Abstract:
An inexpensive surgical stapler, such as for use in securing vascular catheters, has a plastic applicator made for use with a single staple. The applicator has a backbone and two identical arms. The inside face of the backbone has a retaining channel that secures the crown portion of the staple against movement. The inside faces of the arms have guidance grooves that direct the movement of the staple as the applicator arms are squeezed with finger pressure. The outside faces of the arms are configured to permit gripping by the operator&#39;s fingers. The stapler can be used in lieu of suturing. Other staple and applicator assemblies can include two or more of such assemblies.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to medical staples and stapling devices. More particularly, the invention relates to a staple in combination with a flexible, digitally manipulable, anvilless staple applicator that is useful for affixing catheters to the skin and for other medical procedures. 
     Medical stapling devices have been routinely in use for some time. They are designed chiefly to replace the suturing process because of the significantly less time used in stapling. A variety of devices are known. For example, Green, U.S. Pat. No. 5,158,567, describes an anvilless surgical stapler with articulated handles and a slidable staple cartridge mounted in a block at the distal end of the handles. Samuels, U.S. Pat. No. 4,399,810, describes a skin clip applied with an articulating device containing a substantial number of staples. The staples are closed by a lateral pressure from the articulating applier. U.S. Pat. Nos. 4,719,917 and 4,526,174 disclose other medical staples. 
     In surgical and anesthetic practice, it is common to place indwelling catheters for vascular access. These catheters require fixation to the skin to maintain their position, thus avoiding potential injury to the patient or withdrawal of the catheter. Currently, fixation to the skin is accomplished by suturing the catheter hub to the underlying skin. A needle and suture are passed through the skin and hub eye, or eyes, and tied into a knot. 
     This procedure includes an attendant risk of needle stick. To avoid that risk would require the use of a stapler kit, which is far too costly to justify its use for one or two staples. The use of a stapler would save considerable time over suturing, especially when considering the daily frequency of catheter fixations in clinical situations, but the cost of a stapler kit is orders of magnitude greater than that for a suturing kit. 
     SUMMARY OF THE INVENTION 
     The present invention allows fixation of catheters to the skin in a less time-consuming and safer manner than either suturing or the use of traditional medical staplers. The cost of the materials is anticipated to be, for practical purposes, approximately the equivalent of suturing. 
     The present invention is a method of stapling and a device for performing that method. The device comprises an applicator assembly, preferably made of sterilizable, medical grade plastic, and is disposable. A staple is fabricated from stainless steel or other commonly used FDA approved staple material, and is inserted into the applicator to form the assembly. The applicator has no anvil and is both flexible and digitally manipulable. 
     The staple includes a crown portion with legs obliquely positioned at the ends of the crown. The legs terminate in points capable of piercing the skin. In the preferred embodiments of the invention, a single staple is mounted in the applicator. 
     The applicator is shaped generally like an inverted “U,” with an open bottom to permit the exiting of a closed staple attached to the skin. The inner faces of the applicator include a stabilizing channel and grooves that retain the staple during both storage and application, and guide it during the application process. The outside faces of the two opposing arms of the applicator are preferably a relatively non-slip surface to facilitate a digital grasp of the applicator and to permit digital deformation of the applicator, which in turn deforms the staple. 
     In its preferred use, an applicator with staple is positioned to cause one of the two staple legs to traverse the catheter hub eye and both staple legs to pierce the skin when lateral forces are manually applied to the applicator arms. Closure of the staple then results in fixation of the catheter to the skin. The applicator can subsequently be slid off the staple, which is no longer held by the applicator due to the change in staple configuration relative to the released applicator. 
     In an alternate embodiment, two or more applicator and staple combinations are joined together to provide a device that can be used when two or more staples are necessary. 
     Accordingly, there are several objects and advantages to my invention. One advantage provides a means for securing a catheter to the skin using a surgical staple and applicator in a less time-consuming procedure than suturing. 
     Another advantage permits securing the catheter to the skin with less risk of needle stick injury when compared to the traditional method of suturing. 
     An object of the invention is to provide a stapler for affixing a catheter to the skin that is, relative to other staplers, less expensive to manufacture, easy to distribute and store in a clinical environment, and is both simple and reliable to use. 
     Still another object of the invention is to provide the availability of a small number of staples when the use of a traditional stapler kit is not economical. 
     These and other objects and advantages will become apparent in conjunction with the detailed description and the following drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a surgical staple in the open position. 
     FIG. 2 shows the staple in the closed position. 
     FIG. 3 is a perspective view of a staple applicator and staple. 
     FIG. 4 is a cross section of one embodiment of the applicator and staple. 
     FIG. 5 is an elevation view of the applicator with the staple in the open position. 
     FIG. 6 is an elevation view of the applicator containing the staple in the closed position. 
     FIG. 7 is a perspective view of the applicator and staple adjacent to, and prior to the clamping of, the skin and hub eye. 
     FIG. 8 is a perspective view of the applicator and staple after clamping the skin and hub eye. 
     FIG. 9 is an elevation view of the applied staple after the legs of the applicator have been released. 
     FIG. 10 depicts a standard staple remover, which is part of the prior art. 
     FIG. 11 is a cross section of a staple being removed. 
     FIG. 12 is an alternate embodiment of the invention, with two applicators joined together. 
     FIG. 13 is a perspective view of the alternate embodiment. 
     FIG. 14 is a perspective view of another alternate embodiment. 
     FIG. 15 is a cross section of one of the tabs in FIG.  14 . 
     FIG. 16 is yet another embodiment, with deeper grooves. 
     FIG. 17 is another embodiment of the dual applicator assembly. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to FIG. 1, a staple  10  is constructed of stainless steel, titanium, or other similarly deformable material which retains the shape to which it has been deformed. The staple  10  includes a crown portion  20  and opposingly disposed legs  22 . In the preferred embodiment, the crown  20  is generally horizontal and connected to legs  22  at each end. Legs  22  are preferably identical and comprised of three segments,  24 ,  26 , and  28 , terminating in skin piercing point  29 . The three leg segments  24 ,  26 ,  28  are offset by three oblique angles A, B, and C, which are approximately 120 degrees each. 
     FIG. 2 depicts the staple in its closed, deformed configuration. After the staple has been completely closed and the applicator withdrawn, angle A between crown  20  and leg segment  24  should be approximately a 90 degree right angle. 
     FIGS. 3,  4 , and  5  depict an anvilless applicator  30  holding a staple  10  in the open position. The applicator comprises a top or backbone portion  32  and two arms  34 . The inside face  33  of backbone  32  includes a stabilizing block  40  with stabilizing channel  42  that prevents the staple from rotating about point  25  between leg segments  24  and  26 . 
     The inside faces  35  of the applicator arms  34  contain guidance and retaining grooves  44  into which staple leg points  25  are slidably and releasably mounted. Grooves  44  terminate in a curved portion  46 , so that contact between the staple and the applicator is maintained while the staple is compressed during application. The staple should be mounted and retained in the applicator with a slight degree of snugness, so the staple does not fall out prior to use. At the same time, the staple should be easily releasable from grooves  44  and channel  42  once the staple has been applied. The outside face of the applicator arms  34  includes a means for digitally holding and compressing the applicator arms  34 . In the present invention, that means is preferably a series of ribs  52  on each applicator arm  34 . Other cupped, polygonal, non-uniform, or rough surfaces are equivalent to the ribs, as those of skill in the art will appreciate. 
     It should be noted that the present invention comprises a Class I medical device, e.g., a skin stapler with removable staples and nonabsorbent legs. Under FDA regulations, a Class I medical device does not require pre-notification of, or approval from, the FDA. Thus, this invention can be practiced with little or no regulatory costs or delays. 
     Prior to using the present invention, a transcutaneous vascular catheter is placed in the patient in the usual manner (not shown). Referring now to the additional figures, the applicator  30  containing a staple  10  is held between the thumb and second finger of the operator&#39;s dominant hand. The open staple points  29  are held away from the operator. The operator&#39;s other hand is used to manipulate the catheter hub  60  and underlying skin  62 , so the skin  62  is tented (see FIG. 7) and positioned to receive staple  10 . The applicator and staple assembly is positioned so one staple piercing point  29  traverses the eye  64  of catheter tub  60  and both points  29  come to rest on the base of the tented skin. The tented skin  62  has been manipulated to rest between the open staple legs  22  through a combination of tenting by the non-dominant hand and positioning of the applicator  30  and staple  10  by the dominant hand. 
     The staple is closed by squeezing the applicator arms  34  with one&#39;s fingers, which generates a closing force F (see FIG.  8 ). This causes the piercing points  29  to penetrate the skin. The medical progress of the applicator arms  34  is arrested by the ends of crown  20  at approximately a ninety degree angel D (see FIGS.  5  and  6 ). After the applicator arms  34  are released (see FIG.  9 ), there is a small, almost imperceptible, spring-like rebound of the staple legs  22 . For practical purposes, the angle between the staple crown  20  and legs  22  remains approximately 90 degrees. 
     A staple used in the described embodiment must have at least two leg segments that form an angle whose intersecting point is outside the ends of crown portion  20 . Such a configuration would be analogous to leg segments  24 , 26  meeting at point  25 , which is outside the end of staple crown  20 —a necessary configuration so that the applicator arms  34  can provide a lateral force to secure the staple to the skin. While the preferred embodiment contemplates a staple like that shown in FIG. 1, it is possible to employ other, differently shaped staples that come within the scope of the patent. Indeed, the applicator and staple could be configured so that the applicator backbone and arms would begin the application with angle D at approximately 90 degrees. 
     When the squeezed applicator arms  34  are released, applicator arms  34  generally regain their original configuration in relation to applicator backbone  32 . Applicator  30  can then be removed from staple  10 , because staple  10  is no longer held by grooves  44 . In the preferred embodiment, it is contemplated that grooves  44  frictionally hold staple  10  prior to use, although only a small force is required to release staple  10  from grooves  44 . Here that force would simply consist of the rebound of plastic applicator arms  34 . Also in the preferred embodiment, stabilizing channel  42  is large enough so that staple crown  20  can be loosely contained in the space of channel  42 . Thus, in FIG. 9 the upward force FF required to lift the applicator  30  off staple  10  after use is simply the force required to overcome the weight of the applicator  30 . 
     Once the staple is applied, the applicator can be discarded. When the staple must be removed from the patient, it can be accomplished in a traditional, prior art manner (see FIGS. 10-11) and a dressing applied as necessary. 
     For a catheter hub with two eyes, one can approach the problem in at least two different ways. First, one can use two separate assemblies of a single applicator and staple. Alternatively, one can use a second embodiment of the invention, a dual applicator  100  (FIG. 12) that is made from two separate assemblies  100 A,  100 B, with each assembly made of a single staple  110  and single applicator  130 . The assemblies are preferably connected by a plastic bridge or joining member  120 . The second staple can be applied by rotating the applicator one hundred eighty degrees with the dominant hand. Thus, a two-eyed hub can be secured to the skin without setting down the staple applicator. In a similar manner, two staples can be used in a situation not requiring a catheter, such as for a small wound that would otherwise be closed by suturing. 
     Another embodiment contemplates three or more staples and applicators. There are a number of ways to join the applicators. One way would be to add additional joining members and assemblies in a manner similar to that in FIG.  12 . The preferred arrangement comprises a series of spoke-like joining members emanating from a hub or hub-like point  511  (see FIG. 7) and can be called the L-shaped or partial “ferris wheel” configuration. Two or more spokes  520 , like joining member  120  above, the applicator assemblies  530 , can be added to the device depicted in FIG.  17 . In FIG. 17, ribs  552  correspond to ribs  52  discussed above, and are disposed on the outside face of applicator arms  534 . 
     Another multi-assembly configuration could contain a substantial number of staples mounted inside applicators and arranged in a “centipede” like strip of 4,10,20, or more assemblies. Each assembly could be joined by a short connecting piece, like plastic connector or joining member  120  (FIG.  12 ). Then the medical care giver could cut off one or two assemblies as necessary. 
     Numerous other embodiments and uses are contemplated of the present invention, resulting from the simple geometry underlying the staple and staple applicator. As one of ordinary skill in the art can appreciate, grooves  44  and channel  42  function to (1) retain staple  10  in applicator  30  prior to and during the use of the invention, (2) guide the staple downward while it is closing, and (3) stabilize the staple so that is does not rotate around axis A—A through points  25 . 
     Given the nature of the invention, innumerable additional embodiments can be envisioned. Some examples appear in FIGS. 13-16. In FIG. 13, stabilizing block  40  and channel  42  of FIG. 3 have been replaced by two small stabilizing blocks  240  and two corresponding stabilizing channels  242 . Leg segment intersections  225  (FIG.  13 ), like intersection points  25  (FIG.  3 ), slide in grooves  244  that retain intersection points  225  and guide the staple in the direction of the skin (not shown). If the intersection points  225  sit shallowly in grooves  244 , and the staple is elastic enough, the intersection points may function more like points rather than three dimensional structures. Thus, without stabilizing blocks  240  and channels  242 , staple  210  might rotate about axis A—A (FIG.  13 ). 
     The device in FIG. 13 could function with only one thin stabilizing block  240  and channel  242 , or even simply a clip (not shown) attached to inner backbone face  233  and into which staple crown  220  could fit. An equivalent structure to a stabilizing block and channel (small or large, one or many) would replace block  240  and channel  242  with a slot or hole in applicator backbone  232  into which a pin, hump, or raised portion atop staple crown  220  could be inserted. In other words, any number of male-female attachments could be used to interrelate staple crown  220  and backbone  232  of applicator  230 . 
     FIGS. 14 and 15 show still another embodiment of the present invention. Two pairs  341  of tabs  341   a  and  341   b  are fastened to inner face  333  of backbone  332 . Each tab holds one end of staple crown  320  and an upper portion of leg segment  324 . Together, the two tabs  341  both guide staple  310  downward when the applicator arms  334  are squeezed. In addition, the same tabs  341  also stabilize staple  310 , preventing it from rotating about an axis through leg segment intersection points  325 . The same functions can be accomplished by placing tabs  341  at the top of inner face  335  of applicator arms  334 . 
     Tabs  341  must also retain single  310  in applicator  330  until the staple is secured to the skin. In the preferred embodiment discussed above (e.g., FIG.  3 ), staple  10  is fit with slight frictional resistance into grooves  44 . FIG. 15 depicts an alternative that can be used with the embodiment of FIG.  14 . Two small nubs  345   a  and  345   b  retain crown  320  of staple  310 , so that a small force must be used to disengage the staple from the tabs by pulling crown  320  through hubs  345   a  and  345   b.  An equivalent structure for accomplishing the same result would eliminate hubs  345   a,b  and instead angle tabs  341   a,b  so that tab ends  346   a,b  are separated by a distance slightly less than the diameter of staple  310 . 
     Thus, one of ordinarly skill in the art will understand that a singular structure may provide more than one function. As described above, for example, two sets of tabs  341 , as depicted in FIG. 14, could provide the retaining, guiding, and stabilizing functions of the present invention. Grooves  444  in FIG. 16 do likewise. 
     In keeping with the numerous structures that can comprise the present invention, one of ordinary skill will understand that an improvement of the embodiment in FIG. 14 can be created by adding the guidance grooves  44  depicted in FIG.  3 . FIG. 16 alters that configuration by eliminating the tabs, so that grooves  444  accomplish the function of both guiding staple  410  toward its application while retaining the staple in applicator  430  and preventing rotation about intersection points  425  (not shown) where leg segments  424  and  426  meet. Grooves  444  in FIG. 16 differ from grooves  44  in FIG. 3 in that grooves  444  must be deeper than grooves  44 , and points  425  must protrude into grooves  444  deeper than do intersection points  25  into grooves  44 . Consequently, in FIG. 16, grooves  444  of staple  410  retain the staple so it does not fall out of applicator  430 , guide the staple as it changes shape and is secured to the patient, and stabilizes it against rotation. This differs from the configuration in FIG. 3 in that leg segments  24 , 26  of both legs  22  are inserted into groove  44  shallowly enough that as a practical matter leg segments  24 , 26  are secured at intersection points  25  more as points than as three dimensional structures. 
     To described yet another alternative embodiment, the grooves  444  in FIG. 16 are depicted without curves at the bottom of applicator arm  434 . As shown in FIG. 4, the preferred structure terminates grooves  44  with a curved and/or inwardly facing portion  46 . In FIG. 16, grooves  444  terminate before the end of applicator arms  434  to ensure that staple  410  does not slide out of groove  444 . 
     The applicator itself can be configured in still other ways, such as by using a different finger grip on the outside face of the applicator arms (e.g., finger cups, polygonal ridges, or simply a rough surface that will not slip) or by shaping the applicator backbone in a different manner. As the preceding discussion demonstrates, there are numerous equivalent structures that can be utilized in the present invention, which one of ordinary skill will understand and appreciate. 
     Staples of different configuration can be used as long as they function properly with the applicator. They may, for example, include small notches at various positions on the staple to facilitate bending during application, or they may simply be shaped differently than described above. 
     As noted above, it is contemplated that the present invention could be used in a non-catheter situation for small wounds that require only a few staples, although at some point it becomes more efficient to use a traditional stapler if the wound is too large. Conversely, a dual applicator could be used for only one staple. The wasted material would be of minimal cost and would eliminate the need to manufacture and stock two different varieties of the device. In the claimed method of medical stapling, it is also contemplated that the staple and applicator assembly can be created or fabricated in a number of ways, and that an emergency might even require one to manually insert a single staple into a single applicator. Nor should one be able to defeat the intent of this invention by squeezing the applicator with forceps or the like, rather than with one&#39;s own fingers. One could, however, include short handles attached to the applicator arms for ease of handling or leverage in squeezing the applicator arms. 
     Therefore, it will be understood by those of skill in the art that changes may be made to the present invention in its fabrication and configuration, and that the invention may be used differently without departing from its spirit. The invention is defined in the following claims.