Proust and his team of Auto-chir (ACA n o 17). Leriche was asked by the Lyon histologist and radiobiologist Claudius Regaud to enter the training he was preparing for to serve as a "School of Medicine and War Surgery in HOE 4 de Bouleuse, near Reims. It became such a renowned centre of instruction and improvement for all physicians and surgeons who passed it that it was decided to admit into active formation the newly-arrived Americans. René Leriche found several great names in medicine: the brilliant specialist in thoracic surgery Jean-Louis Roux-Berger (well ahead of what was done elsewhere), Lemaître who will remain the creator of the primitive suture of the wounds, the neurologist Georges Guillain, Lyon radiologist Thomas Nogier and pathologist Pierre Masson. However, he had the support for assistant Paul Santy and convert for his department of fractures and joint lesions. A young doctor, freshly arrived, hastened to meet him: Georges Duhamel. With the help of Paul Santy, Leriche undertook very extensive research work on osteogenesis and was particularly interested in repairing fractures with experiments carried out on rabbits, and he was already pursuing scholarly reflections on the role of vasa motricity in the site of trauma. That required many cuts histological and as many X-rays or photographs, but the environment and the organization of the very large 3,000-bed field hospital permitted it. He became chief surgeon on 28 December 1917. During the war, Leriche's idea was to differentiate the traditional white linen in which the wounded were brought from the laundry of the aseptic surgical operating rooms. He chose blue and had the surgical rooms painted blue. All the linen of the operating rooms is also blue: operating linen, casaques, caps, masks. The colour would be adopted worldwide, and the convention will make it possible to minimise infectious contamination. Interwar period He became a surgeon of the hospitals in Lyon in 1919. A stay in the United States allowed for him to meet Simon Flexner (who advocates "smooth" surgery) at the Rockefeller Foundation and then William Halsted in Baltimore but a number of surgeons also had an influence on him. In 1924, he was the holder of the chair at The University of Strasbourg, who responded to the call of the dean Georges Weiss after the death of Louis Sencert. He introduced the important notion of non aggressive surgery. In 1925, during his inaugural lecture at the