Mr Byrne is a consultant upper gastrointestinal surgeon and honorary Senior Lecturer at University Hospital Southampton and was appointed in 2002.

He has been a member of the bariatric (obesity) surgical team in Southampton since it was established in 2004. He offers laparoscopic Gastric banding, Laparoscopic Roux Y gastric bypass and revision surgery following gastric banding or other procedures. Since April 2004 the team has performed over 1500 procedures with excellent outcomes in terms of patient safety and weight loss.

Mr Byrne also has a strong research interest in weight loss and new technologies / techniques to promote this such as Endobarrier, an incisionless procedure involving placement of a plastic liner in the upper intestine that is effective particularly for overweight diabetics to improve the control of their diabetes and help them lose weight. Southampton is one of three centres in the UK participating in a study to evaluate this device in UK patients. He is also the only person with UK experience of the abiliti, an electronic programmable implantable device that helps patients manage their eating behaviour by means of stimulus during disallowed eating periods and also recording both eating behaviour and physical activity.