This invention is a surgical device. It is a guidewire for use in a catheter and is used for accessing a targeted site in a lumen system of a patient's body. The guidewire may be of a high elasticity metal alloy, preferably a Ni-Ti alloy, having specified physical parameters, and is especially useful for accessing peripheral or soft tissue targets. A special variation of the inventive guidewire includes the concept of coating the wire with a one or more lubricious polymers to enhance its suitability for use within catheters and with the interior of vascular lumen. The "necked" guidewire tip also forms a specific variant of the invention.