a preferred embodiment of the present invention will now be described by reference to fig1 through 3 . fig1 is a schematic view showing an endoscope apparatus with a surgical instrument for endoscope according to one embodiment of the present invention when the instrument is coupled a forceps channel of the endoscope apparatus , and fig2 is a longitudinal cross - sectional view showing an enlarged distal end portion of the surgical instrument for endoscope according to the present embodiment . fig3 a , 3b and 3c are explanatory views showing steps of using the surgical instrument for endoscope according to the present embodiment . as shown in fig1 an endoscope apparatus 11 is provided with an operation section 12 at the handgrip end thereof and an insertion section 13 formed from a flexible tube engaging with the operation section 12 . an end structure section 15 is coupled to the insertion section 13 by way of a curved section 14 for curving operation purposes . at the handgrip end of the operation section 12 there is provided a forceps insert socket 16 together with a curved operation knob , an air - and - water feed button , a suction button , and an eyepiece . one end of a channel not shown provided in the endoscope 11 connects to the forceps insert socket 16 , and the other end of the forceps channel couples to a forceps socket 17 formed in the end structure section 15 . a surgical instrument 18 for endoscope according to the present invention is provided with a sheath 19 inserted into the forceps channel through the forceps insert socket 16 of the endoscope apparatus 11 . the sheath 19 is constituted by a tube made of polymeric resin having an electrical insulating property such as , for example , ptfe and fep . the sheath 19 is designed to have flexibility sufficient to enter the forceps channel . at the handgrip end of the surgical instrument 18 for endoscope 18 there is provided a surgical instrument operation section 20 . a guide 22 extends longitudinally from an operation section body 21 of the instrument operation section 20 . a slider 23 is attached to the guide 22 to be slidable in a longitudinal direction thereof . a cock 24 protrudes from the side of the slider 23 , and a syringe not shown for injecting a fluid , such as a physiological salt solution , is to be attached to the cock 24 . the configuration of the distal end portion of the surgical instrument 18 for endoscope thus provided will be described in detail with reference to fig2 . a flexible tube 25 disposed inside the sheath 19 forms a channel for permitting flow of a fluid such as a physiological salt solution . the flexible tube 25 is formed from polymeric resin such as ptff , fep and the like . the flexible tube 25 may be formed from a material having an electrically insulating property . a fluid injection needle 26 is fixedly attached to the distal end portion of the flexible tube 25 . further , the handgrip end portion of the flexible tube 25 extends up to the surgical instrument operation section 20 and is fixedly coupled to the cock 24 . hence , a fluid can be poured into the flexible tube 25 from a syringe or the like fitted to the cock 24 . further , by sliding the slider 23 on the guide 22 , the flexible tube 25 and the fluid injection needle 26 can be operated to protrude from or retract into the end opening of the sheath 19 . one end of a metal wire 27 formed from a single or stranded wire connects to the fluid injection needle 26 by , e . g ., brazing , soldering , or adhesion by an adhesive . the end part of the wire 27 is imparted with a property of spreading into a substantially elliptical shape thereby constituting an resecting section 28 , so that the resecting section 28 spreads like a loop when it protrudes from the end opening of the sheath 19 . the other end of the wire 27 passes through the sheath 19 and secured to the slider 23 of the surgical instrument operation section 20 . the resecting section 28 can be retracted into the sheath 19 by sliding the slider 23 on the guide 22 . in short , when the slider 23 is operated to slide along the guide 22 , both the fluid injection needle 26 and the resecting section 28 are actuated to protrude from and retract into the end opening of the sheath 19 at the same time . the end portion of the sheath 19 , the fluid injection needle 26 and the resecting section 28 of the wire 27 constitute a surgical section 40 . the operation of the surgical instrument for endoscope having the foregoing configuration will now be described with reference to fig3 a , 3b , and 3c . first , the flexible tube 25 used for injecting a fluid and the wire 27 are inserted into the sheath 19 . further , the slider 23 of the surgical instrument operation section 20 is pulled back toward an operator . while the fluid injection needle 26 secured to the distal end of the flexible tube 25 and the resecting section 28 provided at the end portion of the wire 27 are retracted into the sheath 19 , the surgical section 40 of the surgical instrument 18 for endoscope is inserted into the body cavity through the forceps channel of the endoscope apparatus 11 . while the distal end of the sheath 19 of the surgical instrument 18 for endoscope is guided to the vicinity of a lesion q of tissue p , the slider 23 is pushed forward along the guide 22 . as a result , as shown in fig3 a , the fluid injection needle 26 is stuck into the area of the lesion q facing the surgical instrument for endoscope . a physiological salt solution r is poured into the lesion q from a syringe fitted to the cock 24 . next , as shown in fig3 b , a lesion q &# 39 ;, which has protruded as a result of the injection of a physiological salt water r , is fitted into the loop shaped resecting section 28 . next , as shown in fig3 c , the slider 23 is operated to slide back along the guide 22 toward the operator , whereby the fluid injection needle 26 and the resecting section 28 are retracted into the sheath 19 at the same time , thus resecting the lesion q &# 39 ;. on example of resecting the lesion employs a certain level of high frequency energy supplied to the wire 27 from a high frequency generation device . as described above , the surgical instrument for endoscope according to the present embodiment enables operations for resecting a lesion after having injected a fluid into the lesion and for removing the fluid injection needle by way of a single sliding operation of the slider 23 . accordingly , the operations are simplified , and the efficiency of strip biopsy can be improved . one modification of the present embodiment will now be described with reference to fig4 . fig4 is a longitudinal cross - sectional view showing the configuration of the distal end of a surgical instrument for endoscope according to a modification of the present embodiment . the same parts and components used in the foregoing embodiment and that of the modification are assigned the same reference numerals , and their explanations will be omitted here for brevity . one end of a metal wire 30 formed from a single or stranded wire is fixedly connected to the fluid injection needle 26 secured to the distal end of the flexible tube 25 which is provided in the sheath 19 of a surgical instrument 29 for endoscope . slip - prevention members 32 , which are small pins or needles , are provided at intervals along the inside of an resecting section 31 of the wire 30 which is imparted with a property of spreading into a substantially elliptical loop such a way as to protrude toward the center of the resecting section . the other end of the wire 30 is fixedly connected to the slider of the surgical instrument operation section , as in the case of the wire in the foregoing embodiment . the slip - prevention members 32 may be formed separately from the wire , and attached to the wire before the surgical instrument is assembled . according to the modified embodiment , when the resecting section 30 is fitted around a lesion that has been protruded , the resecting section can be prevented from slipping and , therefore , the operability of the surgical instrument can be improved more . according to the preferred embodiment of the invention as described above , one end of the wire 27 , 30 is connected to the fluid injection needle 26 while the other end of which is connected to the slider 23 of the surgical instrument operation section 20 . however , the invention is not limited thereto or thereby . for example , both the ends of the wire may be fixedly connected to the slider 23 of the surgical instrument operation section 20 to accomplish the purpose of the invention . the important point is , the wire should be connected to any part which moves or slides relative to the sheath 19 and to which high frequency can be applied . further , the fluid injection needle 25 may be formed from a material having a certain rigidity to make a sharp tip . one example of the material of the needle is metal , though the invention is not limited thereto . as has been mentioned above , the surgical instrument for endoscope according to the present invention enables operations for resecting a lesion after having injected a fluid into the lesion and for removing the fluid injection needle by way of a single sliding operation . as a result , operations can be simplified , and the efficiency of operations required by strip biopsy can be improved .
in a surgical instrument for endoscopes , one end of an resecting section of a wire to be used for resecting a lesion is fixedly connected to a fluid injection needle , and the other end of the same is fixedly connected to a surgical instrument operation section . as a result , the retraction of the fluid injection needle and the resection of the lesion can be carried out by means of a single operation for sliding the treatment instrument operation section .