PROBLEM TO BE SOLVED: To provide a trocar section of a trocar with the composition in the periphery of an instrument insertion opening being extremely compact without deteriorating the performance of a means retaining the airtightness of the instrument insertion opening.SOLUTION: The trocar section of the trocar includes: an annular sealing member 14 for sealing the instrument insertion opening to be airtight when the instrument is inserted a truncated cone shaped lid body 12 for opening/closing the instrument insertion opening and a connection member 17 for connecting a connection portion on an end surface of the instrument insertion opening and an end surface in the opening direction of the lid body. In this case, a connection member is composed by a flexible member having a shape supporting the lid body above the instrument insertion opening when the instrument insertion opening is opened and taking a shape extending from the connection portion along the axial direction of the instrument insertion opening, curving and extending to the end section of the lid body when the instrument insertion opening is sealed by the lid body.COPYRIGHT: (C)2012,JPO&INPIT【課題】器具挿入口の気密性を保持する手段の性能を劣化させることなく器具挿入口の周囲の構成が極力コンパクトなトロカーの外套管部を提供する。【解決手段】トロカーの外套管部において、器具挿入時には器具挿入口を気密に塞ぐ円環状の密着部材14と、器具挿入口を開閉するための円錐台状の蓋体12と、器具挿入口の端面上の接続部位と蓋体の開方向側端面とを接続する接続部材17とを設け、器具挿入口の開放時には蓋体を器具挿入口の上方において支持し、器具挿入口を蓋体が閉塞しているときには前記接続部位から器具挿入口の軸方向に沿って伸び、湾曲し、そして蓋体の端面に至る形状を呈する可撓性の部材により接続部材を構成する。【選択図】図2
