Endoscopic puncture needle and method of acquiring tissue from a target region by using the endoscopic puncture needle

An endoscopic puncture needle, comprising:

• a sheath having flexibility;
• a hollow outer needle which is movable along an axial direction of the sheath in the sheath and whose a distal end is retractable with respect to a distal end of the sheath;
• an outer needle moving mechanism disposed at a proximal end of the outer needle and moving the outer needle with respect to the sheath;
• an inner needle which moves along the axial direction of the sheath in the outer needle and is retractable with respect to the distal end of the outer needle;
• an inner needle moving mechanism disposed at a proximal end of the inner needle and moving the inner needle with respect to the outer needle;
• an operation portion disposed at a proximal end portion of the sheath and operating the outer needle moving mechanism and the inner needle moving mechanism;
• a duct which runs through an inner space of the outer needle and an inner space of the outer needle moving mechanism and communicates with the operation portion;
• and
• a packing material which is positioned in the operation portion and which air-tightly holds the duct at all times;
• wherein the packing material includes:
• a seal member having a through hole through which the inner needle moving mechanism is inserted;
• and
• an engagement mechanism which is positioned on the seal member and is engaged with the operation portion.