Abstract:
A medical treatment device includes a ligating member, a stopper and a ligation releasing member. The ligating member has a distal end portion and a proximal end portion, that ligates biological tissue. The stopper is provided to be movable forward or backward with respect to the ligating member, and stoppable by friction on the ligating member to maintain the biological tissue in a ligated state by the ligating member. The ligation releasing member is provided on the ligating member to release the ligation state between the ligating member and the stopper by moving the ligating member to the distal end side with respect to the stopper.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims the benefit of U.S. Provisional Application No. 60/572,968, filed May 20, 2004. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to a treatment system for living tissues, which is designed for use in combination with an endoscope and another type of an instrument to perform an endoscopic treatment such as suture and ligation on the living tissues in the body.  
         [0004]     2. Description of the Related Art  
         [0005]     U.S. Patent Application Publication No. 2003/0236535A1 (hereinafter referred to as “publication”) discloses a ligation apparatus for use in endoscopic treatment, i.e., the apparatus that a surgeon uses to suture or ligate the living tissues in the body while observing the tissues through an endoscope. The apparatus disclosed in the publication enables the surgeon to suture or ligate the tissues by passing the ligature attached to a holding member, through the tissues. To release the tissues from the sutured or ligated state, the surgeon cuts the ligature, or grasps and removes the holding member from the tissues. The tissues may not be sutured or ligated at desired parts. In this case, the surgeon cuts the ligature to release the tissues from the sutured or ligated state. To cut the ligature the surgeon uses, for example, surgical scissors, while observing the tissues through an endoscope. Otherwise, the surgeon may grasp the holding member with a grasping forceps or the like and then remove the holding member from the tissues, while observing the tissues through the endoscope.  
       BRIEF SUMMARY OF THE INVENTION  
       [0006]     According to an aspect of this invention, there is provided a medical treatment device includes a ligating member, a stopper and a ligation releasing member. The ligating member has a distal end portion and a proximal end portion, that ligates biological tissue. The stopper is provided to be movable forward or backward with respect to the ligating member, and stoppable by friction on the ligating member to maintain the biological tissue in a ligated state by the ligating member. The ligation releasing member is provided on the ligating member to release the ligation state between the ligating member and the stopper by moving the ligating member to the distal end side with respect to the stopper.  
         [0007]     Advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter. 
     
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING  
       [0008]     The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention, and together with the general description given above and the detailed description of the embodiments given below, serve to explain the principles of the invention.  
         [0009]      FIG. 1  is a schematic sectional view of a treatment system for living tissues, according to a first embodiment of the invention, showing the ligation apparatus and the ligation instrument coupled to the apparatus;  
         [0010]      FIG. 2  is a schematic perspective view of the ligation apparatus according to the first embodiment;  
         [0011]      FIG. 3  is a schematic sectional view of the treatment system according to the first embodiment, depicting a ligature wrapped around the tissue to be treated;  
         [0012]      FIG. 4  is a schematic perspective view of the ligature wrapped around the living tissue by using the ligation apparatus of the treatment system according to the first embodiment, the ligature cut at the parts protruding from a silicone tube;  
         [0013]      FIG. 5  is a schematic perspective view of the ligature which is wrapped around the living tissue by using the ligation apparatus of the treatment system according to the first embodiment, illustrating a flexible wire that is held with a grasping forceps and pulled to release the tissue from the ligated state;  
         [0014]      FIG. 6  is a schematic top view showing how the tissue is released from the ligated state as the flexible wire is pulled and one of the ends of the ligature is thereby pulled out of the silicone tube in the treatment system according to the first embodiment;  
         [0015]      FIG. 7  is a schematic perspective view illustrating how the flexible wire held with the grasping forceps is pulled in the treatment system according to the first embodiment, in order to remove the ligature from the tissue;  
         [0016]      FIG. 8  is a schematic perspective view of the ligation apparatus incorporated in a treatment system for living tissues, according to a second embodiment of the invention;  
         [0017]      FIG. 9  is a schematic perspective view of the ligation apparatus provided in a treatment system for living tissues, according to a third embodiment of the invention;  
         [0018]      FIG. 10  is a schematic perspective view of the ligation apparatus used in a treatment system for living tissues, according to a fourth embodiment of the invention;  
         [0019]      FIG. 11  is a schematic perspective view of the ligation apparatus provided in a treatment system for living tissues, according to a fifth embodiment of the invention;  
         [0020]      FIG. 12  is a schematic perspective view of the ligation apparatus incorporated in a treatment system for living tissues, according to a sixth embodiment of the invention;  
         [0021]      FIG. 13  is a schematic sectional view illustrating a silicone tube holding a ligature by virtue of friction, in the ligation apparatus of the treatment system according to the sixth embodiment;  
         [0022]      FIG. 14  is a schematic sectional view showing the silicone tube in which the ligature can slide, in the ligation apparatus of the treatment system according to the sixth embodiment;  
         [0023]      FIG. 15  is a schematic perspective view of the ligation apparatus incorporated in a treatment system for living tissues, according to a seventh embodiment of the invention;  
         [0024]      FIG. 16  is a schematic perspective view, illustrating how a flexible wire is held and pulled with a grasping forceps after the tissue has been ligated, thereby to split a silicone tube toward its proximal end, in the treatment system according to the seventh embodiment;  
         [0025]      FIG. 17  is a schematic perspective view, showing how the silicone tube is split to release the ligature with the flexible wire in the treatment system according to the seventh embodiment;  
         [0026]      FIG. 18  is a schematic perspective view depicting the ligation apparatus used in a treatment system for living tissues, according to an eighth embodiment of the invention; and  
         [0027]      FIG. 19  is a schematic perspective view, illustrating how one of the three silicone tubes is removed from the ligature after the tissue has been ligated, thereby to adjust the ligated condition of the tissue, in the treatment system according to the eighth embodiment. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0028]     Preferred embodiments of the invention will be described, with reference to the accompanying drawings.  
         [0029]     First, the first embodiment will be described with reference to FIGS.  1  to  7 .  
         [0030]     The treatment system  10  for living tissues, shown in  FIG. 1 , is a system designed to ligate living tissues. The system  10  may be endoscopically used, or in combination with an endoscope, to ligate a polyp or the like before removing it, thereby to control bleeding. The system  10  comprises a ligation apparatus  12  and a ligation instrument  14 . The instrument  14  is used in combination with the ligation apparatus  12 .  
         [0031]     As  FIG. 2  shows, the ligation apparatus  12  comprises a ligature (ligating member)  22 , a silicone tube (stopper)  26 , a proximal loop  28 , and a flexible wire (ligation-releasing member)  30 . The proximal loop  28  is formed at the proximal ends of the ligature  22 .  
         [0032]     The ligature  22  is provided in the form of a loop. Therefore, its two end portions pass through the silicone tube  26 . The silicone tube  26  is held, by virtue of a frictional force, on any desired part of the ligature  22 . The tube  26  can be moved when a force greater than a prescribed value is applied along the ligature  22 . Thus, the silicone tube  26  performs the function of a stopper that holds the ligature  22  at a desired position with respect to the tissue that is to be treated.  
         [0033]     The flexible wire  30  is connected to the ligature  22 , at a position close to the distal end of the ligature  22  and deviated from the axis X of the lumen into which the ligature  22  should be inserted. One flexible wire is used in this embodiment. Nonetheless, two, three or more flexible wires may be connected to the ligature  22 . It is desirable to connect one or two flexible wires to the ligature  22 . If too many flexible wires are connected to the ligature  22 , they may entangle while the ligation apparatus  12  remains in the body. The flexible wire  30  may be replaced by a member of a different shape, such as a band.  
         [0034]     The flexible wire  30  can be made of any material that is flexible and strong enough to withstand a pulling force applied to release the tissue from a ligated state. It may be made of the same material as suture thread, e.g., drawn polyamide synthetic fiber, polypropylene, polyethyleneterephthalate, polytetrafluoroethylene. Alternatively, it may be made of bioabsorbable material such as polyglycolic acid. The wire may be either a monofilament one or a twisted thread. The flexible wire  30  is colored not similar to the living tissues, not white, red or yellow, and different in color from the ligature  22 . Hence, the surgeon can well distinguish the wire  30  when he or she sees it through the endoscope.  
         [0035]     As  FIG. 1  depicts, the ligation instrument  14  comprises a ligation sheath  38 , a hook wire  40 , and an operation handle (not shown). The hook wire  40  is connected, at its distal end, to a hook  40   a , and extends through the ligation sheath  38 . The hook  40   a  catches the proximal loop  28  of the ligature  22 . The operation handle is provided at the proximal end of the ligation sheath  38  and that of the hook wire  40 .  
         [0036]     How this embodiment is operated will be explained. Note that the embodiment is endoscopically operated, though the operation may not be explained without referring to the endoscope used. Here, it will be described how the embodiment is manipulated to ligate the tissue  60  to be treated and to release the tissue  60  from the ligated state. First, it will be described how to ligate the tissue  60 .  
         [0037]     As shown in  FIG. 1 , the ligation instrument  14  is coupled to the ligation apparatus  12  (see  FIG. 2 ). The proximal loop  28  of the ligation apparatus  12  is set into engagement with the hook  40   a  fastened to the hook wire  40  of the ligation instrument  14 . The silicone tube  26  of the ligation apparatus  12  is moved until it abuts on the distal end of the ligation sheath  38  of the ligation instrument  14 .  
         [0038]     As  FIG. 3  shows, the looped ligature  22  of the treatment system  10  is rapped around the tissue  60  that is to be treated. When the hook wire  40  of the ligation instrument  14  is pulled with respect to the ligation sheath  38 , the silicone tube  26  is pushed at the distal end of the ligation sheath  38 . As a result, the silicone tube  26  moves toward the distal end of the ligature  22 .  
         [0039]     As  FIG. 4  depicts, the ligature  22  squeezes the tissue  60  as the loop of the ligature  22  becomes smaller. The tissue  60  is thereby ligated. The silicone tube  26  is prevented from moving relative to the ligature  22 , by virtue of a frictional force. The tissue  60  therefore remains ligated. After the tissue  60  has been thus ligated, the parts of the ligature  22 , which protrude from the proximal end of the silicone tube  26 , are cut off.  
         [0040]     It will be explained how the tissue  60  is released from the ligated state.  
         [0041]     As  FIG. 5  shows, an endoscope  50  having a channel  50   a  that can guide a grasping forceps  48  is used to release the tissue  60  from the ligated state. The grasping forceps  48  extending through the channel  50   a  holds the flexible wire  30 . The forceps  48  is pulled, thus pulling the flexible wire  30  with a force greater than the frictional force that the silicone tube  26  exerts on the wire  30 .  
         [0042]     As is illustrated in  FIG. 6 , the flexible wire  30  is connected to the distal part of the looped ligature  22 , at a position deviated from the axis X of the lumen (see  FIG. 2 ). When the flexible wire  30  is pulled, one of the end portions of the ligature  22 , which extend through the silicone tube  26 , is pulled from the silicone tube  26 . As a result, the diameter of the looped ligature  22  increases, and the ligature  22  is removed from the tissue  60 . When the flexible wire  30  is pulled by manipulating the gasping forceps  48 , the portions of the ligature  22  is pulled out of the silicone tube  26 , one after the other. Hence, the ligature  22  can be released from the silicone tube  26  with a smaller force than in the case where both end portions are pulled at the same time.  
         [0043]     As  FIG. 7  shows, the ligature  22  and the silicone tube  26  are moved away from the tissue, while the flexible wire  30  remains held by the grasping forceps  48 .  
         [0044]     The embodiment described above is advantageous in the following respects.  
         [0045]     To release the tissue  60  from the ligated state, the flexible wire  30  is held with the grasping forceps  48 . It is easier for the surgeon to hold the flexible wire  30  than to hold the ligature  22  directly, while observing the tissue through the endoscope  50 . This prevents any damage to the tissue  60 . Further, the surgeon would not fail to hold the flexible wire  30  with the grasping forceps  48 , because the flexible wire  30  has a loop  31  at the distal end.  
         [0046]     Once the flexible wire  30  has been held with the grasping forceps  48 , the ligature  22  can be removed from the tissue  60  and pulled from the silicone tube  26 , in whichever direction the flexible wire  30  is pulled.  
         [0047]     The second embodiment of the invention will be described, with reference to  FIG. 8 . The embodiment is a modification of the first embodiment. The components identical to those of the first embodiment are designated at the same reference numerals and will not be described in detail.  
         [0048]     As can be seen from  FIG. 8 , the ligation apparatus  12   a  according to the embodiment differs from the ligation apparatus  12  (see  FIG. 2 ) according to the first embodiment in that the flexible wire  30  has a looped part  32  and is connected to the ligature  22 .  
         [0049]     When the apparatus  12   a  is used, it performs the same operation as the first embodiment and can achieve the same result as the first embodiment. In addition, the flexible wire  30  can be easily held with, for example, a grasping forceps  48 , because the flexible wire  30  has a looped part  32 . Thanks to the looped part  32 , the grasping forceps  48  can hold the flexible wire  30  at two parts. Hence, the flexible wire  30  can be pulled by using the grasping forceps  48 , with a greater force than when the forceps  48  holds the wire  30  at only one part (see  FIG. 2 ).  
         [0050]     The third embodiment will be described, with reference to  FIG. 9 . The embodiment is a modification of the first embodiment. The components identical to those of the first embodiment are designated at the same reference numerals and will not be described in detail.  
         [0051]     As can be seen from  FIG. 9 , the ligation apparatus  12   b  according to the embodiment differs from the ligation apparatus  12  (see  FIG. 2 ) according to the first embodiment in several respects.  
         [0052]     A distal pledget  54  is arranged near the distal end of the looped ligature  22  and positioned symmetrical with respect to the axis X of the lumen of the silicone tube  26  (see  FIG. 2 ). The distal pledget  54  has a pair of holes, which are symmetrical to each other with respect to axis X of the lumen of the silicone tube  26 . Two parts of the ligature  22  pass through these holes, respectively.  
         [0053]     A proximal pledget  56  is provided between the distal pledget  54  and the silicone tube  26  and located near the silicone tube  26 . The proximal pledget  56  has a hole made in the center part. Two parts of the looped ligature  22  pass through this hole. Hence, the tissue  60  can be ligated, while being held between the distal pledget  54  and the proximal pledget  56 .  
         [0054]     When the apparatus  12   b  is used, it performs the same operation as the first embodiment and can achieve the same result as the first embodiment. In addition, the flexible wire  30  can be prevented from contacting the tissue  60  when the tissue  60  is ligated, because the distal pledget  54  contacts the tissue  60  at a large area. Thus, the flexible wire  30  can be easily grasped with the grasping forceps  48  in order to remove the ligature  22  from the tissue  60  that has been ligated by using the ligation apparatus  12   b.    
         [0055]     Once the tissue  60  has been ligated, the distal pledget  54  contacts the tissue  60  at a large area. This reliably prevents the ligature  22  from being embedded in the tissue  22 . Further, the proximal pledget  56  contacts the tissue  60  at a large area once the tissue  60  has been ligated. This also reliably prevents the ligature  22  from being embedded in the tissue  22 .  
         [0056]     The fourth embodiment will be described, with reference to  FIG. 10 . The embodiment is a modification of the third embodiment. The components identical to those of the third embodiment are denoted at the same reference numerals and will not be described in detail.  
         [0057]     As can be understood from  FIG. 10 , the ligation apparatus  12   c  according to the embodiment differs from the ligation apparatus  12   b  (see  FIG. 9 ) according to the third embodiment in that the flexible wire  30  has a looped part  32  that is connected to the distal pledget  54 . The flexible wire  30  can slide with respect to the distal pledget  54 . The ligation apparatus  12   c  has no proximal pledgets  56 .  
         [0058]     When this apparatus  12   c  is used, it performs the same operation as the third embodiment and can achieve the same result as the third embodiment. In addition, the flexible wire  30  can be easily held with, for example, a grasping forceps  48 , because the flexible wire  30  has a looped part  32 . Thanks to the looped part  32 , the grasping forceps  48  can hold the flexible wire  30  at two parts. Hence, the flexible wire  30  can be pulled by using the grasping forceps  48 , with a greater force than when the forceps  48  holds the wire  30  at only one part (see  FIG. 9 ).  
         [0059]     Moreover, that part of the flexible wire  30 , which is connected to the distal pledget  54 , would not interfere with the distal pledget  54  when the tissue  60  is ligated. The tissue  60  can therefore be ligated more reliably.  
         [0060]     The fifth embodiment will be described, with reference to  FIG. 11 . The embodiment is a modification of the fourth embodiment. The components identical to those of the fourth embodiment are denoted at the same reference numerals and will not be described in detail.  
         [0061]     As can be seen from  FIG. 11 , the ligation apparatus  12   d  according to the embodiment differs from the ligation apparatus  12   c  (see  FIG. 10 ) according to the fourth embodiment in that a flexible wire  30  having an expanded part  31  is connected to the distal pledget  54 .  
         [0062]     When this apparatus  12   d  is used, it performs the same operation as the fourth embodiment and can achieve the same result as the fourth embodiment. In addition, the flexible wire  30  is so shaped not to occupy much space, when the apparatus  12   d  is endoscopically left in a body cavity. This prevents the flexible wire  30  from entangling with the food being swallowed, the endoscope  50  being removed, or the grasping forceps  48  being removed.  
         [0063]     The sixth embodiment will be described, with reference to FIGS.  12  to  14 . The embodiment is a modification of the first embodiment. The components identical to those of the first embodiment are designated at the same reference numerals and will not be described in detail.  
         [0064]     As can be seen from  FIG. 12 , the ligation apparatus  12   e  according to this embodiment differs from the ligation apparatus  12  (see  FIG. 2 ) according to the first embodiment in some respects.  
         [0065]     As  FIGS. 13 and 14  show, the silicone tube  26   a  according to the embodiment has two lumens, i.e., a ligature-guiding lumen  72  and a plug-receiving lumen  74 . The lumens  72  and  74  are arranged adjacent to each other and extend parallel to the axis X (see  FIG. 2 ) of the silicone tube  26 .  
         [0066]     A ligature  22  passes through the ligature-guiding lumen  72 . The ligature-guiding lumen  72  has an inside diameter large, allowing the ligature  22  to slide smoothly.  
         [0067]     A plug  76  has been pushed into the plug-receiving lumen  74 . The plug-receiving lumen  74  has an inside diameter small than the diameter of the plug  76 . Nonetheless, the plug  76  can be inserted into the plug-receiving lumen  74 . To the proximal end of the plug  76  there is connected to a flexible wire  30  that has a looped part  32 .  
         [0068]     How the embodiment is operated will be explained. First, it will be described how the embodiment ligates tissue  60  to be treated. The ligation apparatus  12   e  shown in  FIG. 12 , which has the plug  76  inserted in the plug-receiving lumen  74 , is used in place of the apparatus  12  (see  FIG. 2 ) according to the first embodiment.  
         [0069]     As illustrated in  FIG. 3 , the hook wire  40  of the ligation instrument  14  is pulled with respect to the ligation sheath  38 . The silicone tube  26  is therefore pushed at the distal end and moved toward the distal end of the ligature  22  along the ligature  22 . As a result, the apparatus  12   e  shown in  FIG. 13  gradually reduces the diameter of the looped part of the ligature  22 , clamping the tissue  60  with the ligature  22 . Thus, the apparatus  12   e  ligates the tissue  60 .  
         [0070]     As  FIG. 4  shows, the parts of the ligature  22 , which protrude from the proximal end of the silicone tube  26 , are cut off after the tissue  60  has been thus ligated.  
         [0071]     It will be explained how the tissue  60  is released from the ligated state.  
         [0072]     To release the tissue  60  from the ligated state, the endoscope  50  (see  FIG. 5 ) is used, which has a channel  50   a  that can guide a grasping forceps  48 . The flexible wire  30  is held with the grasping forceps  48  that extends through the channel  50   a . Then, the flexible wire  30  is pulled with a force greater than the frictional force that retains the plug  76  in the plug-receiving lumen  74 . As a result, the ligature-guiding lumen  72  expands, having its inside diameter increases. The ligature  22  can now slide. That is, there is no long a ligature-holding force resulting from the friction between the silicone tube  26  and the ligature  22 . Either the silicone tube  26  or the ligature  22  is held with the grasping forceps  48 , the tube  26  is move away from the ligature  22  or vice versa. The tissue  60  is thereby released from the ligated state.  
         [0073]     The embodiment described above is advantageous in some respects. When this apparatus  12   e  is used, it performs the same operation as the first embodiment and can achieve the same result as the first embodiment. In addition, the looped part of the ligature  22  can easily expand because the ligature  22  smoothly moves in the ligature-guiding lumen  72 . Because of this, it is easy to release the tissue  60  from the ligated state.  
         [0074]     While the tissue  60  is being released from the ligated state, no tension is applied on the ligature  22  or the silicone tube  26 . The ligature  22  can be removed from the tissue  60 , not influencing the tissue  60  at all.  
         [0075]     The seventh embodiment will be described, with reference to FIGS.  15  to  17 . The embodiment is a modification of the first embodiment. The components identical to those of the first embodiment are designated at the same reference numerals and will not be described in detail.  
         [0076]     As  FIG. 15  may suggest, the ligation apparatus  12   e  according to this embodiment differs from the ligation apparatus  12  (see  FIG. 2 ) according to the first embodiment in some respects.  
         [0077]     As FIGS.  15  to  17  depict, the silicone tube  26   b  according to the embodiment has a slit  80  that extends at right angles to the axis X (see  FIG. 2 ) of the lumen. A flexible wire  30  having a looped part  32  passes through the slit  80 .  
         [0078]     How the embodiment is operated will be explained. To ligate the tissue  60  to be treated, it is operated in the same manner as the first embodiment. Therefore, it will be described how the embodiment is operated to release the tissue  60  from the ligated state.  
         [0079]     To release the tissue  60  from the ligated state, the endoscope  50  is used, which has a channel  50   a  that can guide a grasping forceps  48 . As shown in  FIG. 16 , the flexible wire  30  is held with the grasping forceps  48  that extends through the channel  50   a . Then, the flexible wire  30  is held with a grasping forceps  48  that extends through the channel  50   a . As the flexible wire  30  is pulled, the silicone tube  26   b  is split, from the slit  80  toward the proximal end of the silicone tube  26   b.    
         [0080]     When the flexible wire  30  is further pulled, the silicone tube  26   b  splits into two parts as illustrated in  FIG. 17 . As a result, the ligature  22  can no longer remain looped. Hence, the ligature  22  is easily removed from the tissue  60 , releasing the tissue  60  from the ligated state.  
         [0081]     The embodiment described above is advantageous in some respects. When the apparatus  12   f  is used, it performs the same operation as the first embodiment and can achieve the same result as the first embodiment. In addition, the silicone tube  26   b  can slits into two parts along the axis X of the lumen to release the tissue  60  from the ligated state, when the flexible wire  30  is held with the grasping forceps  48  and pulled toward its proximal end. Thus, the tissue  60  can easily be released from the ligated state. Even if the ligature  22  hardly slides on the silicone tube  26   b  and the friction between the ligature  22  and the tube  26   b  is high, the ligature  22  that was held by the silicone tube  26   b  can easily be removed from the tissue  60 .  
         [0082]     The eighth embodiment will be described, with reference to FIGS.  18  to  19 . The embodiment is a modification of the first embodiment. The components identical to those of the first embodiment are designated at the same reference numerals and will not be described in detail.  
         [0083]     As seen from  FIG. 18 , the ligation apparatus  12   g  according to this embodiment differs from the ligation apparatus  12  (see  FIG. 2 ) according to the first embodiment in that a silicone tube  26   c  is used in place of the silicone tube  26 . The tube  26   c  has the same length as the silicone tube  26 , but is composed of three silicone tubes  82 ,  84  and  86 . In other words, the tube  26   c  is divided into three parts, along lines perpendicular to the longitudinal axis.  
         [0084]     How the embodiment is operated will be explained. To ligate the tissue  60  to be treated, it is operated in the same manner as the first embodiment. Therefore, it will be described how the embodiment is operated to release the tissue  60  from the ligated state.  
         [0085]     To release the tissue  60  from the ligated state, the endoscope  50  is used as shown in  FIG. 19 , which has a channel  50   a  that can guide a grasping forceps  48 . The first silicone tube  82  is held with the grasping forceps  48  that extends through the channel  50   a . Then, the first silicone tube  82  is pulled toward the proximal end of the ligature  22 . Similarly, the second silicone tube  84  and the third silicone tube  86  are pulled toward the proximal end of the ligature  22 , by using the grasping forceps  48 . Since the total length of the first to third silicone tube  82 ,  84  and  86  is equal to the silicone tube  26  of the first embodiment, the friction between the ligature  22  and each of the silicone tubes  82 ,  84  and  86  is smaller than the frictional force between the ligature  22  and the silicone tube  26  of the first embodiment. The silicone tubes  82 ,  84  and  86  can therefore be moved toward the proximal end of the ligature  22 . This makes it easy to remove the ligature  22  from the tissue  60  and, hence, to release the tissue  60  from the ligated state. As long as the ligature  22  extends through the first to third silicone tubes  82 ,  84  and  86 , a desired frictional force of course remains exerted on the ligature  22 .  
         [0086]     The embodiment described above is advantageous in some respects. When the apparatus  12   g  is used, it performs the same operation as the first embodiment and can achieve the same result as the first embodiment. In addition, the silicone tubes  82 ,  84  and  86  can be removed, one by one, from the ligature  22 , to release the tissue  60  from the ligated state. Hence, a small grasping force suffices to hold one silicone tube in the process of removing the tube from the ligature  22 . The surgeon would not fail to hold each silicone tube with the grasping forceps  48  and can therefore easily release the tissue  60  from the ligated state.  
         [0087]     After the tissue  60  has been ligated, one, two or three tubes that constitute the silicone tube  26   c  may be removed. Thus, the ligating force applied to the tissue  60  can be adjusted.  
         [0088]     Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited td the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.