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 are fluidly connected to form a common lumen , 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 , - the first and second end portions 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 are fluidly connected to form a common lumen , - the proximal tubular part has a first lumen , the distal tubular part has a second lumen , and the first and second lumens are fluidly connected to form a common lumen , 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 , - the first and second end portions 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 , - the first and second end portions 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 . <EOS>