Fran Curtis said in a brief statement that Richards would remain an outpatient at The Ascot Hospital in Auckland and would return for checkups.
Richards suffered the injury April 27 in Fiji. News reports have variously claimed that he fell out of a palm tree or from a jet ski. It was unclear how long Richards would remain an outpatient and Curtis could not immediately be reached for comment.
Richards was "up and talking" soon after surgery May 8 at The Ascot Hospital in Auckland, but was expected to take several weeks to recuperate, LD Communications said in a statement issued in London.
"Last week Keith was under observation in Auckland following a fall in Fiji and was feeling well after being examined by doctors last week," the statement said. "However after complaining of headaches yesterday, doctors thought it prudent to move ahead with a small operation to remove the pressure."
The Stones' "A Bigger Bang European" tour, which was scheduled to start in Barcelona, Spain, later this month, will be postponed until June, London-based publicists LD Communications said in a statement earlier this week.