The Spacemaker™ structural balloon trocar consists of a blunt obturator connected to a handle and a valve body assembly. The valve body assembly contains an internal flapper valve and seal to prevent gas leakage when instruments are inserted or withdrawn. The Spacemaker™ structural balloon trocar includes built-in converters to allow insertion of instruments of different diameters than the main seal. In addition, the device has an external one-way valve for gas insufflation.