Abstract: The invention relates to an endothelized artificial matrix comprising a fibrin gel, which is a superproducer of proantiogenic factors. The inventive matrix comprises a fibrin gel containing embedded endothelial cells which have been transfected in vitro with at least one adenoviral vector containing the sequence encoding at least one proangiogenic factor, which is inserted such that it can be overexpressed in said endothelial cells. The insertion of the aforementioned matrix between a flap and the receptor site thereof during a transplant procedure improves the survival rates of said flap, since the endothelized matrix can induce angiogenesis both in the flap and in the receptor site and, in this way, improve the vascularization of the transplanted area.