Abstract: The balloon is fixed to a catheter close to its distal portion; the catheter has two ducts passing through within in; one duct can be used for a guide wire, while the other is used to pump air in or out; after passing through the catheter, the air emerges from a hole in the wall of the distal portion of the catheter, within the balloon; the distal portion of the catheter emerging from the balloon is rigid and slightly curved with respect to the axis of the catheter so that, when used, the distal portion—fitted with a sphere at the very tip—is curved upwards; the sides of the inflatable balloon are of varying thickness so that, when inflated, it takes on the form of a mattress; its inflation enables the detachment without trauma of two layers of tissue.