A luminal endoprosthesis for treating aneurysms, particularly aneurysms located at an arterial bifurcation. One feature of the endoprosthesis is a tubular armature that can expand radially from a compressed state to an expanded state. A further feature of the endoprosthesis, when in the expanded state, is a lenticular head whom axis coincides with that of the tubular armature, and which can be inserted into an aneurysm pocket. A method of manufacturing such an endoprosthesis is also described.