[A case of emergency operation of entrapped intra-aortic balloon].

We report a case of emergency operation for entrapped intra-aortic balloon. The cause of entrapment of balloon was formation of a clot inside the balloon, which necessitated surgical removal. When intra-aortic balloon rupture by contact of calcific atheromatous plaque, the alarm is not often triggered. In this case, perforation is diagnosed by the presence of blood in the tube connecting the balloon. It is recommended that the balloon should be removed at the presence of blood in the tube.