A system for treating a target tissue includes (a) an instrument head sized and shaped for insertion into a hollow organ of a living body, the instrument head including a working chamber movable between an open position in which the working chamber is exposed to an exterior of the head and a closed position in which the working chamber is substantially sealed with respect to an exterior of the instrument head, the instrument head including a first imaging device having a field of view extending distally of a distal end thereof and a second imaging device having a field of view within the working chamber; (b) a handle which, during use, remains outside the living body, the handle including an actuator; (c) a steering mechanism coupled to the actuator for steering the instrument head within the hollow organ based on actuation of the actuator; and (d) a controller coupled to the first and second imaging devices for processing the image data received from the first and second imaging devices and providing images to an operator.