US Patent 6863674 Operating trocar

An operating trocar according to the invention includes a guide tube inserted through a body surface to introduce an endoscope and an operating instrument into a living body, and a flange portion provided on the guide tube to make a predetermined angle with a plane approximately perpendicular to an axial direction of the guide tube, the flange portion being fixed to an outer surface of the body surface. Preferably, the operating trocar also includes a gastightness retaining portion provided in the guide tube to retain gastightness between a circumferential surface of an internal hole of the guide tube and a medical instrument such as an endoscope and an operating instrument inserted in the internal hole of the guide tube.