Abstract:
In accordance with one embodiment a surgical device consisting of a rigid frame with a spindle straddling the lateral members and coupled with a ratcheting traction unit for the purpose of anchoring an organ and, to apply controlled incremental traction to the tissues connecting the organ to the body enabling exposure of a working length of the tissue and its associated structures for the application of ligatures etc.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     Provisional U.S. Application No. 61/385,827, filed on Sep. 23, 2010 by Subhakar Patthi Rao for a “Surgical Spay and Neuter Assist Platform System” (‘SNAP’ system). 
    
    
     BACKGROUND 
     Prior Art 
     
         
         (1) Patent # US 2006/0079932 A1 issued to Brian T. Dowling on Apr. 13, 2006 
         (2) The ‘Hauptman OHE Retractor’ available from Jorgenson Laboratories of Loveland Colo. 
       
    
     FEDERALLY SPONSORED RESEARCH 
     None 
     Surgical neutering (Ovario-hysterectomy or removal of the female reproductive organs commonly referred to as ‘Spaying’ and, Orchiectomy is the removal of the testes in the male is usually referred to as ‘Castration’) is one of the most routinely performed elective procedures carried out by veterinarians. It demands a working knowledge of regional anatomy, skill and, manual dexterity. In the case of ‘Spaying’ sometimes an ‘additional’ pair of hands comes into play to complete the procedure. 
     After gaining access to the abdomen of the female dog or cat, the uterine horn is identified, isolated, exteriorized and followed cranially to locate the ovary. Once this is done the ovary is held by the ‘Proper’ ligament (the ligament that attaches the ovary to the uterus) and adequate traction is applied to identify the ‘suspensory’ or ovarian ligament (a strong fibrous band that is attached to the ovary at the distal end and arises as a fan shaped structure from the vertebral end of the last two ribs) by digital palpation as a taut band arising from the an area near pole of the ipsilateral kidney. Holding and maintaining traction on the proper ligament by the power hand, the index finger of the free hand is slid along the cranial border of the suspensory ligament (closer to the kidney) and is either stretched or torn to facilitate exteriorizing the ovary. 
     At this stage a ‘fenestration’ or a window is made in the broad ligament (the structure that comprises of a peritoneal fold that suspends the uterus) caudal to the ovary and one or two crushing type of forceps (depending upon the choice of the surgeon) are placed across the ovarian ‘Pedicle’ (comprising of the tortuous ovarian artery and vein; the suspensory ligament and its vasculature) and one across the proper ligament. Once removed, the most proximal clamp serves to form a groove for the placement of a circumferential ligature which is applied in a fashion that is comfortable to the surgeon. The middle clamp assists to hold the pedicle for ligation. Depending upon the skill of the surgeon, size of the pedicle and the amount of fat surrounding it a second ligature may be applied after releasing (and ‘flashing’) the middle forceps. The suspensory ligament is held as close to the ovary as possible by a smaller forceps and the pedicle is transected distal to this forceps. The stump is checked for any bleeding and is released back into the abdominal cavity. The contralateral ovary is removed in the same way. Removal of the uterus is done in a routine way. 
     The preceding paragraph illustrates the steps needed to complete the procedure (in this instance removal of the ovaries) after the body wall is opened the ovaries need to be exteriorized and the pedicle visible and accessible for the application ligatures. There has to be adequate traction applied to the ovarian pedicle to keep the ovary in an exteriorized position. 
     While maintaining traction, the index finger of the free hand is used to feel for the taut ovarian ligament and with controlled traction from the said finger the said ligament is ‘tweaked’ until it tears or stretched for adequate pedicle exposure. Since the application of the ligature requires two hands, the step to hold the traction on the ovarian pedicle lies in the improvisation of the surgeon using the back or the edge of the palm to anchor the clamps or seek the assistance from an extra pair of hands. One method to secure and stabilize the ovarian pedicle (for a solo surgeon) is to apply a crushing clamp (or two clamps placed opposite to each other across the opened body wall) proximal to the intended placement of the ligature, apply the ligature and release the clamp (or clamps). Since the groove or tract made by the clamp is left behind in the body, there is a chance that the integrity of the vascular walls of the pedicle might be compromised leading to bleeding and subsequent complications. 
     At present there are two alternatives that offer relief for the solo practitioner: 
     (a) The ‘Hauptman OHE Retractor’ (available in three sizes from Jorgenson Laboratories of Loveland Colo.) lets the veterinary surgeon clamp the proper ligament (using existing clamps like the Carmalt etc) after stretching or tearing the suspensory ligament make a fenestration in the broad ligament to pass the lower arm of the retractor and use the two prongs to secure the clamp. Steady traction is applied on the pronged arm away from the bottom arm to stretch, stabilize and pull the ovarian pedicle into view and then proceed to ligate the same. The taut ovarian pedicle over the straight bottom arm of the device tends to act as a ‘fulcrum’ and as such the set up could have a tendency to lift up. 
     (b) The ‘Dowling Retractor’ invented by Brian T. Dowling of Elma Wash., (patent # US 20060079932A1, date: Apr. 13, 2006) is a much simpler rendition. Before clamping the proper ligament the surgeon has to secure the ligament using his fingers (and a piece of gauze for added traction) to wiggle and exteriorize the ovary, make a fenestration in the broad ligament, pass the fixed lower curved arm of the retractor through the opening and apply enough traction to exteriorize the ovarian ligament and then place the clamp across the proper ligament. Depending upon the amount of traction that is applied to the ovarian ligament, the tip of the lower curved arm (if it lacks adequate support from the body wall) could have a tendency to tip over as the curved arm could act as a fulcrum. The said retractor is available in two lower arm sizes. 
     The shortcomings of the aforementioned retractors is based on the laws of physics, specifically that of Class I Levers and the fulcrum which is placed farther away from the load (here the attachment of the ovarian ligament and its associated structures) than it is to the point of force (the forceps clamped across the proper ligament) and as such a significantly higher tendency for the device to tip over. 
     ADVANTAGES 
     The described embodiment offers a more stable and elegant solution to expose the ovarian ligament with a more controlled traction as the device takes advantage of the fulcrum in Class I Levers. When the load increases (tension from the ovarian ligament) so does the stability of the device and prevents any tipping over. This device can accommodate anatomical variations as reproductive anatomical parts come in different sizes and lengths. There is no need to break the ovarian ligament for a working exposure of the ligament and the veterinarian has both the hands free to ligate the pedicle in a more comfortable manner. The procedural time is shortened since this device eliminates the step of breaking the ovarian ligament and there is no ‘fumbling’ of the instrumentation to complete the application of the ligatures. This device is to augment the standard set of instruments that are routinely used in spay and neuter procedures. 
     In a neutering procedure the ‘cord’ is clamped and anchored between the two prongs and adequate traction applied to stretch the same. A second clamp is temporarily applied across the cord to ‘crush’ the cremaster muscle and provide a track for the application of the ligature. 
     SUMMARY 
     The ‘SNAP’ System addresses the need to a more secure, controlled, and confident method of exposing and anchoring reproductive tissues when performing one of the most common surgical procedures (spaying and neutering) in a veterinary hospital. 
     In accordance with the described embodiment (the ‘SNAP’ system) consists of a rigid frame and a spindle straddling the lateral members. The traction unit resembles a ‘three-tined pitchfork’ or a ‘trident’ shape with a flat stump for a handle. The stump is attached to a set of prongs cranially and the central tine is shaped in the form of a flat ratcheting bar that slides into a channel located in the ratcheting housing that is located on the rear cross member. The rear opening of the channel has a partial height beveled end plate attached at a predetermined height to act as a rigid pawl to control the movement of the ratcheting bar. The traction system has a pair of guide rods on either side of the ratcheting bar that slide in and out the corresponding open sleeves found on the traction housing. This set up will help align the unit and prevent the same from racking during operation. To impart traction, the thumb support on the traction unit and the finger grip on the traction unit housing are squeezed together. To release the ratcheting bar, downward digital pressure is applied to the caudal tip of the ratcheting bar to disengage the ratcheting teeth and slide the bar out cranially. 
     In accordance with another simpler rendition of the device the mechanical traction system is eliminated and instead the caudal portion of the rigid lateral members of the main frame sports a plurality of caudally raked congruent notches on the dorsal surface. 
     The proper ligament is cross-clamped with the power hand using user supplied forceps; the thumb and fingers of the free hand are placed on either side of the central annular concavity of the spindle to stabilize the frame and to apply downward pressure. The tip of the forceps is maneuvered into the first notch on the far side and this is used as a pivot to maneuver the body of the forceps into the corresponding first notch on the near side. This operation of ‘walking’ and alternately pivoting the tip and the body of the forceps is progressively advanced till a working length of the ovarian ligament is exposed. 
    
    
     
       DRAWINGS 
         FIG. 1  is the one of the embodiments of the ‘SNAP’ system. 
         FIG. 2  is an exploded view showing the parts of the ‘SNAP” system. 
         FIG. 3  is the sliding components of the traction unit. 
         FIG. 4  is the caudal view of the traction unit housing 
         FIG. 5  is the cranial view of the traction unit housing 
         FIG. 6  is the rigid spindle. 
         FIG. 7  is another embodiment of the ‘SNAP’ system. 
         FIG. 8  is an exploded view of the second embodiment. 
         FIG. 9  is a variation of the ‘SNAP’ system. 
         FIG. 10  is yet another variation of the ‘SNAP’ system. 
     
    
    
     REFERENCE NUMERALS 
     
         
         
           
               101  is the cranial cross member of the rigid frame. 
               102 L &amp;  102 R are the two lateral members of the rigid frame. 
               103  is the spindle seen in an operational position. 
               104 L &amp;  104 R the set of prongs that support the user supplied forceps. 
               105  the body of the traction unit with the dorsal thumb support. 
               105 A the thumb support on the body of traction unit. 
               106 L &amp;  106 R are the lateral guide rods of the traction unit. 
               107  is the finger support that is on the top of the traction unit housing. 
               108  is the ratcheting bar of the traction unit. 
               109  is the caudal cross member of the rigid frame. 
               110  is the rigid platform that rests on the prepped and draped abdomen of the pet. 
               111 L &amp;  111 R are the two congruent cranially raked notches that receive the spindle 
               112  is the sliding traction unit. 
               113  is the housing for the sliding traction unit. 
               115 L &amp;  115 R are the tubular channels for the movement of the lateral guide rods. 
               116 L &amp;  116 R are the openings of the tubular channels. 
               117  is the beveled fixed pawl to stop the cranial movement of the ratcheting bar. 
               118  is the cranial opening of the channel that receives the ratcheting bar. 
               119 A &amp;  119 B are the ends of the spindle that will rest in the notches of the rigid frame. 
               120 A &amp;  120 B are the collars that prevent the lateral movement of the spindle while seated in the notches of the rigid frame. 
               121 A &amp;  121 B are rings that guide the connecting tissues to the center of the spindle. 
               122  is the central annular concavity that channels the connecting tissues. 
               123  is the rigid frame of the second embodiment. 
               124 L &amp;  124 R are a set of caudally raked congruent notches to trap the user supplied forceps. 
           
         
       
    
     DETAILED DESCRIPTION 
       FIG. 1  is a perspective view of the device showing the embodiment in an assembled state that is ready for use. The two prongs  104 R and  104 L helps anchor the forceps that is clamped across the proper ligament. The squeezing together of the thumb support  105 A and the finger support  107  helps the application of necessary traction to expose a working length of the ovarian ligament and its associated structures. Other parts are the spindle  103 , the main rigid frame  110 . 
       FIG. 2  is an exploded view of the embodiment. The cross members  101  and  109  to be permanently attached to the lateral members  102 R and  102 L of the rigid frame  110 . The pair of cranially rake notches  111 R and  111 L located on the dorsal surface of the lateral members receives the ends of the spindle  103  during operation. The raised fixed vertical member  105 A behind the prongs serves as a support for the thumb and the upright raised member  107  which is located at the entrance of the traction housing  113  serves as resting place for the fingers of the surgeon during the act of applying traction to the connecting ovarian structures. The ratcheting bar  108  of the sliding part of the traction unit helps maintain traction on the ovarian structures during operation and can be disengaged by the surgeon as needed. 
       FIG. 3  shows the sliding traction unit  112 , the body  105 , the thumb support  105 A and, the centrally located flat ratcheting bar  108  shows a set of cranially raked elongate teeth  116  on the dorsal surface. The two guide rods  106 R and  106 L located laterally prevent the sliding unit from racking during operation. The two prongs  106 R and  106 L in front of the body  105 . 
       FIG. 4  shows the caudal view of the traction unit housing located above the caudal cross member  109 . The lateral channels  115 R and  115 L show the two hollow tubes  116 R and  116 L that receives the two guide rods during operation. The fixed beveled rigid pawl  117  located at a predetermined height above the caudal opening of the central channel serves to lock the sliding ratcheting bar as needed. 
       FIG. 5  shows the cranial view of the traction unit housing located above the caudal cross member  109 . The cranial opening of the central channel  118  receives the flat ratcheting bar of the sliding traction unit. The lateral channels  115 R and  115 L show the two hollow tubes  116 R and  116 L that receives the two guide rods during operation. 
       FIG. 6  shows the spindle  103 . The two collars  120 A and  120 B prevent the spindle from sliding out of the dorsal notches  111 R and  111 L located on the lateral members  102 R and  102 L. The central annular sulcus  122  is bounded by a set of annular rings  121 A and  121 B that help guide the ovarian structures to stay confined within the concavity of the annular sulcus  122 . 
       FIG. 7  shows a simpler rendition of the surgical device without a built-in traction unit. The caudal portion of the modified lateral members of the rigid frame  123  have a set of dorsally placed caudally raked congruent notches in areas  124 R and  124 L. These notches help in pivoting the tip and the body of the forceps to advance caudally and incrementally expose the ovarian ligament and its associated structures. Other parts are the spindle  103 , the modified main frame  123  and the rear cross member  109 . 
       FIG. 8  shows an exploded view of the simpler version of the device. Cranial cross member  101 , caudal cross member  109 , lateral members  102 R and  102 L to be permanently fused in the predetermined configuration. Dorsal notches  111 R and  111 L receive the spindle  103 . 
       FIG. 9  shows the embodiment with a variation of the traction unit with an articulating pawl and a modified spindle. 
       FIG. 10  shows yet another embodiment with a variation of the traction unit showing an unassembled floating roller pin instead of a pawl and another variation of the spindle. 
     MATERIALS, RAMIFICATIONS AND CONCLUSIONS 
     The embodiment to be made with a metal that is light weight, can withstand thermal stress that typical surgical instruments undergo during the sterilization process, be resistant to body fluids and chemicals in the cleaning solutions, be resistant to corrosion or oxidative damage, be adequately hard to withstand routine surgical handling and occasional mishandling, retain surface integrity for ease of use and cleaning etc. Options would include 316L or 904L type of surgical grade stainless steel or, production costs permitting Titanium could also be considered. 
     The top contact surface of the raked dentils on the ratcheting bar and the lower beveled edge of the fixed pawl could be laminated with tungsten carbide inserts to extend the longevity of the device. 
     The anterior face of the thumb support on the ratcheting body and the posterior face of the finger support on the ratcheting stop housing unit could have a milled cross-hatched or reticulated surface to increase frictional grip during the traction process. 
     The lateral members of the frame, the sliding traction unit, the traction housing of the embodiment to be ‘bead’ blasted (glass bead #10 size with a mesh of 100/170) or other similar process to give it a soft satin luster thereby reducing any reflections from the lights in the operatory and marginally increase haptic properties. For purely aesthetic reasons, the two cross members to have a polished satin finish. 
     In accordance with another variation of the device a larger sliding ratcheting platform travels in a open channel located in the ratcheting pawl housing and the movement of the ratcheting platform is controlled by an articulating pawl that is secured atop the housing. The sliding platform has an articulating stop at the caudal end that prevents the platform from sliding completely out of the housing during a surgical procedure. The pawl can be engaged or disengaged depending upon the different stages of the surgical procedure. The pawl housing unit is attached to the rear cross member of the metal frame. 
     In accordance with another variation of the articulating pawl would be to replace the articulating pawl with a roller pin with capped ends that travels in caudally raked embrasures located in the side walls of the housing. The pin mates with the raked teeth on the sliding ratcheting platform and it moves up in the opening when the platform is pushed caudally into the housing and drops in front of the teeth thereby locking the platform. 
     In accordance with yet another embodiment of the device provides the necessary traction via a horizontally placed gear that is attached to a lever at the top. The gear meshes with a ratcheting bar that bears dentils on the lateral side facing the gear and, the bar bears a set of prongs at the cranial end. The movement of the gear is controlled by an articulating spring loaded pawl with a thumb grip to facilitate the engagement or disengagement of the pawl. To impart the necessary traction to the ovarian ligament the lever is moved in a radial direction till the ligament is in a position to be ligated 
     With all the variations shown, the reader will see at least one embodiment of the surgical device to be more effective and easy to operate. These embodiments are simple in design, light-weight and economical to manufacture. The specificities of the description should not be construed as limitations of the scope of the embodiments but rather as an exemplification of several variations. In keeping with the principle of the class-1 levers, the embodiment can be designed to adapt to other organs that need to be secured when exteriorized outside the body. 
     Operation 
     This description follows after the anesthetized patient has undergone a celiotomy and the uterine horn with the connected ovarian structures (the side nearest to the surgeon) is exteriorized. The proper ligament is identified and cross-clamped with a forceps. The forceps is held above the surface of the abdomen and the broad ligament is identified and a small (size adequate for the passage of the spindle) fenestration is made just below the proximal limit of the ovary. The forceps is now transferred to the free hand and the power hand secures the uterine horn. At this juncture the forceps (still cross clamped to the proper ligament) is let to passively drape on the near side of the body. The uterine horn is followed caudally towards the bifurcation and the far side uterine horn is exteriorized, (in younger patients the body wall incision may have to be extended caudally to reach the uterine bifurcation) cross clamped with a second forceps and a second fenestration is made in the broad ligament below the ovary. 
     Both the forceps (that are still securely clamped to the proper ligaments) are held up vertically with one hand and passed thru the rigid frame of the device (the prongs of the sliding rack is set at full extension) which is placed on the draped surface of the abdomen centering the celiotomy opening. The spindle is now passed thru the two fenestrations and the ends are placed in the two notches in the lateral members of the main frame. The forceps and the uterine horn that is away from the operator are draped over the farther side of the rigid frame. The forceps that is near to the operator is held by the power hand, the ovarian ligament and its associated structures are guided over the central annular concavity of the spindle and the forceps is secured behind the two prongs of the sliding rack. The rigid frame of the device can be repositioned to ensure that the ovarian ligament below the spindle is in a near vertical position. 
     If the forceps cannot be comfortably placed in the prongs, a little downward pressure on the spindle by the free hand should achieve the desired objective. Now the thumb grip on the sliding traction component and the finger support on the traction unit housing are squeezed together using the fingers of the power hand alone or with both the hands. This exposes a working length of the ovarian ligament and the associated structures. The structures are ligated based the surgeon&#39;s choice of material and method. A smaller forceps is used to clamp the ovarian ligament that is distal to the placement of the ligature and below the proximal end of the ovary. The pedicle comprising of the vasculature, other soft tissue and the ovarian ligament is transected distal to the small forceps. The cut end of the pedicle is checked for any hemorrhage and released into the abdominal cavity. The forceps is removed from the prongs of the sliding ratcheting platform and let to drape on the side of the body wall nearest to the operator. 
     The caudal tip of the ratcheting bar is digitally depressed and pulled out to the original extended position and digital pressure released to engage in the rigid pawl. The same steps are now followed for the second ovary and uterine horn. The spindle is now removed from its position and set aside. Both the forceps (that are still cross clamped to the respective proper ligaments) are held up and checked to ensure that no tissue or small organs are trapped in the bifurcation. The two broad ligaments attached to the uterine horns are manually separated making sure any small vessels are properly ligated. The uterine horns are straightened cranially and the spindle is now placed on top of the horns and dropped in the notches. The frame is slid back caudally to a position where the seated spindle is just above the caudal commisure of the abdominal incision. One of the forceps that is cross-clamped on the proper ligament is released and the same forceps is reapplied across both the exposed uterine horns at a level that is in line with the two prongs of the traction unit. The forceps with clamped uterine horns is set in the prongs. Moderate traction is applied to the uterine structures which are ligated based on the operator&#39;s choice of method and material. The second forceps that is still attached to the other proper ligament is released and applied across the uterine structures that are between the applied ligatures and the prongs of the sliding bar. The uterine structures are transected just between the applied forceps and the prongs. The stumps are checked for any hemorrhage and released back into the abdominal cavity. The embodiment is removed and set aside. The celiotomy incision is closed based on the choice of the surgeon.