An active cannula (10) can include a plurality of hollow tubes (100, 110, 120), a plurality of blocks (200, 210, 220), and a track (1800). Each of the blocks can be connected to one of the hollow tubes. Each of the blocks can be operably connected to the track for movement therealong. In a first position, the blocks can be separate from each other along the track and the plurality of hollow tubes can be nested. In a second position, the blocks can be adjacent to each other along the track and the plurality of hollow tubes can be extended. In the second position, the plurality of hollow tubes can provide access to the targeted anatomical region from outside of the body. Other embodiments are disclosed.