A mechanism for guiding and/or releasing an endoprosthesis at a blood vessel lesion region, used in a medical device of the type of a catheter, represents an inventive solution in the field of medicine, being particularly useful for the treatment of vascular diseases, in particular for specific pathologies such as aneurysms and aortic dissections, the invention being used in a medical device of the type of a catheter (1), it being possible to remove the entire endoprosthesis (17), which was ergonomically improved in the way in which it is guided and handled when mounted together with this catheter (1), including structural and operational improvements to the mechanism for fastening and releasing the distal portion of the endoprosthesis, and also to the mechanism for fastening and releasing the proximal portion of the endoprosthesis, achieving a distinct final quality of the application of the endoprosthesis.
