Provided is a vascular anastomosis device by which blood vessels differing in vascular diameter can be successfully anastomosed.The vascular anastomosis device is provided with two pinned rings (21) configured from a flexible material and a pair of open/close ring retainers (22) for detachably retaining the two pinned rings (21), said ring retainers (22) being provided with a pinned ring-deforming means. An end of a blood vessel having a larger diameter is inserted into one of the pinned rings (21) and the vascular wall thereof is expanded outward by 90° and then pricked with pins. An end of a blood vessel having a smaller diameter is inserted into the other pinned ring (21) and the blood vessel having a smaller diameter is incised from the end section thereof along the long axis direction. Then, the two pinned rings (21) are deformed into the same ellipsoidal shapes by the pinned ring-deforming means, the short diameter of the ellipses being the same as the diameter of the blood vessel having a smaller diameter. The blood vessel having a smaller diameter is ellipsoidally opened and the vascular wall thereof is expanded outward by 90° and then pricked with pins. Next, the pins of the two pinned rings (21) are pricked into each others rings and thus the pinned rings are joined together.Linvention concerne un dispositif danastomose vasculaire par lequel des vaisseaux sanguins de diamètre vasculaire différent peuvent être anastomosés avec succès. Le dispositif danastomose vasculaire comporte deux anneaux à broches (21) faits dune matière souple et deux éléments de retenue danneau ouvert/fermé (22) pour retenir de façon détachable les deux anneaux à broches (21), lesdits éléments de retenue danneau (22) comportant un moyen de déformation danneau à broches. Une extrémité dun vaisseau sanguin ayant un plus grand diamètre est introduite dans lun des anneaux à broches (21) et la paroi vasculaire de celui-ci est expansée vers lextérieur de 90° puis piquée par les broches. Un
