Abstract: A device for sealing puncture wounds in blood vessels is open at one end and closed at the other end. The tube closure is generally flat and pivotable, and the tube region near the closed end is expandable. The device is initially contained in a sleeve, which is inserted through a cannula, so that the closed end is within the vessel to be sealed. After the cannula is removed, the closure is pivoted and the device withdrawn to a point where the closure abuts the puncture wound. After the sleeve is removed, the expandable region is expanded, so that the blood vessel wall around the puncture is sandwiched between the closure and the expanded region. The device prevents blood from seeping out of the punctured vessel during the healing process.