Devices and methods are provided for inserting a sterile catheter, and for maintaining a sterilely sealed catheter and catheter insertion site over time. In one embodiment, a four-part integrated system is provided that includes (1) a novel vascular catheter with integrated uniform diameter mounting, capping, and needle safety procurement features, (2) a novel vascular catheter dressing designed to specifically mate with and seal to this vascular catheter to achieve a sterile seal both at the catheter-skin insertion site and the catheter-dressing exit site, (3) a hub protection and sterilizing apparatus that serves to stabilize, protect, and sterilize the working end of the catheter hub as it protrudes from the sterile dressing, and that also helps to improve the ergonomics of the catheter-dressing complex in order to avoid snagging on clothing etc., and (4) a whole dressing accessory secondary cover and securement device.