PROBLEM TO BE SOLVED: To provide a vitrectomy surgical instrument for efficiently and conservatively (gently) removing a vitreous body from an eye, specifically, the inside of a body.SOLUTION: A vitrectomy device (1) or vitrectomy tool (1) includes a hollow needle (2), which is specifically a cannula (2), including a cylindrical wall surrounding a cavity of the hollow needle (2). The hollow needle (2) is closed by an end surface of a distal end (5) disposed in a longer direction of the hollow needle (2). The hollow needle (2) includes a vitrectomy opening (6) whose opening normal line is arranged so as to be in a radial direction and in a direction crossing the longer direction. The vitrectomy opening (6) is at a given minimum distance from the distal end (5) and has an opening cross-sectional region in the longer direction, a direction crossing the longer direction (L), or a circumferential direction (U), the opening cross-sectional region being slender, having at least partially curved shape, and, more specifically, having an elliptical shape.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2020,JPO&INPIT【課題】効率的で保守的に（優しく）眼、具体的には体内から硝子体を取り除く硝子体切除用の手術器具を提供する。【解決手段】硝子体切除装置（１）又は硝子体切除具（１）は、中空ニードル（２）、具体的にはカニューレ（２）であって、中空ニードル（２）のキャビティを囲む円筒壁を含み、中空ニードル（２）は、中空ニードル（２）の長手方向に配置された遠位端（５）の端面で閉じられており、中空ニードル（２）は、その開口法線が半径方向に、かつ長手方向を横切る方向に配置された硝子体切除開口（６）を含み、硝子体切除開口（６）は、遠位端（５）から所与の最小距離を有し、長手方向、長手方向（Ｌ）を横切る方向、又は円周方向（Ｕ）の開口断面領域は、細長く、少なくとも部分的にカーブ形状を有し、より具体的には楕円状をなす形状を有する。【選択図】図１
