Their rare birth may have provided a sizable challenge to doctors, but conjoined twins Charity and Kathleen Lincoln did one particular thing right - they arrived in the year 2000.
Surgical techniques and imaging technology developed over the past 30 years gave doctors the tools they needed in their attempt to separate the 7-month-old twins Saturday at Children's Hospital and Medical Center.
Even in 2000, it's a highly involved process that includes surgery that could last 20 hours, said lead surgeon Dr. John Waldhausen.
Four teams of specialists - two each of pediatric surgeons, urologists, orthopedists and plastic surgeons - started working together months ago to test the twins for possible separation and plan the surgery.
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Eventually, one specialist in each team would be assigned to one of the twins.
"This is a real team effort, " said Waldhausen, who met with the twins' parents before their birth. "This couldn't be done by one physician, or without the support of the hospital."
In addition to five or six in-depth planning meetings by the surgical teams, there has been a lot of discussion in the hallways about how to do things individually, Waldhausen said.
Tests of the twins included many of the new imaging types of technology, like CAT scans, MRI exams, CTs and more. Dye tests to check the babies' urinary tract and intestinal construction were done, and casts were made of their pelvises.
All of the tests - some not available even in 1990 - give doctors the best possible picture of the twins' internal structure and the likelihood of a successful surgery.
"We have a good idea of what to expect, " Waldhausen said. "I think the chance of it not being able to be done is pretty small."
Physicians felt comfortable and confident going into Saturday's surgery, said Waldhausen, who assisted in the separation of conjoined twins in 1993.
"Nobody in the world has had a lot of experience with conjoined twins, " he said.
But team members have a great deal of experience with many of the individual conditions the girls have, he said.
"These girls just happen to have them all combined, " Waldhausen said.
The surgical separation plan
·Pediatric specialists entered Saturday's surgery to separate the conjoined Lincoln twins with a complex but highly flexible plan. There would be much they would not know until the surgery began. Their plan going into Saturday morning included the following steps:
·Pediatric plastic surgeons Joe Gruss and Michael Whelan would assist pediatric surgeons Robert Sawin and John Waldhausen in locating where to make the initial incisions.
·After the incisions, Sawin and Waldhausen would explore the abdomen to ensure the twins have what they need to be separable. If they do not, the separation halts, and the twins remain conjoined.
Of particular interest: Do the twins have two sets of bile ducts to drain from the livers, or enough there to construct needed sets? And do the twins have enough small intestine for each. Small intestines are critical for absorbing nutrients.
·If the surgery proceeds, Waldhausen and Sawin planned to separate the fused livers.
·Next, surgeons would divide the shared large intestine, deciding which baby gets which part.
·Pediatric urologists Michael Mitchell and Richard Grady would then decide if the shared bladder can be separated. If it can't, the physicians must decide which baby keeps the bladder and then construct a bladder from a piece of intestine for the other baby.
·Pediatric orthopedists Kit Song and Mohammed Diab would separate the fused pelvises.
·Surgeons would then remove the low-functioning third leg and use muscle and tissue from it to help close the babies' wounds.
·At about this time, the babies would be separate. One would stay in the original operating room, and one would go into another with her own set of surgeons.
· Mitchell and Grady would correct urinary tract and bowel irregularities and construct an anus for each baby.
·Song and Diab would probably need to reposition the babies' pelvis bones, which are splayed open rather than closed into a ring.
·Gruss and Whelan would help close the large wounds left by the removal of the other baby, using artificial "fascia" or muscle, and skin that has been stretched through balloons inserted under the babies' skin and slowly inflated. This would complete the initial separation surgery, though other surgeries are likely to follow in later months and years.