As an NHS surgeon with more than 33 years' experience, Richard Collins was used to dealing with complex operations. But nothing could prepare him when he was asked to treat a sick gorilla in a world first.
Worried staff at Howlett's wildlife park in Kent had noticed their 22-year-old gorilla Tambabi had lost a large amount of weight.
'We did a number of tests to find out what was wrong with her but I was shocked by the result,' said head vet Jane Hoppe.
The ape was diagnosed with hyperparathyroidism. Her body was overproducing a parathyroid hormone, which was disrupting the calcium and phosphate levels in her blood and making her unwell.
Richard Collins operated alongside vet Jane Hoppe on their gorilla patient Tambabi
The poorly primate required urgent neck surgery to remove two of her four parathyroid glands, but although the operation if fairly common in humans it had never before been performed on a gorilla.
So Ms Hoppe, 30, called on a local 'human specialist', top endocrine consultant Mr Collins, who jumped at the opportunity.
'I have performed numerous operations of this type but felt that it was a privilege to be asked to be present to help one of the famous Aspinall gorillas,' the 65-year-old said.
'The glands have a habit of not being where they should be and I know where to look and how to get to them.'
In the hours leading up to the operation her keeper and vet slowly coaxed Tambabi away from her troup and family, so that neither became distressed or agitated.
Once moved out of the cage she was sedated and moved to a small operating room.
Mr Collins said: 'It was slightly bizarre seeing her on the operation table but I just treated it as a regular op.
'Gorillas are big animals; but they are very wide, rather than tall. Tambabi was just shorter than an average person.'
Tambabi is on the road to recovery thanks to the world first operation
Tambabi was anaesthetised for two hours and Mr Collins and Ms Hopper performed the surgery in just over an hour.
Mr Collins said: 'We found out the anatomy of a gorilla is slightly different from a human.
'With a gorilla there is an air sack that great apes have to help them resonate their calls, in the jungle for example.
'But it went extremely well and she was back up and about in no time.'
Tambabi was given time to recover and then reunited with her group, including her two offspring; Kifta, eight, and Moanda, five.
Richard has been back several times to the animal park to check up on his patient and feed her the odd banana. He says she is making daily progress and is on the road to recovery.
Vet Jane Hopper said: 'The unique operation was a complete success and Tambabi seems to be putting on some weight. She seems content and loves to eat! We were extremely grateful to Mr Collins for all his help.'
Mr Collins said he is happy to help out again, but thinks it will never happen.
He said: 'It was a very special operation and one I will obviously always remember. It certainly has a novelty value at dinner parties!'
Gorilla back from the brink after NHS surgeon guides world first operation | Mail Online