A temporary diameter reduction constraint arrangement for a stent graft is disclosed. The arrangement comprises: primary and secondary release wires extending along the graft; a plurality of loops of thread, each loop engaged with either the primary or secondary wire and engaged around a portion of the graft circumferentially spaced away from its release wire, and drawn tight to reduce the diameter of the graft; an end constraint arrangement comprising four of the plurality of loops of thread arranged into a first and second pairs engaged with respective primary and secondary wires; and an intermediate constraint arrangement comprising a fifth and sixth of the plurality of loops of thread arranged into a third pair, the third pair engaged with the primary release wire, the primary release wire deviating towards the secondary release wire so as to locate the intermediate constraint arrangement substantially in-line with the end constraint arrangement.