Abstract:
A surgical kit is used for performing an anterior cervical disectomy, the surgical kit having a sheath that is inserted into a mammal by using a bullet coupled to the sheath and impacting on the bullet. Various cutters, including a cervical cutter having a drill tip end, a serrated cutter having an enclave for receiving cutting spoils therein, and a deburrment cutter having a burr end, are insertable through the sheath for cutting bone and disc matter. An impactor can be used to move the sheath within the mammal during use of the serrated cutter and deburrment cutter without the need to remove either tool. A pituitaries is used to remove loose bone and disc material.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a kit of surgical tools for performing a minimally invasive anterior cervical disectomy and the method for the tools&#39; use. 
   2. Background of the Prior Art 
   The human spine is formed from 33 vertebrae divided into five different regions, the cervical, dorsal, lumbar, sacral, and coccygeal, in descending order. Of the five regions, the vertebrae of the upper three remain separated through the life of a person while the lower two fuse in an adult to form two bones, the sacral vertebrae forming the sacrum and the coccygeal vertebrae forming the coccyx. The human spine, which is a weight bearing column, may be afflicted with a variety of ailments such as a disc herniation which may compress the spinal cord or the nerve roots leading to pain, loss of function, and in severe cases, complete paralysis of the legs with an attendant loss of bowel and bladder control. Surgical intervention to remove the offending discal tissue is the prescribed course of treatment. Traditionally, such procedures were not only difficult, but oftentimes dangerous. Traditional surgical techniques called for a large incision to be made, the appropriate disectomy to be performed, and the patient to be closed. Such a surgical procedure is extremely invasive causing substantial trauma to the intervening tissue and leading to an extended post operative recovery period which is typically accompanied by substantial discomfort and pain. Additionally, substantial scarring of the patient occurs and in the case of a cervical disectomy, such scarring is not easily disguised by the patient. As often the amount of post operative discomfort and the size of the scar are the only objective criteria used by the patient to judge the quality of the surgeon&#39;s work, it is advantageous to reduce the size of the incision made and the scar left behind. 
   Toward that end and in order to address the other drawbacks of traditional surgical procedures for curing disc herniation, minimally invasive procedures have been developed wherein the spine is approached by making one or more small incisions into the patient and placing a sheath into the body via each incision and passing various instruments through the sheaths in order to gain mechanical access to the desired area. Such access may include placement of video cameras into the body cavity in order to allow the surgeon to have visual access to the affected area as well as placing deburrment and removal tools into the body cavity in order to extricate the offending disc material. The sheaths protect the surrounding blood vessels and organs during traversal of the body by the various instruments. 
   The use of minimally invasive surgical procedures has greatly reduced the complexity and inherent danger associated with spinal surgery. Additionally, many procedures are performed under local anesthesia wherein the patient maintains consciousness resulting in a dramatic decrease in post operative discomfort of the patient and compression of the post operative recovery period. Furthermore, the scarring of the patient is dramatically reduced with the surgical procedure leaving only one or more small wounds which tend to bypass scrutiny by the casual observer even for a cervical procedure. Accordingly, minimally invasive surgical techniques for dissecting offending material from the spine have achieved wide acceptance and advances in various minimally invasive techniques are constantly being made. 
   Of the various disectomy procedures that are performed, perhaps the trickiest is that of the cervical disectomy. Unlike the back of a person, the neck is relatively narrow and vital arteries and organs, including the carotid, the jugular, the trachea, and the esophagus, are bunched much more tightly. This places an even greater burden on the surgeon to exercise the utmost care in performing the surgery so as to not cause trauma to these organs and arteries. 
   Providing the surgeon with the appropriate tools to perform the cervical disectomy, enables the surgeon to achieve a high level of surgical success while minimizing the risk to the patient. Such tools must be effective for all aspects of the procedure including placement of the initial incision and insertion of the protective sheath into the neck, deburrment of the offending tissue, and extraction of the offending tissue. The tools must be simple in design yet elegant in operation without the need for undue indwelling of the tools within the patient. 
   SUMMARY OF THE INVENTION 
   The anterior cervical disectomy surgery kit and method for its use of the present invention address the aforementioned needs in the art. The tools of the surgery kit are effective for all aspects of the procedure including placement of the initial incision and insertion of the protective sheath into the neck, deburrment of the offending tissue, and extraction of the offending tissue, the surgeon being able to achieve a high level of surgical success while minimizing the risk to the patient. The tools are simple in design yet elegant in operation eliminating the need for undue indwelling of the tools within the patient. 
   The anterior cervical disectomy surgery kit and method for its use of the present invention are comprised of a sheath having a hollow core, a proximal end and a distal end such that the distal end is passed through the body of a mammal, the sheath also having a cap located on its distal end. A serrated cutter has a proximal end and a distal end that is serrated, such that the distal end of the serrated cutter is inserted into the hollow core of the sheath and into the mammal. A cap is removably attached to the proximal end of the serrated cutter for turning the serrated cutter upon insertion into the sheath. An impactor has a hollow core such that the distal end of the serrated cutter is received within the impactor&#39;s hollow core and the impactor abuts against the cap of the sheath. The serrated cutter has a hollow core for passage of a guide wire therethrough. The distal end of the serrated cutter has an opening leading to a hollow enclave for capturing spoils resulting from the bone and disc cutting process. The sheath is inserted anterior of the neck of the mammal at an angle of about 45 degrees such that the sheath passes through the neck just behind a trachea and an esophagus within the neck and just medial to a carotid and a jugular within the neck. A bullet has a proximal end, a distal end, and a hollow core for passage of a guide wire therethrough, the proximal end of the bullet having a cap thereon, such that the bullet and the sheath are coupled by passing the distal end of the bullet into the hollow core of the sheath proximate the proximal end of the sheath and passing the bullet through the hollow core of the sheath such that the distal end of the bullet seats within the distal end of the sheath. The distal end of the bullet is pointed and extends beyond the distal end of the sheath whenever the sheath and the bullet are coupled. The proximal end of the sheath is locked in dovetail fashion with the proximal end of the bullet when the sheath and the bullet are coupled. A hammer is used for impacting on the impactor and the cap of the bullet. A cervical cutter has a proximal end with a handle thereon, and a distal end that is drill bit tipped, such that the distal end of the cervical cutter is inserted into the hollow core of the sheath and into the mammal for cutting bone and disc. A deburrment cutter has a proximal end, and a distal end that has a burr thereon, such that the distal end of the deburrment cutter is inserted into the hollow core of the sheath and into the mammal for deburring, either initially or after use of the serrated cutter or the cervical cutter, bone and disc. A cap is removably attached to the proximal end of the deburrment cutter such that when this cap is removed from the deburrment cutter, the proximal end of the deburrment cutter is received within the hollow core of the impactor. The deburrment cutter has a hollow core for passage of the guide wire therethrough. A pituitaries has a handle end and a grasping end, such that the grasping end is inserted into the hollow core of the sheath and into the mammal for retrieving bone and disc fragments. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of the sheath used with the anterior cervical disectomy surgery kit and method for its use of the present invention. 
       FIG. 2  is a perspective view of the bullet used with the anterior cervical disectomy surgery kit and method for its use. 
       FIG. 3  is a perspective view of the bullet and the sheath mated together. 
       FIG. 4  is a perspective view of the bullet and the sheath mated together accompanied by the hammer used for impacting the bullet. 
       FIG. 5  is a side view of the bullet and the sheath illustrating the interior detail. 
       FIG. 6  is a side view of the bullet and the sheath with a guide wire passing therethrough. 
       FIG. 7  is a side view of the cervical cutters used with the anterior cervical disectomy surgery kit and method for its use of the present invention. 
       FIG. 8  is a side view of the cervical cutter passed through the sheath. 
       FIG. 9  is a perspective view of the serrated cutter used with the anterior cervical disectomy surgery kit and method for its use, with the serrated cutter mated to its cap. 
       FIG. 10  is a perspective view of the serrated cutter illustrating its interior detail as well as illustrating the detail of the cap. 
       FIG. 11  is a perspective view of the serrated cutter passed through the sheath. 
       FIG. 12  is a perspective view of the impactor used with the anterior cervical disectomy surgery kit and method for its use. 
       FIG. 13  is a perspective view of the impactor being used with the serrated cutter. 
       FIG. 14  is a perspective view of the deburrment tool and its cap that are used with the anterior cervical disectomy surgery kit and method for its use. 
       FIG. 15  is a perspective view of the deburrment cutter passed through the sheath. 
       FIG. 16  is a side view of the pituitaries used with the anterior cervical disectomy surgery kit and method for its use, the pituitaries passed through the sheath. 
       FIG. 17  is an environmental view of the pituitaries being used on a patient. 
   

   Similar reference numerals refer to similar parts throughout the several views of the drawings. 
   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring now to the drawings, it is seen that the anterior cervical disectomy surgery kit and method for its use of the present invention is comprised of a sheath  12  that has a first hollow core  14  and also has a first proximal end  16  and a first distal end  18 . A first cap  20 , which may be knurled for better gripping thereof, is located on the sheath&#39;s proximal end  14 . The distal end  18  of the sheath  12  is slightly beveled. The sheath  12  is made from any appropriate bioacceptable material such as metal or plastic and must be able to endure mild hammering and must be relatively thin, on the order of less than about 1 millimeter in thickness, yet strong enough to not easily bend. The diameter of the sheath  12  is on the order of just a few millimeters and the inside diameter of the first hollow core  14  may be approximately 5 millimeters with the outside diameter of the sheath  12  being approximately 6 millimeters, although both the inside diameter and the outside diameter of the sheath  12  may be greater or less than the above values in keeping within the scope and spirit of the present invention  10 . 
   A bullet  22  has a second proximal end  24  and a second distal end  26 . A second cap  28  is located on the proximal end  24  of the bullet  22 , which second cap  28  may also be knurled for better gripping thereof. The second cap  28  may be about the size of the first cap  20 . The distal end  26  of the bullet  22  is pointed. The bullet  22  has a second hollow core  30  which may be on the order of less than 1 millimeter in diameter although the diameter may be more or less than this value. The bullet  22  is also made from a bioacceptable material such as metal or plastic and may be made from the same material as the sheath  12  and must also be able to endure hammering thereupon. 
   The sheath  12  and the bullet  22  are coupled by passing the second distal end  26  of the bullet  22  into the first hollow core  14  at the first proximal end  16  of the sheath  12  and passing the bullet  22  through the first hollow core  14  such that the second distal end  26  of the bullet  22  seats within the first distal end  18  of the sheath  12 . In such a configuration, the second distal end  26  of the bullet  22  extends beyond the first distal end  18  of the sheath  12 . Once the bullet  22  is received within the sheath  12  the two members  12  and  22  are locked to one another. This can be accomplished by providing a standard dovetailing arrangement wherein a peg  32  is provided on the second proximal end  24  of the bullet  22  which peg  32  is received within a relatively wide opening  34  located on the first proximal end  16  of the sheath  12  and the bullet  22  is twisted in order to pass the peg  32  into the relatively smaller restricted area  36  on the proximal end  16  of the sheath  12  thereby locking the bullet  22  to the sheath  12 . The peg and openings can be reversed such that the peg is located on the sheath and the openings located on the bullet. Additionally, other locking mechanisms may also be used for locking the sheath  12  with the bullet  22 . 
   A guide wire or K-wire  38  is passed through the second hollow core  30  of the bullet  22 . The coupled sheath  12  and bullet  22  are passed through a mammalian body to a desired area wherein a surgical procedure is performed. This is accomplished by hammering on the proximal end  24  of the bullet  22 . The pointed distal end  22  of the bullet  22  helps facilitate passage of the bullet  22  through the body, the hammer  40  being of any appropriate design. As the bullet  22  passes through the body, the sheath  12  coupled to the bullet  22  also passes through the body of the patient. 
   In a cervical disectomy procedure, the coupled sheath  12  and the bullet  22  are positioned at the front of the neck N of the patient P at about 45 degrees to the front midline of the neck such that the sheath  12  and bullet  22  pass through the neck N just behind the trachea and esophagus and just medial to the carotid and jugular. Once the coupled sheath  12  and bullet  22  are in proper position within the patient&#39;s body, the K-wire  38  is secured and the bullet  22  is unlocked from the sheath  12 , decoupled from the sheath  12 , and removed from the body with the K-wire  38  remaining in the patient and passing through the sheath  12 . Additional sheaths  12  may be inserted into the patient&#39;s body as needed such as to give the surgeon additional visual access to surgical area of the patient P. 
   Thereafter, the surgeon uses one or more cutting tools in order to cut disc and bone for removal from the patient P. The various cutting tools are illustrated in  FIGS. 7-15 , and with specific reference to  FIGS. 7 and 8  there is illustrated a cervical cutter  42  that has a third distal end  44  and a third proximal end  46 . The third distal end  46  of the cervical cutter  42  is drill bit tipped and is front cutting and has a cutting point to the end of the tip. The third proximal end  42  of the cervical cutter  42  has an appropriate handle  48  thereon which may be knurled in order to afford the surgeon a better grip of the cutter  42 . As illustrated in  FIG. 7 , the distal end  46  of the cervical cutter  42  may come in different diameters, for example ⅛ or 3/16 inches in diameter, although other diameters are possible. The length of the cervical cutter  42  is sufficient in order to allow the handle  48  of the cutter to be spaced sufficient distance from the sheath  12  so that as the cutter  42  descends into the disc or bone during the cutting procedure, and thus further into the sheath  12 , the sheath  12  does not interfere with the handle  48 . In order to use the cervical cutter  42 , the distal end  46  of the cutter is inserted through the proximal end  14  of the sheath until the pointed distal end  46  of the cutter  42  reaches the point of cutting, at which point the surgeon rotates the cutter  42  via the handle  48 . Once use of this cutter  42  is no longer needed, the cutter  42  is removed from the sheath  12 . 
   A serrated cutter  50  is illustrated in  FIGS. 9-15 , which cutter  50  has a fourth proximal end  52  and a fourth distal end  54 , which distal end  54  has serrations  56  thereon. The distal end  54  of the serrated cutter  50  is open and leads to a hollow enclave  58  that extends toward the proximal end  52  of this cutter  50 . The serrated cutter  50  has a third hollow core  60  which may be on the order of less than 1 millimeter in diameter although the diameter may be more or less than this value, the third hollow core  60  allowing passage of the K-wire  38  therethrough. A third cap  62  is removably attached to the proximal end  52  of the serrated cutter  50 . As seen, the third cap  62  has a fourth hollow core  64 , which hollow core  64  is non-circular in shape and the proximal end  52  of the serrated cutter  50  has a similar shape in order to facilitate a keyed attachment of the cap  62  to the cutter  50  and thereafter permit turning of the cutter  50  via the cap  62 . The serrated cutter  50  is several inches longer than the length of the sheath  12 . In use, the third cap  62  is attached to the proximal end  52  of the cutter  50  and the distal end  54  of the serrated cutter  50  is passed over the K-wire  38  and into the proximal end  14  of the sheath  12  and passed through the sheath  12  until the cutter  50  reaches the desired point of procedure. The cutter  50  is rotated via the third cap  62  such that the serrations cut into bone and disc matter. Much of the cutaway spoils of the bone and disc being cut are received within the hollow enclave  58  of the cutter  50  for subsequent removal from the body of the patient P when the cutter  50  is removed. Oftentimes it is desirable to move the sheath  12  in conjunction with the dissension of the serrated cutter  50  deeper into the body. In order to accomplish this movement of the sheath  12 , an impactor  66  is provided, the impactor  66  having a fourth hollow core  68 , the diameter of this hollow core  68  being slightly greater than the outside diameter of the serrated cutter  50 . The impactor  66  is several inches long in order to afford the surgeon a good grip thereon and may be knurled. The third cap  62  is removed from the serrated cutter  50  and the impactor is positioned so as to slide over the serrated cutter  50  and abut against the first cap  20  of the sheath  12 . The hammer  40  is used to strike the end of the impactor  66  that is opposite the end abutting the sheath  12 , which hammering force transfers to the sheath  12  causing movement of the sheath  12 . As the serrated cutter  50  is within the first hollow core  14  of the sheath  12  and the fourth hollow core  68  of the impactor  66  and slides within these hollow cores  14  and  68 , the hammering force does not transfer to the serrated cutter  50  and therefore the cutter  50  does not move as a result of the hammering. Once the sheath  12  is appropriately repositioned, the impactor  66  is removed from about the serrated cutter  50  and the third cap  62  is replaced onto the proximal end  52  of the cutter  50 , and the surgeon once again cuts bone and disc matter as desired. Accordingly, the sheath  12  is movable within the patient&#39;s body without the need to remove and thereafter replace the serrated cutter  50 . 
   A deburrment cutter  70  is illustrated in  FIGS. 14 and 15 , the deburrment tool having a fourth proximal end  72  and a fourth distal end  74 . The deburrment cutter  70  has a fifth hollow core  76  which may be on the order of less than 1 millimeter in diameter although the diameter may be more or less than this value, the fifth hollow core  76  allowing passage of the K-wire  38  therethrough. A burr  78  is located on the fourth distal end  74  of the deburrment cutter  70 , while a fourth cap  80  is removably attached to the proximal end of the deburrment cutter  70 . As seen, the fourth cap  80  has a fifth hollow core  82 , which hollow core  82  is non-circular in shape and the proximal end  72  of the deburrment cutter  70  has a similar shape in order to facilitate a keyed attachment of the cap  80  to the cutter  70  and thereafter permit turning of the cutter  70  via the cap  80 . It is recognized that the same cap may be used for both the serrated cutter  50  and the deburrment cutter  70  although most surgeons prefer each tool to have its own cap. 
   The deburrment cutter  70  is several inches longer than the length of the sheath  12 . In use, the fourth cap  80  is attached to the proximal end  72  of the cutter  70  and the distal end  74  of the deburrment cutter  70  is passed over the K-wire  38  and into the proximal end  14  of the sheath  12  and passed through the sheath  12  until the cutter  70  reaches the desired point of procedure. The cutter  70  is rotated via the third cap  80  such that the burr  76  burrs away jagged edges and helps smooth out bone and disc matter. Oftentimes it is desirable to move the sheath  12  in conjunction with the use of the deburrment cutter  70 . In order to accomplish this movement of the sheath  12 , the fourth cap  80  is removed from the deburrment cutter  70  and the impactor  66  is positioned so as to slide over the deburrment cutter  70  and abut against the first cap  20  of the sheath  12 . The hammer  40  is used to strike the end of the impactor  66  that is opposite the end abutting the sheath  12 , which hammering force transfers to the sheath  12  causing movement of the sheath  12 . As the deburrment cutter  70  is within the first hollow core  14  of the sheath  12  and the fourth hollow core  68  of the impactor  66  and slides within these hollow cores  14  and  68 , the hammering force does not transfer to the deburrment cutter  70  and therefore the cutter  70  does not move as a result of the hammering. Once the sheath  12  is appropriately repositioned, the impactor  66  is removed from about the deburrment cutter  70  and the fourth cap  80  is replaced onto the proximal end  72  of the cutter  70 , and the surgeon once again deburrs bone and disc matter as desired. Accordingly, the sheath  12  is movable within the patient&#39;s body without the need to remove and thereafter replace the deburrment cutter  70 . 
   As seen in  FIGS. 14 and 15 , a pituitaries  84 , of standard design known in the art, is provided with the surgical kit, the pituitaries  84  having a handle end  86  form manipulation by the surgeon and a grasping end  88  for retrieval of bone and disc matter, such that the grasping end  88  of the pituitaries  84  is passed through the sheath  12  in order to remove bone and disc matter from the surgical sight. The pituitaries  84  can be used at the start of the surgical procedure after the sheath  12  is in place and the bullet  22  is removed therefrom, in order to remove loose disc and bone that may have accumulated prior to the surgical procedure or the pituitaries  84  can be used as bone and disc are cut away during the surgical procedure by one of the cutting tools. 
   While the invention has been particularly shown and described with reference to an embodiment thereof, it will be appreciated by those skilled in the art that various changes in form and detail may be made without departing from the spirit and scope of the invention.