Abstract:
A suture thread having a textured exposed surface, wherein the texture of the exposed surface enables the suture thread to easily move in a first longitudinal direction, but resist movement in a second longitudinal direction. The texture of the exposed surface being formed by imprinting or by cutting microscopic, angled incisions.

Description:
Related Applications  
       [0001]     This application claims the benefit of co-pending U.S. provisional patent application Ser. No. 60/704,506, filed 1 Aug. 2005. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     The need for this invention arises from surgical practice, particularly surgical practice in which tissue must be held together for healing, as in a wound or incision. During healing of a wound or incision, tissue is typically held together with filament or suture thread.  
         [0003]     In surgical practice, it is usually desired that suture thread be able to be pulled smoothly through tissue to be sutured. This characteristic reduces tissue trauma during the suturing procedure. Additionally, it is desired that suture thread maintains placement and resists reverse pull out, or slippage, once in place during healing. In the past, suture thread has been manufactured with purpose to enhance pull-through during suturing. For example, it is known to coat the exposed surface of suture thread with a lubricant to reduce surface friction during suturing. While this feature is helpful during suturing, it does not address slippage after suturing, in fact, this feature may actually increase slippage when it is not desired during healing. Thus, the abilities of suture thread to slide easily during suturing but also resist slippage after suturing are usually mutually exclusive. The very quality desired during suturing is that which is unwanted after suturing and during healing.  
       SUMMARY OF THE INVENTION  
       [0004]     It is therefore a principal object of the present invention to provide for a suture thread that slides easily in a first longitudinal direction during suturing, yet resists slippage in a second longitudinal direction after suturing and during healing.  
         [0005]     To attain the object described, there is provided a suture thread having a longitudinal axis. The thread further includes an exposed surface that is configured to have a first coefficient of friction as the thread is moved in a first longitudinal direction, while having a second coefficient of friction as the thread is moved in a second longitudinal direction. For example, the first coefficient of friction may be adapted to ease the thread through the tissue to be sutured in a first longitudinal direction, while the second coefficient may be increased to therefore resist longitudinal movement in a second longitudinal direction.  
         [0006]     By altering the texture of the suture thread exposed surface, the frictional properties of the thread may also be altered. For example, the exposed surface may be provided with a microscopic pattern that resembles fish scales. Alternatively, suture thread according to the present invention may include an exposed surface having incomplete cuts extending laterally from the exposed surface a predetermined distance toward the thread axis. The cuts may be preferably angled relative the longitudinal axis of the thread to form an overlapping, scale-like pattern comprised of overlapping members. The overlapping members remain flattened as the thread is moved in a first longitudinal direction, but create friction and resist movement as the thread is moved in an opposite longitudinal direction.  
         [0007]     Patterns of the overlapping members as applied to the exposed surface of suture thread may be varied as to size and shape as desired by particular application. Further, if cuts are used to create the pattern, the cuts may also be varied as to location and depth to allow for variation thereof and flexibility in application. A method according to the present invention allows for the suture thread to be imprinted or cut to achieve the desired configuration. The method may also provide the claimed texture either in random or patterned configuration as well as covering the complete thread or a portion thereof, depending upon, among other things, the type of tissue being repaired. A further method includes the steps of suturing using the unique thread of the present invention. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]      FIG. 1  is a fragmentary side plan view of an embodiment of the suture thread according to the present invention and showing the thread moving in a first longitudinal direction.  
         [0009]      FIG. 2  is a fragmentary side plan view of the suture thread shown in  FIG. 1  but showing the thread moving in a second longitudinal direction with the trailing edges of the overlapping members providing added friction to thereby resist movement in the illustrated direction.  
         [0010]      FIG. 3  is a fragmentary view of the thread illustrated in  FIGS. 1 and 2  as it is moved in a first longitudinal direction, and in conjunction with a suture lock.  
         [0011]      FIG. 4  is a view similar to that of FIG.  3 , but illustrating the suture thread moving in a second longitudinal direction and resisting movement in the direction of the arrow.  
         [0012]      FIG. 5  illustrates an alternative embodiment in which the suture thread may be further provided with an enlarged portion.  
         [0013]      FIG. 6  illustrates a plurality of suture threads, similar to those shown in  FIG. 5 , but braided together.  
         [0014]      FIG. 7  depicts a single suture thread and showing an enlarged portion.  
         [0015]      FIG. 8  is a fragmentary side view of another alternative embodiment and illustrating suture thread wherein an enlarged portion is provided with overlapping members with the remainder being conventionally smooth. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0016]     Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention, which may be embodied in other specific structures. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.  
         [0017]     The present invention is directed to suture thread, and in particular suture thread having unidirectional pull capabilities. Specifically, the present invention pertains to suture thread having the capability to be pulled easily in one longitudinal direction, while resisting movement in an opposite longitudinal direction.  
         [0018]     The purpose of the present invention is to provide a suture thread  10  with an exposed surface  12  having a first coefficient of friction when the thread  10  is moved in a first longitudinal direction and a second coefficient of friction when the thread  10  is moved in a second longitudinal direction. To accomplish this purpose, several different embodiments of suture thread are disclosed, which are directed to examples of suture thread having an exposed surface provided with overlapping, scale-like members  14 . As will be described, the suture thread  10  with textured exposed surface  12  is adapted for use in a variety of settings.  
         [0019]     As may be seen in the Figures, suture thread  10  preferably includes an exposed surface  12 , having a predetermined texture, such as the scale-like members  14  shown.  FIG. 1  illustrates a suture thread  10  with a texture according to the present invention, in which individual members  14  lay smoothly flat as the thread  10  is moved in the direction of arrow A.  FIG. 2  illustrates the thread  10  moving in the longitudinal direction indicated by arrow B. As seen, thread movement in the direction of arrow B encourages the trailing edges  16  of respective members  14  to move laterally relative the exposed surface  12 . As the trailing edges  16  move laterally relative the exposed surface  12 , they serve to increase the coefficient of friction, thereby resisting thread  10  movement in the direction of arrow B.  
         [0020]     An application of the present suture thread  10  may be seen in  FIGS. 3 and 4 . As illustrated, the suture thread  10  may be used in conjunction with a suture lock  18 . Although suture lock  18  is illustrated, it is to be understood that suture thread  10  may be used in conjunction with other known suture locks (not shown) to thereby assist in strengthening the suture.  
         [0021]     An alternative embodiment of the present suture thread  10  may be seen in  FIGS. 5 and 7 . As illustrated, at least one enlarged portion  20  may be provided. One, or a series, or plurality of spaced apart enlarged portions  20  may be formed in suture thread  10 a. The needle (not shown) may, after passing through the tissue to be sutured, be drawn through an enlarged portion  20  a distance suitable to the surgeon making the stitch. The enlarged portion  20 , in conjunction with the scale members  14 , provides locking of the suture thread  10   a  in place without the necessity of tying a knot.  
         [0022]     Another alternative embodiment suture thread  10   b  may be seen in  FIG. 6 . In this embodiment, the previously discussed suture thread  10   a , having an enlarged portion  20 , is additionally braided with multiple suture threads  10   a , to thereby create a multi-strand combination suture thread  10   b  with enlarged portion  20   a . The braided suture thread  10   b  offers added frictional resistance against pull out of the thread once passed through desired tissue to be sutured. Additionally the braided enlarged portion  20   a  offers added friction resistance against pull out after the needle (not shown) is drawn through portion  20   a  after making a stitch.  
         [0023]     Referring now to  FIG. 8 , a design similar to that of  FIGS. 5-7  is illustrated except that the enlarged portion  20  is covered in scale members  14 , while the thread itself is conventionally smooth. This alternative embodiment is referenced generally as  10   c , and offers added friction resistance against pull out after the needle (not shown) is drawn through portion  20  after making a stitch, while utilizing a conventionally smooth thread length.  
         [0024]     It is to be understood that while the scale members  14  of the present invention may be imprinted or cut into the exposed surface  12 , the size of each individual scale  14  may vary according to desired application according to an individual end user&#39;s requirements. Further, if the scales  14  are cut into the exposed surface  12 , the depth of individual cuts may also vary to influence the size and shape of each trailing edge  16 .  
         [0025]     The foregoing is considered as illustrative only of the principles of the invention. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described. While the preferred embodiment has been described, the details may be changed without departing from the invention.