Doctors this week gave Kat DeVoe of Huntsville the green light to start swimming again.

It doesn't sound that remarkable until you consider that barely three months ago, surgeons in Nashville cracked open DeVoe's chest and removed both of her lungs.

On Jan. 7, an army of transplant surgeons, anesthesiologists, nurses and other medical workers at Vanderbilt University Medical Center spent nine grueling hours swapping out DeVoe's diseased lungs for a healthy pair from an organ donor.

Devoe, 28, could have died on the operating table; doctors had to pump in 10 pints of blood, replacing nearly every drop inside of her thin frame.

Her old lungs - scarred by lifelong battle with cystic fibrosis - fell apart as surgeons lifted them out.

Today, DeVoe is back home in the Rocket City and literally breathing easier. While there is still a risk that her body will reject the donor lungs, they are functioning at 55 percent of normal capacity and getting stronger by the day.

"I feel a thousand times better than I used to," DeVoe said in a recent interview with AL.com.

Defective gene

DeVoe's parents were both unsuspecting carriers of a defective gene that affects the flow of salt and water into the cells of the lungs, pancreas and other organs.

During a routine checkup at nine months old, DeVoe's pediatrician noticed she had lost weight since her previous visit. He suspected cystic fibrosis but referred the family to Children's Hospital in Birmingham for tests.

Joni DeVoe, Kat's mother, started reading everything she could find about cystic fibrosis. One detail jumped out: People with cystic fibrosis have salty-tasting skin because of the high levels of chloride in their sweat.

"When I would kiss her, it would burn my lips," Joni DeVoe recalled. "I really knew then, before I even got the test results."

The defective gene that Kat DeVoe inherited from her parents also caused her lungs to be coated with thick, sticky mucus that interfered with breathing and trapped bacteria. Infection became a constant worry.

Joni Devoe learned on the fly to become both caregiver and mother.

For a full hour every day, she thumped Kat's back and chest with her palm to loosen the mucus. Enzyme pills became another new ritual; mucus clinging to Kat's pancreas blocked the release of natural digestive enzymes needed to break down food and absorb nutrients.

Beginning around age 10, young Kat would have to be periodically admitted to the hospital for antibiotic therapy and chest percussion treatments.

Her family called the visits "tune-ups."

As DeVoe got older, swimming became her favorite outlet. It was fun and also gave her ailing lungs a good workout. She was managing life with cystic fibrosis.

Infection

And then, just like that, she wasn't.

A routine November 2013 lung "tune-up" at Huntsville Hospital took a grave turn when DeVoe contracted stenotrophomonas maltophilia, a rare and hard-to-treat infection. The strain was too much for her weakened lungs.

For most of the next 17 months, DeVoe would be confined to a hospital bed as the life slowly leaked from her lungs. Her shallow breathing also meant that DeVoe was not exhaling enough carbon dioxide.

"My CO2 was pretty high, so I don't remember a lot of that time," she said. "I was pretty foggy."

"We thought she wasn't going to make it," said her mother.

Doctors at UAB told the family a lung transplant was DeVoe's only hope for long-term survival. On Feb. 17, 2014, she was added to the national transplant waiting list.

Winter turned to spring and spring to summer. Still, she waited.

'Getting sicker and sicker'

Donor lungs would occasionally become available. More than once, DeVoe was wheeled back into surgery and her family hastily summoned. But none of the lungs were a perfect match: too large; too small; too compromised by pneumonia or other illnesses.

"I was really feeling like it was never going to happen," said DeVoe. "And I was getting sicker and sicker."

Her lung function eventually dipped to about 12 percent of normal; DeVoe needed a super-sized supplemental oxygen tank just to leave her hospital room at UAB. A friend painted the tank to look like R2-D2 from "Star Wars."

In mid-November, DeVoe was moved to Vanderbilt University Medical Center and admitted directly to intensive care. She was beyond weak but would only qualify for a lung transplant if she could walk 750 feet in less than six minutes.

"We'd crank up the oxygen, and she would walk," said John Toelaer, DeVoe's fiance and full-time caregiver.

New lungs

On Nov. 20 - one week before Thanksgiving - DeVoe was listed for a double-lung transplant at Vanderbilt. Her family was asked to raise $5,000 to help cover what would eventually balloon to a $900,000-plus medical bill.

Joni DeVoe sought help from her co- workers at Kailos Genetics in Huntsville. "Before the weekend was over, we had the money," she said.

Kat DeVoe didn't have to wait long for her miracle. On Jan. 7, 2015, Vanderbilt's transplant team located a set of healthy, matching lungs.

Toelaer said DeVoe had the biggest smile as nurses wheeled her into the operating room. "She looked so ready."

DeVoe woke up the next morning hooked to a ventilator and in excruciating pain. The transplant team, led by Drs. Eric Grogan and Eric Lambright, had to crack her ribs to get to the lungs and then closed the huge chest incision with staples.

Sixty of them.

But progress came quickly.

A week after the surgery, DeVoe was able to breathe without supplemental oxygen for the first time in months. She checked out of the hospital the following day and started a pulmonary rehabilitation program at Vanderbilt Dayani Center for Health & Wellness.

Not enough donors

DeVoe isn't out of the woods. She has to be vigilant about taking immunosuppressant drugs to prevent her body from rejecting the new lungs. The medicine weakens the immune system, which leaves DeVoe vulnerable to infection.

For the next few months, she'll have to wear a surgical mask around strangers.

The family expects health insurance to pick up most of the tab for DeVoe's transplant surgery and hospital stay. Meanwhile, the Indiana-based Children's Organ Transplant Association has created a fundraising web page for her continuing medical expenses.

About $8,600 has been donated toward the $55,000 goal so far. If you would like to help with DeVoe's medical expenses, visit COTAforKatD.com.

On Monday, doctors cleared DeVoe to start swimming again. Her dream is to swim in next year's Donate Life Transplant Games of America in Cleveland.

Before then, DeVoe plans to write to her lung donor's family. She doesn't know the person's age, race or gender - only that they cared enough to save a stranger's life through organ donation. During her long hospital stay, DeVoe met several patients who died awaiting a transplant.

"There are so many people waiting on lungs and other organs," she said, "and not enough donors."