The operation involved deconstructing her male genitals and repurposing the nerves and skin as female anatomy.

When it was over, Kat developed aspiration pneumonia and had vomiting and dry heaves for days, normal reactions to anesthesia, narcotics and antibiotics, but Dr. McGinn said Kat was hit harder than most.

Before the surgery, she had been impish and playful. Now she buried her nose in her Nintendo 3DS and cracked a rare smile at an old text message consisting entirely of “Meow,” “Meow.”

Her father felt helpless as she refused food and lost about 20 pounds. Dr. McGinn said it was not unusual for patients to become depressed after surgery and compared this to postpartum depression.

Kat was anxious about having enough privacy in college, since her new vagina needs constant care or it will close off like a wound. “The only thing I’m thinking about now is the room situation,” she said.

Six weeks after the operation, she was still so weak that she had to take the elevator at school instead of the stairs.