An arrangement for surgery including a hub and a cannula assembly connected thereto. The cannula assembly defines a first fully enclosed chamber extending substantially along a length of the cannula assembly, with the first fully enclosed chamber being coextensive with a head central passage of the hub such that a first tool is configured to extend through the hub and the first fully enclosed chamber. The cannula assembly defining a second fully enclosed chamber that extends along only a portion of the length of the cannula assembly and spaced from the hub. The second fully enclosed chamber having an entrance and an exit being spaced from the hub for allowing a second surgical tool to extend through the second fully enclosed chamber without also passing through the hub or the first fully enclosed chamber. The first fully enclosed chamber and the second fully enclosed chamber being substantially parallel.
