Tissue dissecting device, including an inflatable bladder configured to be inserted into a body via an introducer tube in a compact deflated state, and to be inflated to a substantially planar form in a manner which dissects tissue. Method for dissecting tissue, including inserting an inflatable bladder, in a deflated state, via an introducer tube, into a space in a body, and inflating the bladder to substantially planer form, thereby dissecting tissue. Method for dissecting tissue, including inserting an introducer tube via an incision into a body, inserting an inflatable bladder, in a defined state, via the introducer tube, into a space in the body, pulling the introducer tube back at least a length of the deflated bladder, inflating the bladder, via a filling tube, to substantially planar form, thereby dissecting tissue, disconnecting the filling tube from the bladder, retracting the filling tube and the introducer tube from the body.