The present invention is directed to implantable medical device assemblies. The assemblies are primarily used to introduce and deposit implantable medical devices in the vasculatures of implant recipients. The principle implantable medical device used in the assembly is an expandable element in the form of an endovascular device. The expandable element is maintained in a compacted configuration during introduction of the device into the vasculature with a confinement means. The expandable element is released from the confinement means at an implantation site with a control line. The control line has high tensile strength, high modulus, structural rigidity, and low compressibility. These features of the control line provide a practitioner with tactile feedback of the release of the expandable element from the confinement means. The tactile feedback is present during the entire deployment of the expandable element. The tactile feedback enables the practitioner to better track and control deployment of the expandable element at an implantation site.