Delaware surgeon lends hands to Florida conjoined twins

Throughout his medical life Dr. Stephen Dunn's hands have deftly separated and transplanted around 400 livers.

But as of last Thursday Nemours/Alfred I. duPont Hospital for Children's chief of general surgery and solid organ transplantation can say he has four high-risk conjoined twin organ surgeries under his belt, a feat in spite of the rare condition and low survival rate.

"It's not as many as I would have liked to have done," Dunn said.

Dunn was part of a 20-person surgical team tasked with separating a rare set of conjoined twins born in Jacksonville, Florida. The 5-month-old twins, Carter and Conner Mirabal, were born facing one another with their livers, bile ducts and intestinal tracts connected from below the breastbone to bellybutton.

The First Coast News, one of the News Journal's sister tv stations, reported that their surgery is believed to be the first performed in Northeast Florida.

"There was an enormous amount of planning," Dunn said Thursday, a week later. He had specifically worked on separating the twins' livers. Dunn's last conjoined twin surgery was five years ago when he helped twins from India who were connected in practically the same way.

It's a little bit like music, he says of the surgeries, referencing how Mozart would do multiple variations on a classical music theme.

"You learn something different from every child you take care of," he said.

The boys are doing well, Dunn said, but because of where they were conjoined, they have a long road ahead.

Their chest cavities and lungs did form properly so there were difficulties closing the muscles and skin around the abdomen without compromising the lungs. But, that is not unusual and it's expected that the twins will undergo a follow-up surgery in the coming days to fully close the cavity, Dunn said.

"They're otherwise pretty healthy young men, but this kind of abnormality has implications for one's longer term health," he said.

Still, they "are significantly better than before."

The separation surgery is risky for a condition that is extremely rare. It's estimated that conjoined twins occur one in every 200,000 births. Less than half survive long enough to be candidates for separation surgery, according to the Mayo Clinic.

Physicians and medical staff from Nemours Children's Specialty Care, Wolfson Children's Hospital and UF Health Jacksonville all lent their hands.

The 12-hour surgery came early, Dunn said. Initially the boys' operation was scheduled for September, but they had some medical setbacks.

"Occasionally they would act in a way that made it seem like one had a negative effect on the other," Dunn said.

There were cross circulation issues with their connected livers that caused problems with hypertension, feeding and urination. For them to grow bigger and stronger, they had to be separated sooner, but it was going to take some careful planning.

Surgeons are used to operating on patients laying face-up or in the case of a spine surgeon, face-down, Dunn said. Things get more complicated if they have to assess patients on their side.

"You are coming into all of the structures you are looking at 90-degrees," he said.

Carter's and Conner's livers were fully-formed, but connected in such a way that it was difficult to discern how to separate them. They looked more like a singular liver volleyball, Dunn said, and the babies' gallbladders (which regulate bile into the small intestine) were mismatched – each had the other's.

Using a special ultrasound machine, a radiologist provided the literal path to separation by following blood vessels from the livers directly to the babies' hearts. The machine highlighted how each liver's blood vessels ran to Carter and Conner.

Once the surgeons found that line, it took about an hour to separate the livers, Dunn said. They even repaired an abnormal bile duct, that caused bile duct stones to form, making the movement of digestive liquid from the liver to the small intestine difficult.

Even with all hands on deck, with these types of surgeries, expect the unexpected, like the bile duct stones, Dunn says.

"You'll have to change your approach and what you do," he said.

Jen Rini can be reached at (302) 324-2386 or jrini@delawareonline.com. Follow @JenRini on Twitter.