Devices and methods for exploiting intramural space of a vascular wall to facilitate the treatment of vascular disease, particularly total occlusions. The thin film transistor comprising a first gate electrode, a second gate electrode formed on the first gate electrode, a first semiconductor formed on the first gate electrode and including a polycrystalline semiconductor, a second semiconductor formed on the second gate electrode and including an amorphous semiconductor. After the trench is etched into the semiconductor substrate, a nitride layer is formed over a sidewall of the trench.