Clarence and Carl Aguirre will turn 3 this April as independent little boys, a huge change from their birth as identical twins joined at the top of their heads.
Their lives, which doctors predict will be very normal, were shaped in part by a method of separating conjoined twins pioneered in Utah more than 25 years ago.
It centers around "staging" the separation, dividing it into several smaller — though still daylong — surgeries to divide and reroute shared blood supply and allowing a couple of months for some healing and for the little bodies each to take over some of the functions previously shared before the next step is taken.
Dr. Marion "Jack" Walker, professor and chairman of the Division of Pediatric Neurosurgery at the University of Utah and Primary Children's Medical Center, separated conjoined twins Lisa and Elisa Hansen in 1979 using such a series of operations. Since then, he has separated in stages two other sets of twins joined at the head (called craniopagus), most recently Bessy and Doris Gonzales of Honduras in 1996. All six of his young patients survived the complex surgeries, in itself unusual.
He's the "guru" and was one of the doctors consulted before the Aguirre boys were separated in a series of four operations, full separation completed in August, said Dr. James Goodrich, director of the Division of Pediatric Neurosurgery at Children's Hospital at Montefiore in New York. He was the lead surgeon for the boys, who are from the Philippines.
Goodrich was in Salt Lake City Wednesday to present a neurosurgery grand rounds at Primary Children's and to visit with Walker.
A panel of neurosurgeons recently agreed that the best way to separate twins joined at the head is slowly, using multiple operations. Still, the idea is not universally accepted, Walker said. And though he used staging 25 years ago, it is just beginning to become the consensus.
The boys are both "thriving," although their speech is somewhat delayed and they're undergoing intensive speech therapy. They're expected to catch up, with no intellectual impairments. They have good motor skills and are very "age appropriate."
It used to be that one child was sacrificed in the hope that the other would survive, Goodrich said. If one lived, the operation was considered a success.
When Goodrich, who'd never separated conjoined twins before, started researching what he might do for the Aguirres, he was distressed to see the high mortality rate and learn of complications that were "enormous." Taking it step by step, he said, outcomes are better. "It's a credit to the U. The concept was formulated here."
Despite advances, Walker and Goodrich agreed, it's not always possible to separate conjoined twins. It depends on how they are joined and the vital organs and tissues they share.
Goodrich's team went into the surgeries convinced the Aguirres shared a mass of blood vessels, but no actual brain material. They were unpleasantly surprised to find some of the parietal lobe was not even fused together, but actually shared. Working carefully, in the fourth surgery, they were able to divide it. With the Gonzales girls, Walker found a finger-sized section of shared brain.
Without staging, Goodrich said, Carl would have taken a "major hit." He had extremely low blood pressure, while his brother's was excessively high. In the surgery, most of the vessels were "donated" to Clarence, and his own other vessels were expected to become capable of supporting his blood circulation needs. Had they divided the vessels differently, it's likely both would have died, Goodrich said.
With each surgery, the boys were a little more alike in their prospects for survival, a little stronger.
By staging the surgery, the amount of transfused blood needed was drastically reduced. Goodrich said they used six units; one previous separation required more than 90.
Major technological changes have made more successful separations possible, too. Forty years ago, twins were separated using an angiogram to show the doctors what they were working with. Goodrich used a number of imaging options, including a holographic image that he could "reach inside," produced by a Utah County company, Voxel. He also had a model of their joined heads that showed where the vessels were pooled.
The difference in imaging is like driving to Los Angeles with a paper map and using the new global positioning technology, Goodrich said.
Walker predicts one day soon surgeons will be able to line up holographic images precisely with the brain. Imaging is already so accurate they "know which way the blood is flowing" between conjoined twins, he said.
Conjoined-twin births occur about one in every 50,000 births. Those joined at the head are about one in 5 million, Goodrich said. Many of them die in the first two days, and fewer than 20 percent survive two years if they are not separated.
E-mail: lois@desnews.com