A medical closure device (1； 20) comprising an inner member (2； 23), which is adapted to be positioned against an inner surface of a tissue wall, and a retaining member (3； 13； 21), which is attached to the inner member, wherein the retaining member is in the form of a loop made up by multiple coils of at least one filament, the coils lying side-by-side one another such that when increasing tension is applied in the loop, at least one of the at least one filament breaks apart before side-by-side portions of the at least one filament slide readily with respect to one another.
