The present invention relates to a surgical device (1) comprising: an elongate, flexible and tubular arm (3) having a distal end and a proximal end; a flexible pulling means (6) which is arranged inside the arm (3); a tool (4) which is arranged at the distal end of the arm (3) and which comprises at least two parts (11,12), which are operable by said pulling means (6); and an operating means (15) which is arranged at the proximal end of the arm to operate said pulling means (6) and, thus, said tool (4). The invention is characterised in that said arm (3) is made of a material, which resumes its shape by heating and which has a transformation temperature which allows the arm (3) to be deformable to the desired shape at room temperature and to keep the thus obtained shape at a patient's body temperature during use of the device (1), so as then to allow resumption of its original shape when exposed to a temperature exceeding the body temperature.