PROBLEM TO BE SOLVED: To provide an extracorporeal circulation indwelling needle capable of easily bending a portion to be placed in a blood vessel.SOLUTION: The extracorporeal circulation indwelling needle includes: a first seal part 31 for closing, into a liquid-tight state, an interval between a rear end of an outer peripheral space 13 and a rear end of an inner space 11a formed between an inner tube 11 and an outer tube 12 a second seal part 32 closely holding an inner needle 2 such that the needle can be inserted/removed freely an outer peripheral opening part 17 formed on the outer peripheral surface at the distal end side of the outer tube 12 for communicating the inside of the blood vessel to the outer peripheral space 13 a first connection part for communicating the outer peripheral space 13 to one end of a blood circuit and a second connection part for communicating the inner space 11a to the other end of the blood circuit. The inner needle 2 is punctured in the blood vessel, with a puncture part 2a projected from the distal opening of the inner tube 11, and after the puncture, the inner needle 2 is removed from the inner space 11a and the second seal part 32.SELECTED DRAWING: Figure 4COPYRIGHT: (C)2016,JPO&INPIT【課題】血管内へ留置する部分を曲げ易くすることができる体外循環用留置針を提供する。【解決手段】内側管部11と外側管部12との間に形成される外周空間13の後端部と内部空間11aの後端部との間を液密状態に閉塞する第1シール部31と、内針2を挿脱可能な状態で密着保持する第2シール部32と、外側管部12の先端側の外周面に形成され、血管内と外周空間13とを連通する外周開口部17と、外周空間13と血液回路の一端とを連通させる第1接続部と、内部空間11aと血液回路の他端とを連通させる第2接続部とを備え、内針2が穿刺部2aを内側管部11の先端開口から突出した状態で血管内に穿刺され、穿刺後に内針2が内部空間11aおよび第2シール部32から抜去される。【選択図】図4
