The present invention is a packaged system that includes a housing to protect a treatment device mounted on a distal portion of a catheter. The housing holds the device suspended such that there is little or no contact between the housing and the device, protecting the device from physical damage and also from exchange of chemical components between the device and the packaging materials, which can occur when a device remains in contact with packaging materials over an extended period of time. A port in the housing allows a controlled environment, for example a vacuum, to be maintained within the housing. A hollow stylet inserted into the distal end of the catheter before the catheter is placed in the housing precludes compression of the catheter and provides an injection port through which the catheter may be flushed with a fluid prior to use, eliminating the need for a separate flushing cannula.