Abstract: A reattachable introducer and method of using such introducer is disclosed for inserting an embolic coil deployment system into the tortuous vasculature of the human brain for placing an embolic coil within an aneurysm. The introducer includes a sheath having a lumen, a side opening and a longitudinal slit and includes a cylindrical sleeve slideably disposed about the sheath. A deployment catheter with a conical expander member is slideably disposed through the side opening of the sheath and through the lumen of the sheath. The conical expander member detaches the introducer from the deployment catheter through the longitudinal slit of the sheath, while the cylindrical sleeve reattaches the introducer to the deployment catheter through the longitudinal slit.