An apparatus for tissue dissection and instrument anchoring, including a dissection balloon having a viewing window (preferably a rigid, transparent window) at its distal end, or including an anchoring or dissection balloon having nonuniform elasticity selected to achieve desired inflated shape and pressure characteristics, and methods for using such apparatus. The window, which can be a lens (such as a wide angle lens), is transparent and either rigid or non-rigid but sufficiently strong to retain a desired optical shape while (and after) being pushed against tissue layers by a rigid instrument deployed within the balloon. In preferred embodiments, the balloon is a long-necked dissection balloon deployed through a cannula. In other embodiments, the invention is a dissection balloon having a viewing window at its distal end, or an anchoring or dissection balloon having nonuniform elasticity selected to achieve desired inflated shape and pressure characteristics, for use in an apparatus for tissue dissection, tissue retraction, and instrument anchoring. In other embodiments, the invention is a dissection balloon assembly including a long-necked dissection balloon having a viewing window at its distal end, and a housing to which the dissection balloon's mouth is attached. In accordance with the method of the invention, the distal end of a long-necked dissection balloon (deployed through a cannula) is inserted between tissue layers and inflated to dissect the tissue layers. The dissection balloon has a window at its distal end, or nonuniform elasticity selected to achieve desired inflated shape and pressure characteristics, or both such a window and such nonuniform elasticity.