Catheterization systems and methods for treatment of a condition within a blood vessel are provided that include the use of a catheter, a balloon immediately adjacent to the distal end of the catheter, an inflation device for expanding the balloon, and an occlusion-penetrating device for gaining access through an occlusion. The occlusion-penetrating device may include an indeflator configured to injected fluid at a high pressure, an RF wire, a hollow needle wire, a dissection tool, a laser wire, or even a very small balloon to exploit existing microchannels in the occlusion.