Methods and devices retract tissue for minimally invasive surgery in a patient. A retractor (20, 320) includes a working channel (50, 350) formed by a first portion (22, 322) and a second portion (24, 324.) The first and second portions (22, 322, 24, 324) are movable relative to one another from a first configuration for insertion that minimizes trauma to skin and tissue to an enlarged configuration after insertion to further retract skin and tissue in a minimally invasive manner. Instruments (70, 90, 140, 220, 360) are engageable to the first and second portions (22, 322, 24, 324) and operable to move the first and second portions (22, 322, 24, 324) relative to one another.