HOUSTON (AP) -- Rep. Gabrielle Giffords' recovery isn't slowing down while her astronaut husband speeds around the Earth.
Giffords will undergo surgery Wednesday so doctors can replace a piece of her skull with a plastic implant, another encouraging step since the Arizona congresswoman was shot in the head more than four months ago.
The surgery -- coming just days after Giffords traveled to Florida to watch her husband, Mark Kelly, launch into space -- was confirmed to The Associated Press by two people familiar with the congresswoman's care. They spoke on condition of anonymity because the information has not officially been released.
Doctors removed a piece of Giffords' skull to allow room for brain swelling shortly after a would-be assassin shot her in the head Jan. 8, critically wounding her, killing six people and injuring 12 others at a political event in her hometown of Tucson, Ariz.
The three-term Democratic congresswoman has been wearing a helmet adorned with an Arizona state flag. Doctors said when she arrived in Houston in late January they hoped to do the cranial surgery in May.
Dr. Richard Riggs, chair of physical medicine and rehabilitation at Cedars-Sinai Medical Center in Los Angeles, said the surgery to place the plastic implant is relatively simple. Recovery is short -- a day or two at the most -- and is mostly from the effects of anesthesia, he said.
"This gives her quality of life because she won't have to worry about the helmet and protection when moving around," said Riggs, who is not involved in Giffords' care.
The implant is placed under the scalp, allowing hair to grow on top so it is not visible. Riggs said the piece of skull that doctors removed likely was contaminated or shattered by the bullet that pierced the left side of Giffords' brain. That would make the skull unfit to be reattached, which is why doctors would use an implant, Riggs said.
Giffords' chief of staff, Pia Carusone, declined to comment on whether Giffords would undergo the surgery on Wednesday. Giffords' doctors do not comment on her condition without approval from her family.
Giffords returned to Houston and rehab late Monday after watching her husband's shuttle launch in Florida. When Endeavour's five Americans and one Italian got off the ground Monday, Giffords watched in private from a wheelchair on the roof of the launch control center and remarked, "good stuff, good stuff," according to her staff.
That Giffords would watch the shuttle launch seemed improbable a little more than four months ago. And some patients don't have this type of surgery until after they are released from the hospital.
Her doctors have said she has made remarkable progress in what will be a long recovery.
The next step will be to release her from the hospital. Then she will continue speech, occupational and physical therapy at an outpatient clinic.
(Copyright 2011 by The Associated Press. All Rights Reserved.)