The present invention relates to a surgical instrument (1) for deploying a prosthesis (200) and includes a first layer and second layer assembled together so as to define an internal space accessible to said surgical instrument (1) by means of an opening provided in said first layer, said surgical instrument including at least one sheet (2) made of a flexible resilient material, said sheet continuously overlapping itself one or more times so as to define a plurality of levels forming a spiral (3). The invention also relates to a kit including such a surgical instrument and such a prosthesis.