A surgical sheath system for performing surgery of the head includes a flexible tubular braided sheath which is radially expandable. An expansion tube is insertable into the sheath to radially expand the sheath. A locking assembly includes tube position shift means, such as a cap threaded onto a flange, with a washer contained in a recess in the flange, the recess having an inside diameter greater than an outside diameter of the washer. When unlocked, the expansion tube can be shift horizontally, to access a different area of a surgical site, without moving the locking assembly. A stylet stabilizing assembly may be pivotally or releasably attached to the locking assembly.
