An eleven year old boy from Bradley Stoke has undergone his fourth life-saving open-heart operation. Calum Morris has a rare defect that affects fewer than 1 in 10 thousand people.
He agreed for his operation to be filmed, to help people understand what it is like to have the condition and to raise money for the British Heart Foundation.
He wants other people to know what it's like to have a heart defect.
Calum's parents have waited anxiously for the results of their son's surgery before. This is the fourth time they've watched their son head-off to an operating theatre for open-heart surgery.
Heart disease is the most common type of birth defect, affecting around 1 in every 180 babies. Calum had his first operation when he was just 10 days old.
Since then, he's had two others, because his heart's growing but the artificial repair patches are not.
In fact, Calum's heart gave his surgeon Massimo Caputo an idea: would it be possible to use a baby's stem cells to make a living repair patch, which would grow with the heart, and end the need for repeat operations? The stem cell research at Bristol University is being funded by the British Heart Foundation. The method could be used on patients within the next 5-10 years.
For now though, surgery is the only way to keep Calum and others like him alive. In the end, yesterday's operation took 12 hours, but it was successful.