Abstract: An implantable device for occluding a body duct, especially a blood vessel. The device includes a flexible, elongate plate to be fixed around the duct, a plurality of communicating bulbs which are arranged on one side of the plate and have a variable volume, and a connection for supplying fluid to the bulbs for occluding the duct and for evacuating fluid from the bulbs to open the duct after the occlusion. The flexible plate has a perforation at one end and a locking member in the form of a thickened portion at the other end. The locking member is passed through the perforation for safely fixing the device around the body duct.To improve the occlusive function of the device, the bulbs may be made of an elastic material, the thickness of which is smallest at the tops of the bulbs.