There is no "lengthening" surgery (yet). All the "barbers" do is cut suspensory ligaments. Making your penis "bigger" does not require exposing "internal" penis. (Though it helps :D)
Make your penis bigger by adding cells through mitosis. Cause enough separation between helixes, mitosis occurs, new cells are "created". Keep creating these and you penis will "grow". And there is no theoretical limit to how many cells that you can create over time. No surgery, just continued Penis Enlargement :D
Hang in their Brother, force and duration combined with the beautiful and wonderful biological machine that we are, can create any penis that you would like over time with commitment and exercise.
Tom