Demetrios Nectarios Mallios, MD

Demetrios N. Mallios, MD, is a board-certified cardiothoracic surgeon at Keck Medicine of USC. He specializes in the surgical management of congenital heart disease in both adults and children, with broad experience in a range of techniques used to treat the most complex heart conditions.

Dr. Mallios completed his residency in cardiothoracic surgery at the Keck School of Medicine of USC and Los Angeles General, formerly known as Los Angeles County + USC Medical Center. During that time, he spent a year as a clinical research fellow and was also named thoracic surgery resident of the year in 2021. He also served as a chief resident in 2022. Dr. Mallios then went on to complete a subspecialty fellowship at Children’s Hospital Los Angeles, again under the instruction of Dr. Vaughn A. Starnes.

Dr. Mallios has many clinical and research interests, including neonatal heart surgery, adult congenital heart disease and surgical management of the aortic root and aortic arch. He has presented research findings at multiple national and international meetings, including the American Association for Thoracic Surgery and the Society of Thoracic Surgeons. In addition, he has contributed to numerous studies in peer-reviewed medical journals.

Away from clinical practice, Dr. Mallios enjoys spending time exercising, trying out new recipes in the kitchen and exploring the Los Angeles food scene. He is fluent in Greek language and makes frequent trips back to Greece to visit with family and friends.