Abstract: An occlusive device is disclosed for surgical implant to occlude the lumen of an internal organ. The device includes a cuff A having a backing collar (10) and two isolated cuff chambers B and C. The fluid pressure of chamber B is regulated by a pump/valve reservoir unit E. Chamber C is unregulated in pressure but its fluid volume is adjusted by removing or adding fluid to a septum/reservoir D by means of a hypodermic needle. Pressure changes are transmitted between the two cuff chambers via faying surfaces (12) and (14) which are sufficiently large in contact area and thin as to transmit pressure generally without attenuation. By adjusting the fluid volume of septum D, the operating pressure of the device may be adjusted to accommodate tubular organs of different diameter sizes as well as to compensate for changes in the organ following implant without re-operation.