PROBLEM TO BE SOLVED: To provide a surgical tool capable of safely and securely preventing leakage of fluid under pressure without damaging a blood vessel in a vasodilation surgery, and a vasodilatation device composed of the surgical tool and an insertion tube.SOLUTION: A vasodilatation device includes an insertion tube 10 and a surgical tool 20. The insertion tube 10 includes a step formed in a shape that a connection 15 is smaller in diameter than that of an insertion tip 11. The surgical tool 20 includes a first recess 26a recessed in an arc shape formed on a first holding member 26, a second recess 27a recessed in an arc shape formed at a position corresponding to the first recess 26a on a second holding member 27, a retention mechanism 24 to keep a closed state of the first holding member 26 and the second holding member 27. In the state where the first holding member 26 and the second holding member 27 are closed, a diameter of a blood vessel holder 23 formed with the first recess 26a and the second recess 27a is substantially equal to that of the connection 15 at the step.SELECTED DRAWING: Figure 4COPYRIGHT: (C)2016,JPO&INPIT【課題】血管拡張の手術において、血管を損傷させることなく安全で確実に加圧による液体の漏れを防ぐことができる手術器具、並びに手術器具及び挿入管からなる血管拡張器具を提供すること。【解決手段】挿入管10と手術器具20とを備える血管拡張器具であって、挿入管10は、挿入先端部11側の外径よりも接続部15側の外径が小さく形成された段差部を備え、手術器具20は、第1挟持部材26に形成される円弧状に凹んだ第1凹部26aと、第2挟持部材27における第1凹部26aに対応する位置に形成される円弧状に凹んだ第2凹部27aと、第1挟持部材26及び第2挟持部材27の閉状態を保持する保持機構24と、を備え、第1挟持部材26及び第2挟持部材27の閉状態において第1凹部26a及び第2凹部27aにより形成される血管挟持部23の径は、段差部における接続部15側の外径と略等しく形成される。【選択図】図4
