A very good reference.  Really shows a lot of what happens during the
surgery.  But the photographic scale is way too large to show "a pipe" that
is a fraction of a mm thick.

Notice how smooth the channel appears in the before surgery video.  That is
probably the mucus membrane lining the urethral wall.  The after surgery
video does not have the same appearance because the mucus membrane and
urethral wall have been removed.