Denial of Payment after Successful Prior Authorization: The Latest Commercial Payer Ruse featuring Luis Tumialan, MD, FAANSLuis Manuel Tumialán is a Professor of Neurosurgery at the Barrow Neurological Institute specializing in minimally invasive spinal surgery. He graduated from Georgetown University School of Medicine, completed his internship at the Naval Medical Center in San Diego. Dr. Tumialán completed additional training in undersea medicine in Groton Connecticut and Navy Dive School ...