| 摘要 |
This medical treatment instrument comprises: a sheath; a needle which is inserted through the sheath so as to be capable of advancing and retracting; and a stylet which is inserted through the needle so as to be capable of advancing and retracting and has a first outer diameter. The distal end portion of the needle is provided with a housing portion, a small-diameter portion provided at the proximal end of the housing portion and having a smaller inner diameter than the inner diameter of the housing portion, and a slit extending at least from the distal end of the housing portion to the proximal end of the small-diameter portion. The distal end portion of the stylet is provided with a large-diameter portion having a second outer diameter that is larger than the first outer diameter. The large-diameter portion is engaged with the small-diameter portion so that the width of the slit is increased and so that the small-diameter portion and the housing portion are elastically deformed to expand in the radial direction of the needle. |
