Seve Ballesteros had surgery to remove a brain tumor, and the 51-year-old golf great was conscious and stable Wednesday.

La Paz hospital said there were no complications from Tuesday’s surgery. Spanish state news agency Efe reported the operation lasted 12 hours.

The hospital said a sizable part of the tumor was removed. It was not immediately known if it was malignant and it would be several days before the results were announced.

‘‘At the moment he is conscious and stable, although he will not be able to receive any visitors in the coming days until he has recovered from the surgical process,’’ the hospital said in a statement.