[Indwelling venous catheters. Results of a clinical and experimental study]

Six venous indwelling cannulas were observed under constant frame conditions (low osmolar solutions, constant infusion solution, prospective randomized study). There is a close correlation between the complication rate in the vein and quality of the material and puncture. The best results were achieved with Teflon cannulas. Here the condition of the transitional zone between mandrin and synthetic material was of special importance as well as the fact that the form stability also had to be guaranteed after application. The thrombotic dry weights of these cannulas, determined in animal experiments, yielded low values for polytetrafluorethylene (PTFE) or polyethylene (PE), but PTFE and PE cannulas have led to an increase of the thrombotic dry weight in 24 and 48 h of indwelling time.