Catheter for chest drainage and chest drainage system

A catheter for chest drainage intended for removal of excess fluid from a chest space of a living body and to be placed in the living body in such a manner as to extend from an inside of the chest space to an outside of the living body, the catheter comprising:

• a passage member having a passage through which the excess fluid is to be drained;
• and
• an indwelling member provided at a proximal end of the passage member, the indwelling member
• having an inlet that allows the excess fluid to flow through, and
• a retaining portion having a flange shape and a plate shape facing perpendicular to the passage member at normal times,
• wherein the passage member is collapsed in a flat sheet-like shape at normal times when the passage member is not used to drain the excess fluid,
• wherein the retaining portion is formed of an elastic body and is elastically bent to face in a horizontal direction with respect to the passage member and elastically foldable into a sheet while being inserted into the living body, and spreads in a flange shape perpendicularly with respect to the passage member with restoring force exerted by the rubber elastic body forming the retaining portion after being inserted into the living body and is retainable at a chest wall.