A method of constructing a detachment system for delivering an implantable medical device to a target location of a body vessel is presented. The method includes forming a compressible portion on a distal tube, engaging an implantable medical device with an engagement system, extending the engagement system through the distal tube such that the implantable medical device is distal of a distal end of the distal tube, applying a force to the engagement system to compress the compressible portion to a compressed state, fixing the engagement system to the distal tube to maintain the compressed state of the compressible portion, and joining a proximal end of the distal tube to a distal end of a proximal tube. The engagement system can include a loop wire that is fixed to the distal tube and engages the medical device.