Gerhard Ziemer, MD, PhD, is currently Professor of Surgery at the University of Chicago, Illinois, USA. He is also Director of Pediatric Cardiac Surgery at Comer Children’s Hospital and Director of Adult Congenital Heart Surgery at the University of Chicago Medical Center. Prior to moving to Chicago, he served for 15 years as Professor of Surgery and Director of the Department Thoracic, Cardiac, and Vascular Surgery at Eberhard-Karls University, Tübingen, Germany. Dr. Ziemer specializes in a wide range of congenital cardiac surgery procedures, including complex, primary, and multistage repair in newborns as well as primary and repeat surgery in adults. In 1989, he performed the first successful neonatal autograft aortic valve replacement (Ross operation) in the world. Each year Dr. Ziemer visits Lima, Peru, to operate on 20-25 children with congenital heart disease, and he is an Honorary Professor at the National University of San Marcos in Lima. Dr. Ziemer has been involved in manyinternational scientific societies and academic boards. Since 2005 he has been an Examiner in Cardiac Surgery for the European Board of Thoracic and Cardiovascular Surgeons. He was a member of the Founding Governing Council of the World Society for Pediatric and Congenital Heart Surgery and also is a member of the editorial board for the World Journal for Pediatric & Congenital Heart Surgery.Axel Haverich, MD is a Professor of Medicine and Surgery and serves as Director of the Department of Cardiac, Thoracic, Transplantatiion, and Vascular Surgery. Prof. Haverich serves as Member of the Scientific Advisory Board at Vital Sensors, Inc. He served as president for various national and international societies. He studied at Hannover Medical School, Hannover, Germany.