Patent Publication Number: US-2010113873-A1

Title: Suturing device and suturing system

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a suturing device inserted into a body cavity, and more particularly, to a suturing device used to suture a perforation formed in a hollow organ such as a stomach or an intestine by means of a suturing thread, of which an end portion is mounted with an anchor, and a suturing system including the suturing device. 
     2. Description of the Related Art 
     Conventionally, there is known a suturing device which uses a suturing thread, of which an end portion is mounted with an anchor, for the purpose of suturing a perforation or a laceration formed in a hollow organ such as a stomach or an intestine (for example, see PCT International Publication No. WO2007-37326). In this suturing device, the suturing operation is carried out in such a manner that the anchor released from a distal end of a needle is locked on a tissue in the vicinity of a perforation inside or outside the tissue, and the suturing thread is pulled by means of a stopper or the like so as to pull the tissues locked by the anchors. 
     SUMMARY OF THE INVENTION 
     According to a first aspect of the invention, there is disclosed a suturing device for suturing tissues by using a suturing unit having an anchor mounted to an end portion of a suturing thread is provided, the suturing device including: a pair of first and second jaws which are opened or closed so as to grip the tissue; a hollow needle tube which receives the anchor in an inner cavity thereof; and a pusher which is inserted through the needle tube in a freely advancing and retracting manner and is capable of pushing the anchor received in the needle tube toward-a distal end of the needle tube, in which the needle tube is disposed so as to intersect the first jaw and to allow the distal end thereof to face the second jaw, and in which, when the tissue is gripped by the first and second jaws, the needle tube is inserted into the tissue. 
     According to a second aspect of the invention, there is disclosed a suturing system including: an endoscope device; a holding mechanism capable of holding a tissue in a body cavity; and a suturing mechanism for suturing tissues by using a suturing unit having an anchor mounted to an end portion of a suturing thread. The suturing mechanism includes: a hollow needle tube which is capable of receiving the anchor in an inner cavity thereof; and a pusher which is inserted through the needle tube in a freely advancing and retracting manner and is capable of pushing the anchor received in the needle tube toward a distal end of the needle tube. The holding mechanism includes: a holding portion which is provided in a distal end portion and is capable of holding the tissue in the body cavity; a through-hole which is provided in the holding portion and is capable of allowing the needle tube to penetrate the held tissue in the body cavity; a guide surface which is provided in the holding portion so as to guide the distal end of the needle tube to the through-hole; and a bending portion which changes a direction of the holding portion. The suturing mechanism and the holding mechanism are inserted into channels of the endoscope device in use so that the guide surface faces the suturing mechanism. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a view showing a suturing device according to a first embodiment of the invention. 
         FIG. 2  is a view showing a suturing unit used in the suturing device. 
         FIG. 3  is a partially enlarged sectional view showing a distal end part of the suturing device. 
         FIGS. 4 to 6  are views showing an operation upon using the suturing device. 
         FIG. 7  is an overall view showing a configuration of the suturing device according to a second embodiment of the invention. 
         FIGS. 8A and 8B  are partially enlarged sectional views respectively showing a distal end part of a suturing mechanism of the suturing device and an operation part of the suturing mechanism. 
         FIGS. 9 to 15  are views showing operations upon using the suturing device. 
         FIG. 16  is a view showing a distal end part of the suturing device according to a third embodiment of the invention. 
         FIG. 17  is an enlarged sectional view showing the distal end part. 
         FIG. 18  is a view showing the operation part of the suturing device. 
         FIG. 19  is a sectional view showing the operation part. 
         FIGS. 20 to 30  are views showing operations upon using the suturing device. 
         FIG. 31  is an enlarged sectional view showing a distal end part of the suturing device according to a modified example of the embodiment. 
         FIGS. 32 to 35  are views showing operations upon using the suturing device. 
         FIG. 36  is a view showing a needle tube of the suturing device according to another modified example of the embodiment. 
         FIG. 37  is an enlarged sectional view showing the needle tube. 
         FIGS. 38 and 39  are views showing operations upon using the suturing device. 
         FIG. 40  is a view showing the needle tube of the suturing device according to still another embodiment of the invention. 
         FIG. 41A  is a sectional view taken along the line A-A of  FIG. 40 . 
         FIG. 41B  is a sectional view taken along the line B-B of  FIG. 40 . 
         FIG. 41C  is a sectional view taken along the line C-C of  FIG. 40 . 
         FIG. 42  is a view showing an example of an endoscope forceps of a suturing system according to a fourth embodiment of the invention. 
         FIG. 43  is an enlarged view showing a distal end part of the endoscope forceps. 
         FIG. 44  is an enlarged view showing a distal end part of the suturing system. 
         FIGS. 45 to 48  are views showing operations upon using the suturing system. 
         FIG. 49  is a view showing a distal end part of the suturing system according to a fifth embodiment of the invention. 
         FIG. 50  is a front view showing the distal end part of the suturing system. 
         FIGS. 51 to 54  are views showing operations upon using the suturing system. 
         FIG. 55  is an overall view showing the suturing system according to a sixth embodiment of the invention. 
         FIGS. 56 to 58  are views showing operations upon using the suturing system. 
         FIG. 59  is a view showing a distal end part of the suturing system according to a seventh embodiment of the invention. 
         FIG. 60  is a sectional view showing a puncture cap of the suturing system in an axial direction. 
         FIGS. 61 to 64  are views showing operations upon using the suturing system. 
         FIG. 65  is an overall view showing the suturing system according to an eighth embodiment of the invention. 
         FIGS. 66 to 68  are views showing operations upon using the suturing system. 
         FIG. 69  is a view showing a distal end part of the suturing system according to a ninth embodiment of the invention. 
         FIG. 70  is a view showing an operation upon using the suturing system. 
         FIG. 71  is a view showing a distal end part of the suturing system according to a modified example of the embodiment. 
         FIG. 72  is a view showing an operation upon using the suturing system. 
         FIG. 73  is a view showing the needle tube of the suturing device according to a tenth embodiment of the invention. 
         FIG. 74  is a view showing a state where the needle tube is received in a sheath. 
         FIG. 75  is a view showing an operation upon using the suturing device. 
         FIG. 76  is a view showing an operation upon using the suturing device. 
         FIG. 77  is a view showing the needle tube of the suturing device according to a modified example of the embodiment. 
         FIG. 78A  is a view showing the needle tube of the suturing device according to the modified example of the embodiment and  FIG. 78B  is a view showing a state where an anchor passes through the needle tube. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Hereinafter, a suturing device according to a first embodiment of the invention will be described with reference to  FIGS. 1 to 5 . 
       FIG. 1  is a view showing a suturing device  1  according to this embodiment. The suturing device  1  is tied with an endoscope device  100  by means of a tape, or the like, so as to be inserted into a patient&#39;s body cavity. 
     The suturing device  1  includes an insertion part  2  which is inserted into a body, a distal end part  3  which is formed at the distal end portion of the insertion part  2  so as to carry out a suturing operation, and an operation part  4  which is provided on the side of the proximal end of the insertion part  2  so as to operate the distal end part  3 . 
       FIG. 2  is a view showing a suturing unit  103  mounted to the suturing device  1  so as to be received in the suturing device  1 . The suturing unit  103  includes a suturing thread  104 , a stopper  105  through which the suturing thread  104  is inserted, and first and second bar-shaped anchors  106  and  107  which are mounted to both ends of the suturing thread  104 . The anchors  106  and  107  are respectively provided with engagement grooves  106 A and  107 A which are formed in the whole circumference of a part of outer surfaces thereof. 
     The stopper  105  is formed in such a manner that a plate-shaped member made of metal or a resin such as a biodegradable resin is bent so as to allow left and right end portions  105 A and  105 B to face each other and the end portions  105 A and  105 B engage with each other. 
     A hole  105 C is formed in the vicinity of a center portion of the stopper  105  in a horizontal direction. The suturing thread  104  bent at a center point  104 A is inserted through the hole  105 C from a surface opposite to the end portions  105 A and  105 B and is disposed so as to pass through a gap between the end portions  105 A and  105 B engaging with each other. An operation upon using the stopper  105  will be described below. 
     The insertion part  2  is a tubular member having flexibility. A wire used to operate the distal end part  3  or a pusher used to release the anchors  106  and  107  of the suturing unit  103  is inserted therethrough. 
       FIG. 3  is a partially enlarged sectional view showing the distal end part  3 . The distal end part  3  includes a pair of jaws  10  which grip a tissue of a treatment target portion (hereinafter, referred to as “target tissue”), a needle tube  11  which punctures the target tissue so as to release the anchors  106  and  107  therefrom, and a stopper support portion  12  by which the stopper  105  of the suturing unit  103  is supported. 
     The jaws  10  include a first upper jaw  10 A and a second lower jaw  10 B shown in  FIG. 3 , and are capable of gripping the target tissue by closing the upper and lower jaws so as to allow mutually facing surfaces (gripping surfaces) to be close to each other. A wire (not shown) used to open or close the jaw  10  is connected to the operation part  4  via the insertion part  2 . 
     The needle tube  11  is configured as a hollow member having a sharp distal end. As shown in  FIG. 3 , the distal end portion of the needle tube  11  is formed in a hook shape so as to be curvedly folded back toward the distal end of the insertion part  2 , and is integrally fixed to the first jaw  10 A so as to pass through the gripping surface of the first jaw  10 A. Accordingly, the needle tube  11  is interlocked with the open/close operation of the jaw  10  and moves so as to be rotated about the proximal end of the first jaw  10 A. 
     In order to carry out the above-described movement, it is desirable that a base portion  11 A of the needle tube  11  protruding from the insertion part  2  have constant flexibility. Such flexibility can be ensured in such a manner that the whole part of the needle tube  11  is made of super-elastic metal such as nickel titanium or a region of the proximal end portion rather than the base portion  11 A is made of a resin or the like. 
     The anchors  106  and  107  of the suturing unit are received in an inner cavity of the needle tube  11 . The engagement grooves  106 A and  107 A of the anchors respectively engage with engagement protrusions (not shown) protruding to the inside of the needle tube  11 , thereby preventing the anchors  106  and  107  from being erroneously released or naturally coming off. 
     The suturing thread  104  of the suturing unit  103  is drawn to the outside of the needle tube  11  from a groove  11 B formed in the inner peripheral side of the hook shape of the needle tube  11 . A pusher  13  used to release the anchors  106  and  107  is inserted through the proximal end side rather than the anchors  106  and  107 . The pusher  13  extends up to the operation part  4  via the insertion part  2 . 
     Since the anchors  106  and  107  are received in the curved inner cavity of the needle tube  11  as shown in  FIG. 3 , it is desirable to form the anchors in a tapered shape in which the diameter gradually decreases toward both end portions in a longitudinal direction, where the both end portions are hardly caught by the inner wall of the needle tube  11 . Additionally, when the anchors are made of the above-described super-elastic metal or biodegradable plastic so as to have flexibility, it is desirable in that the movement and the releasing in the needle tube  11  are smooth. In the same manner, the pusher  13  is also formed to have flexibility since it advances and retracts in the curved inner cavity. 
     The stopper support portion  12  includes a sheath  14  which is inserted through the insertion part and a lock member  15  which is inserted through the sheath  14 . The sheath  14  is configured as a tubular member having flexibility so as to freely advance and retract in an axial direction of the insertion part  2 . The lock member  15  includes a hook  15 A formed at the distal end portion thereof and extends up to the operation part  4 . 
     As shown in  FIG. 3 , the suturing thread  104  drawn out from the groove  11 B of the needle tube  11  is drawn into the inside of the sheath  14 . Then, the center point  104 A where the suturing thread  104  is bent is locked in the hook  15 A of the lock member  15 , and the stopper  105  comes into contact with the distal end portion of the sheath  14  and is supported thereby. 
     Returning to  FIG. 1 , the operation part  4  includes a first operation part  16  which is used to operate the jaws  10  and the pusher  13  and a second operation part  17  which is used to operate the stopper support portion  12 . 
     The first operation part  16  includes a body  18 , a slider  19  which is mounted to the body  18  in a freely sliding manner in an axial direction, and a pusher operation portion  20  of which one end portion is mounted to the body  18 . The slider  19  is connected to the end portion of the wire connected to the jaws  10 . When the slider  19  is slid on the body  18 , the jaws  10  are opened or closed. 
     The pusher operation portion  20  is configured as a cylindrical member and extends toward the proximal end of the body  18  while forming a predetermined angle with respect to the body  18 . The proximal end portion of the pusher  13  which has passed through the inside of the insertion part  2  and the body  18  is inserted through the pusher operation portion  20  in a freely advancing and retracting manner, and a handle  21  is mounted to the end portion of the protruding pusher  13 . When a user advances the pusher  13  toward the pusher operation portion  20  by means of the handle  21 , it is possible to release the anchors  106  and  107  from the needle tube  11 . 
     The second operation part  17  includes a body  22  and a slider  23  which is mounted to the body  22  in a freely sliding manner in an axial direction. The body  22  is connected to the proximal end of the sheath  14  inserted through the insertion part  2 . When the body  22  advances or retracts with respect to the insertion part  2 , it is possible to change a protrusion length of the sheath  14  from the distal end of the insertion part  2 . The slider  23  is connected to the proximal end of the lock member  15  inserted through the sheath  14 . When the slider  23  is slid on the body  22 , it is possible to change a positional relationship between the sheath  14  and the lock member  15  in a longitudinal direction. 
     An operation upon using the suturing device  1  with the above-described configuration will be described. 
     First, a user inserts the suturing device I into a body cavity of a patient or the like so that the distal end part  3  moves up to a position in the vicinity of a stomach wall or the like having a treatment target portion such as a perforation or a laceration. At this time, first, an endoscope device  100  is inserted into the body cavity, and the proximal end portion of the endoscope device  100  is inserted through a known overtube (not shown). Subsequently, the overtube is inserted into the body cavity by using the endoscope device  100  as a guide, and the endoscope device  100  is once taken out. Subsequently, as shown in  FIG. 1 , the endoscope device  100  and the suturing device  1  are tied together by means of a tape, a band or the like, and are inserted into the overtube so as to be inserted into the body cavity, thereby smoothly introducing the distal end part  3  having a complex shape up to a position in the vicinity of the target tissue. 
     The user opens the jaws  10  by operating the slider  19  of the first operation part  16 , moves the jaws to be close to one target tissue T 1  of the treatment target portion, and then closes the jaws  10 . Then, as shown in  FIG. 3 , the target tissue T 1  is gripped by the jaws  10  and the sharp distal end portion of the needle tube  11  passing through the gripping surface of the first jaw  10 A is inserted into the target tissue T 1  at the same time. When the user further closes the jaws  10 , the distal end of the needle tube  11  penetrates the target tissue T 1  while passing through a gap between both bridges of the second jaw  10 B. 
     Subsequently, when the user advances the pusher  13  by operating the pusher operation portion  20 , as shown in  FIG. 4 , the pusher pushes the anchors  106  and  107  toward the distal end of the needle tube, and the first anchor  106  disposed on the distal end side is first released from the needle tube  11 . The user can recognizes a fact that the first anchor  106  is released by means of the sense of touch (click-feeling) occurring when the engagement protrusion formed inside the needle tube  11  passes over the engagement groove  106 A of the first anchor  106 . 
     In the same manner, as shown in  FIG. 5 , the user releases the second anchor  107  to lock it on the other target tissue T 2  of the treatment target portion. After the needle tube  11  is taken out from the target tissue T 2 , the user pushes the body  22  of the second operation part  17  into the insertion part  2  while maintaining a positional relationship between the body  22  and the slider  23 . Then, as shown in  FIG. 6 , the sheath  14  of the stopper support portion  12  protrudes from the insertion part  2 . 
     When the sheath  14  protrudes from the insertion part  2 , the suturing thread  104  of the suturing unit  103  locked in the hook  15 A of the lock member  15  is received in the sheath  14 , and only the suturing thread  104  is received in the sheath  14  in a state where the stopper  115  still comes into contact with the distal end surface of the sheath  14 , thereby shortening the distance between the stopper  105  and the anchors  106  and  107 . 
     Since the anchors  106  and  107  are locked on the tissues T 1  and T 2 , respectively, as shown in  FIG. 6 , as the stopper  105  moves closer to the anchors  106  and  107 , the target tissues T 1  and T 2  are drawn toward the suturing device  1  together with the anchors  106  and  107  so as to come into close contact with each other. In this manner, the suturing operation of the treatment target portion T is carried out. 
     At this time, although the engagement between the end portions  105 A and  105 B of the stopper  105  is loosened when the suturing thread  104  moves toward the center point  104 A so as to be received in the sheath  14 , the end portions  105 A and  105 B more forcedly engage with each other by means of a force acting on the suturing thread  104  even if the suturing thread  104  tries to move toward the anchors  106  and  107 , thereby prohibiting the movement of the suturing thread in the corresponding direction. That is, since the stopper  105  moves only in a direction toward the anchors  106  and  107  and is not moved in an opposite direction, the suturing degree of the treatment target portion T is not loosened or released. 
     After the suturing operation ends, the user retracts the sheath  14 . Subsequently, the user advances the lock member  15  with respect to the sheath  14  by operating the slider  23  so as to protrude from the sheath  14 . Subsequently, the user releases the engagement between the hook  15 A and the suturing thread  104  while observing by means of the endoscope device  100  so as to separate the suturing unit  104  from the suturing device  1 . In this manner, a series of treatments ends. 
     In the suturing device  1  according to this embodiment, the needle tube  11 , from which the anchors  106  and  107  are released, is curved so as to pass through the gripping surface of the first jaw  10 A of the pair of jaws  10  which are capable of opening and closing. Accordingly, when the needle tube  11  is inserted into the target tissues T 1  and T 2 , it is possible to observe the needle tube by means of the endoscope device  100 . Also, since the distal end of the needle tube  11  faces the insertion part  2  even after the needle tube  11  penetrates the tissue, it is possible to observe the needle tube by means of the endoscope device  100 . 
     In the known suturing device, since the needle tube is formed in a linear shape, it is difficult to visibly recognize the position of the distal end portion of the needle tube when it is inserted into the tissue by means of the endoscope device, and the distal end of the needle tube is not visibly recognized enough for a reliable releasing operation of the anchor. In the suturing device  1  according to this embodiment, it is possible to check that the distal end of the needle tube  11  comes out from the target tissue T 1  or the like by means of the endoscope device  100 . Also, it is possible to release the anchors  106  and  107  while observing them by means of the endoscope device  100 . Accordingly, it is possible to accurately carry out the suturing operation by reliably locking the suturing unit  103  on the treatment target tissues. 
     Next, a second embodiment of the invention will be described with reference to  FIGS. 7 to 15 . A suturing device  31  according to this embodiment is different from the above-described suturing device  1  in that the needle tube is introduced via a channel extending up to the jaws. 
     Note that, in the following description, the same reference numerals are given to the same components as those of the above-described embodiment, and the descriptions thereof will be omitted. 
       FIG. 7  is an overall view showing a configuration of the suturing device  31 . The suturing device  31  includes a gripping mechanism  32  which is provided with a pair of jaws and a suturing mechanism  33  which is inserted through the gripping mechanism  32 . 
     A basic configuration of the gripping mechanism  32  is described in United States Patent Application, Publication No. 2006-0271073, and is briefly described as below. 
     The gripping mechanism  32  includes an insertion part  34  which is substantially equal to the insertion part  2 , a pair of jaws  35  which is mounted to the distal end of the insertion part  34 , and a handle  36  which is used to open or close the jaw  35 . 
     A first upper jaw  35 A is shorter than a second lower jaw  35 B, and the proximal end of the first jaw  35 A is rotatably supported to a position in the vicinity of a center portion of the second jaw  35 B in a longitudinal direction. The proximal end of the second jaw  35 B is rotatably supported to a position in the vicinity of the distal end of the insertion part  34 . 
     The first jaw  35 A is connected to a jaw open/close sheath  37  having flexibility. The jaw open/close sheath  37  in inserted through a channel provided in the insertion part  34  in a freely advancing and retracting manner, and has the proximal end connected to the handle  36 . Accordingly, when a user advances or retracts the jaw open/close sheath  37  with respect to the insertion part  34  by operating the handle  36 , the first jaw  35 A is rotated, thereby opening or closing the jaws  35 . 
     Since a through-hole  38  (see  FIG. 10 ) is formed through a gripping surface of the first jaw  35 A facing the second jaw  35 B, and the distal end of the jaw open/close sheath  37  is inserted through the through-hole  38  to be fixed thereto, the inner cavity of the jaw open/close sheath  37  extends up to the gripping surface of the first jaw  35 A. The second jaw  35 B is provided with a through-hole or a slit at a position corresponding to the through-hole  38 , and the needle tube of the suturing mechanism  33  can pass through the gripping surface of the second jaw  35 B during an operation described below. 
     Since the configuration of the suturing mechanism  33  is substantially equal to that of the suturing device  1  according to the first embodiment, the different points will be mainly described. 
       FIGS. 8A and 8B  are partially enlarged sectional views respectively showing the distal end portion of the suturing mechanism  33  and an operation part  41  of the suturing mechanism  33 . As shown in  FIG. 8A , a needle tube  39  is formed in a linear shape. The needle tube  39  is inserted through a sheath  40  in a freely advancing and retracting manner, and the stopper  105  of the suturing unit  103  is also received in the inner cavity of the sheath  40 . The center point  104 A of the suturing thread  104  is inserted from a through-hole  39 A formed in the needle tube  39  into the inner cavity of the needle tube  39  so as to be caught and rotated by the pusher  13 . 
     As shown in  FIG. 8B , the proximal end of the sheath  40  is connected to the body  18  of the operation part  41 , and the proximal end of the needle tube  39  is connected to the slider  19 . The pusher operation portion  20  is mounted to the slider  19  and is slid on the body  18  together with the slider  19 . 
     With the above-described configuration, when a user advances or retracts the slider  19  with respect to the body  18 , it is possible to relatively move the needle tube  39  with respect to the sheath  40  and to protrude or depress the distal end of the needle tube  39  from the sheath  40 . At this time, since the pusher operation portion  20  is slid together with the slider  19 , a positional relationship between the needle tube  39  and the pusher  13  is not changed. 
     As shown in  FIG. 7 , the suturing mechanism  33  is inserted from an insertion hole (not shown) provided in the handle  36  of the gripping mechanism  32  into the jaw open/close sheath  37  in a freely advancing and retracting manner. Accordingly, when the user pushes the body  18  toward the handle  36 , it is possible to protrude the sheath  40  from the gripping surface of the first jaw  35 A. 
     An operation upon using the suturing device  31  with the above-described configuration will be described. 
     First, the user ties the suturing device  31  and the endoscope device  100  together and introduces the jaws  35  up to a position in the vicinity of the treatment target portion. The timing when the suturing device  31  into the channel is inserted may be before or after the endoscope device  100  is inserted into the inner cavity of the body. 
     Subsequently, as shown in  FIG. 9 , the user operates the handle  36  so that one target tissue T 1  is gripped while being interposed between the jaws  35 . Subsequently, the body  18  of the suturing mechanism  33  is advanced with respect to the insertion part  34 , and the distal end of the sheath  40  moves to a position in the vicinity of the first jaw  35 A. At the same time, the slide  19  is advanced with respect to the body  18  so as to penetrate the target tissue T 1  by means of the needle tube  39  as shown in  FIG. 10 , and the pusher  13  is operated so as to release the first anchor  106  from the needle tube  39  as shown in  FIG. 11 , thereby locking the anchor on the target tissue T 1 . 
     At this time, since the distal end of the needle tube  39  faces the distal end portion of the endoscope device  100 , the user is capable of easily observing a position of the distal end of the needle tube  39  or a state where the anchor is released by means of the endoscope device  100 . After the first anchor  106  is released, the user retracts the needle tube  39  and releases the gripping state of the target tissue T 1 . 
     As shown in  FIG. 12 , the user locks the second anchor  107  on the target tissue T 2  in the same sequence. Then, after the stopper  105  is drawn to the outside of the sheath  40  as shown in  FIG. 13 , the body  18  is advanced with respect to the jaw open/close sheath  37 , and the stopper  105  is pushed by the sheath  40  as shown in  FIG. 14  so as to be moved toward the anchors  106  to  107 . In this manner, the treatment target portion is tightly sutured. 
     When the user sufficiently retracts the pusher  13  with respect to the needle tube  39  by operating the pusher operation portion  20 , the engagement between the suturing thread  104  and the pusher  13  is released, and the suturing unit  103  is separated from the suturing device  31  as shown in  FIG. 15 . 
     In the case where the suturing operation is carried out in combination of the gripping mechanism  32  and the known suturing mechanism using a suturing unit in which an anchor is mounted to one end of a suturing thread and a stopper is not provided, it is necessary to insert the needle tube into the target tissues T 1  and T 2  while gripping both the target tissues T 1  and T 2  by the gripping mechanism  32  simultaneously. Since the two tissues are not easily gripped at the same time, the surgical technique is not easy. 
     In the suturing device according to the invention, since the suturing unit  103  including the stopper  105  and two anchors  106  and  107  is used, it is possible to carry out the suturing operation of the treatment target tissues while reliably observing the distal end of the needle tube  39  in such a manner that the target tissues T 1  and T 2  are just separately gripped to lock the anchors thereon. Accordingly, it is possible to further easily and reliably carry out the suturing surgical technique. 
     Next, a third embodiment of the invention will be described with reference to  FIGS. 16 to 41C . A suturing device  51  according to this embodiment is different from the suturing devices according to the above-described embodiments in that two needle tubes are provided. 
       FIG. 16  is a view showing the distal end portion of the suturing device  51 . Two needle tubes, that is, a first needle tube  52  and a second needle tube  53  are inserted through the sheath  40 . Each of the needle tubes  52  and  53  includes a first region R 1  which is curved in a substantially circular-arc shape and is located on the distal end side, a second region R 2  which is connected to the proximal end of the first region R 1  and of which a portion closer to the distal end extends in a direction moving away from the axis of the sheath  40 , and a third region R 3  which is connected to the proximal end of the second region R 2  and is connected to an operation part described below. 
     Although each of the needle tubes  52  and  53  is made of super-elastic metal as a whole, the first region R 1  inserted into the tissue is made of rigid super-elastic metal having elasticity smaller than that of the second region R 2 , and the second region R 2  is made of super-elastic metal having elasticity larger than that of the first region R 1 . Then, each of the needle tubes  52  and  53  is formed by means of welding or the like so as to integrally form the first region R 1  and the second region R 2  made of super-elastic metals having different elasticity. The third region R 3  is made of the same super-elastic metal as that of the second region R 2 , and is formed by bending a boundary portion between the regions R 2  and R 3 . Alternatively, the third region R 3  may be made of flexible super-elastic metal having larger elasticity or a flexible resin, and may be bonded to the second region R 2 . In the case of the resin, for example, polyetheretherketone (PEEK) can be appropriately used. 
     As shown in  FIG. 16 , the first regions R 1  of the needle tubes  52  and  53  are convexly formed to the outside in a radial direction of the sheath  40  so as to face each other. The distal ends of the needle tubes  52  and  53  are respectively provided with engagement protrusions  52 A and  53 A which are capable of engaging with each other in a freely detaching manner. When both the engagement protrusions engage with each other, it is possible to form the first regions of the needle tubes  52  and  53  in a substantially annular shape. Additionally, a releasing protrusion  52 B protrudes from the inner peripheral surface in the vicinity of the engagement protrusion  52 A so as to release the engagement between the engagement protrusions  52 A and  53 A. An angle of an inclined surface on the side of the proximal end portion of the releasing protrusion  52 B is set to be not more than taper angles on the side of the distal end portions  106 B and  107 B of the anchors  106  and  107 . The taper angles on the side of the proximal end portions  106 C and  107 C of the anchors  106  and  107  are smaller than those on the side of the distal end portions  106 B and  107 B, and the diameter reduction on the side of the proximal end portions is smaller than that on the side of the distal end portions. 
     First and second pusher  54  and  55 , which are equal to the pusher  13 , are respectively inserted through the needle tubes  52  and  53  so as to extend up to an operation part  56 . 
       FIG. 18  is a view showing the operation part  56  of the suturing device  51 , and  FIG. 19  is a sectional view showing the operation part  56 . The body  18  includes two sliders, that is, a first slider  57  which is connected to the proximal end of the first needle tube  52  and a second slider  58  which is connected to the proximal end of the second needle tube  53 , where the two sliders are independently mounted to the body  18  in a freely sliding manner. The sliders  57  and  58  are respectively mounted with a first pusher operation portion  59  and a second pusher operation portion  60 , and the proximal end portions of the first pusher  54  and the second pusher  55  are respectively inserted through the first pusher operation portion  59  and the second pusher operation portion  60 . 
     An operation upon using the suturing device  51  with the above-described configuration will be described with reference to  FIGS. 20 to 30 . 
     As shown in  FIG. 20 , a user first inserts the sheath  40  into the channel of the endoscope device  100  in a state where the sliders  57  and  58  are retracted such that the stopper  105  and the needle tubes  52  and  53  are received in the sheath  40 . Then, the endoscope device  100  is inserted into a patient&#39;s body so that the distal end of the endoscope device  100  moves up to a position in the vicinity of the treatment target portion. 
     Subsequently, the user advances the sliders  57  and  58  so as to protrude the stopper  105  and the needle tubes  52  and  53  from the sheath  40 . Then, the first regions R 1  and the second regions R 2  of the needle tubes  52  and  53  are restored by means of elasticity of super-elastic metal so as to be a shape before the needle tubes are received in the sheath as shown in  FIG. 21 . 
     The user positions the target tissue T 1  between the first needle tube  52  and the second needle tube  53  and retracts the sliders  57  and  58 . Then, as shown in  FIG. 22 , the needle tubes  52  and  53  are inserted into the target tissue T 1 , and the engagement protrusions  52 A and  53 A engage with each other in the inside of the target tissue T 1 , thereby forming the first needle tube  52  and the second needle tube  53  in a substantially annular shape. 
     Subsequently, in order to release the anchors, the user moves the engagement portion between the needle tubes  52  and  53  to the outside of the target tissue T 1 . At this time, the user may rotate the annular needle tubes  52  and  53  by operating the endoscope device  100  as shown in  FIG. 23 , or may move the engagement portion between the needle tubes  52  and  53  by advancing one slider (for example, the first slider  57 ) and retracting the other slider (for example, the second slider  58 ) as shown in  FIG. 24 . 
     When the engagement portion moves to the outside of the target tissue T 1 , the user advances the first pusher  54  by operating the first pusher operation portion  59  as shown in  FIG. 25 . The first anchor  106  and the second anchor  107  pushed by the first pusher  54  move in the inside of the first needle tube  52  toward the distal end so as to be close to the releasing protrusion  52 B. 
     Since the angle of the inclined surface on the side of the proximal end portion of the releasing protrusion  52 B is not more than the taper angle on the side of the distal end portion  106 B of the first anchor  106 , the distal end portion  106 B hardly comes into contact with the releasing protrusion  52 B, and the first anchor  106  smoothly moves toward the second needle tube  53 . 
     When the groove  106 A moves to the second needle tube  53  rather than the releasing protrusion  52 B, the proximal end portion  106 C having a larger diameter comes into contact with the releasing protrusion  52 B. As a result, as shown in  FIG. 26 , the releasing protrusion  52 B pushed by the proximal end portion  106 C moves so as to be separated from the second needle tube  53 , thereby releasing the engagement between the engagement protrusions  52 A and  53 A and releasing the first anchor  106  as shown in FIG  27 . At this time, in the case where the first anchor  106  remains in the second needle tube  53 , the first anchor  106  may be released by advancing the second pusher  55 . 
     After the user takes out the first needle tube  52  from the target tissue T 1  as shown in  FIG. 28 , the user reverses the entire suturing device  51  around an axial direction and, as shown in  FIG. 29 , locks the second anchor  107  on the target tissue T 2  in the same sequence. Then, as shown in  FIG. 30 , the user pulls the needle tubes  52  and  53  to the inside of the sheath  40  so as to move the stopper  105  toward the anchors  106  and  107 , thereby suturing the treatment target portion. Finally, when the user sufficiently retracts the first pusher  54 , the suturing unit  103  is separated from the suturing device  51 , thereby ending the surgical technique. 
     In the suturing device  51  according to this embodiment, since the anchors  106  and  107  are released from the distal end of the first needle tube  52  curved in a circular-arc shape, it is possible to carry out the accurate surgical technique while appropriately observing the distal end of the needle tube and the anchor by means of the endoscope device  100 . 
     When the internal configuration of the suturing device  51  according to this embodiment is modified, it is possible to further easily lock the anchor. Hereinafter, the modified example will be described. 
       FIG. 31  is an enlarged sectional view showing a portion in the vicinity of the distal ends of the needle tubes  52  and  53  of a suturing device  51 A which is a modified example of the suturing device  51 . Receiving protrusions  61  and  62  are circumferentially formed in the inner surfaces in the vicinity of the distal ends of the needle tubes  52  and  53 , respectively, so as to deliver and receive the anchors. The receiving protrusions  61  and  62  can engage with the grooves  106 A and  107 A of the anchors  106  and  107 , respectively. A length of each of the receiving protrusions  61  and  62  may be appropriately determined depending on strength for holding the anchors. Additionally, in the operation part  56 , as shown in  FIG. 32 , the first slider  57  is integrally formed with the second slider  58 . 
     An operation upon using the suturing device  51 A with the above-described configuration will be described. 
     In the same manner as the suturing device  51 , the needle tubes  52  and  53  are inserted in the target tissue T 1 , and the slider is advanced so that the needle tubes  52  and  53  engage with each other in an annular shape in the inside of the target tissue T 1 . Subsequently, when the first pusher  54  is advanced, as shown in  FIG. 32 , the groove  106 A of the first anchor  106  engage with the receiving protrusion  62  of the second needle tube  53 , and the first anchor  106  is delivered from the first needle tube  52  to be received in the second needle tube  53 . 
     When the user further pushes the first pusher  54 , as shown in  FIG. 33 , the proximal end portion  106 C of the first anchor passes over the releasing protrusion  52 B, thereby releasing the engagement between the needle tubes  52  and  53 . At the same time, the groove  107 A of the second anchor  107  engages with the receiving protrusion  61  of the first needle tube  52 . 
     When the user retracts the sliders  57  and  58 , as shown in  FIG. 34 , the first needle tube  52  and the second needle tube  53  are taken out from the target tissue T 1  in a state where the second anchor  107  and the first anchor  106  are respectively received in the vicinity of the distal ends of the needle tubes. Accordingly, the first anchor  106  which has been inserted from the first needle tube  52  into the target tissue T 1  passes through the inside of the target tissue T 1  and moves to the second needle tube  53 . Then, when the user advances the second pusher  55  so as to push the first anchor  106  from the second needle tube  53 , as shown in  FIG. 35 , the releasing operation of the first anchor  106  ends. 
     The user reverses the suturing device  51 A around an axial direction, and delivers the second anchor  107  to be received in the second needle tube  53  in the same sequence, thereby locking the second anchor on the target tissue T 2 . 
     In the suturing device  51 A, the first anchor  106  received in the first needle tube  52  is delivered to be received in the second needle tube  53  in the inside of the target tissue T 1  or the like. For this reason, it is possible that only the anchor penetrates the target tissue T 1  or the like so as to move toward the second needle tube  53  for a locking operation thereon without the first needle tube  52  penetrating the target tissue T 1  or the like. Accordingly, it is possible to further simply carry out the suturing operation. 
     Additionally, in the above-described suturing device  51 A, a case is exemplified in which the anchor is delivered and received in a state where the first needle tube  52  and the second needle tube  53  engage with each other. However, the anchor can be delivered and received without engaging both needle tubes with each other so long as the distal ends of the needle tubes are ensured to satisfactorily face each other. 
     Further, in the suturing device  51 A, since it is not necessary to expose the engagement portion between the needle tubes  52  and  53  to the outside of the target tissue T 1  unlike the suturing device  51 , as shown in  FIGS. 32 and 35 , no problem arises even when the first slider  57  is integrally formed with the second slider  58 . Although it is possible to further simply carry out the operation in this case, it is not essential that the suturing device  51 A have such configuration, and the sliders  57  and  58  may be configured to be independently slidable in the same manner as the suturing device  51 . 
     Furthermore, in the above-described suturing devices  51  and  51 A, the structures of the needle tubes  52  and  53  are not limited to the above-described structures. For example, like a modified example shown in  FIGS. 36 and 37 , the needle tubes  52  and  53  may be configured such that plural needle members  63  are rotatably connected to each other. 
     In this case, as shown in  FIG. 37 , one end of a tension wire  64  for holding the needle members  63  in the shapes of the needle tubes  52  and  53  is fixed to a needle member  63 A located on the side of the foremost distal end of each of the needle tubes  52  and  53  Then, the other end of the tension wire  64  extends up to each of the pusher operation portions  59  and  60  while passing through a guide  65  formed in the curved inner surface on the outer peripheral side of each needle member  63 , and is mounted with an operation handle  66  (see  FIG. 39 ). 
     At the time of using the suturing device, after the sliders  57  and  58  are advanced so as to protrude the needle members  63  from the sheath  40  as shown in  FIG. 38 , the tension wires  64  respectively connected to the needle tubes  52  and  53  are pulled toward the proximal ends by operating the handle  66 . Then, as shown in  FIG. 39 , the needle members  63  are held to be in the curved shape of the needle tubes  52  and  53 , which can be inserted into the target tissue T 1  or the like. 
     With such a configuration, when the tension wires  64  are pulled, the first regions R 1  of the needle tubes  52  and  53  becomes substantially rigid, and when the tension wires  64  are loosened, the first regions R 1  becomes substantially soft. As a result, it is possible to easily insert and extract the needle tubes  52  and  53  into or from the sheath  40  with a smaller force. Also, upon inserting the needle tube into the tissue, it is possible to further reliably carry out the puncture operation by allowing the needle tubes  52  and  53  to have sufficient rigidity. 
       FIG. 40  is a view showing a needle tube according to another modified example of the suturing device  51 .  FIGS. 41A ,  41 B, and  41 C are sectional views respectively taken along the line A-A, the line B-B, and the line C-C. As shown in  FIG. 41A , the distal end portion of the first region R 1  of the needle tube  67  applied with a large force upon being inserted into the tissue is formed by only a rigid member  68  made of metal such as stainless steel. In the remainder portion of the first region R 1  and the distal end portion of the second region R 2  required to have constant elasticity, as shown in  FIG. 41B , a part, for example, only the outer peripheral portion of the curved shape thereof is formed by the rigid member  68 , and the remainder portion is formed by a soft member  69  such as elastic resin. Then, the proximal end portion of the second region R 2  and the third region R 3  are formed by only the soft member  69 . Likewise, the needle tube  67  is formed so that a ratio of the rigid member  68  gradually decreases in a direction toward the proximal end. As a result, even when super-elastic metal is not used as material, it is possible to form the needle tube  67  having desired elasticity so as to be received in the sheath  40  and to be formed in a desired curve shape at a time when the needle tube protrudes from the sheath  40 . Such the needle tube  67  can be reliably formed by insert-molding or the like by means of the rigid member  68  formed in a shape shown in  FIG. 40 . Note that, in the above description, a position where the ratio of the rigid material changes is an example, and may be appropriately changed in accordance with rigidity or elasticity required for the needle tube  67 . 
     Next, a fourth embodiment of the invention will be described with reference to  FIGS. 42 to 48 . This embodiment provides a suturing system including an endoscope device, a suturing mechanism, and an endoscope forceps. In a suturing system  71  according to this embodiment, the endoscope device and the suturing mechanism may be appropriately configured as the endoscope device  100  and the suturing mechanism  33  described above, respectively, but the invention is not limited thereto. 
       FIG. 42  is a view showing an example of the endoscope forceps  72  used in the suturing system  71 . The endoscope forceps  72  include an insertion part  73  which is inserted into the body cavity, a gripping part  74  which is formed at the distal end of the insertion part  73 , and an operation part  75  which is provided in the proximal end portion of the insertion part  73 . 
     The insertion part  73  includes a soft portion  76  which has flexibility and a bending portion  77  which is rotatably supported by the distal end of the soft portion  76 . A rotation surface of the bending portion  77  is aligned to be in parallel to a direction where the gripping part  74  is opened or closed. The bending portion  77  is connected to a transmission member such as a wire, and extends up to the operation part  75  via the insertion part  73 . 
     The gripping part  74  includes a pair of jaws  74 A and  74 B. The transmission member such as the wire used to open or close the jaws  74 A and  74 B extends up to the operation part  75 . As shown in  FIGS. 42 and 43 , the jaws  74 A and  74 B are respectively provided with through-holes  78 A and  78 B which penetrate the jaws in the direction where the jaws  74 A and  74 B are opened or closed so as to communicate with each other, and slits  79 A and  79 B which respectively communicate with the through-holes  78 A and  78 B and extend up to the peripheral edges of the gripping surfaces of the jaws  74 A and  74 B facing each other. The inner diameters of the through-holes  78 A and  78 B are set to be smaller than the outer diameter of the sheath  40  of the suturing mechanism  33 , thereby prohibiting the entry of the sheath  40 . 
     Additionally, at least one of the jaws  74 A and  74 B is provided with a guide surface  80  which is formed in an inclined surface shape in which the opening peripheral edge of the through-hole located on the opposite side of the gripping surface becomes gradually deeper in a direction moving closer to the through-hole. The guide surface  80  may be provided in both jaws. 
     The operation part  75  includes a body  81  which is connected to the insertion part  73 , a slider  82  which is used to operate the gripping part  74 , and a bending operation portion  83  which is used to operate the bending portion  77 . The slider  82  is connected to the transmission member extending from the gripping part  74 . When the slider  82  is slid on the body  81 , it is possible to open or close the gripping part  74 . The bending operation portion  83  is configured as a bar-shaped member, and a center portion thereof in a longitudinal direction is rotatably supported by the body  81 . Both longitudinal end portions of the bending operation portion  83  are connected to the transmission members extending from the bending portion  77 . When the bending operation portion  83  is rotated, as shown in the drawing, it is possible to change a direction of the gripping part  74  by changing an angle formed between the bending portion  77  and the soft portion  76 . 
     An operation upon using the suturing system  71  with the above-described configuration will be described. Upon using the suturing system  71 , the suturing mechanism  33  and the endoscope forceps  72  are inserted into the channel of the endoscope device  100  so as to protrude therefrom as shown in  FIG. 44 . The timing when the suturing mechanism  33  and the endoscope forceps  72  are inserted may be the timing before or after the endoscope device  100  is inserted into the body cavity. 
     A user introduces the endoscope device  100  into a position in the vicinity of the treatment target portion, and grips the target tissue T 1  by means of the endoscope forceps  72  as shown in  FIG. 45 . At this time, the guide surface  80  is disposed so as to face the suturing mechanism  33 . 
     The user operates the bending operation portion  83  while gripping the target tissue T 1  so as to allow the gripping part  74  to face the suturing mechanism  33 . At this time, it is desirable that the needle tube  39  of the suturing mechanism  33  is received in the sheath  40  so as not to be erroneously inserted into the target tissue T 1 . 
     When the gripping part  74  faces the suturing mechanism  33 , the guide surface  80  moves to a position in front of the suturing mechanism  33 . When the user advances the sheath  40 , the distal end of the sheath  40  is guided by the guide surface  80  so as to be close to the through-hole  78 B, and the inner cavity of the sheath  40  communicates with the through-hole  78 B. When the user further pushes the sheath  40  in a forward direction, the distal end of the sheath  40  rotates together with the gripping part  74  about the proximal end of the bending portion  77 , and the distal end portion of the sheath  40  is curved so as to be substantially perpendicular to the axis of the endoscope device  100  as shown in  FIG. 47 . 
     When the user advances the slider  19  in this state, the needle tube  39  penetrates the target tissue T 1  via the through-hole  78 B as shown in  FIG. 48 , and passes through the through-hole  78 A to protrude therefrom. In this manner, it is possible to release the first anchor  106  to be locked on the target tissue T 1 . When the gripping state of the gripping part  74  is released after the anchor is locked thereon, the suturing thread  104  of the suturing unit  103  is separated from the gripping part  74  via the slits  79 A and  79 B. 
     In the suturing system  71  according to this embodiment, by gripping the target tissue with the endoscope forceps  72  having the bending portion  77 , the sheath  40  of the suturing mechanism  33  rotates together with the gripping part  74  so that the distal end portion is curved so as to be substantially perpendicular to the axis of the endoscope device  100 . As a result, since it is possible to release the anchor while reliably observing the distal end of the protruding needle tube  39  by means of the endoscope device  100 , it is possible to improve reliability of the anchor releasing operation. 
     Further, since the guide surface  80  is provided in the through-hole, even when a position of the through-hole slightly deviates from the axis of the suturing mechanism  33 , the distal end of the sheath  40  is reliably guided so that the inner cavity of the sheath  40  communicates with the through-hole. 
     Furthermore, since the diameter of the through-hole is set to be smaller than the outer diameter of the sheath  40 , it is possible to prevent a problem that the sheath  40  enters the through-hole so that the sheath is caught therein and is not separated therefrom. Accordingly, it is possible to further easily carry out the surgical technique. 
     Next, a fifth embodiment of the invention will be described with reference to  FIGS. 49 to 54 . A suturing system  91  according to this embodiment is different from the suturing system  71  according to the fourth embodiment in that a suction cap is used instead of the endoscope forceps. 
       FIG. 49  is a view showing a distal end portion of the suturing system  91  at the time of using. In the suturing system  91 , a suction cap  92  tied with the endoscope device  100  and inserted into the body cavity is used instead of the endoscope forceps  72 . 
     The suction cap  92  includes an insertion part  93  which is inserted into the body cavity, a cap part  94  which is mounted to the distal end of the insertion part  93 , and a suction tube  95  which is connected to the cap part  94 . 
     The insertion part  93  includes a bending portion  96 , and the cap part  94  can be operated so as to be curved toward the suturing mechanism  33  as shown in  FIG. 49 . 
     As shown in  FIGS. 49 and 50 , the cap part  94  is configured as a cylindrical member having a bottom, where through-holes  97 A and  97 B and thread-extraction slits  98 A and  98 B are formed at the same position as those of the gripping part  74  of the above-described endoscope forceps  72 . In the same manner as the through-hole  78 B, a guide surface  99  is formed in the through-hole  97 B in the side of the suturing mechanism  33 . 
     The distal end of the suction tube  95  is connected to a bottom surface of the cap part  94  so as to be opened to the inside of the cap part  94 , and the proximal end thereof is connected to a suction mechanism (not shown). Then, when the suction mechanism is operated, a negative pressure occurs in the inside of the cap part  94  so as to suck the tissue located inside the cap part  94 . 
     The suturing system  91  with the above-described configuration is capable of carrying out the releasing operation and the locking operation of the anchors in the substantially same sequence as that of the suturing system  71 . That is, as shown in  FIG. 51 , the bending portion  96  is operated so as to be curved toward the suturing mechanism  33  in a state where the target tissue T 1  is sucked by the cap part  94 . Then, the distal end of the sheath  40  comes into contact with the guide surface  99  as shown in  FIG. 52 , and then the needle tube  39  passes through the target tissue T 1  to release the first anchor  106  as shown in  FIG. 53 , thereby locking the first anchor  106  on the target tissue T 1  as shown in  FIG. 54 . 
     Even in the suturing system  91  according to this embodiment, it is possible to reliably release the anchors  106  and  107  while observing the distal end of the needle tube  39  penetrating the target tissue T 1  by means of the endoscope device  100  in the same manner as the suturing system  71 . 
     Note that, in the above-described fourth and fifth embodiments, a case is exemplified in which the suturing mechanism is inserted into the channel of the endoscope device. However, instead, the suturing mechanism may be attached to the outside of the endoscope device so as to be relatively movable with respect to the endoscope device in a longitudinal direction. 
     Next, a sixth embodiment of the invention will be described with reference to  FIGS. 55 to 58 . A suturing system  121  according to this embodiment is different from the suturing systems according to the above-described embodiments in that the distal end portion of the endoscope device as an observation member is movable up to a position where the needle tube of the suturing mechanism after penetrating the target tissue can be observed. 
       FIG. 55  is an overall view showing the suturing system  121 . Although the suturing system  121  includes the endoscope device  100  and the suturing mechanism  33 , the suturing mechanism  33  is not inserted into the channel of the endoscope device  100 , but is tied with the endoscope device  100  in a state where both insertion parts thereof are disposed in parallel to each other. 
     As shown in  FIG. 55 , the suturing mechanism  33  is inserted through a scope holder  122 , and the endoscope device  100  is inserted through a first guide  123  mounted to the scope holder  122  in a freely advancing and retracting manner. Then, an insertion part  101  of the endoscope device  100  is tied with the sheath  40  of the suturing mechanism  33  by means of auxiliary guides  124 . The number of the auxiliary guides  124  may be appropriately determined in accordance with a length of the insertion part  101  or the sheath  40 . Additionally, the auxiliary guide  124  may be fixed to any one of the insertion part  101  and the sheath  40 . 
     A scope fixing band  125  is mounted to the distal end portion of the insertion part  101 , and a suturing mechanism fixing band  126  is mounted to a position located at the distal end portion of the suturing mechanism  33  and located closer to the distal end than the scope fixing band  125 . The scope fixing band  125  is connected to the suturing mechanism fixing band  126  by means of a rigid link  127 . Both ends of the link  127  are pivotally supported by the scope fixing band  125  and the suturing mechanism fixing band  126 , respectively, in a freely rotating manner. The both ends of the link  127  are pivotally supported so as to rotate on the same plane. 
     An operation upon using the suturing system  121  with the above-described configuration will be described. First, the suturing system  121  is introduced into the body cavity, and the needle tube  39  is inserted into the target tissue T 1 . At this time, as shown in  FIG. 56 , since the distal end of the endoscope device  100  is located in the vicinity of the distal end of the sheath  40  in an initial state where the suturing mechanism fixing band  126  is located in front of (at a position closer to the distal end than) the scope fixing band  125 , it is possible to reliably observe the insertion operation of the needle tube  39 . 
     In a state where the needle tube  39  is located in the inside of the target tissue T 1 , the user pushes forward the endoscope device  100  while holding the scope holder  122 . Then, as shown in  FIG. 57 , the link  127  rotates about the end portion on the side of the suturing mechanism fixing band  126  such that the distal end of the treatment endoscope device  100 , to which the scope fixing band  125  is fixed, moves to a position in front of the distal end of the sheath  40 . 
     When the needle tube  39  penetrates the target tissue T 1  in this state, since it is possible to reliably observe the distal end of the needle tube  39  by means of the treatment endoscope device  100  as shown in  FIG. 58 , it is possible to reliably release the first anchor  106  or the like. 
     In the suturing system  121  according to this embodiment, when the sheath  40  of the suturing mechanism  33  is formed to have rigidity in which the sheath is not easily bent by the pushing operation and the rotation operation of the above-described treatment endoscope device  100 , it is desirable in that the distal end of the endoscope device  100  smoothly moves. Additionally, from the view point of reliably maintaining the insertion performance of the tied endoscope device into the body cavity, it is desirable that the endoscope device  100  is configured as a so-called thin scope in which the diameter of the insertion part  101  is about 5 to 8 mm. 
     Next, a seventh embodiment of the invention will be described with reference to  FIGS. 59 to 64 . A suturing system  131  according to this embodiment is different from the suturing systems according to the above-described embodiments in that the needle tube of the suturing mechanism protrudes in a different manner. 
       FIG. 59  is a perspective view showing the distal end portion of the suturing system  131 . The distal end of the sheath  40  of the suturing mechanism  33  is connected to a puncture cap  132  used for a mounting operation to the distal end of the endoscope device  100 . 
       FIG. 60  is a sectional view showing the puncture cap  132  along an axial direction. The puncture cap  132  includes an outer cylindrical body  133  and a suction cup  134  which is mounted to the inside of the cylindrical body  133 . 
     The cylindrical body  133  is configured as a substantially cylindrical member made of a resin or the like. When a fitting portion  133 A located on the side of the proximal end is fitted to the distal end of the treatment endoscope device  100 , both portions can be connected to each other. Additionally, a wall surface of the cylindrical body  133  is provided with a spiral needle tube channel  133 B, through which the needle tube  39  is inserted. The distal end of the needle tube  133 B is opened to the inner surface of the cylindrical body  133 . 
     The needle tube  39  according to this embodiment is made of super-elastic metal in the same manner as the above-described needle tube, and is curved in a spiral loop shape so as to be smoothly inserted through the needle tube channel  133 B. However, a region with a predetermined length, which protrudes in use from the distal end of the needle tube channel  133 B, is more curved than other regions of the loop. 
     The suction cup  134  is supported by an inner wall of the cylindrical body  133  via a support portion  134 A. When a proximal end  134 B of the suction cup  134  is inserted into the channel of the endoscope device  100 , the proximal end air-tightly comes into contact with the channel. Accordingly, when the suction cup  134  is connected to the channel, and the channel is connected to a suction device (not shown), it is possible to suck the tissue by means of the suction cup  134 . 
     It is desirable that the cylindrical body  133  and the suction cup  134  be made of a transparent resin or the like in order to reliably observe the tissue sucked by the suction cup  134  by means of the endoscope device. For example, polychlorinated biphenyl (PCB) having high transparency may be appropriately adopted. 
     An operation upon using the suturing system  131  with the above-described configuration will be described. A user first mounts the cylindrical body  133  to the distal end of the endoscope device  100  so that the proximal end  134 B of the suction cup  134  is connected to the channel of the endoscope device  100 , and inserts the suturing system  131  into the body cavity so that the distal end thereof moves to a position in the vicinity of the target tissue T 1 . 
     Next, the user pushes the cylindrical body  133  against the target tissue T 1  and operates the suction device, thereby sucking a part of the target tissue T 1  into the inside of the cylindrical body  133  by means of the suction cup  134  as shown in  FIG. 61 . Then, the user operates the slider  19  so as to advance the needle tube  39 . 
     The needle tube  39  advances in the inside of the needle tube channel  133 B of the cylindrical body  133 , and protrudes from an opening located in the distal end of the needle tube channel  133 B to the inside of the cylindrical body  133 . As described above, since the distal end portion of the needle tube  39  is more curved than other regions, as shown in  FIG. 62 , the distal end portion protrudes toward the axis of the puncture cap  132 . That is, the needle tube  39  protrudes in a direction where the needle tube is easily inserted into the part of the target tissue T 1  sucked by the suction cup  134 . 
     Accordingly, when the user further advances the needle tube  39  in a forward direction, as shown in  FIG. 63 , the needle tube  39  is inserted into the target tissue T 1  so as to penetrate the tissue. Since the needle tube  39  is inserted into the target tissue T 1  so as to penetrate the tissue in the inside of the cylindrical body  133 , the user is capable of visibly recognizing a series of movements of the distal end of the needle tube  39  in a reliable manner by means of the endoscope device  100 . 
     Subsequently, as shown in  FIG. 64 , the first anchor  106  is released from the needle tube  39  in the substantially same sequence as those of the above-described embodiments. When the needle tube  39  is taken out from the target tissue T 1  and the suction operation of the suction cup  134  is stopped, the operation of locking the first anchor  106  on the target tissue T 1  ends. 
     In the suturing system  131  according to this embodiment, the user is capable of reliably releasing the anchor just by sucking the target tissue T 1  by means of the suction cup  134  and operating the needle tube  39  by means of the slider  19 . Accordingly, since it is not necessary to carry out the second-stage operation in which the target tissue is gripped and then curved toward the suturing mechanism  33  unlike the suturing systems  91  and  121 , it is possible to further simply and reliably carry out the suturing operation including the releasing operation of the anchors. 
     In the above-described embodiments, a case is exemplified in which the target tissue T 1  is sucked and held by the suction cup  134 , but the target tissue may be held by other means. For example, the tissue may be directly sucked by the cylindrical body  133  or the target tissue may be gripped by the forceps or the like protruding from the channel of the endoscope device  100 . 
     Next, an eighth embodiment of the invention will be described with reference to  FIGS. 65 to 68 . A suturing system  141  according to this embodiment is different from the suturing systems according to the above-described embodiments in that the suturing mechanism is connected to the endoscope device in a different manner. 
       FIG. 65  is an overall view showing a configuration of the suturing system  141 . The suturing mechanism  33  is inserted through a cap sheath  143  of which a distal end is mounted with a lifting cap  142 . The lifting cap  142  includes a cylindrical body  142 A located on the side of the distal end and a sleeve  142 B located on the side of a proximal end. 
     Similar to the puncture cap  132 , the cylindrical body  142 A can be fixed to the endoscope device  100  by fitting the distal end portion of the endoscope device  100  to the cylindrical body. The sleeve  142 B is made of a soft material, and supports the cap sheath  143  so that the distal end is not separated from the endoscope device  100 . 
     A link fixing portion  144  is fixed to the distal end of the sheath  40  protruding from the cap sheath  143 . The link fixing portion  144  is connected to an outer peripheral surface of the cylindrical body  142 A via a rigid link  145  which is substantially equal to the link  127  of the suturing system  121 . The link  145  is movable with respect to the link fixing portion  144  and the cylindrical body  142 A. 
     An operation upon using the suturing system  141  with the above-described configuration will be described. A user first mounts the lifting cap  142  to the distal end of the endoscope device  100 , and inserts the suturing mechanism  33  into the cap sheath  143  form the proximal end. The insertion operation of the suturing mechanism  33  may be carried out after the endoscope device  100  and the cap sheath  143  are inserted into the body cavity. 
     Next, as shown in  FIG. 66 , the user grips the target tissue T 1  by means of an endoscope forceps  146  inserted through the endoscope device  100 . Since the endoscope forceps  146  does not include a portion such as the bending portion  77  of the endoscope forceps  72 , the endoscope forceps only moves straight to grip the target tissue T 1 . 
     In a state where the target tissue T 1  is gripped by the endoscope forceps  146 , the user pushes the suturing mechanism  33  toward the distal end while holding the cap sheath  143 , and advances the suturing mechanism  33  with respect to the cap sheath  143 . When the suturing mechanism  33  is further advanced, the link  145  rotates about an end portion thereof on the side of the lifting cap  142  such that, as shown in  FIG. 67 , the distal end of the sheath  40  moves to a position in front of the endoscope device  100 , and the opening on the side of the distal end faces the target tissue T 1  gripped by the forceps  146 . In this state, as shown in  FIG. 68 , the user operates the slider  19  so that the needle tube  39  penetrates the target tissue T 1  and then the first anchor  106  is released therefrom. 
     In the suturing system  141  according to this embodiment, when the suturing mechanism  33  is advanced, the distal end of the sheath  40  moves to a position in front of the endoscope device  100  by means of the link  145 , and so the needle tube  39  protrudes so as to be substantially perpendicular to the axis of the endoscope device  100 . Accordingly, it is possible to carry out the releasing operation of the anchor while reliably observing the distal end of the needle tube  39  after penetrating the target tissue T 1  by means of the endoscope device  100 . 
     Next, a ninth embodiment of the invention will be described with reference to  FIGS. 69 to 72 . A suturing system  151  according to this embodiment is different from the suturing systems according to the above-described embodiments in that a second observation member is provided in addition to the endoscope device. 
       FIG. 69  is a view showing a distal end portion of the suturing system  151 . The forceps  146  and the suturing mechanism  33  are inserted through the channels of the endoscope device  100 . A shaft member  154 , of which a distal end is mounted with a mirror  153  as a second observation member, is inserted through a cap  152  mounted to the distal end portion of the endoscope device in a freely advancing and retracting manner. The mirror  153  is mounted with an operation member such as a wire (not shown). When the operation member is operated, it is possible to adjust an angle formed between the mirror  153  and the shaft member  154 . 
     In the suturing system  151  with the above-described configuration, as shown in  FIG. 70 , it is possible to observe the distal end of the needle tube  39  penetrating the target tissue T 1  by seeing an image of the distal end reflected by the mirror  153  by means of the endoscope device  100 . Accordingly, it is possible to reliably release the anchors while visibly recognizing the distal end of the needle tube  39 . At this time, an angle formed between the mirror  153  and the shaft member  154  may be appropriately adjusted so as to obtain a satisfactory field of view. 
     Additionally, the second observation member is not limited to the mirror  153 , but may be, for example, a thin endoscope  155  shown in  FIG. 71 . Even in this case, as shown in  FIG. 72 , it is possible to further reliably release the anchors while observing the distal end of the needle tube  39  penetrating the target tissue T 1  by means of the thin endoscope  155 . 
     Next, a tenth embodiment of the invention will be described with reference to  FIGS. 73 to 78 . A suturing device  161  according to this embodiment is different from the suturing devices or the suturing systems according to the above-described embodiments in that the needle tube protruding from the sheath can be changed to a puncture shape described below. 
       FIG. 73  is a view showing a distal end portion of the suturing device  161 . A needle tube  162  has a distal end portion  162 A which receives the suturing unit  103  and is formed in a substantially circular-arc shape. Further, at a boundary  162 C between the distal end portion  162 A and a proximal end portion  162 B formed in a substantially linear shape, the distal end portion  162 A is inclined so as to form an angle a with respect to the proximal end portion  162 B. 
     As shown in  FIG. 73 , the angle a is an angle formed by a plane Q including the curved distal end portion  162 A and a plane P including an axis O of the proximal end portion  162 B, and is set to be larger than 0 in general, where an upper limit is set to 90°. In a state where the needle tube  162  protrudes from the sheath  40 , as shown in  FIG. 73 , the needle tube  162  is naturally deformed to a shape (hereinafter, referred to as “puncture shape”) suitable for the insertion operation into the tissue. 
     Further, when the needle tube  162  is received in the sheath  40 , as shown in  FIG. 74 , the needle tube  162  is deformed in a substantially linear shape in a degree that the sheath  40  basically formed in a substantially linear shape is not deformed. Also, flexibility of the needle tube  162  is maintained in a degree that the sheath  40  receiving the needle tube  162  can be inserted into the channel of the endoscope device  100 . In order that the needle tube  162  has such characteristics, the distal end portion  162 A of the needle tube  162  according to this embodiment is made of super-elastic alloy. 
     Furthermore, at the time when the needle tube  162  punctures the target tissue or the like as described below, since the whole part of the needle tube  162  rotates about a center axis of the proximal end portion  162 B, the proximal end portion  162 B is made of a material having torsion rigidity enough for a transmission of a rotary torque input from the operation part. 
     As a specific example, the proximal end portion  162 B may be configured as a super-elastic alloy pipe or the proximal end portion  162 B may be configured as a tubular member formed by a closely wound coil. It is possible to effectively improve torsion rigidity if the closely wound coil is formed by multiple thread winding method of winding multiple wires arranged in parallel or multilayer winding method of coaxially arranging multiple coils. 
     At the time when the needle tube  162  punctures the tissue, the user operates an operation part (not shown) so that the needle tube  162  rotates about the center axis of the proximal end portion  162 B and a distal end of the needle tube comes into contact with the target tissue T 1  as shown in  FIG. 75 . Subsequently, as shown in  FIG. 76 , the needle tube  162  is rotated to be inserted into or separated from the target tissue T 1  in the same manner as a general surgical operation in which the suturing operation is carried out by holding a curved needle by a needle forceps. Since the angle a is set to be more than 0° and equal to or less than 90°, it is possible to insert and separate the needle tube  162  into or from the target tissue just by rotating the needle tube  162  in an axial direction. Additionally, since the distal end portion  162 A of the needle tube  162  is inclined with respect to the center axis O of the proximal end portion  162 B, it is possible to insert or separate the needle tube  162  under the observation using the endoscope device  100 . Accordingly, in the same manner as the suturing devices and the suturing systems according to the above-described embodiments, it is possible to reliably carry out the suturing operation. 
       FIG. 77  is a view showing a suturing device  161  A according to a modified example of this embodiment. The received suturing unit  103  is omitted in the drawing. A needle tube  165  includes a distal end portion  165 A, a proximal end portion  165 B, and a middle portion  165 C between the distal end portion  165 A and the proximal end portion  165 B, and the respective portions are rotatably connected to each other by means of a first rotary pin  166  and a second rotary pin  167 . The middle portion  165 C can rotate about the first rotary pin  166  in the range that an angle formed between the proximal end portion  165 B and the middle portion  165 C is within the above-described angle a. In the same manner, the distal end portion  165 A can rotate about the second rotary pin  167  so that an angle formed between an axis of the side of the proximal end of the front end portion  165 A and the middle portion  165 C is within an angle β. An upper limit of the angle β may be set to 90° in the same manner as the angle α. 
     In the same manner as the modified example shown in  FIGS. 36 to 39 , the tension wire  64  is inserted through the inner cavity of the needle tube  165  and the pusher  13  is also inserted therethrough. The distal end of the tension wire  64  is fixed to an inner wall of the distal end portion  165 A. In the same manner as the modified example of the third embodiment, the tension wire  64  is inserted through the guide  65  formed in an inner wall of the middle portion  165 C and extends up to an operation part (not shown), provided at a region where the user&#39;s hand can approach, so as to be fixed to a handle (not shown). The tension wire  64  closer to the distal end than the guide  65  can be exposed from a notch (not shown) formed in an outer surface of the curved shape of the distal end portion  165 A. 
     At the time when the suturing device or the suturing mechanism having the needle tube  165  with the above-described configuration is inserted into the channel of the endoscope device, the needle tube  165  is received in the sheath  40  without applying a pulling force to the tension wire  64 . After the sheath  40  protrudes from the distal end of the endoscope device, when the needle tube  165  is made to protrude from the sheath  40  and the handle is pulled, the distal end portion  165 A rotates about the second rotary pin  167  by means of the tension wire  64  and collides with an end surface of the middle portion  165 C at an angle β to be held thereon. In the same manner, the middle portion  165 C rotates about the first rotary pin  166  and collides with an end surface of the proximal end portion  165 B at an angle α to be held thereon. In this manner, the needle tube  165  is deformed to the puncture shape by means of the user&#39;s operation. 
     In the above-described modified example, it is possible to maintain the needle tube  165  to be in a substantially rigid puncture shape by pulling the tension wire  64  via the handle, and to carry out the suturing operation with stronger force. 
     In the above-described modified example, as shown in  FIG. 78A , the needle tube may be formed so that both end portions of a groove  168 , formed in substantially parallel at the distal end portion  165 A of the needle tube  165 , are curled inward until colliding with each other. With this structure, the distal end portion of the needle tube becomes sharper and the outer diameter becomes smaller, thereby easily puncturing the target tissue or the like with a small force. 
     As described above, since the needle tube  165  is made of an elastically deformable material, as shown in  FIG. 78B , the distal end portion of the groove  168  is instantly pushed to spread in accordance with a passage of the anchor upon releasing the anchor, thereby ejecting the anchor  106  or the like. After the passage of the anchor, the needle tube  165  is restored by means of elasticity so as to have a shape before the anchor is released. 
     As described above, the first to tenth embodiments are described, and an important common point in the above-described embodiments of the invention is that the material of the needle tube has both suitable elasticity and rigidity. In the case where the needle tube has such elasticity and rigidity, in addition to the super-elastic alloy mentioned so far, for example, a resin material such as polyamide, polyetheretherketone (PEEK), polysulfone, or liquid crystal polymer (LCP) or a biocompatible ceramic material such as alumina or silicon nitride may be appropriately adopted. 
     As described above, the preferred embodiments of the invention are described, but the invention is not limited to the embodiments. Additions, omissions, substitutions, and other modifications can be made without departing from the spirit of the invention. 
     For example, in the above-described embodiments, there is described a case where the suturing unit is used in which the end portions of the suturing thread are mounted with two anchors, that is, the first anchor and the second anchor, but instead, the suturing unit may be used in which only one end portion of the suturing thread is mounted with one anchor. 
     In this case, the anchor penetrates two target tissues, facing each other with the treatment target portion interposed therebetween, at the same time so as to be locked thereon, the end portion of the suturing thread without the anchor is taken outside, and then an anchor is mounted to the end portion. Then, the anchor is introduced up to the treatment target portion along the suturing thread, and the suturing operation is carried out by means of the two anchors. 
     The invention is not limited to the foregoing description, but is limited by only the scope of the appended claims.