Twins prepare for separation ordeal.
sisters whose bodies are fused at the mid-section in an operation that could take 14 to 30 hours.
Kendra and Maliyah Herrin, who are practically face to face, share one pair of legs, a liver, one functioning kidney and part of the large intestine.
If all goes according to plan on Monday at Primary Children's Medical Centre, each girl will get one leg and Kendra the kidney.
Maliyah will be put on dialysis until she is strong enough for a kidney transplant from her mother, Erin Herrin, ideally within three to six months.
Dr Rebecka Meyers, the hospital's chief of paediatric surgery, said she believes this will be the first time separation surgery has been attempted on twins with a shared kidney.
The sisters were born in a perpetual hug, and have grown into outgoing girls who chatter away and finish each other's sentences. They say they like being together all the time, but they are also full of plans for separate lives. They want to walk without using their wheeled walker, sleep in bunk beds and ride bikes.
"I want to have a princess bike," Kendra said. "I can go fast."
Conjoined twins occur about once in every 50,000 to 100,000 births. Only about 20% survive to become viable candidates for separation, and most separation surgeries occur when the twins are six to 12 months old.
"The reason for that is partly psychological, partly mechanical," Meyers said. "If Maliyah had had a kidney, these girls would have been separated a long time ago."
A kidney transplant would have been harder before the age of four, and doctors advised waiting.
Before deciding to go ahead, doctors and the girls' parents ( who also have a six-year-old daughter and 14-month-old twin boys ( talked with ethicists, because the surgery could make things worse for Maliyah, who faces the risky prospect of an organ transplant.
"We have more than one ethicist who thinks these girls don't need to be separated," Meyers said. "Mom and Dad have had a chance to hear all of that and talk to people on both sides."
Before making their decision earlier this year, the Herrins had Kendra and Maliyah talk with a psychologist. The couple concluded that while the girls expressed some fear about the surgery, separate "was how they saw themselves when they were older," Jake Herrin said.