[Notions of fluids mechanics useful for vascular surgeons (author's transl)]

With a few restrictions, the laws of fluid mechanics may give qualitative indications concerning the best type of surgical anastomosis. After recalling the basic principles of physics, the loss of physical capacity in various intestinal situations are considered, e.g. stenosis, enlargement, angulation, bifurcation. Even if this hemodynamic factor is not necessarily predominant, compared with other biological factors (state of the resistances beyond the anastomoses, the cardiac output, the state of blood coagulation) it can be shown what is geometrically advisable to overcome the mechanical causes of failure of an anastomosis.