Dr. Thomaidis was born and raised in Athens, Greece. He graduated with honors from the 2nd High School of Papagou and then entered the Medical School of the University of Crete with the system of the pan-Hellenic examinations. In 2003 he graduated first from the Medical School of Athens University with degree “Excellent”. During his studies he attended as “clinical elective” at the Medical School of the “Semmelweis” University of Budapest, at the Medical School of the University of Prague and at St. George’s Hospital in London, United Kingdom. As an undergraduate student, he received scholarships from the State Scholarship Foundation (IKY) and the Anagnos Foundation, while after completing his studies he worked as a rural doctor at the regional clinic of Arkesini in Amorgos.

In 2004 he received the license to practice medicine in Germany. In 2006 he completed his doctoral dissertation at Johannes-Gutenberg University in Mainz, Germany where he remained and completed the medical specialty of Internal Medicine and Gastroenterology in 2014.

After his residency, Dr. Thomaidis remained at the University Clinic of the Johannes-Gutenberg Universität in Mainz where he performed extensive clinical, didactic and research work with multiple publications in prestigious international journals. As a result, in 2017 he was named Ass. Professor of Gastroenterology at the Johannes-Gutenberg University. His clinical experience includes the wide range of gastroenterology, hepatology, gastrointestinal tumors and invasive endoscopy.

In 2017 he was trained in the latest advanced techniques of minimally invasive endoscopy (ESD, POEM, EFTR) at the largest endoscopy unit worldwide, at the University of  Fudan in Shanghai, China under the guidance of Professor PH. Zhou . In 2018-2019 Dr. Thomaidis was trained in therapeutic and invasive endoscopy (EUS, ERCP) in St. Michael’s Hospital, University of Toronto, Canada , which is one of the few recognized “Centers of Excellence” by the World Intelligence Agency (WEO) .

During his clinical career he was awarded the Waltner-Krienitz Prize for his research on gastric cancer, and has received multiple awards and travel grants for presentations at international conferences. Since November 2019, he has been the Secretary General of the Hellenic Society of Digestive Oncology.

Dr. Thomaidis is a member of the Hellenic Gastroenterological Society (EGE), the Hellenic Society of Digestive Oncology (HSGO), the German Gastroenterological Society (DGVS), the American Society of Endoscopy (ASGE), etc.

He participates as a speaker and President in many international conferences, while at the same time he is investigator in clinical trials on invasive endoscopy and gastroenterology oncology.

Since July 2019, he has returned to Greece and maintains a private practise in Maroussi.