A catheter and associated method. A catheter designed for accessing a tissue location in the human body, typically a location within the vascular system or accessible through the vasculature. The catheter has an adjustable region(s) between its hub or proximal terminating unit and the surface of the patients body which enables the physician to elongate or shorten the catheter through direct manipulation, either during catheter placement or after the catheter has been deployed within the body. The adjustable region(s) are lined with an elastic membrane that maintains a uniform inner diameter as the catheter length changes. The catheter maintains a continuous smooth uninterrupted lumen available for the passage of other catheters and/or fluids. The catheter and method of proximal length adjustment may be applied to any catheter, including indwelling catheters, guiding catheters and microcatheters.
