The drummer, who refused to be part of Black Sabbath's current reunion, is expected to make a full recovery following the procedure in California, but he has cancelled the art gallery reception in Maryland later this month, where he was supposed to discuss his fine art debut collection Absence Of Corners.

The surgery news comes just months after Black Sabbath frontman Ozzy Osbourne criticized the drummer's ability to keep up with the rest of the reunited group. The singer told the New York Daily News:

"I don't think he could have done the gig, to be honest. He's incredibly overweight. A drummer has to be in shape. He's already had two heart attacks. I don't want to be responsible for his life."

Rage Against The Machine's Brad Wilk laid down the drum tracks on Black Sabbath's latest album, titled '13', which came out June 11. For live shows, Black Sabbath has used Tommy Clufetos, drummer in Ozzy's solo band.