Centers of Excellence


Physicians & Nurses 

P. David Adelson, MD, FACS, FAAP, is the Director of Barrow Neurological Institute at Phoenix Children’s Hospital and Chief Pediatric Neurosurgeon at Phoenix Children's Hospital. He is on faculty at Arizona State University and at the University of Arizona-College of Medicine-Phoenix. Dr. Adelson is an internationally recognized expert in the area of pediatric traumatic brain injury, in particular in the acute clinical management of these injured children as well as in the neural recovery and plasticity of the developing brain following injury. Prior to moving to Phoenix in 2008, Dr. Adelson was the A. Leland Albright Professor of Pediatric Neurosurgery and vice chairman for research for the Department of Neurological Surgery at the University of Pittsburgh and Children's Hospital of Pittsburgh. He continues to run an active basic science laboratory as well as clinical research programs. Dr. Adelson has been the recipient of multiple awards, including The Best Doctors in America, Young Investigator Award, and Congress of Neurological Surgeons Clinical Investigation Award, to name a few. His research has resulted in his authoring more than 140 publications, 36 book chapter and he has edited eight books including the well regarded "Principles and Practice of Pediatric Neurosurgery", the authoritative textbook in the field of pediatric neurosurgery.

Ratan Bhardwaj, MD, PhD, FRCSC, is a pediatric neurosurgeon at Barrow Neurological at Phoenix Children's Hospital. He holds a special focus in minimally invasive endoscopic approaches, brain tumors, hydrocephalus and functional neurosurgery.  Dr. Bhardwaj combines his innovative research and clinical expertise in pediatric neuroscience with the Hospital’s commitment to compassionately treating and healing children with neurosurgical conditions. He received his medical degree from Queen’s University in Kingston, Canada in 2000 and completed his neurosurgical training at the University of Toronto in 2010. Dr. Bhardwaj also completed his PhD in molecular biology at the Nobel Medical Institute at the Korolinska Institute in Stockhold, Sweden in 2007. There, he developed successful projects involving human stem biology in the brain and heart, as well as endogenous regenerative strategies to cure disease states. Dr. Bhardwaj has lectured extensively around the globe and has received numerous prestigious awards throughout his clinical and research training. He has authored book chapters and numerous papers in clinical neurosurgery as well as in basic science. He has published novel research in high impact journals such as Science, Cell, and PNAS, and is a strong advocate for advances through research.

Ruth Bristol, MD, is a pediatric neurosurgeon who made the transition to Phoenix Children's Hospital with the other pediatric specialty practitioners, and is proud to remain part of the Barrow Neurological Institute. She remains a member of the Barrow Children's Cleft and Craniofacial Center, which offes at eam approach to children with craniosyonostosis and other skull anomalies. Dr. Bristol treats all areas of pediatric neurosurgery, including brain and spine tumores, trauma, and developmental anomalies. Her research interests include brain tumors and craniosynostosis. Dr. Bristol believes that a supportive and involved family is very important for healing in children. Many children do not have the ability to understand complex medical problems, so gaining their trust and making them feel safe are essential to providing good care. Originally from New Hampshire, Dr. Bristol attended Medical School at Tulane University in New Orleans. She then completed a Neurological Surgery Residency at the BARROW Neurological Institute in Phoenix. Post-residency subspecialty training included a Pediatric Neurosurgery Fellowship at Children's Hospital of Los Angeles. 

David Shafron, MD, a pediatric neurosurgeon and fellow of American Association of Neurological Surgeons and Congress of Neurological Surgeons has been published exxtensively including authoring a book chapter on gene therapy for cerebrovascular disease. He arrived at Phoenix Children's Hospital in 2003. Dr. Shafron earned his medical degree at Case Western Reserve University School of Medicine in Cleveland, Ohio, before completing an internship in Genral Surgery and residency in Neurosurgery at University of Florida Coolege of Medicien in gainesville, Florida Dr. Shafron finished his training with fellowships in Pediatric Neurosurgery at University of Pittsburgh and the University of Aizona School of Medicine. He is board certified in Neurological Surgery and Pediatric Neurosurgery. Dr. Shafron practices all aspects of pediatric neurosurgery, such as hydrocephalus, brain tumors, Chiari malformations, and congenital disorders. He has a strong interest in the treatment of patients with cerebral palsy and other movement disorders, utilizing medical managemetn botulinum toxin (Botox®), intrathecal baclofen therapy, and other modalities. He also has a special interest in the treatmetn of craniofacial disorders, and has extensive experience with the use of minimally invasive techniques for forms of craniosynostosis. 

Krystal L. Tomei, MD, MPH, joined Barrow Neurological Institute at Phoenix Children’s Hospital as this year’s Pediatric Neurosurgery Fellow. Dr. Tomei recently completed her residency in Neurological Surgery at the University of Medicine and Dentistry of New Jersey at New Jersey Medical School after attending the University Of Florida College Of Medicine. Dr. Tomei also received a Master in Public Health from the Harvard School of Public Health. She has a demonstrated passion for improving medical education through her service as the resident member on the American Medical Association’s Council on Medical Education and as a recipient of both the Arnold P. Gold Foundation Humanism and Excellence in Teaching Award and the first NJMS Golden Apple Specialty Resident Teaching Award. Dr. Tomei serves as Secretary of the American Association of Neurological Surgeons Young Neurosurgeons Committee, and  is a member of the Neurosurgery PAC Board of Directors. She has a particular interest in neurotrauma and injury prevention serving as a member of the ThinkFirst National Injury Prevention Organization Board of Directors. Dr. Tomei has authored several book chapters and peer-reviewed articles.Her research interests include congenital spinal disorders, neurotrauma, and outcomes based quality improvement.

Kathleen Klas, RN, FA, MS, CPNP-AC/PC, received the Margaret P. Curry Silver Medal of Nursing in her Bachelor of Science program at D’Youville College in Buffalo, New York. She then moved to Phoenix Arizona and worked with special needs children as a home health care nurse while pursuing her Master's of Science, specializing as a Pediatric Nurse Practitioner, from Arizona State University. She completed her program Magna Cum Laude in 2002. Katie has a special interest in neonatal neurosurgery of congenital conditions, as well as shunt independence.  Katie has lectured in the community to support groups with a focus on neurosurgical conditions, as well as community physicians, resident programs and nursing lectures. Katie holds national certification from the Pediatric Nursing Certification Board in Primary Care since 2002, and accomplished her Acute Care certification in 2007. She is also an active member in the National Association of Pediatric Nurse Practitioners as well as being involved in the State Chapter as a previous officer. Katie is also involved with the  American Association of Neurologic Surgeons through conferences and their journals. 

Camille Bloom, MS, MMS, RD, PA-C

Medical Support Staff

Debbie Beaman, Medical Assistant

Administrative Support Staff

Christina Casanova, Executive Assistant

Barbara Disbro, Administrative Assistant

Sherry Gibson, Administrative Assistant

Maria Rivas, Administrative Assistant

Pam Antillion, Scheduling

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