This is a prospective, single-centre, observational clinical study. Patients who have not expressed their non-opposition, who are of age and who are undergoing open surgery on the abdominal aorta by laparotomy will be included. The aim is to mathematically model the working volume for abdominal aortic surgery as a function of the preoperative CT scan, the length and orientation of the incision and the morphometric characteristics of the patient, and thus predict the surgical risk. To meet this objective, the dimensions of the working volume of open abdominal aortic surgery will be measured using a camera to create an algorithm by associating them with the preoperative images and morphometric data of the patient.