The present invention relates to an implantable apparatus for obtaining urinary control and emptying of the urinary bladder, thereby preventing from or treating involuntary urinary retention. In general terms, the apparatus comprises an expandable member adapted to be implanted inside the urinary bladder of the patient for discharging urine, and a control device for controlling the volume of the expandable member. The control device is adapted to be connected to the expandable member through the wall of the urinary bladder.
