Nineteen months ago, Erin and Abby Delaney were dared to operate at the Children's Hospital of Philadelphia to separate their interconnected heads.
The twins are now two and a half years old and live with their parents in Charlotte, NC, a suburb of Mooresville. Heather, 28, and Riley, 25. Girls' weekdays revolve around physical, developmental, linguistic, and other therapies.
How are you? In a word, they thrive, their parents and doctors agree.
"Erin crawls everywhere as if it were her mission," her mother said. "She's starting to get involved in things. She likes to grab the coffee table and reach for the remote control. Abby sits alone and rolls around. Somehow she gets where she wants to be. It's like, if I want that, I understand it. "
On Wednesday, the pigtailed redheads ̵
Publication in a reputed journal is exciting, says reconstructive surgeon Jesse Taylor and neurosurgeon Gregory Heuer, who led the team. But nothing compares to the observation of the steady progress of the twins, who returned to CHOP three times for follow-up examinations.
"I think they are doing much better than we expected. You may have delays, but the separation process is slowing down the development clock, "said Heuer. "We're not sure how good they will be in the end, but that's a good thing, if we do not have any answers [doctors]we feel reasonably good because it tells us the door is wide open."  Heather Delaney with her daughters Erin and Abby at the Children's Hospital of Philadelphia before the twins were separated on June 6, 2017. ” data-src=”http://www.philly.com/resizer/LaXj5BHnJ-rC_CHTb4cB-_Rf-sI=/1400×0/center/middle/arc-anglerfish-arc2-prod-pmn.s3.amazonaws.com/public/MET7ELUJHVFXROOLKHAGCMF3LM.jpg” src=”http://www.philly.com/resizer/ZUy3Xftz1mzztWPAKhU8thFLr-8=/0x10/center/middle/arc-anglerfish-arc2-prod-pmn.s3.amazonaws.com/public/MET7ELUJHVFXROOLKHAGCMF3LM.jpg”/>
Twins melded at the head, known as craniopagus, are the rarest paired pairs that occur in 2.5 million births The World's Most Experienced Craniopagus Surgeon James T. Goodrich at the Montefiore Children's Hospital in New York City pioneered a staged approach in which each quadrant of the brain is operated on for about 10 months.  But Goodrich & # 39; s Twins – including 4-year-old Anias and Jadon McDonald, who were followed by CNN – suffered from persistent wound healing problems and fluid retention called hydrocephalus. Erin and Abby had no such complications.
Shortly after Heather first talked to CHOP when she was about 12 weeks pregnant, Taylor suggested a way to start the breakup. The technique, called distraction osteogenesis, was well established for the correction of cranial deformities, but was never used in the separation of craniopagus. She takes advantage of the paradoxical fact that when a bone is cut and the two ends are slowly and gently pulled apart, the process stimulates bone growth as the tissue attempts to heal.
The twins were just four months old when their skulls were cut at the intersection of the heads. They were equipped with custom padded distraction devices that painlessly pulled their heads apart about seven hundredths of an inch a day for two months.
When the surgeons explained to Inquirer 2017 and now in the journal, this traction served several purposes. It improved the position of the twins' heads, producing additional tissue that was helpful in later reconstructions, and, most importantly, an inch-wide open channel that allowed more favorable access to cranial blood vessels.
These vessels are a major obstacle, even to twins like Erin and Abby, who shared only a small part of the brain. Not only does cranial blood drain off to feed other vital organs, but a twin – in this case Erin – has a disproportionate amount of vessels. The division of this circulatory tissue is particularly risky and potentially debilitating for the mutant twin, in this case Abby.
The doctors decided to separate Erin and Abby at the age of 10 months – younger than any previous Craniopagus twins – in the hope of capitalizing on the resilience or plasticity of infant brains. Theoretically, the team wrote in the journal, this would allow for "a faster and more complete recovery than at an older age".
However, this theoretical advantage had to be weighed against a biological reality: "In infants … even a modest loss of blood can be life threatening."
Originally, the doctors planned to perform a two-stage operation in which the babies were asked three weeks, to heal between treatments. The second stage culminates in the cutting of a large vein, the sagittal sinus, which is a vital channel for blood and cerebrospinal fluid.
However, the first stage was without complications, with minimal blood loss and in less than four hours, "she wrote in the journal. "Therefore, it was decided to continue the separation without delay."
Scientific journals try to be strictly factual and dispassionate, so this seven-hour second stage is simply called "more complicated."
But in 2017, the surgeons said, the race for the tireless blood loss of the twins in this second phase of the operation was a staggering event.
"If Abby's bleeding lasted much longer," said Heuer, "we could have lost her.
In a blog she has shared with the twins since her pregnancy, Heather, a former nanny, confided to one of the hardest parts of her parental journey.  "There is no book to follow," she wrote in September 2018. "I can not read to toddlers what to expect because my toddlers are different."
One difference is that Erin and Abby can swallow and normally digest food, they do not feel like it. Almost everything they eat is mashed by her mother and injected into the abdomen through a tube that she connects to an access port in her stomach.
"We've tasted so many different foods, textures, sweet, savory, crunchy, puree, 'puff, melts, teething biscuits, and nothing really seems to interest them," complained Heather.
Nevertheless, the growth of the twins is on the right track and they are on average old for their age. Although neither path is yet in effect – a milestone that is usually reached at the age of about one year – Erin's ability to stand up to furniture is an encouraging transitional step. Both girls use therapeutic devices to help them learn how to walk. Abby, whose recoil was greater because she got less of the crucial vein, also hangs in a stool that strains the legs to strengthen her muscles.
As far as verbal communication is concerned, this is Also restrained, but the twins seem to be at the edge of the breakthrough.
"They say" Mama "and" Dada, "but I do not think they know what they are saying," Heather said, "According to the speech therapist, they do advanced babbling and even make noises," when they hear from
There is no doubt about the ability of the twins to communicate without words.
" When Daddy comes in, they get excited, "Heather said of her husband, who works for a shoe company. "If he pays too much attention to one of them, the other starts screaming and kicking. He gets the best giggle and smiles.
Heather has recently noticed another insightful interaction – between the sisters.