an assembly and method for percutaneous placement of a catheter comprising an elongated hollow catheter having a distal end and a reduced cross - section portion at a proximal end thereof . an introducer needle is slidably mounted over said catheter . the introducer needle has an elongated slit adapted to slide over the reduced cross - section portion to separate the needle from the catheter . a syringe may be attached to the proximal end of the catheter . also , a valve may be attached to the catheter to permit easy collection of fluid .