Hemostatic clipping devices and methods
A tissue clipping apparatus, comprises a flexible, elongate member, a proximal end of which remains external to the body accessible to a user while a distal end of the flexible member is inserted into the body to a location adjacent to target tissue to be clipped and a control wire extending through the flexible member in combination with a capsule releasably coupled to a distal end of the flexible member and a clip a proximal portion of which is received within the capsule. A joint releasably coupling the clip to the control wire, includes a yoke extending around a proximal end of the clip and a frangible link which fails when subject to a predetermined force to separate the clip from the control wire.
1. A tissue clipping apparatus, comprising:
a flexible insertion member extending from a proximal end which, in an operative configuration, remains outside a body accessible to a user to a distal end which is inserted into the body through a naturally occurring body lumen;
a clip including first and second clip arms, the clip aims bent along a curve to bias proximal and distal ends thereof radially away from one another, curves of a proximal portion of the clip arms forming a pocket therebetween;
a capsule housing a portion of the clip therein;
a control wire extending through the flexible insertion member from a proximal end to a distal end, the control wire operable to move the first and second clip arms between an open configuration in which distal ends of the first and second clip arms are separated from one another and a closed configuration in which the distal ends of the first and second clip arms are drawn together to grip tissue located therebetween; and
a joint releasably coupling the distal end of the control wire to the clip arms, the joint forcing the proximal ends of the first and second clip anus towards one another against the natural bias of the first and second clip arms, the joint configured to be separated from the first and second clip arms when subjected to a predeteimined force by the control member releasing the proximal ends of the first and second clip arms to spring radially outward away from one another to engage a portion of the capsule.
2. The apparatus of claim 1 , wherein each of the first and second clip arms includes a locking tab at the proximal end thereof.
3. The apparatus of claim 2 , wherein the capsule includes at least one locking feature configured to lockingly engage the locking tab when the first and second clip aims are separated from the control member to lock the clip within the capsule with the first and second arms in the closed configuration.
4. The apparatus of claim 1 , wherein the joint is a wire loop.
5. The apparatus of claim 4 , wherein proximal portions of the first and second clip arms each include an opening through which the wire loop is passed to couple the control wire to the clip.
6. The apparatus of claim 1 , further comprising a locking mechanism configured to lock the control wire within the distal end of the flexible insertion member once the control wire is separated from the clip.
7. The apparatus of claim 1 , further comprising a bushing coupled to the distal end of the flexible sheath and releasably coupled to the proximal end of the capsule.
8. The apparatus of claim 7 , wherein the flexible sheath is formed as a coil shaft defining a lumen through which the control member extends, a proximal end of the bushing being coupled to a distal end of the coil shaft.
9. A method for treating tissue, comprising:
inserting a clip to a target area within a living body adjacent a target tissue, the clip including first and second clip arms, the first and second clip arms bent along a curve to bias proximal and distal ends thereof radially away from one another, curves of a proximal portion of the first and second clip anus forming a pocket therebetween;
moving a control member coupled to the clip distally to move the clip from the closed configuration to the expanded configuration, wherein the control member is coupled to the clip via a separable joint, the joint forcing the proximal ends of the first and second clip arms towards one another against the natural bias of the first and second clip arms, the joint configured to be separated from the first and second clip arms when subjected to a predetermined force by the control member;
positioning the clip so that target tissue to be clipped is positioned between distal ends of the first and second clip arms;
moving the control member proximally to draw the first and second clip arms to the closed configuration to grip the target tissue; and
exerting an additional proximal force on the control member to separate the joint from the clip arms, separating the clip from the control member.
10. The method of claim 9 , wherein the joint is a wire loop.
11. The method of claim 10 , wherein proximal portions of the first and second clip arms each include an opening through which the wire loop is passed to couple the control wire to the clip.
12. The method of claim 9 , wherein each of the first and second clip aims includes a locking tab at the proximal end thereof.
13. The method of claim 9 , wherein the capsule includes at least one locking feature configured to lockingly engage the locking tab when the first and second clip arms are separated from the control member to lock the clip within the capsule with the first and second arms in the closed configuration.