Mr Martin Kostolny serves as a Consultant Cardiothoracic Surgeon at Great Ormond Street Hospital (GOSH) and The Harley Street Clinic, specialising in aortic valve repair, congenitally corrected transposition of the great arteries, and complex biventricular repairs. His expertise extends to surgical interventions for pulmonary atresia, Ventricular septal defects (VSD), and Major aortopulmonary collateral arteries (MAPCAs).

Having earned his degree in Medicine from Comenius University, Mr Kostolny underwent training at renowned institutions, including the Heart Centre at the Children's Hospital in Bratislava under Prof Hraska, the German Heart Centre in Munich under Prof Lange, and GOSH. His professional journey led to his appointment as a consultant at the GOSH Cardiothoracic Unit in 2006, where he currently serves as the Head of Clinical Service for Cardiothoracic Surgery. The National Congenital Heart Disease Audit in 2019 recognised the GOSH congenital heart surgical program for consistently achieving outcomes higher than predicted for four consecutive years.

Beyond his contributions at GOSH, Mr Kostolny actively supports congenital heart programs worldwide, collaborating with medical professionals in Serbia, Germany, France, and Turkey. A sought-after expert, he is a frequent presenter at international meetings and holds memberships in various professional societies. Mr Kostolny has contributed significantly to the field, with authorship and co-authorship of over 70 manuscripts and book chapters.

His areas of expertise and services include Aortic Valve Repair, Complex Biventricular Repairs, Major Aortopulmonary Collateral Artery (MAPCA) Surgery, Pulmonary Atresia Surgery, Ventricular Septal Defect (VSD) Surgery, and addressing issues related to the dysfunction of the Aortic Valve, Major Aortopulmonary Collateral Arteries (MAPCAs), Pulmonary Atresia, and Ventricular Septal Defects (VSD).