A medical device (100) for the treatment of an aneurysm, comprising: an expandable tubular member to an expanded state, the tubular member comprising a plurality of braided filaments (120, 142, 144, 146, 148, 300), each of the filaments (120, 142, 144, 146, 148, 300) crossing with others of the filaments (120, 142, 144, 146, 148, 300) at respective crossing points, which form a side wall and a plurality of pores in the side wall, the tubular member comprising a section to encompass an aneurysm neck, the section having first pores sized to inhibit blood flow through the side wall to the aneurysm to a degree sufficient to lead to thrombosis and Aneurysm healing when the tubular member is located in a blood vessel and adjacent to the aneurysm, where the first pores have an average pore size that is less than, or equal to, approximately 500 microns when the tubular member is á in the expanded state； and an antithrombogenic material distributed over the section of the tubular member in which the first pores are substantially free of membranes formed by the antithrombogenic material, where the membranes are few in number and are present in less than 5% of the crossing points and / or in less than 5% of the first pores.Un dispositivo médico (100) para el tratamiento de un aneurisma, que comprende: un miembro tubular expansible hasta un estado expandido, comprendiendo el miembro tubular una pluralidad de filamentos trenzados (120, 142, 144, 146, 148, 300), cada uno de los filamentos (120, 142, 144, 146, 148, 300) cruzando con otros de los filamentos (120, 142, 144, 146, 148, 300) en respectivos puntos de cruce, que forman una pared lateral y una pluralidad de poros en la pared lateral, comprendiendo el miembro tubular una sección para abarcar un cuello de aneurisma, teniendo la sección primeros poros dimensionados para inhibir el flujo de sangre a través de la pared lateral al aneurisma en un grado suficiente para conducir a la trombosis y a la curación del aneurisma cuando
