Abstract:
An improved trocar is provided which includes converters for adapting to different size surgical instruments while maintaining sealing. The invention also includes an improved trocar tube body seal design which accepts and accommodates surgical tool angulation while still maintaining sealing. Still further, the invention provides a trocar obturator with a snap-fit joint which permits the forward portion of the obturator to be detached from the trocar body and separately used with the trocar tube subassembly. With this option, a latch mechanism is configured opposite to a converter to retain the obturator fixed with the trocar tube subassembly.

Description:
This is a continuation of co-pending application Ser. No. 07/753,326 filed on Aug. 30, 1991, now abandoned. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to surgical instruments, and particularly to an improved trocar. More specifically, it relates to a trocar for providing communication with a body cavity including converters to adapt to different size surgical tools. It also relates to such a trocar wherein the trocar point and obturator may be detached from the point retraction mechanism. It also relates to a trocar tube body seal design which accepts surgical tool angulation without leakage. 
     BACKGROUND OF THE INVENTION 
     Trocars are surgical instruments that have found wide application in many types of operations where puncture-type incisions are to be made. Early configurations were in the form of sharp pointed stylets or obturators closely surrounded by a hollow trocar tube. The sharp point of the stylet normally extends a short distance from the distal end of the trocar tube when the trocar is in its assembled condition. After thrusting through the body wall into a body cavity, the surgeon uses skill to avoid damaging body tissue and body organs. This type of simple trocar is still widely used. 
     More recently, improved trocars with means for protecting body organs from unintended incidental damage have been devised. Two such improved trocars are shown in U.S. Pat. No. 4,601,710 to Moll and U.S. Pat. No. 4,654,030 to Moll, et al. With these improved devices, the surrounding trocar tube is forced back against a biasing spring by the action of the obturator tip passing through body wall tissue, so as to expose the stylet point. After passing through the body wall, the protective trocar tube returns to its normal position covering the point, thereby protecting against patient organ damage. 
     While the prior art trocars are very useful, there are some features that are missing, creating problems. One is the lack of versatility in that the forward trocar tube body cannot be used with simple trocar obturators. Another is the lack of adaptability of the trocar tube main seal to various sizes of surgical instruments while maintaining the sealing effect. Still another is the lack of ability to fully accommodate angulation of the surgical instruments while maintaining the sealing effect. 
     SUMMARY AND OBJECTS OF THE INVENTION 
     It is to a solution to the above-described and other problems that this invention is directed. The invention provides a detachable distal portion of the obturator including the sharp pointed stylet, which can thus be used as a full featured &#34;point exposed&#34; trocar, or via a single connection, a &#34;point protected&#34; trocar. At the same time, the invention provides a trocar having multiple built-in converters that effectively change the size of the annular seal, which is located on the trocar tube subassembly and which seals around the subsequent surgical tools introduced. In this manner, the same trocar body subassembly and trocar tube subassembly can be used for various sizes of surgical tools. At the same time, the invention provides an improved main body seal which effectively improves converter sealing and resists gas loss due to tool angulation during use. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a top plan view of the inventive trocar showing its subassemblies fully engaged; 
     FIG. 2 is a side elevation view of the same; 
     FIG. 3 is an exploded view of the device shown in FIG. 1, illustrating the interengagement of its subassemblies; 
     FIG. 4 is an enlarged partial fragmentary top quarter isometric view of the trocar tube subassembly, rotated 90 degrees, illustrating a converter subassembly in its stored condition; 
     FIG. 4A is a cross-sectional view taken along lines 4A--4A in FIG. 4; 
     FIG. 4B is a cross-sectional view showing an alternate embodiment of the seal which accommodates seal angulation of the obturator; FIG. 4C is a cross-sectional view similar to FIG. 4B illustrating how angulation is accommodated; 
     FIG. 5 is a view similar to FIG. 4 showing a converter subassembly in its operative condition; 
     FIG. 5A is a cross-sectional view taken along lines 5A--5A in FIG. 5; 
     FIG. 6 is a view similar to FIG. 4 of an alternate embodiment of the converter; 
     FIG. 7 is a view of the same showing the converter subassembly in its operative condition; 
     FIGS. 8A and 8B are enlarged partial cross-sectional views of the means for engaging the proximal portion to the distal portion of the obturator; and 
     FIG. 9 is an enlarged view of a further alternate embodiment showing a means for retaining the distal obturator portion. 
    
    
     DETAILED DESCRIPTION 
     As shown in FIGS. 1, 2 and 3, trocar 10 is comprised of two interengaging main parts, a trocar body subassembly 12 and a trocar tube subassembly 14.The two subassemblies are designed to be separable from each other. Trocar body subassembly 12 includes upper and lower hollow housings 16, 18, respectively, which combine together to form a grip 20. These housings forming the grip 20 may be made of ABS plastic. Contained within grip 20 is a mechanism (not shown) for extending and retracting the obturator 22 and thereby its attached piercing tip or point 24 within the distal open end 26 of hollow, tapered trocar tube 28. The mechanism for extending and retracting an obturator may be in accordance with that shown in U.S. Pat. No. 4,601,710, aforementioned. 
     The distal portion of grip 20 is of generally U-shaped configuration defined by a pair of spaced parallel arms 30, 32. Trocar tube subassembly 14 has a body 34, which can also be made of plastic material such as ABS plastic, and is dimensioned to closely fit within slot 36. In the engaged position, parallel side walls 38, 40 of the body 34 closely contact parallel side walls 42, 44 of grip 20. Similarly, rear wall 46 of trocar tube body 34 will be in contact with rear wall 48 of grip 20 within slot 36. In this position, the surgeon can place one finger on each rounded front wall 50, 52, while at the same time holding rear wall 54 in the palmof the hand. 
     Turning to FIGS. 4 and 5, the inventive converter mechanism will now be described. As with conventional trocars, there is a main seal 56 centrallydisposed in an aperture in the rear wall 58 of trocar body 34. This grommet-like seal is of rubber material. The function of the seal in this location is to seal around the obturator (not shown) so as to maintain positive pressure in body 34, so as to prevent the entry of bacteria whichmight cause infection. The main seal has an aperture 60 therein which closely receives the obturator. Trocar tube subassembly 14 includes therein a flap valve mechanism (not shown) for selectively sealing againstmain seal 56 so as to selectively close off aperture 60. This flap valve mechanism may also be in accordance with the aforementioned &#39;710 patent disclosure. 
     In order to accommodate two different-sized surgical tools, a pair of converters 62, 64 are provided. As may be seen, plate-like top and bottom walls have flange extensions beyond the body 34 to the rear and on both sides. Within the flange extensions, U-shaped grooves or tracks 70, 72 arecut therein. A first sliding door 74 of plastic material having a first alternate seal 76 is normally located as shown on one side of body 34. A pair of pins 78, 80 are captured in the parallel tracks 70, 72 in order todirect the movement of the first door to its operative position shown in FIG. 5. In this position, seal 76 having a smaller aperture 82 than main seal 56 is moved into position over the main seal and thus becomes the operative seal. This permits the use of a smaller surgical tool. It may benoted that tracks 70, 72 make 90 degree bends, and that they are curved at their central point 84 in order to provide a compressive load on the door when it is in its operative position located directly over the main seal. This serves to hold the door 74 in place, as well as to compress first seal 76 against main rib 103 (see FIGS. 4A and 5A). The final location of door 74 is determined by contacting a stop 105 formed by the opposing door 
     In like manner, a second alternate seal (not shown) mounted on second sliding door 86 and having a pair of pins, one of which is shown at 88, permits the use of a still smaller seal to accommodate a still smaller surgical tool. 
     As shown in FIGS. 4B and 4C, a still further embodiment of the seal 56&#34; is constructed to be a bellows shape to accommodate angulation of the obturator 106 while still maintaining the sealing effect. 
     Referring to FIGS. 6 and 7, there is shown an alternate embodiment wherein primes denote elements having their counterparts in the preferred embodiment. With this alternate embodiment, door 74&#39; is hinged rather thanon tracks. Hinge pins 90&#39;, 92&#39; captured in body 34&#39; serve as pivots to allow door 74&#39; to be articulated from its inoperative position in FIG. 6 to its operative position in FIG. 7. In this position, seal 76&#39; is directly over main seal 56&#39;. Locking of the door 74&#39; in this position is achieved when two ridges 94, 96 on arms 98, 100 snap into grooves 102, 104on the inner sides of sidewalls 66&#39;, 68&#39;. In order to unlock the door, arms98, 100 are pushed towards each other to remove the ridges from the grooves, and the door may then be returned to its original inoperative position. Recesses 99, 101 are provided to receive arms 98, 100, respectively, when in the inoperative position against the one side of thebody 34&#39;. It may be understood that a second door (not shown) with associated locking structure could also be provided so as to permit use ofthree different sizes of obturators. 
     While it is possible to use a different trocar for surgeons using a point exposed trocar (point retracting type shown) subassemblies, each with a different size of obturator, with the converter trocar tube subassemblies thus described, another more economical and versatile approach is possible. As shown in FIGS. 8A and 8B, the obturator may be in two parts, rather than one as is conventional. The distal obturator part 106 is separable from the proximal obturator part 108 by means of a male 112, female 114 snap fitting. Male fitting 112 has an elongated groove 113 therein which facilitates deformation for engagement in bore 115 within female fitting 114. Male fitting 112 also has a groove 117 therearound of a diameter slightly less than that of the inner diameter of bore 115. 
     As shown in FIG. 9, it is also possible to use the distal obturator part 106 without the trocar body subassembly 12. In this case, a latch 116 could be configured opposite the converter 62 and operated in a similar manner. That is, the latch occupies the position of a single converter andis movable from a latched position to an unlatched position. The latch 116 has an elongated slot 122 having a width to engage notches 118, 120 in oneedge thereof which selectively engages notches 118, 120 of female snap fitting or connector 114, and would be released by movement in the arrow direction. The latch 116 could be configured to slightly lift the distal obturator part 106 for ease of grasping, and prevent the trocar body subassembly from attaching unless the latch were in the down and unattended position. 
     It is to be understood that while the invention has been described above inconjunction with the preferred specific embodiments, the description and examples are intended to illustrate and not limit the scope of the invention, which is defined by the scope of the appended claims.