A retractor apparatus for a surgical robotic system includes a frame defining a central open region, a connecting member that connects the frame to a robotic arm, a plurality of coupling mechanisms for attaching a set of retractor blades within the central open region of the frame such that blades define a working channel interior of the blades, and a plurality of actuators extending between the frame and each of the coupling mechanisms and configured to move the blades with respect to the frame to vary a dimension of the working channel. Further embodiments include a surgical robotic system that includes a robotic arm and a retractor apparatus attached to the robotic arm, and methods for performing a robot-assisted surgical procedure using a retractor apparatus attached to a robotic arm.
