Dr Karentzos is a general and visceral surgeon with a multinational training and working experience. He was accredited as a general surgeon in 2014 in Greece after completing a part of his training in Colmar and in Strasbourg, France. He continued his post-CCT training in the UK (Royal Free London and Imperial College NHS Trusts) and in 2016 he moved to Geneva, Switzerland, where he worked at the University Hospital (HUG). In 2020 he pursued a Royal College of Surgeons of England accredited fellowship in benign upper GI surgery at Torbay Hospital in the UK which enabled him to acquire a significant amount of knowledge and expertise regarding the treatment of benign pathologies of the esophagus, the stomach and the diaphragm as well as the laparoscopic exploration of the bile ducts. In 2021 he returned to Switzerland to work in the department of surgery of the cantonal hospital of Fribourg as well as in the department of pediatric surgery of the university hospital of Geneva and in May 2023 he started his private practice in Geneva.