The invention relates to a vascular prosthesis (1) for forming an anastomosis, including: a first tube (2) comprising: a sealed wall (21) forming a channel between first and second openings (23, 24), and a stent (22) rigidly connected to the sealed wall (21). Said sealed wall (21) comprises a side opening (25). The prosthesis further comprises a second tube forming a channel between first and second ends, the second tube being sealingly attached by the first end thereof to the first tube around said side opening (25), the second end of the second tube being closed.
