The invention relates to a surgical device (10), comprising a tubular outer shaft (12,) and an inner element (14) having an elongated shape, the outer shaft comprising a distal (30a) and a proximal (30b) outer hinges, the inner element comprising an inner hinge (80),the surgical device having : a first and a second distal stiffnesses considered at the distal outer hinge ; and a first and a second proximal stiffnesses considered at the proximal outer hinge ; each of the second distal and proximal stiffnesses being superior to, respectively, the first distal and proximal stiffness ;the inner element being able to move angularly and/or axially in the tubular outer shaft, between a first configuration and a second configuration,so that in the first configuration, the surgical device has the second distal stiffness and the first proximal stiffness.