The Carlsen twins have come a long way since they were born on the 29th of November, 2005. The two sisters, Abbigail and Isabelle, were born conjoined at the chest and abdomen: they shared a liver, an intestine and their hearts were intertwined.
Conjoined twins are extremely rare phenomena
Its occurrence is estimated to range from 1 in 49,000 births to 1 in 189,000 births.
The young Carlson sisters were separated soon after birth in a daring surgical procedure performed by doctors at the Mayo Clinic in Rochester, Minnesota. The successful operation still astonishes the family and doctors.
“My heart leaps every time I hear about the Carlsen girls or see a picture of them doing so well,” said Dr. Christopher Moir, who led a team of 17 surgeons to separate the girls on May 12, 2006, “because I know they beat the odds.”
More than 45 percent of conjoined twins are stillborn when delivered, and another 35 percent survive only the first day, according to the University of Maryland Medical Center. When the separation of the Carlsen sisters took place, 60 percent of all such procedures ended in fatalities.
Wonder And Worry
The girls’ parents, Jesse and Amy Carlsen from Mandan, North Dakota, still alternate between wonder and worry when it comes to their family’s past and future.
The wonder comes from the fact that two twins who are so similar and actually shared parts of one body, can be so different in character. They’re alike enough in appearance. So much so they were able to pull off an April Fools’ joke couple of years ago. They switched clothes and went to school as the other one. The project was given the go ahead by their mom.
But even as conjoined infants, they were different. Abby was the sensitive snuggler and Belle the hyper talker — and in some ways, those differences have held up.
The worry comes from what they have been through. The surgery left gaps in their chest walls, and girls needed Gore-Tex implants to cover the openings. Belle in particular needed extra protection for her heart and lungs.
The surgeons had to make some delicate decisions. They gave the twins’ shared bile duct and duodenum — the top end of the small intestine that breaks down food — to Belle, while the lower section went to Abby, who had been the healthier of the two babies when they were conjoined. They correctly surmised that the remaining intestine in each girl would take over the roles of the missing sections. However, Abby needed a particularly harsh surgery to reconnect her digestive system.
So naturally, any abdominal discomfort is a big thing at the Carlsens. “Little things scare me,” said Amy, a registered nurse at Sanford Health in Bismarck, North Dakota, “because you just don’t know.”
The parents know, however, that being overbearing or sheltering the twins is not the way forward. Abby and Belle compete in gymnastics and they are not excluded from any activity their peers are involved in.
Separation surgery was possible because the girls had their own hearts and lungs, but the fusion of their liver and intestine made it unlike the two previous separations attempted at the Mayo Clinic.
“You had to create two out of one,” Moir said. “We were getting right down to the limits of what each girl had left for reconstruction.”
One challenge was moving Belle’s heart into her chest. Several attempts caused dangerous drops in her blood pressure until doctors found a placement that worked.
The nightmare scenario came hours later, when the surgeons were severing the liver. Despite planning, the anatomy wasn’t what doctors expected, and they couldn’t distinguish a blood vessel that Belle needed intact from a bile duct that Abby needed cut.
It was like defusing a bomb with wires in different colors in a spy movie, Moir said. “When we got to that point in the operation it was like, ‘Now, I understand. Now I know why these other twins died” 60 percent of the time.
As the operating room team of 30 stood silently, Moir chose one vessel to cut and exhaled when bile dripped out. He had picked the right one.
Medical Science Has Gained From The Experience
Preparation was everything in the Carlsens’ case. It made Moir’s team able to adapt to the challenges that arose during the surgery, and it paid off months later when another set of twins needed emergency separation.
Nowadays, Mayo is the go-to place when the possibility of separation is being determined.
Perhaps the biggest change that followed the Carlsen surgery was the broad use of 3-D printing of internal anatomy. Mayo doctors are exploring 3-D printing of actual implants, but Moir said that was inspired by a 3-D model of the Carlsens’ organs that was used for planning and practice.
He keeps that model in his office.