An interventional medical closure device comprises a first engagement element for engagement with an external surface of a vessel on a first side of an opening through the vessel wall and a second engagement element for engagement with an external surface on a second side of the opening. A closure element extends from the first engagement element, into the vessel, and to the second engagement element to assist in closure of the opening. The device may include a foot element to engage the internal surface of the vessel on both sides of the opening. The foot element may provide a guide with a pathway for the closure element.