A hydraulic guidewire advancement system for enhancing access through lesions or occlusions in distal regions of a patients vasculature includes a catheter comprising a sheath, a guidewire lumen, and a proximal catheter port connected to a hydraulic driver. A hydraulic guidewire is coaxially disposed through the guidewire lumen, the hydraulic guidewire comprising a piston movably disposed in the guidewire lumen, the piston forming a seal with an interior surface of the sheath. The hydraulic driver is configured to generate hydraulic pressure against the piston sufficient to advance or retract the hydraulic guidewire relative to the catheter. The hydraulic driver can apply positive or negative pressure to the piston, so as to repeatedly contact and break through the lesion with the distal end of the hydraulic guidewire.
