A retractor assembly for percutaneous surgery in a patient includes first and second retractor portions positionable opposite one another in an incision of the patient. A working channel extends between the first and second retractor portions and provides access to a location within the patient adjacent to distal ends of the first and second retractor portions. The first and second retractor portions are movable relative to one another to adjust the size of the working channel. In addition, the first and second retractor portions are further configured to longitudinally overlap with one another such that the working channel is peripherally surrounded or enclosed by the first and second retractor portions as the working channel is adjusted across a plurality of different sizes. In another form, a method is directed to retracting tissue for percutaneous access to a surgical site. However, other embodiments, forms and applications are also envisioned.