A medical device system may include an elongate shaft having a lumen extending from a proximal end of the elongate shaft to a distal end of the elongate shaft, a medical device disposed proximate the distal end of the elongate shaft, a release wire disposed within the lumen of the elongate shaft, wherein the release wire releasably secures the medical device to the distal end of the elongate shaft, a securement member fixedly attached to the proximal end of the elongate shaft and to a proximal end of the release wire, and a microcatheter configured to deliver the medical device to a treatment site, the elongate shaft and the medical device being slidably disposed within a lumen of the microcatheter. A proximal portion of the securement member may be configured to disengage from a distal portion of the securement member.