The device has a lock (43') e.g. peel-away-lock, comprising a distal end for arrangement in a patient body and a proximate end for arrangement outside of the body. The lock comprises a tubular portion (41) and lock housings with a retainer channel (46) for a strand-like body e.g. sleeve-shaped lock (20'''). A resilient clamping device (56') and a mechanical stop unit (57') are provided at the retainer channel for fixing the strand-like body in the retainer channel by clamping. A slot clamping ring is made of plastic or metal. The clamping ring is inwardly expanded by an axial screwing device. An independent claim is also included for a method for insertion of a catheter into a patient body.
