The invention relates to an occlusive system implantable in an animal or human body to occlude a natural conduit (10) of an animal or human body, comprising:an occlusive element (9) designed to surround part of the natural conduit (10) to be occluded,an activation device (2) of said occlusive element (10) for varying the compression exerted by said occlusive element (9) on said conduit (10),a control unit (7) adapted to urge the activation device (2) so as to exert determined compression on the conduit (10), anda detection device of atrophy of said natural conduit (10), comprising: (i) a sensor adapted to measure the compression exerted by the occlusive element (9) on the natural conduit (10), and(ii) a processing unit adapted to: determine a representative parameter of strain to be applied to the activation device (2) to achieve determined compression of the conduit (10) by the occlusive element (9),monitor said parameter over time, anddetect atrophy of the natural conduit (10) when said representative parameter fulfils a predetermined criterion.