Bono has revealed that he underwent an eight-hour heart operation in 2016 to repair a “blister” on his aorta.

The U2 frontman recalled the medical issue and the subsequent procedure in his new memoir Surrender: 40 Songs, One Story, which was released on Tuesday (November 1).

“I was born with an eccentric heart,” Bono wrote. “In one of the chambers of my heart, where most people have three doors, I have two. Two swinging doors, which at Christmas 2016 were coming off their hinges.”

The singer went on to explain that his aorta – “your main artery, your lifeline, carrying the blood oxygenated by your lungs, and becoming your life”, as he put it – had become “stressed” over time and eventually developed a “blister”.

“A blister that’s about to burst,” Bono continued, “which would put me in the next life faster than I can make an emergency call. Faster than I can say goodbye to this life.”

As a result, the star was admitted to the Mount Sinai Hospital in New York City where he went under the knife in order to fix the problem.

“I know it’s not going to feel like a good day when I wake up after these eight hours of surgery, but I also know that waking up is better than the alternative,” Bono said.

“Even if I can’t breathe and feel as if I am suffocating. Even if I’m desperately drawing for air and can’t find any. Even if I’m hallucinating, cause I’m seeing visions now and it’s all getting a little William Blake.”

The 576-page Surrender… explores the origins of 40 key songs in U2’s extensive discography. Each chapter is named for the tune it covers, with Bono’s life story weaved throughout.

The story of his 2016 heart surgery comes under the ‘Lights Of Home’ chapter; the track in question appears on U2’s 2017 album ‘Songs Of Experience’.

Bono published the opening lyrics to the song to introduce the section: “I shouldn’t be here ’cause I should be dead/ I can see the lights in front of me/ I believe my best days are ahead/ I can see the lights in front of me.”

Elsewhere in the book, Bono talked about discovering that his cousin is also his half-brother, the alleged death threats he’s received in his life, and the 2014 controversy in which U2 arranged for their album ‘Songs Of Innocence‘ to be automatically downloaded onto the devices of 500million iTunes users.

Last month, the frontman made a surprise visit to his old secondary school in Clontarf, Dublin, where he read from his new memoir.

Bono is currently out on a 14-city book tour dubbed ‘Stories Of Surrender’, which kicked off in New York City yesterday (November 2).