Catheterization apparatus for implanting devices is provided with a device tether. The apparatus includes a device delivery tube that provides a pathway for moving implant devices through a patient's vasculature to internal body cavities. The implant devices are carried or pushed through the device delivery tube by a tubular push rod. The implant devices are tethered to a line passing through the push rod lumen. After deployment, the implant devices may be retracted into the device delivery tube for repositioning or retrieval by pulling on the tether.