Improved endoprosthesis (100) for a total vascular exclusion of the liver (120), to be used in most critical surgical operations like in example in major hepatectomy and in hepatic trauma with relevant venous damage, characterized in that comprising: - an endovenous catheter (101), having the shape of a cylinder extended longitudinally, and being flexible in the transversal direction in order to be inserted preferably from the femoral vein or saphena vein (114), directed to the inferior caval vein (102)； said endovenous catheter (101) having a diameter in the order of the inner diameter of the same femoral vein or saphena vein (114)； - a self-expanding sheet (103), rolled around itself and fixed at the distal part (133) of said endovenous catheter (101), characterized in that: - said sheet (103) is achieved by using a shape memory alloy, having two states: a first state having a shape rolled around itself (131a), called martensite, associated to a first temperature T1, and a second state having an expanded shape (131 b), called austenite, associated to a second temperature T2, - said endoprosthesis (100) comprises means of heat generation and/or transmission, between said endovenous catheter (101) and said self-expanding sheet (103), and means of respective warming up or cooling down of said sheet (103)； at said second temperature T2, the self-expanding sheet (103) changes its shape and achieves automatically the expanded shape (131 b), adapting itself perfectly to the surface of the caval vein, maintaining therefore the function of blood flowing back to the heart； at said first temperature T1, the self-expanding sheet (103) changes its shape and achieves automatically the shape rolled around itself (131a), facilitating its reinsertion into the distal part (133) of said endovenous catheter (101), so that, under control of an operator, the endovenous catheter (101) is firstly installed by insertion from the femoral vein or saphena vein (114) directed to the caval vei
