A surgical instrument for creating a cavity in the human or animal body in view of inserting a medical device or for other purposes. The surgical instrument comprises a handle (1) and a head (2) whose upper surface (3) has the general shape of a ducks bill, the proximal portion being more upwardly prominent than the distal portion, both portions being in smooth continuity, and whose lower surface (6) of the head is flat. The limit between these surfaces forms a clearly marked, non-cutting blunt edge (7) for facilitating non traumatic penetration of tissues and/or dissection of tissue plans.
