Doctors surgically removed a portion of illusionist Roy Horn's skull after he was mauled by a trained white tiger during a performance on the Las Vegas Strip, a neurosurgeon said.
Dr. Lonnie Hammargren said about one-fourth of the right side of the Siegfried & Roy star's skull was removed to relieve cranial pressure in the crucial hours after the Oct. 3 attack. He said Horn suffered a "pretty big stroke" but that his paralysis might only be temporary.
Horn remained in critical condition Thursday at University Medical Center in Las Vegas. Hammargren, who is in private practice, said it was unclear when Horn would undergo surgery to return the piece of skull.
MGM Mirage spokesman Alan Feldman said Thursday that Hammargren was not a member of Horn's medical team, had no authority to speak about Horn's condition and didn't have official access to the performer's medical records.
"All of us at the hotel are deeply saddened and shocked that Dr. Hammargren would have speculated on Roy's care publicly," Feldman said. "It's a violation of Roy's privacy, a violation of UMC policy, and it is clearly a violation of federal law, which was designed specifically to prevent this kind of irresponsible action."
The federal Health Insurance Portability and Accountability Act, which went into effect on April, prohibits disclosure of patient medical information by health providers, insurance companies and pharmacies without the patient's permission.
Hammargren did not immediately respond to a request for comment from The Associated Press.
UMC spokeswoman Cheryl Persinger said the hospital was investigating whether patient confidentially had been violated.
Hammargren, a former Nevada lieutenant governor, told the Las Vegas Review-Journal that he was commenting about Horn's treatment to correct misinformation about the procedure.
Hammargren didn't operate on Horn, but said he talked with Horn's surgeon, Dr. Derek Duke, about Horn's treatment.
Hammargren denied published reports that Horn, 59, underwent a radical procedure called a hemicraniectomy, involving surgical removal of half the skull.
He said Horn's surgeons instead performed a decompressive craniectomy, a more common procedure involving removal of about one-quarter of the skull.
"Dr. Duke did exactly the operation he should have," Hammargren said Wednesday. "Otherwise, Roy would be dead."
Hammargren said surgeons can remove a portion of the skull to give the brain room to expand following surgery, trauma, stroke or other medical problems.
The removed portion of the skull can then be surgically placed in the abdomen or frozen until it can be replaced, Hammargren said. He said he was told Horn's skull had been implanted in a pouch in Horn's abdomen.
Hammargren confirmed that Horn suffered a stroke and was paralyzed on the left side after the tiger attacked his neck.
"He had a pretty big stroke," Hammargren said. "We just don't know yet. Fortunately, the stroke didn't hit on the side where he talks, thinks and remembers. He can still comprehend things and do things."
The 7-year-old male tiger that attacked Horn was released Tuesday from quarantine after 10 days of isolation. Clark County officials said they determined it did not have rabies.
MGM Mirage officials said the animal, named Montecore, will continue to live at the Secret Garden, an animal habitat at The Mirage hotel-casino.
Clark County Animal Control on Thursday also revealed the animal's weight, which previously had been reported at about 600 pounds by MGM Mirage officials.
In fact, Montecore weighed 381 pounds on Sept. 20, 13 days before the attack, according to an animal control report.