Systems, apparatus and methods are disclosed for medical treatment comprising bone access and dilatation and/or cavity creation or enlargement using a narrow gauge, preferably 11-gauge or smaller, cannula wherein a catheter/expandable element assembly meeting medical protocols for such procedures is designed, adapted and fabricated to fit through the interior of the associated 11-gauge or smaller cannula, and further including apparatus and methods for wrapping and/or folding the expandable element either before or after a procedure to reduce its profile to fit through the cannula.
