大象传媒

Being a heart surgeon is a difficult and challenging job, but being a children's heart surgeon is even more pressurised.

Dr Victor Tsang does that job at the internationally renowned Great Ormond Street Children's Hospital in London.

The babies' hearts he works on are about the size of a walnut, so a steady hand, a steady eye, and a steady nerve are vital.

And often he faces a terrible moral dilemma - the decision whether complex surgery on a tiny premature baby will do any good, or whether the baby should be left to die.

When Mr Tsang came into the Outlook studio, he told Matthew Bannister about the intricate operations he performs.