Abstract:
A surgical barrier to be introduced during spinal fusion surgery in order to protect a specified area of the patient from adverse effects associated with surgical techniques. A method of using the surgical barrier including: establishing an operative corridor to a target surgical site; introducing a spinal fusion implant into the through said operative corridor, the fusion implant including fusion-enhancing material; introducing at least a portion of an intraoperative surgical barrier through the operative corridor to the surgical target site, the intraoperative surgical barrier including an expandable seal member; and expanding the expandable seal member to establish a barrier between the fusion implant and at least a portion of the surgical target site and the operative corridor.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     The present non-provisional patent application claims the benefit of priority from commonly owned and co-pending U.S. Provisional Patent Application Ser. No. 60/851,185, entitled “Intraoperative Surgical Barrier,” filed on Oct. 11, 2006, the entire contents of which are hereby expressly incorporated by reference into this disclosure as if set forth fully herein. 
    
    
     BACKGROUND OF THE INVENTION 
     I. Field of the Invention 
     The present invention relates generally to spinal surgery and, more particularly, to a method and device for protecting a surgical site from adverse effects during operative wound irrigation. 
     II. Discussion of the Prior Art 
     Currently there are nearly 500,000 spine lumbar and cervical fusion procedures performed each year in the United States. One of the causes of back pain and disability results from the rupture or degeneration of one or more intervertebral discs in the spine. Surgical procedures are commonly performed to correct problems with displaced, damaged, or degenerated intervertebral discs due to trauma, disease, or aging. Generally, spinal fusion procedures involve removing some or the all of the diseased or damaged disc, and inserting one or more intervertebral implants into the resulting disc space. 
     Introducing the intervertebral implant serves to restore the height between adjacent vertebrae (“disc height”), which reduces if not eliminates neural impingement commonly associated with a damaged or diseased disc. Distraction of the disc space with subsequent decompression of nerve roots can be accomplished by inserting such a device between the adjacent vertebrae. 
     Current spinal fusion implants utilize grafts of either bone or artificial implants to fill the intervertebral disc space. Spinal fusion implants or grafts may be made of metal, plastic composites, ceramics, or bone. Natural bone grafts have also been developed including autologous and allograft bone grafts. Other bone grafts may include certain man-made substances including binder joining bone chips and composite bone structures. 
     Often these spinal implants are accompanied by bone morphogenic proteins (BMPs) which serve to enhance fusion of the two vertebrae. BMPs are highly effective growth factors, in that they promote the formation of new bone and the fusion of existing bone. A primary drawback to the use of BMPs is a generally high, and sometimes prohibitive, cost associated therewith. As such, surgeons seek to be cautious with BMP use, so as not to waste the costly proteins. 
     A common problem with BMP use in spinal fusion is the loss of BMP during irrigation of the surgical site. Irrigation of the operative wound is a standard operative technique, and is vital for the prevention of peri-operative infection. Thus surgeons are often left with the difficult choice of irrigating the surgical site, and thus risking the loss of expensive BMP and lessening the efficacy of the spinal fusion, or not irrigating the site and risking infection. 
     Thus a need remains for a device which can facilitate the irrigation of the operative wound, while preserving the integrity and precise location of BMP. The present invention is directed at solving this problem. 
     SUMMARY OF THE INVENTION 
     The present invention addresses this problem by providing an inflatable intra-operative barrier which protects the spinal fusion site, and thus the BMP, from dilution or disruption during irrigation. The barrier facilitates proper irrigation of the operative wound by providing a temporary waterproof seal which prevents the irrigating fluid (including but not limited to water, air, or saline) from disrupting or diluting the BMP. The intra-operative surgical barrier of the present invention may be comprised of any suitable flexible material, including but not limited to silicone, rubber/latex, polyvinyl chloride, or any combination of these materials. The intra-operative surgical barrier of the present invention may be provided in any number of suitable shapes and sizes depending upon the particular surgical procedure or need. The barrier may be used in various regions of the spine, and from various approach angles (ie. posterior, anterior, lateral, transverse or off-midline posterior, etc.) without departing from the scope of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Many advantages of the present invention will be apparent to those skilled in the art with a reading of this specification in conjunction with the attached drawings, wherein like reference numerals are applied to like elements and wherein: 
         FIG. 1  is a top view of one example of a surgical barrier according to a first embodiment of present invention, shown in a deflated state; 
         FIG. 2  is a top view of the surgical barrier of  FIG. 1 , shown in an inflated state; 
         FIG. 3  is a side view of the deflated surgical barrier of  FIG. 1 ; 
         FIG. 4  is a side view of the inflated surgical barrier of  FIG. 2 ; 
         FIG. 5  is a cross-sectional view of the deflated surgical barrier of  FIG. 1 ; 
         FIG. 6  is a cross-sectional view of the inflated surgical barrier of  FIG. 2 ; 
         FIGS. 7-8  are side and top views, respectively, of the inflated surgical barrier of  FIG. 2  applied within an intervertebral space from an anterior aspect of the spine, illustrating one example of use according to the present invention; 
         FIGS. 9-10  are top and side views, respectively, of the inflated surgical barrier of  FIG. 2  applied within an intervertebral space from a lateral aspect of the spine, illustrating a second example of use according to the present invention; 
         FIG. 11  is a side view of the inflated surgical barrier of  FIG. 2  applied within an intervertebral space from an anterior aspect of the spine, illustrating another example of a use according to the present invention; 
         FIG. 12  is a side view of the inflated surgical barrier of  FIG. 2  applied just outside an intervertebral space from an anterior aspect of the spine, illustrating another example of a use according to the present invention; 
         FIG. 13  is a top cross-sectional view of one example of a surgical barrier according to a second embodiment of the present invention, shown in a deflated state; 
         FIG. 14  is a top cross-sectional view of the surgical barrier of  FIG. 13 , shown in an inflated state; 
         FIG. 15  is a top view of the inflated surgical barrier of  FIG. 14  applied adjacent to an intervertebral space from an anterior aspect of the spine, illustrating one example of use according to the present invention; 
         FIG. 16  is a top view of the inflated surgical barrier of  FIG. 14  applied adjacent to an intervertebral space from a lateral aspect of the spine, illustrating one example of use according to the present invention; 
         FIG. 17  is a top view of the inflated surgical barrier of  FIG. 14  applied within an intervertebral space from an anterior aspect of the spine, illustrating one example of use according to the present invention; 
         FIG. 18  is a top view of the inflated surgical barrier of  FIG. 14  applied within an intervertebral space from a lateral aspect of the spine, illustrating one example of use according to the present invention; 
         FIG. 19  is a side view of one example of a surgical barrier according to a third embodiment of the present invention, shown in an inflated state; 
         FIG. 20  is a side view of the inflated surgical barrier of  FIG. 19  applied within an intervertebral space from an anterior aspect of the spine, illustrating one example of use according to the present invention; and 
         FIG. 21  is a top view of the inflated surgical barrier of  FIG. 19  applied within an intervertebral space from an anterior aspect of the spine, illustrating one example of use according to the present invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Illustrative embodiments of the invention are described below. In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developers&#39; specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure. The intra-operative surgical barrier disclosed herein boasts a variety of inventive features and components that warrant patent protection, both individually and in combination. 
       FIGS. 1-4  illustrate an intra-operative surgical barrier  10  according to a first broad aspect of the present invention. The surgical barrier  10  of the present invention includes a valve unit  12 , tubing  14 , and an inflatable seal  16 . The surgical barrier  10  may be provided with varying length and width dimensions, for both the tubing  14  and the inflatable seal  16 , depending on the size of the operative wound of a patient. The intra-operative surgical barrier  10  of the present invention may be comprised of any suitable flexible material, including but not limited to silicone, rubber/latex, polyvinyl chloride, or any combination of these materials. 
     In the latter stages of a surgical procedure, specifically the fusion of adjacent vertebrae using bone morphogenic protein (BMP), a surgeon or technician may introduce the surgical barrier  10  into the operative wound site in a deflated state, as illustrated in  FIGS. 1 and 3 . The barrier  10  may be passed through a wound site into a position adjacent to a fusion implant or cage, which contains BMP. The surgeon or technician may then attach the valve unit  12  of the barrier  10  to any sort of pressurized fluid pump, and engage the pump. This action causes the inflation fluid (typically, but not limited to, air, water, or saline) to traverse the interior lumen of the tubing  14  and enter the inflatable barrier  16 . The inflatable seal  16  then expands to take the shape depicted in  FIGS. 2 and 4 . The expandable nature of the inflatable seal  16  serves to allow for uncomplicated introduction into the operative wound site while the seal  16  is deflated, and adequate covering of the fusion site when the seal  16  is inflated. As the seal  16  is adjacent to, and covering, the fusion implant (and thus the BMP), it provides a protective covering over the spinal fusion implant. Thus the surgeon or technician may irrigate the operative wound without fear of diluting or removing the BMP. 
     The external pump need only serve to provide a pressure at a level sufficient to force the inflation fluid down the tubing  14 , into the seal  16 , and thereafter expanding the seal  16 . As such, one skilled in the art may envision any number of devices capable of performing this function, including but not limited to: a bulb-style syringe aspirator, an air compressor, or a pressurized water faucet. 
     The valve unit  12  serves to allow the passage of the inflation fluid from the external pump, through the tubing  14 , and into the inflatable seal  16 . As such, one skilled in the art may envision any of a number of shapes and structures capable of performing this function, including but not limited to: a hose clamp, regulator, needle valve, or stopcock. It is also desirable that the valve unit  12  have a cut off device to at least temporarily prevent reverse flow of the fluid, so that once the inflatable seal  16  is inflated to the proper size, the external pump may be disengaged while the seal  16  remains the proper size. That is to say, the cut off device may create a temporary one-way valve (or check-valve), so that inflation fluid may be added to the barrier  10 , but not withdrawn. Then, at the conclusion of the irrigation procedure, the cut off device may be disengaged to allow the draining, deflation, and removal of the barrier  10 . 
     The tubing  14  may be composed of any suitable water-tight flexible material, including but not limited to silicone, rubber/latex, polyvinyl chloride, or any combination of these materials. The tubing  14  may be composed in such a manner as to be flexible in movement, but less flexible in expansion, so that the fluid traverses (rather than expands) the tubing  14  causing the inflatable seal  16  to expand. 
     The inflatable seal  16  may be composed of any suitable water-tight flexible material, including but not limited to silicone, rubber/latex, polyvinyl chloride, or any combination of these materials. The seal  16  may be composed in such a way that, upon inflation with inflating fluid, the seal  16  has a generally rectangular shape. This may be accomplished by the lateral sides  20  expanding to create a wider seal  16  (as shown in  FIG. 6 ), and/or the top and bottom sides  22  expanding to create a taller seal  16 . It is not necessary that the thickness of the seal  16  increase, as any amount of thickness will be adequate to protect the fusion site from disruption due to irrigation. Additionally, it may be counter-productive for the thickness of the seal  16  to expand, as that itself may cause dislodgment of the fusion device or BMP. 
       FIGS. 5 and 6  depict one example of a structural configuration in which the inflatable seal  16  may be provided so that, upon inflation, it expands in the manner described above. As shown in the deflated state of  FIG. 5 , the wall thickness of the lateral sides  20  is significantly less than that of the anterior and posterior sides  24 , as well as that of the tubing  14 . This creates less resistance for the inflating fluid at the lateral sides  20  than at the anterior and posterior sides  24 . Thus as the inflating fluid is forced into the seal  16 , the lateral sides  20  expand laterally, while the anterior and posterior sides  24  generally do not expand anteriorly or posteriorly (or do so in a small amount relative to lateral expansion).  FIG. 6  depicts this expanded state. Additionally, as previously disclosed, the walls of the tubing  14  should also be constructed of thicker (or entirely different, and less elastic) material, as to force the fluid into the seal  16 , rather than expanding the tubing  14 . 
       FIGS. 7 and 8  display side and top views, respectively, of one example of an in situ application of the intraoperative surgical barrier  10  of the present invention. In this instance, the barrier  10  is introduced from an anterior aspect of the spine into the intervertebral space  26  between two vertebrae  28 ,  30 , and adjacent to a fusion implant  32 . This fusion implant  32  contains BMP  34  to promote the fusion of the adjacent vertebral bodies  28 ,  30 . Upon insertion into the proper location, the external pump fills the tubing  14 , via the valve unit  12 , with the inflating fluid. The fluid travels down the tubing  14  and fills the inflatable seal  16 , which then inflates and expands (the stage shown in  FIG. 7 ) to protect the fusion implant  32  and BMP  34  from dislodgement or dilution during irrigation. 
       FIGS. 9 and 10  display side and top views, respectively, of a second example of an in situ application of the intraoperative surgical barrier  10  of the present invention. As spinal fusion procedures vary in entry manner (from anterior, posterior, and lateral) it is preferable that the barrier  10  be adaptable to these various procedures. In this instance, the barrier  10  is introduced from a lateral aspect of the spine (to coincide with the lateral insertion of fusion implant  32 ) into the intervertebral space  26  between two vertebrae  28 ,  30 , and adjacent to fusion cage implant  32 . This fusion cage implant  32  contains BMP  34  to promote the fusion of the adjacent vertebral bodies  28 ,  30 . Upon insertion into the proper location, an external pump (not shown) fills the tubing  14 , via the valve unit  12 , with the inflating fluid. The fluid travels down the tubing  14  and fills the inflatable seal  16 , which then inflates and expands (the stage shown in  FIG. 7 ) to protect the fusion cage and BMP  34  from dislodgement or dilution during irrigation. 
     While  FIGS. 7 and 8  depict the barrier  10  being introduced from an anterior aspect of the spine, and  FIGS. 9 and 10  depict the barrier  10  as being introduced from a lateral aspect of the spine, it is to be appreciated that the barrier may similarly be used in any number of additional surgical techniques, including but not limited to a posterior surgical technique (e.g. PLIF) and a transforaminal surgical technique (e.g. TLIF). As such, the barrier  10  may be introduced from any aspect of the spine, including but not limited to anterior, posterior, lateral, antero-lateral, and postero-lateral. 
       FIGS. 11 and 12  display the adaptable nature of the intraoperative surgical barrier  10  of the present invention in that the barrier may be placed within the intervertebral space  26  ( FIG. 11 ) or outside the intervertebral space  26  and adjacent to the vertebral bodies  28 ,  30  ( FIG. 12 ). This determination will be made largely in part by the size of the spinal fusion implant  32 , and the particular needs of an individual operative wound.  FIGS. 11 and 12  also depict the capability of the barrier  10  to adapt to the shape of the spinal fusion implant  32 . The barrier  10  has a flexibility characteristic due in part to its composition material and also to the fluid nature of inflation, and thus the barrier  10  can accommodate a wide variety of shapes. As such,  FIGS. 11 and 12  depict a differently shaped spinal fusion implant  32  than those found in  FIGS. 7-10 . 
       FIGS. 13-16  depict the application of an alternate embodiment of the barrier  100  of the present invention. Like the previously described embodiment of the barrier  10 , the barrier  100  includes a valve unit  12 , tubing  14 , and an inflatable seal  102 . The valve unit  12  and tubing  14  are substantially identical to that described in relation to barrier  10 . The barrier  100  is composed in such a way that the inflatable seal  102  assumes a curved, or crescent, shape upon inflation. This curved shape may better approximate the shape of the vertebral bodies  105  being fused, and thus may provide better sealing capabilities. 
     As shown in  FIGS. 13 and 14 , this embodiment may be created by varying the thickness of the material used to compose the seal  102  so that, upon inflation, the seal  102  expands to take a curved, or crescent, shape. This can be accomplished by providing a seal with significantly thicker walls on the anterior and posterior sides  103 , than on the corners  104  where expansion is to be the greatest. As such, when the inflation fluid enters the seal  102 , the path of least resistance is through the corners  104 , and thus the corners  104  expand to a greater degree than the thicker walls of the anterior and posterior sides  103 . 
       FIG. 15  depicts this embodiment of the barrier  100  as being introduced in an anterior approach, while  FIG. 16  depicts the barrier  100  as introduced from a lateral approach. Additionally, a third variety of spinal fusion implant  106  is depicted in  FIGS. 15 and 16 , further exemplifying the adaptability of the barrier  100  of the present invention. 
       FIGS. 17 and 18  depict the crescent-shaped embodiment of the present invention, as applied in a situation involving a smaller spinal fusion implant  108 . Thus the barrier  100  may be inserted into the intervertebral space, thereby allowing the surgeon/technician to irrigate the operative wound more effectively (without disturbing the BMP  110  present in the implant  108 ).  FIG. 17  depicts this embodiment of the barrier  100  as being introduced from an anterior approach, while  FIG. 18  depicts the barrier  100  as introduced from a lateral approach. While  FIGS. 15 and 17  depict the barrier  100  being introduced from an anterior aspect of the spine, and  FIGS. 16 and 18  depict the barrier  100  being introduced from a lateral aspect of the spine, it is to be appreciated that the barrier  100  may be introduced from any aspect of the spine, including but not limited to anterior, posterior, lateral, antero-lateral, and postero-lateral. 
       FIGS. 19-21  depict a barrier  200  according to a third embodiment of the present invention. As with the previous embodiments, the barrier  200  includes a valve unit  12 , tubing  14 , and an inflatable seal  102 . The valve unit  12  and tubing  14  are substantially identical to that described in relation to barrier  10 . The inflatable seal  202  assumes a generally spherical shape upon inflation. As such, the barrier  200  may be inserted into a wound site and inflated, whereby the flexibility of the seal  202  allows the generally spherical shape to conform to the contours of the particular site. Thus, it may be preferable for the seal  200  to be composed in a more flexible manner (ie. through the use of different materials, or by creating thinner walls) to allow the seal  200  to conform to the shape of the target site. Both  FIG. 20  and  FIG. 21  depict the entry of the barrier  200  from an anterior aspect of the spine. The figures differ however in the size and shape of the spinal fusion implants  204 ,  205  inserted into the intervertebral space  206 .  FIG. 20  depicts a larger implant  204 , and thus the barrier  200  may be disposed outside the intervertebral space  206 , while  FIG. 21  depicts a smaller fusion implant  205 , and thus the barrier  200  may be disposed within the intervertebral space  206  during irrigation. While  FIGS. 19-21  depict the barrier  200  being introduced from an anterior aspect of the spine, it is to be appreciated that the barrier  200  may be introduced from any aspect of the spine, including but not limited to anterior, posterior, lateral, antero-lateral, and postero-lateral. 
     While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the invention to the particular forms disclosed, but on the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined herein. For instance, although the preferred embodiments described herein describe an intraoperative surgical barrier for use during spinal fusion procedures, it is apparent that the device may be used in any surgical technique where a particular region of a patient&#39;s anatomy must be separated from the general operative environment.