Patent ID: 7854739
Filing Date: 2010-12-21
Classification: A61B

Abstract:
1. A clip apparatus for ligaturing a living tissue, comprising: an insertion part which can be inserted into a forceps channel of an endoscope inserted into a body cavity of a living tissue, and which includes a longitudinally extending passage extending along a longitudinal direction thereof; a clip unit which includes a clip having slender arms capable of elastically opening and closing distal end portions thereof around mutually connected proximal ends thereof, and which can be projected from and retracted into the passage of the insertion part through an opening at a distal end portion of the insertion part; and a clip operating part which extends in the passage of the insertion part, which includes an external operation portion exposed at a proximal end portion of the insertion part and a clip connecting portion connected to the clip unit, and which operates the projection and retraction of the clip by the external operation portion; the clip unit including: a clip holding member which is housed in the passage of the insertion part to project from and to be retracted into the passage through the opening at the distal end portion, and which has a clip projecting/retracting passage in which the clip is housed to project from and to be retracted into the clip projecting/retracting passage so that the slender arms of the clip open and close the distal end portions thereof elastically; an engaging portion, which is cut out from a circumferential wall of the clip holding member to be connected only at its one end to the circumferential wall of the clip holding member, which can open and close elastically around the one end thereof in a radial direction of the clip projecting/retracting passage between an open position and a closed position, and which opens and closes elastically by the projection and retraction of the clip holding member from and into the passage of the insertion part, a rear end of the engaging portion engaging with an end of the distal end portion of the insertion part to prevent the retraction of the clip holding member into the passage through the opening at the distal end portion of the insertion part while the engaging portion opens at the open position, and a connecting member which is movably housed in the clip projecting/retracting passage of the clip holding member, which has a distal end portion, a proximal end portion, and a breakable portion between the distal end portion and the proximal end portion, the distal end portion being connected to the proximal ends of the clip, the proximal end portion being connected to the clip connecting portion of the clip operating part, and the breakable portion being off to and in parallel with a longitudinal center line of the clip projecting/retracting passage in the radial direction of the clip projecting/retracting passage, and in which a deviating force is generated in the distal end portion to direct the distal end portion outward in the radial direction of the clip projecting/retracting passage around the breakable portion when a pulling force over a predetermined value is applied to the clip and the clip operating part, and the clip apparatus further comprising: an engaging portion excessive opening preventing structure which prevents the engaging portion from opening over the opening position while the distal end portion of the connecting member is directed outward in the radial direction of the clip projecting/retracting passage around the breakable portion by the deviating force; wherein the engaging portion excessive opening preventing structure includes an opening restriction portion which projects from the rear end of the engaging portion and which has an abutting region configured to abut a part of an inner periphery of the passage near the opening of the passage at the distal end portion of the insertion part while the engaging portion opens at the open position; and the breakable portion of the connecting member is configured by cutting a part of an outer periphery of the connecting member between the distal end portion and the proximal end portion in a diametrical direction of the clip holding member to cross an extending direction of the clip projecting/retracting passage.