PROBLEM TO BE SOLVED: To provide an indwelling needle for extracorporeal circulation capable of suppressing inconvenience accompanied by a sharp pain in time of puncture into a blood vessel.SOLUTION: An indwelling needle for extracorporeal circulation includes: an outer tube needle tip part 14 and a seal member 23 closing both end parts of a peripheral space 16 formed between the outer circumferential face of an inner needle 2 and the inner circumferential face of an outer tube needle 3 in a liquid-tight state, and closely holding the inner needle 2 in a slidable state opening parts 17 formed in the outer circumferential face of the outer needle 3, and communicating the inside of a blood vessel and the peripheral space 16 an outer tube needle connection part 15 for communicating the peripheral space 16 and one end of a blood circuit and an inner needle connection part 7 for communicating an internal space 2a of the inner needle 2 and the other end of the blood circuit. The inner needle 2 is held movably between a projection position in which a tip part is projected from the tip of the outer tube needle 3 and a storage position in which the tip is stored inside the outer tube needle 3, the inner needle 2 is punctured into the blood vessel in a state that the inner needle 2 is held in the projection position, and is moved to the storage position after the puncture, and the indwelling needle for extracorporeal circulation allows extracorporeal circulation of blood through the outer tube needle connection part 15 and the inner needle connection part 7.COPYRIGHT: (C)2014,JPO&INPIT【課題】血管への穿刺時に激しい痛みが伴う不都合を抑えられる体外循環用留置針を提供する。【解決手段】内針2の外周面と外筒針3の内周面との間に形成される外周空間16の両端部を液密状態に閉塞するとともに、内針2を摺動可能な状態で密着保持する外筒針先端部14およびシール部材23と、外筒針3の外周面に形成され、血管内と外周空間16とを連通する開口部17と、外周空間16と血液回路の一端とを連通させるための外筒針接続部15と、内針2の内部空間2aと血液回路の他端とを連通させるための内針接続部7と、を備え、内針2は、先端部が外筒針3の先端から突出された突出位置と、先端が外筒針3内に収納された収納位置との間で移動可能に保持され、内針2が突出位置に保持された状態で血管内に穿刺され、穿刺後に収納位置に移動されて、外筒針接続部15および内針接続部7を介して血液を体外循環可能にする。【選択図】図2
