Prince Philip underwent a successful procedure for a pre-existing heart condition on Wednesday, over two weeks after he was hospitalised. Buckingham Palace announced that he will continue to stay at the hospital under doctors' observation.

"The Duke of Edinburgh yesterday underwent a successful procedure for a pre-existing heart condition at St Bartholomew's Hospital. His Royal Highness will remain in hospital for treatment, rest and recuperation for a number of days," the palace said in a statement released on Thursday, reports BBC.

The 99-year-old has already spent 16 nights in the hospital. He was first admitted to King Edward VII's hospital in London on February 16 in what was dubbed at the time as a "precautionary measure," but was moved to St. Bartholomew's Hospital this Monday for tests and observation on his heart condition and an unknown infection.

Queen Elizabeth II has continued carrying out her royal engagements from Windsor Castle amid her husband's recent health battle. Meanwhile, the British royal family is keeping "their fingers crossed" for the Duke, who is just months away from celebrating his 100th birthday. The Duchess of Cornwall gave an update on his health when she visited a COVID vaccination centre in Croydon on Wednesday, the day he underwent the procedure.

"We heard today that he's slightly improving. So, that's very good news. We'll keep our fingers crossed," Camilla said about her father-in-law.

This has been the longest hospital stay to date for the Duke, who retired from public duty in 2017 at the age of 96. He was previously treated for a blocked coronary artery in 2011 at Papworth Hospital where he had a stent inserted. In 1987, he was hospitalised for a hernia repair, while a small benign growth was removed from his nose in 1996. He had also received treatment for a bladder infection in 2012, and exploratory surgery on his abdomen in June 2013.

In April 2018, the 99-year-old underwent a successful hip replacement. From 20 to 24 December 2019, he stayed at King Edward VII's Hospital and received treatment for a "pre-existing condition," another visit which was described by Buckingham Palace as a "precautionary measure".

Prince Philip
Profile of Prince Philip, husband of Britain's Queen Elizabeth II, who was admitted to hospital as a precaution on Wednesday. Photo: AFP / STF