WARNING: This post contains images and videos of surgery, which some readers may find graphic.
Mollie and Sam Dolan’s five-month-old son Henry was diagnosed with two heart conditions when he was born 12 weeks premature on 2 May.
The Dolans, from Minnesota, US, endured an “agonising” five month wait for a suitable organ donor and for doctors to declare Henry strong enough to undergo surgery.
Then on Saturday 15 October, they finally received the news they had been waiting for.
“Oh my goodness! I have no words,” Ms Dolan wrote on Facebook.
“Please be praying for us and the donor family as we know they are going through unimaginable grief. How amazing that they have chosen to give a life! Wow!”
The Dolans shared their experiences on the Facebook page Hope for Henry - including photos and videos filmed by doctors inside the operating theatre.
Henry’s surgery was scheduled for the following day, and surgeons kept his parents updated throughout using the app EASE.
Henry is wheeled into surgery.
Surgeons prepare to operate.
Surgeons let Henry’s parents know he is doing well.
Henry’s new heart arrives.
Henry’s old heart is removed.
Dr Eghtesady tends to Henry’s new heart.
The bypass machine which pumped Henry’s blood before his new heart was placed.
Dr Eghtesady reconnects Henry’s vessels.
A surgeon tends to Henry’s new heart.
The family are reunited following the operation.
"What I’ve witnessed today, is nothing short of a miracle,” wrote Ms Dolan.
“A miracle given to us, by a family who is enduring tremendous heartache and pain. What incredible strength they must possess. Please continue to lift this family up in prayer.
“The picture [above] is me listening to Henry’s heartbeat for the first time. Incredible. No more swooshing! Just nice loud thumping.”
Friends of the family have set up a GoFundMe fundraising page to help them with the cost of medical bills.