LOS ANGELES, Sept. 11, 2003 (PRIMEZONE) -- In a rare, highly complex and historic procedure, teams of physicians and surgeons at Childrens Hospital Los Angeles today will complete the separation of identical conjoined twin girls who were born nine months ago along with their sister -- a separate and normally developed fraternal triplet.
The girls, who will be referred to publicly as "Baby A" and "Baby B" out of respect for their parents' wish for privacy, are a type of conjoined twin known as "Ischiopagus Tripus." ("Ischio" is a Greek word for "hip," "Pagus" for "fixed" or "united," and "Tripus" for "three legs.") Of the more than 1,000 conjoined twins cases documented, only 153 have been Ischiopagus, and of those, 58 (6%) have been Ischiopagus Tripus. This is only the second known case of conjoined twins also being part of a set of triplets.
Pediatric General Surgeon James E. Stein, M.D., FACS, FAAP, is leading the team of nearly 50 people, including general, orthopaedic and plastic surgeons, anesthesiologists and nurses who are participating in this milestone surgery expected to last nearly 24 hours. "Ischiopagus twins, while one of the rarest forms, are also in many ways the most complex," says Dr. Stein. "Since they involve so many organ systems -- liver, intestine, urinary, reproductive, vascular and musculo-skeletal systems -- we have utilized nearly every area of expertise offered here at Childrens Hospital Los Angeles."
The twins have separate heads, necks, shoulders, arms, hearts, lungs, and chest walls. They lie face to face, intertwined from just below their diaphragms down to their pelvises. They each have one leg and share a conjoined third leg in back, and from what doctors have discerned from CT (computerized tomography) scans, the internal organs that are conjoined include their livers, colon, and part of their bladders and reproductive organs.
They are engaging, cheerful, mentally alert, and move around as much as their condition permits, but they have been denied the normal developmental milestones of babyhood, like rolling over, crawling or standing, and they sit, eat, play and sleep propped up into a horseshoe-shaped nursing pillow.
"The quality of life for these children is expected to dramatically improve when they have been separated," explains orthopaedic surgeon Richard A.K. Reynolds, M.D., FRCS, who heads the orthopaedic component of the team.
Preparing for this landmark surgery has been a logistically daunting task requiring months of meticulous planning, including rehearsals, and having models built of the babies' pelvises so surgeons could refer to them during surgery. The twins have been seen almost weekly, undergoing diagnostic procedures like angiography and cystoscopy, a reversible colostomy, and the insertion of five "tissue expanders." "We use these to gain additional skin and soft tissue so that after the separation there will be sufficient tissue and skin to close the open wounds," explains plastic surgeon John Gross, M.D., FACS, who is heading the plastic surgery team.
"What makes this surgery so unusual," explains William McIlvaine, M.D., C.M., FRCPC, FAAP, who heads the anesthesia team, "is that we're putting together five very major operations sequentially. We're splitting the liver. We're splitting the gastrointestinal tract. We're splitting the genitourinary tract. We're splitting the pelvis. Then we're putting everybody back together."
The majority of the surgical procedure will involve separation of the liver, the reconstruction of the intestinal tract, as well as the reproductive and urinary tracts, then separation of the musculo-skeletal system using the fused (tripus) leg to reconstruct bone. Closure of the pelvic ring will facilitate soft tissue coverage of the defects left by the separation.
"While the technical aspects of the case from a surgical standpoint are each complex in their own right, preventing systemic complications from occurring is essential," says Dr. Stein. "A great deal of work has gone into establishing a plan for reducing the inflammatory response and abnormalities in blood clotting which occur in long, complex operations. This will be critical in facilitating surgery," he adds.
The general surgical team will separate the livers. The twins' GI tract fuses about a foot from the colon, and each child will be given a nearly complete length of small intestine and each will receive half the large intestine. The orthopaedic team will split the pelvis in front to enable their colleagues to see the lower part of the gastrointestinal and genitourinary tracts. Doctors will need to identify where the bladders are, make certain they come apart successfully, then identify where those bladders empty out, and reroute them, if necessary. Each girl has two hemi (half) vaginas and uteri, which upon separation, can be reconstructed into complete ones for each child. "This is generally one of the most complicated portions in cases of Ischiopagus twins," says Dr. Stein. "Dr. Don Shaul and Dr. Kasper Wang will be reconstructing one of the girl's bladders, vaginas and rectum, while Dr. Neil Sherman and I will be reconstructing those of the other twin."
Another twist in this case is the dual blood supply to one of the twin's good legs and the fused third leg. This may require relocation of one of the blood vessels from one child to the other. "Once this is sorted out," explains Dr. Reynolds, "Dr. J. Dominic Femino and I will cut the back part of the pelvis and the twins will be separated. The blood supply to the leg determines where we cut the pelvis at the back," he adds.
After the children are in separate surgical suites, Dr. Reynolds and Dr. Femino will cut the pelvis of each child, rotate it and close it into a ring. Dr. Gross and his team, including his colleague, Mark Urata, M.D., DDS, then will do the soft tissue reconstruction. "Once we have the children separated we'll deal with how best to use the third leg to close the soft tissue gap on the children," Dr. Gross explains. Since the fused limb is not functional, it will be used to cover the abdominal cavity and pelvis. With everything reconstructed on the inside, the job of getting the skin closed where no skin existed before will fall to the plastic surgeons. While the tissue expanders have been critical in facilitating this process, synthetic skin substitutes may be required to accomplish this goal.
The team of anesthesiologists will be busy carefully monitoring the twins, keeping up with fluid losses and monitoring and correcting abnormalities in the respiratory, cardiac and coagulation functions of the children. One of the critical aspects to assisting in this process is keeping the twins warm. Although warmers are available, the surgical suites will be kept at near-tropical temperatures.
While the time spent in the operating rooms is critical, the ongoing care in the Intensive Care Unit and later on in Rehabilitation will be key to achieving an optimal outcome for these children, emphasizes Dr. Stein.
At nine months, the twins are considered the ideal age to undergo the separation, believes Dr. Stein. "Their tissues at this age tend to be both firm enough to manipulate them easily and of a reasonable size. Getting too far out, you get into issues with more rigid fusion." Beyond the age of one year, he adds, "there are psycho-social issues of separation and identity."
"This is the optimal age," agrees Dr. Reynolds. "The bones are big enough that we can work on them and yet not too big or stiff that we can't work with them. Pelvic osteotomies are easier than if we waited until they were four or five. Whenever we deal with children who have congenital anomalies like absent limbs -- where there is a body image problem," adds Dr. Reynolds, "if we do the surgery before the children are a year old, they tend to accept prosthetic limbs or changes to their limbs much better."
"While the twins have had a good quality of life to date, their anatomy and orientation will begin to limit this over time, taking away their individuality, their ability to walk, and to develop normally," points out Dr. Stein. "Although this is complex surgery, the multidisciplinary health care team and the babies' parents agree that the potential benefits far outweigh the risks."
Since their birth, Baby A and Baby B have been literally inseparable, within arms' length of one another whether they're fighting over a favorite toy or giving each other an impromptu hug. After the surgery, they hopefully will be able to embrace not only each other -- but also their freedom as separate individuals.