 Carson's achievements include performing the only successful separation of conjoined twins joined at the back of the head; performing the first successful neurosurgical procedure on a fetus inside the womb; performing the first completely successful separation of type-2 vertical craniopagus twins; developing new methods to treat brain-stem tumors; and revitalizing hemispherectomy techniques for controlling seizures.He wrote over 100 neurosurgical publications.He retired from medicine in 2013.