The anatomical location of the mesencephalic aqueduct is below the third ventricle and connects to the fourth ventricle. If you want to check the fourth ventricle, you can only use a hose.
In summary, the entire rigid microscopic examination process is to insert a rod obliquely at an angle aligned with the interventricular foramen, just passing by the lateral ventricle and the third ventricle. A lens can be installed to make a rod