Jimmy Kimmel has thanked medical staff for "saving" his son Billy's life on his 5th birthday.
The 54-year-old talk show host's boy underwent open-heart surgery for a rare congenital heart defect just days after he was born in April 2017, and every birthday Jimmy shares his gratitude to the doctors and nurses at Children's Hospital L.A. and Cedars-Sinai Medical Center for their life-saving care.
The comedian captioned a sweet picture of Billy and a birthday cake on Instagram: "Happy 5th birthday to our little nut.
"We are eternally grateful to the brilliant doctors and nurses at @ChildrensLA @CedarsSinai for saving Billy's life and to those of you whose donations, prayers and positive thoughts meant everything. Please support families who need medical care. Link in bio."
The 'Jimmy Kimmel Live!' star - who has Billy with wife Molly McNearney, with whom he also has seven-year-old daughter Jane - announced the news of his son's surgery on his talk show at the time, and said waiting for the operation to finish was "the longest three hours" of his life.
He said: "On Monday morning, Dr. Vaughn Starnes opened his chest and fixed one of the two defects in his heart. He went in there with a scalpel and did some kind of magic that I couldn't even begin to explain. He opened the valve, and the operation was a success. It was the longest three hours of my life.
"He's doing great. He's eating. He's sleeping. He peed on his mother today while she was changing his diaper. He's doing all the things that he's supposed to do. This is the best."
Jimmy - who also has kids Katie, 30, and Kevin, 28, with former wife Gina - previously admitted he didn't want to "get too close" to his son after he was born with the defect.
The TV star and his spouse weren't initially open with their feelings about the situation, but realised after the tot had undergone a second surgery they had shared the same fears.
He said: "There were secrets we kept from each other that we revealed only after the second surgery.
"The biggest one was that, I think subconsciously, we didn't want to get too close to the baby, because we didn't know what was going to happen...I don't know if that's right or wrong or common or uncommon.
"But when I told her I was feeling that way, she said, 'Oh, I'm so happy you said that because I was feeling that way too, and I didn't want to express it.'"