A medical device for clamping the stomach in morbid obesity surgery consists of a silicone frame that is essentially U-shaped, having opposing legs self-hinged to a bight portion interconnecting the legs. The opposing legs have sufficient stiffness to permit limited bending and have inner surfaces that sealingly carry an inflatable balloon which can be selectively inflated or aspirated after the device has been clamped to the stomach to adjust the gastric restriction stoma. A flexible latch member carried by one of the legs has at least one serration which is inserted into a latch cavity of the opposing leg to lock the opposing legs in fixed spaced relationship. Lumens within the legs communicate with a fluid supply source and respective inflatable balloon for selective inflation or aspiration of the inflatable balloons.