to one, two, or three positions. In some embodiments, a retractor system may be adjustable to a finite number of positions. In other embodiments, the distance between one or more components can be increased or decreased to any desired extent, thereby allowing a retractor system to adjust to an almost infinite number of positions. 
     Referring to  FIG. 1 , one embodiment of a retractor system  100  according to the invention is shown. The retractor system  100  includes a frame  102  that is attachable to an arm  104 . Arm  104  may be attached to a supporting structure  105 , which may comprise, for example, a table, a rack, a cart, or the like. In one embodiment, arm  104  is a surgical arm, such as a universal arm, which includes enough joints to provide a desired number of degrees of freedom to easily adjust frame  102  over an incision in a patient. The joints of arm  102  can include either a mechanism or a certain stiffness that allows the surgeon to position the surgical arm easily to a desired position and maintain the surgical arm and retractor system  100  in the new position. Utilizing and moving arm  104  allows frame  102  to be positioned in a substantially stationary position over the surgical access site. Frame  102  may provide a working support for the surgeon to rest his/her hands or arms on while performing a surgical procedure. 
     As shown in  FIGS. 2-3 , retractor system  100  generally comprises retractor blades  110  that may be removably attached to frame  102 . In one embodiment, retractor blades  110  may be attached to the inside of frame  102 . Once frame  102  is positioned over an incision, such as a small minimally invasive incision, each surgical retractor blade  110  may be inserted into a body cavity through the incision. The retractor blade(s)  110  can also create or increase the size of a body cavity through insertion and/or retraction. 
     The retractor blade(s)  110  may be movably attached to positioning means or arms  120 ,  122 . Each arm  120  provides the ability to independently change the position of a surgical retractor blade  110  and can be changed by a translation in an X and/or Y direction and/or a rotation about a horizontal or X-Y plane. According to one embodiment, arms  120  tightly fit within and are slideable with respect to openings  140 . In operation, arms  120  may translate in a horizontal or X-Y plane when a force is applied to force the arms  120  in an outwardly direction. To hold arms  120  in a desired position, a bar clamp mechanism  142  or other fixing means, such as a screw, a latch, or the like, may be used. Such a bar clamp configuration is advantageous when compared to a threaded retraction arrangement since threads are not forced to do the retraction work and thus eliminating the possibility of cross threading. According to one embodiment, one fixed arm  122  may be provided that is fixed in the X-Y direction such that a blade  110  attached to arm  122  is not translatable in the X-Y direction, however, a blade attached thereto may still be rotatable about a horizontal or X-Y plane. 
     In general, each positioning arm  120 ,  122  extends along a longitudinal axis  123  from a proximal end  124  to a distal end  126 . The distal end  126  includes a pivot member  128  to which a retractor blade  110  may be attached, whereby the pivot member is fixably rotatable about a pivot axis  129  extending transverse to the longitudinal axis  123 . The term “fixably rotatable,” as defined herein means that a pivot member is, alternatively, fixed or rotatable, about a pivot axis. The foregoing configuration provides flexibility in manipulating the operating field in the patient. 
     The pivot members  128  of arms  120 ,  122  may include attachment means  130  that may be used to attach retractor blade  110  to system  100 . The attachment means  130  can be any type of means that enables attachment, such as a screw, pin, magnet or the like. Other examples of suitable connectors include clips, hinges, rivets, adhesives, tressits, or the like. In further embodiments, a retractor blade may be attached to, and/or extend from, a frame component. In one embodiment, the attachment means  130  comprises a dovetail groove  132  which facilitates connection and disconnection of the retractor blade  110  to and from the frame, respectively. In one variation, the dovetail groove  132  is open at the top to facilitate top loading of blades  110  and comprises a pin  134  protruding outward from the surface of groove  132  to locate and or stop the blade  110  in the vertical or Z direction. Various lengths and shapes of blades may be provided to accommodate surgical procedures at various depths subcutaneously. The attachment means is secure enough to keep the surgical retractor blades  110  attached to the arms  120 ,  122  while the surgical retractor blades undergo force or torque during retraction. In one embodiment, a pivotable cover  136  is provided to prevent the back out of blades  110  with respect to pivot member  128 . In operation, cover  136  may be pivoted in place to cover the proximal end of a blade  110  to hold it in place in the longitudinal or Z direction with respect to pivot member  128 . 
     In one embodiment, frame  102  comprises a generally diamond shaped frame. However, in alternate embodiments the frame can take any shape, such as elliptical, polygonal, or circular, as long as it is able to provide a base for the retractor blades  110 . Examples of suitable materials of construction for the various portions of the retractor systems according to the invention include metals and metal alloys (e.g., stainless steel, aluminum, titanium, nitinol, cobalt chrome, etc.) and/or plastics (e.g., carbon fiber reinforced polymer (CFRP), ultra-high molecular weight polyethylene (UHMWPE), ultem, radel, vectra, polycarbonate, etc.). 
     In particular embodiments, the number of retractor blades  110  may be two or more. In one embodiment, four retractor blades  110  are provided. In general, each retractor blade has an inner face, an outer face, and a longitudinal axis running the length of the blade from a proximal end  111  to an opposite distal end  112 . In one embodiment, the retractor blades  110  have a curved or partial cylindrical shape, such that when blades  110  are aligned adjacent one another, a cylinder, channel, cannula, or the like is created. The size of the retractor blades  110  is dependent on the type of surgical procedure. For delicate procedures, small or miniature blades may be used, while for macroscopic procedures, blades that are less constrained in size may be used. The retractor blades  110  may be made of any material suitable for surgical procedures known to those skilled in the art. The blades  110  can be elongated and curved. In general, any type of surgical retractor blade  110  can be used as are common in the art. Also, the type, size, and shape of surgical retractor blades  110  can be mixed together as well as changed or renewed during a surgical procedure. Referring to  FIG. 6 , non limiting exemplary alternative embodiments are shown, where the distal end  112  may be angled or contoured. In this regard, blades  110  may accommodate particular anatomical features as required depending on the procedure involved. 
     Referring to  FIGS. 7-8 , in one embodiment, a flexible sleeve  135  may be provided to surround the retractor blades  110  to prevent body tissue from intruding into the space created by the retractor blades once they are retracted. In general, sleeve  135  may be initially assembled on the distal end of blades  110  in a rolled-up position as shown in  FIG. 7 . Sleeve  135  may then be extended or unrolled in a proximal direction to surround a substantial portion of blades  110 . In one embodiment, sleeve  135  may be made from a polyurethane rubber material, however, alternative appropriate materials known to those skilled in the art may also be used. In general, sleeve  135  is substantially resilient such that as blades  110  are moved and/or retracted, sleeve  135  accommodates blade movement while substantially surrounding blades  110  to prevent body tissue from intruding into the space created by the retractor blades once they are retracted. In this regard, sleeve  135  helps to provide a clean unimpeded field of vision for a surgeon utilizing retractor system  100 . 
     The position of each retractor blade  110  can be changed independent from the other retractor blades, which allows a great amount of flexibility to the surgeon to explore an operating field. Furthermore, the position of each retractor blade  110  can be changed without changing the position of the frame  102 . In other words, the frame may remain in a substantially stationary and fixed position over the incision. In this regard, a change in the operating field can be obtained by changing the position of one or more retractor blades  110 . 
     Referring to  FIGS. 11-12 , a handheld retraction tool  150  may be further provided to assist a surgeon in retracting, or moving in an outwardly direction, an arm  120  and, a retractor blade attached thereto. In one embodiment, best seen in  FIG. 17 , a spring  152  biases or pushes latch member  154  against arm  120  to prevent inadvertent inward movement of an arm once it has be retracted outward. In one embodiment, as shown in  FIGS. 11-12 , tool  150  may engage slot  153  in frame  102  and an inner portion of a retraction blade  110  to translate a blade  110  in an outward direction. In this regard, a surgeon may independently actuate a blade  110  while maintaining tactile feed back through the retraction tool  150 . 
     As explained above, in some embodiments, rotation of blades  110  about the X-Y plane can be achieved by pivoting pivot members  128  about pivot axes  129 . As best seen in  FIGS. 15-16 , one example of a pivoting mechanism is shown. Pivoting adjustment nut  160  comprises a hollow internal portion with an internally threaded section that engages an externally threaded pivot rod  162 . Rod  162  is pivotally attached to arm  120 ,  122  at a position spaced from pivot axis  129 . Nut  160  is freely rotatable with respect to pivot member  128  yet fixed in the longitudinal or Z-direction with respect to member  128 . In operation, when nut  160  is rotated a moment arm around pivot axis  129  is created, causing blade  110  to pivot with respect to arm  120 ,  122 . Rotation of nut  160 , enables a rotation about the pivot axis to establish toe-out or toe-in of retractor blade  110 . As one skilled in the art will appreciate, there are different ways and techniques to establish these rotations and translations, which are all included as possible positioning means for the purpose of this invention. Therefore, these examples should be regarded as illustrative rather than limiting to the scope of the present invention. 
     According to one aspect of the aforementioned pivot arrangement, pivot member  128  is connected adjacent the proximal end of blade  110  and pivot member  128  is positioned adjacent the distal tip of arms  120 ,  122 . One skilled in the art may appreciate that utilizing this configuration, the proximal end of blade  110  advantageously moves along a relatively small radius when blade  110  is pivoted which allows greater vision of the working end or distal end of the blades since a wider diameter portal or opening may be achieved at the proximal end of blades  110 . 
     Referring again to  FIGS. 1-3 and 9-14 , in general, the inner faces of the retractor blades define a conduit when the retractor system is at one or more positions. In some embodiments, the conduit is substantially cylindrical or substantially elliptical. Optionally, one or more retractor blades contact each other when the retractor is at one or more positions, such as for example in a first position shown in  FIGS. 1-3 . In still more embodiments, at least some portion of the retractor blades (e.g., the distal ends of one or more blades) provide access to a surgical site when the blades are partially or fully expanded, such as for example in a second or third position as shown in  FIG. 9-10 or 13-14 , respectively.  FIGS. 9-10  show an embodiment of a retractor system in an exemplary second position where all four retractor blades  110  are parallel in the vertical direction and separated or retracted outward.  FIGS. 13-14  show an embodiment of a retractor system in an exemplary third position where all four retractor blades  110  are positioned in a similar manner with their toes or distal ends  112  pointed outward. One skilled in the art will appreciate that there are an innumerable amount of positions that may be achieved and that the positions shown in  FIGS. 1-3, 9-10, and 13-14 , are merely shown for the purpose of illustration and should not be considered as limiting the scope of the invention. The number of combinations of translation(s) and/or rotation(s) of one or more retractor blades provides extensive flexibility to the surgeon or user in exploring the desired operating field with a simultaneous effort to minimize the trauma and size of the incision. 
     As will be appreciated by skilled practitioners, a retractor system such as those described herein may be particularly useful for lumbar spinal surgery with either an anterior, posterior, or anterolateral approach. In one variation, the blades of the retractor system may be placed through the paraspinous muscle using a small sequential dilator without cutting any muscle or underlying fascia. The retractor system can be placed over the sequential dilator, which has created a working channel for the retractor system. Yet another example of use for the retractor relates to brain surgery and vascular surgery where access space is small or sensitive. 
     Some embodiments include methods of performing surgical procedures on the spine of a human using an embodiment of a retractor system of the present invention. According to one method, a patient may be positioned on a table and imaging or fluoroscopy may be utilized to target a surgical site. A lateral table rail may be provided for subsequent placement of a rigid arm assembly, such as arm  104  shown in  FIG. 1 . 
     Once a surgical site has been targeted, a longitudinal incision may be made slightly larger than the retractor system  100  of the invention when in a collapsed or closed position, as shown in  FIGS. 2-3 . In some embodiments, only the skin may be cut since sequential dilators may be used to pierce and dilate the fascia. 
     Once the incision is made, a dilator may be inserted into the incision to dilate the fascia and/or paravertebral muscle tissue down to the laminar level. Once the incision has been dilated, a retractor system  100  of the invention may be directed to the surgical site. According to some embodiments, the retractor system  100  is assembled before it is directed to the surgical site. One or more rigid arms  104  may be attached or secured to retractor system  100 . Arm  104  may be secured to the surgical table and is attached to frame  102 . Arm  104  can be adjusted during the surgical procedure, thereby allowing a practitioner of the invention to direct system  100  to a desired position. 
     Once retractor system  100  has been inserted into an incision, blades  110  can be expanded using a retraction tool, such as tool  150  illustrated in  FIGS. 11-12 . Each blade  110  may be retracted in the cephlad-caudal and/or the medial-lateral directions independently by inserting a part of retraction tool  150  into the slot  153  of frame  102  and another part of tool  150  adjacent the interior of a particular blade to be retracted and squeezing the handle of instrument  150  to the desired extent. As best seen in  FIG. 17 , the bar clamp mechanism  142  associated with each moveable arm  120  allows the arm  120  to move in one direction such that release of the handle of tool  150  instantaneously locks the arm at that position. In this regard, bar clamp  142  allows for infinite adjustment and will hold each arm  120  at the precise expanded position as desired. Blades  110  may also be independently rotated or angled about the distal end of each arm  120 ,  122  as desired by actuating pivot member  128  by turning nut  160 . According to one embodiment of a method of the present invention a flexible sleeve may be provided to substantially surround blades  110  to prevent tissue creep or intrusion into the retracted space or surgical conduit created by the retraction of system  100 . 
     In some embodiments, an illuminated surgical conduit may be created. In one embodiment, a light source, such as for example a thin strip light, may be provided along the interior of one or more blades  110  and may be configured to emit light towards the distal end of the blades  110 . The light source may be in photonic communication with an array of fiber optic wire to power and/or control the light source. In alternate embodiments, fiber optic cable itself may be positioned along or embedded within one or more blades to emit light into the surgical conduit. In some embodiments, an optical interface may be provided adjacent the proximal end of blades  110  to facilitate modular interconnectivity of blades  110  while maintaining the integrity of the optical communication from a power source to the light source. 
     Referring to  FIG. 18 , one embodiment of a fixed diameter retractor system  180  according to the invention is shown. In general, retractor system  180  comprises a tubular member  182  that is removably coupleable to a frame member  184 . According to one embodiment, tube  182  has a generally cylindrical shape with a substantially fixed diameter. In alternate embodiments, when viewed in cross-section tube  182  may have alternative shapes as desired, including but not limited to triangular, rectangular, trapezoidal, or other polygonal shapes as well as elliptical, complex curves, and figure eight shapes. As shown in  FIG. 18 , one or more slits  186  may be provided adjacent the proximal end  187  to accommodate slight contraction to facilitate removable connectivity to frame member  184 . In this regard, according to one embodiment tube  182  may be snappably connected to frame member  184  adjacent proximal end  187 . In some embodiments, tube member  182  may have a contoured or angled distal end  189  to accommodate particular anatomical features at a surgical site among other things. In particular embodiments, frame member  184  may include an extension  191  to connect to a surgical arm, such as arm  104  shown in  FIG. 1 . In this regard, retractor system  180  may be moved adjacent a surgical access site and subsequently positioned in a substantially stationary position over the surgical access site in much the same way as system  100 , described above. Frame member  184  may provide a working support for the surgeon to rest his/her hands or arms on while performing a surgical procedure. 
     In some embodiments, the retractor system may include one or more features that facilitate the support of one or more surgical instruments. Non-limiting examples of surgical instruments may include a light source (e.g., a surgical light), a suction device (e.g., a suction tube), a tissue cutting and evacuation instrument (e.g., a device for cutting and removing disk material, such as a pituitary, or a device for cutting and removing bone material, such as a ronguer), or other surgical instruments known in the art. 
     While the invention herein disclosed has been described with reference to specific embodiments and applications thereof, numerous modifications and variations can be made thereto by those skilled in the art without departing from the scope of the invention as set forth in the claims