Vascular prosthesis configured to be implanted in a vessel, having substantially a T-shape, comprising a proximal tubular part forming the base of the "T" and a distal tubular part forming the head of the "T", wherein: - the proximal tubular part has a first lumen, the distal tubular part has a second lumen, and the first and second lumens (31, 32) are fluidly connected to form a common lumen (31, 32), wherein: - the distal tubular part comprises a first end portion, a second end portion, and an intermediate portion extending axially between the first and second end portions (210, 220), - the first and second end portions (210, 220) are radially expandable, - the proximal tubular part is connected to the intermediate portion, and characterized in that: - the second end portion is movable between a retracted position in which the second end portion is axially restrained and a deployed position in which the second end portion is axially deployed; - the second end portion comprises a folding region, so that, in the retracted position, the second end portion can be folded along the folding region so as to be partly inverted within the second lumen; and - the second end portion comprises a distal end with a circumferential indentation. wherein: - the proximal tubular part has a first lumen, the distal tubular part has a second lumen, and the first and second lumens (31, 32) are fluidly connected to form a common lumen (31, 32), - the proximal tubular part has a first lumen, the distal tubular part has a second lumen, and the first and second lumens (31, 32) are fluidly connected to form a common lumen (31, 32), wherein: - the distal tubular part comprises a first end portion, a second end portion, and an intermediate portion extending axially between the first and second end portions (210, 220), - the first and second end portions (210, 220) are radially expandable, - the proximal tubular part is connected to the intermediate portion, and characterized in that: - the second end portion is movable between a retracted position in which the second end portion is axially restrained and a deployed position in which the second end portion is axially deployed; - the second end portion comprises a folding region, so that, in the retracted position, the second end portion can be folded along the folding region so as to be partly inverted within the second lumen; and - the second end portion comprises a distal end with a circumferential indentation. - the distal tubular part comprises a first end portion, a second end portion, and an intermediate portion extending axially between the first and second end portions (210, 220), - the first and second end portions (210, 220) are radially expandable, - the proximal tubular part is connected to the intermediate portion, and characterized in that: - the second end portion is movable between a retracted position in which the second end portion is axially restrained and a deployed position in which the second end portion is axially deployed; - the second end portion comprises a folding region, so that, in the retracted position, the second end portion can be folded along the folding region so as to be partly inverted within the second lumen; and - the second end portion comprises a distal end with a circumferential indentation.