An occluder for occluding a passage in a circulatory system comprises • - at least one occluding body (4, 5) for occluding the passage, • - a multiple of elongate members (1) forming an expanding unit capable of expanding into at least one fixation structure for fixing the occluding body (4, 5) within the passage thereby expanding the occluding body (4, 5), the elongate members (1) penetrating the at least one occluding body (4, 5), • - a locking unit (2, 3) for locking the expanding unit in its expanded state and • - fixation bushes (10) for restricting relative movement between the elongate members (1) and the at least one occluding body (4, 5), each fixation bush (10) surrounding one single elongate member (1) and abutting one of the at least one occluding body (4, 5), wherein the occluder further comprises at least one thread (11, 12) and wherein at least one of these fixation bushes (10) is fastened to the at least one occluding body (4, 5) with this at least one thread (11, 12), the thread penetrating the at least one bush (10) and the occluding body (4, 5 ). This occluder ensures that the tiny bushes can not wander within the human or animal body and improves even occluders already having protecting jackets.La présente invention concerne un dispositif docclusion destiné à boucher un passage dans un système circulatoire, le dispositif docclusion comprenant • - au moins un corps docclusion (4, 5) pour locclusion du passage, • - de multiples éléments allongés (1) formant une unité déployable capable de se déployer au moins dans une structure de fixation pour fixer le corps docclusion (4, 5) à lintérieur du passage, déployant ainsi le corps docclusion (4, 5), les éléments allongés (1) pénétrant le ou les corps docclusion (4, 5), • - une unité de blocage (2, 3) pour bloquer lunité déployable dans son état déployé et • - des douilles de fixation (10) pour restreindre le mouvement relatif entre les éléments allongés (1) et le ou les corps docclusion ( 4, 5), chaque
