Surgeons began operating Friday on 22-month-old twin boys from the Philippines who are joined at the top of their heads — a risky procedure that doctors say could last up to 10 hours.
Carl and Clarence Aguirre went into surgery around 7:23 a.m., said Pamela Adkins, a spokeswoman at Montefiore Medical Center in the Bronx. It is the third major operation in a monthslong procedure to separate the boys that began last year.
A fourth operation later this year, and possibly a fifth, would still be necessary before the twins can be separated, doctors said.
“As we move toward the back of the head, the anatomy changes,” said Dr. David Staffenberg, chief of pediatric plastic surgery. “The veins get a little larger and it’s a little more dense so it’s really going to be a demanding technical exercise for the neurosurgeons.”
Doctors planned to cut into the twins’ skulls and divide most of the remaining blood vessels, including one of the two major veins, that are connected to both boys’ circulation systems.
The vessels then will be assigned to one twin or the other, establishing two nearly independent blood flows.
Dr. James Goodrich, chief of pediatric neurosurgery, said Clarence, whose vein system is better developed, would likely keep the bulk of the existing system. For Carl, blood flow will be directed into other existing veins.
Risks include bleeding, because the veins’ walls are so thin, and swelling that can damage the boys’ separate brains.
The twins have been growing well and learning some motor skills needed when they are separated. Doctors decided to separate the brothers in stages rather than a single marathon operation — giving them time to heal and gradually adapt to changes in their circulation system.
Last year, 2-year-old twin boys from Egypt were separated in one 34-hour operation that ended Oct. 12 in Dallas. Doctors say Ahmed and Mohamed Ibrahim are responding well to therapy.