Modification of immediately electrically detachable coil

An immediately electrically detachable coil (IEDC) that we previously developed was modified to enhance the reliability in its detachment system. IEDC is detached by applying a monopolar high-frequency electrical current that heat and disrupt a junction between a platinum coil and a delivery wire. The original IEDC immediately detaches only when the junction is just outside the catheter tip and precise positioning of the junction is required. In the modified IEDC, its delivery wire was insulated with polytetra fluoroethylene (PTFE) to concentrate electrical current to the junction. The modified IEDC was tested in vitro and in animal experiments. Modified IEDC always detached instantaneously even when the junction was far beyond the catheter tip. Insulated delivery wire enabled the electrical current to be concentrated at the PVA junction and produce appropriate heat to disrupt the junction.