By Ilaria Polleschi
MILAN (Reuters) - Former Italian prime minister Silvio Berlusconi had open heart surgery at the age of 79 on Tuesday, an operation his family described as a success and his supporters greeted as a sign that he could soon return to the political fray.
The center-right leader and media mogul was taken to hospital last week suffering from what doctors called a life-threatening cardiac deficiency. Berlusconi, still engaged in active politics, has worn a pacemaker for the past decade.
He underwent a four-hour operation at Milan's private San Raffaele hospital to replace a defective aortic valve.
"The operation went well. He was breathing normally. We were not particularly worried before. We are even more relaxed now," Berlusconi's younger brother, Paolo, told reporters outside the hospital, which is well known for its cardiac unit.
"His heart is very strong and in good shape, I am sure that he will overcome this trial and will come out of this the same as before, or even stronger and more determined than before."
Family and supporters have kept a vigil at the hospital since Berlusconi was admitted. One supporter erected a banner -- "Forza Silvio. Don't give up" -- while his girlfriend, 30-year-old Francesca Pascale, was pictured in local media wiping away tears while looking out from a hospital window.
"Francesca was emotional like all women. She is at his side, little by little his children will arrive too," Paolo Berlusconi said.
A hospital statement said Berlusconi had been placed in intensive care, as planned, but gave no more details.
A hospital official said the four-time premier would stay in intensive care for 48 hours and would be under sedation until Wednesday.
In a post on Facebook (NASDAQ:FB), Berlusconi wrote on Monday: "Naturally I am worried, but I have been very much consoled by the outpouring of affection and support that have come from many sides, including from so-called political enemies."
Berlusconi's personal doctor, Alberto Zangrillo, said the operation went as planned.
He had said last week that Berlusconi had been in a very serious condition when he was taken to the hospital but was expected to recover fully from the surgery within a month.
Berlusconi's once-powerful center-right group of parties has become increasingly fragmented in recent years, mostly since he lost his grip on power in 2011 at the height of the euro zone debt crisis.
His Forza Italia (Go Italy!) party suffered mixed fortunes in local elections this month, with his candidate for Rome mayor finishing fourth. The campaign took its toll on Berlusconi and his doctor said he would benefit from quitting politics.
(additional reporting by Valentina Consiglio; Writing by Silvia Aloisi; Editing by Richard Balmforth)