Abstract: Implantable prosthesis fulfilling the natural functions of the oesophagus, characterized in that it consists of a double-walled tube of circular cross-section in its midportion and of elliptical cross-section towards its extremities, the exterior wall being made of a relatively rigid hemocompatible synthetic material and the interior wall being made of a flexible hemocompatible synthetic material providing a perfectly smooth internal surface, a helicoidal band of relatively elastic material being inserted between the two walls in the midportion of said tube.