Dr. Lewis became chief of the neurovascular service, one of the busiest neurovascular practices in the United States. He also developed expertise in endoscopic anterior skull base surgery. The team at the University of Florida specialized in minimally invasive endoscopic approaches to anterior skull base tumours.

Dr. Lewis has a clinical and past NIH funded research interest in cerebrovascular disease, skull base tumours and head injury. He has authored over 70 scientific articles and presented his research findings at multiple national and international scientific meetings. He has co-directed 15 surgical anatomy and surgical skill courses with Professor Rhoton, educating more than 500 participants worldwide.

Dr. Lewis left his position as the James and Newton Eblen Chair in Cerebrovascular Surgery and Associate Professor in the Department of Neurosurgery at the University of Florida to return to his home town of Perth. He has a national neurosurgical reputation in the United States and an international reputation as an accomplished neurosurgeon. He is currently Director of Perth Neurosurgery, a private neurosurgical practice specialising in cerebrovascular neurosurgery, skull base and brain tumour neurosurgery, complex lumbar and cervical spine and general neurosurgical disorders.