A sheathed catheter system is described where the sheath comprises a distal portion and a proximal portion that are moveable axially relative to each other, and relative to a tube carrying a medical device thereon. The distal and proximal sheath portions can be brought together in order to enclose therewithin the medical device. The distal sheath has a proximal section that is configured to bias radially inwardly to minimize an otherwise exposed annular surface catching on protruding surfaces that may exist on the catheter or other medical tool in use at the time, or to minimize scraping the inner native lumen of the patient upon retrieval.
