Endoscopic treatment instrument

Abstract

The endoscopic treatment instrument is equipped with a pliable flexible sheath, an operating wire inserted to be freely advancible and retractable in said flexible sheath, a basket provided on the distal end of said operating wire and configured from multiple elastic wires, and a clasp provided at the distal ends of said elastic wires to tie the multiple elastic wires together. The region of said basket of maximum diameter in the radial direction is located closer to the clasp than the midway point in the central axial direction between the proximal end of the basket and the clasp. Each of the multiple elastic wires has a helical shape that is wound in the same direction over the entire length thereof and the winding pitch becomes gradually smaller when moving from the distal end of the operating wire towards the clasp.

Description

technical field [0001] The present invention relates to a treatment instrument for endoscope. [0002] This application claims priority based on US Patent Application No. 61 / 474833 filed on April 13, 2011 provisionally in the US, and the content thereof is incorporated herein. Background technique [0003] Conventionally, there are known endoscopic treatment instruments that are inserted endoscopically into the body to grasp foreign bodies such as calculi that occur in the biliary tract or the like. For example, Patent Document 1 discloses a cage-shaped basket composed of a plurality of elastic threads having creases. The basket described in Patent Document 1 can hold a stone by taking the stone into the inside from the gap between the plurality of elastic wires and locking the stone on the elastic wires. [0004] In addition, Patent Document 2 discloses a basket-shaped grasping forceps as another example of an endoscopic treatment instrument for grasping stones. Patent D...

AI Technical Summary

Problems solved by technology

[0007] However, in the case of dilation of the bile duct near the duodenal papilla, if a foreign substance such as a stone enters the dilated part of the bile duct, due to the difference in the inner diameter between the bile duct near the duodenal papilla and the duodenal papilla Larger than usual, thus creating a larger than usual step at the border between the bile duct and the duodenal papilla near the duodenal papilla

In the conventional baskets disclosed in Patent Document 1 and Patent Document 2, when pulled into the duodenal papilla, they are deformed so as to shrink as a whole, so that the elastic wires of the basket sometimes have difficulty reaching the expansion part.

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