Slow Separation For Twin Boys

If all goes well during a daylong operation Wednesday, Carl and Clarence Aguirre, 2-year-old twins from the Philippines joined at the top of their heads, will wake up in separate beds.

For the first time, they'll be able to look into each other's faces. And they should soon be able to sit up, stand straight and walk for the first time - no longer the toddlers who couldn't toddle.

"I can't wait to see how they react," said Dr. David Staffenberg, the plastic surgeon on the team that plans to separate the boys at Montefiore Medical Center in the Bronx. "I can imagine them looking at each other and thinking, 'I know that guy, but how come he's over there?"'

Since last year, Carl and Clarence have been the focus of a determined effort by their mother, Arlene Aguirre, as well as two hospitals and a medical team donating their services. The doctors have taken a surgical approach employed only a few times before on conjoined twins, replacing the typical marathon two-day operation with four shorter procedures over 10 months.

The aim is not only the survival of both boys - often one twin dies, even if one makes it through such surgery - but to increase their long-term chances without major complications.

Still, Staffenberg said, success is "very far from a done deal. There's lots that could go wrong."

In previous operations, the boys' skull was opened, their separate-but-touching brains carefully pushed apart and most of their shared blood vessels cut and divided. Magnetic resonance imaging shows that the boys now have nearly equal, thriving circulation systems, said Dr. James Goodrich, the lead surgeon. What had been dormant veins on Carl's side have plumped up and assumed the duties of veins on Clarence's side that had been doing the circulation work for both boys.

Like those operations, the fourth one on Wednesday will be alarmingly delicate.

Goodrich and Staffenberg will cut through skin and bone to open a window on the brains and the surrounding blood vessels. The major vein the boys still share will be cut and divided.

The last area where the brains are touching - about an inch and a half across, Staffenberg said - will be teased apart while doctors keep a sharp eye out for any connecting veins.

"If you just say, 'We're done,' and yank them apart, you wind up with a lot of bleeding and all these strokes, which is an issue we've been trying so hard to avoid," Staffenberg said.

It's difficult work, even with the help of magnifiers. The surgeons have described the tiny veins as having "the consistency of wet toilet paper."

The team will check for excessive bleeding or swelling before deciding whether to continue with the separation. "There's always another day," Goodrich said.

Once the decision is made to go ahead, the last of the connecting skull bone, including a large portion that "flares out in the wrong direction," will be removed, Staffenberg said. The boys' head-to-head tables can then be moved apart to give the doctors more room.

Staffenberg will then have to reconstruct the dura mater, a membrane that covers the brain. Though the boys have separate brains they shared the membrane, and extra material will be needed to cover both brains. It could come from the boys' midsections or a commercially available substitute, he said.

"The dura is the layer that keeps the cerebral spinal fluid in around the brain," he said. "You don't want that leaking."

The next step is to "wash everything out and then start closing the skin," Staffenberg said. He will leave the reconstruction of the skulls - a major project - for later.

"I had to be sure in designing (the procedure) that their hair was going to be growing in the right direction," Staffenberg said. "I didn't want them to have these big cowlicks."

For a finishing touch, Staffenberg said, "I made the suggestion that we put them both into Yankees caps. This is the Bronx." He wasn't sure the hospital would go for it, he said.

Aguirre, the boys' mother, brought them to New York from the Philippines in September and lives with them at Blythedale Children's Hospital in Valhalla between surgeries at the Children's Hospital at Montefiore. She has chosen not to be in the operating room, Staffenberg said, but will get regular updates during the surgery.

Aguirre declined to be interviewed as the operation approached. "I am worried but I am hoping," she said last month.

Goodrich said that although the boys will have to be watched for months before the surgery can be fully assessed, "We'll know a lot on Day One just by how the procedure goes. If we get through this case without a lot of swelling, without a lot of bleeding, then I can make a very good prognostic outcome. Long-term, there's the danger of infection, meningitis, spinal fluid leaks."

Staffenberg said both boys will need a great deal more of the occupational and developmental therapy they've been getting at Blythedale.

Goodrich said he's learned to "divorce myself from the personalities," but added, "There's no way to avoid getting caught up in Carl and Clarence's case and their mom. It's human nature."

Said Staffenberg: "I want to deliver for these little guys."

By Jim Fitzgerald