1 Division of Neurosurgery, Children's Hospital of Philadelphia, PA; Department of Neurosurgery, Hospital of the University of Pennsylvania, Philadelphia, PA.
2 Division of Neurosurgery, Children's Hospital of Philadelphia, PA; Department of Neurosurgery, Hospital of the University of Pennsylvania, Philadelphia, PA. Electronic address: heuerg@email.chop.edu.
3 Division of Plastic and Reconstructive Surgery, Children's Hospital of Philadelphia, PA.