Abstract: An introducer catheter (22) through which a primary device (38) may be inserted having a slidable sleeve (16), which prevents premature disruption of the peelable catheter tube (14) and which also remains in position on the primary device (38) after the introducer catheter has been peeled apart. Also provided is an assembly (10) for the implantation of a peelable introducer catheter (22) the assembly comprising a needle (12), with an introducer catheter tube (14) telescopically disposed over the needle (12) which is provided with rupture means (20); a slidable sleeve (16) telescopically disposed over the needle and introducer catheter tube, which prevents premature disruption of the peelable catheter tube; and a securing means (26) which prevents rotation of the introducer catheter tube (14) relative to the needle (12) during implantation of the catheter (22) in the patient (40).