Conjoined twins are sets of identical twins that are physically connected. Conjoined twins begin as a single fertilized egg, usually this egg will develop into one baby, but sometimes this egg will divide in half, resulting in a set of identical twins. The cause of conjoined twins is when the fertilized egg is dividing, but the process never finishes. About 40% of conjoined twins are stillborn, and 35% die within the first day of being born. If the twins do survive, their quality of life depends on what is joining the them together, which determines their chance of a successful separation surgery and their life span. Because the mortality rate of conjoined twins is so high, researchers are trying to find ways to prevent twins from being conjoined, and surgery options to separate joined twins’ bodies.
Although conjoined twins are very rare and only occur in 1 of every 200,000 live births, there are many different types of conjoined twins. The most common type of conjoined twins are joined at the thoracic cavity, or chest. This is called thoracopagus twins, and make up around 40% of conjoined twins. About 33% of cases are omphalogus, in which the twins are joined around the region of the umbilical cord. 2% of cases are craniophagus twins, which means that they are joined together at the head, these cases are very rare. The remaining 25% are mixed between being joined at the lower back, pelvic area, and even the brain. Unfortunately, it is still unclear weather certain factors put couples at risk for giving birth to conjoined twins because there are too few cases for researchers to find a common factor, but they have found that more conjoined twins are born in Africa and India than in the United States.
Success stories of conjoined twins who have been separated are rare, but they are possible. Johns Hopkins Children’s Center has operated on six sets of twins since 1982. One of their success stories is about Nigerian conjoined twin girls who were joined together at the chest, abdomen, and had fused livers. The surgery was a success and the twin girls went back home a few moths later. The lead surgeon, Dr. Paul Colombani, considered it to be one of the most simple of all conjoined twin surgeries because they weren’t connected by any major organs and the team of surgeons could split the fused liver which happens to be the only organ in the human body that can be easily divided and regenerate itself. Unfortunately, there are surgeries that have ended in tragedy as well. In 2003, The team of Johns Hopkins surgeons operated on 29 year old conjoined twins in Singapore, who were joined at the head. They both died in surgery due to blood loss. Positive steps are being taken to lower the risk of death in separation surgeries, so that hopefully, one day, there is little to no risk of dying for conjoined twins.
Specialists at the Texas Children’s Hospital in Houston thought of a new approach to the surgical challenges brought on with the separation of conjoined twins when they met 10 month old girls, Faith and Hope Mata, who were joined from their chest to their pelvis. The case was one of the most complex cases ever because of the extent of fusion. To prepare for the surgery, doctors performed a CT imaging which showed the intravenous contrast of both twins separately for better views of their vital structures. The surgical team then translated the CT imaging results into a color coded 3D model with skeletal structures, supports, blood vessels, and organs. The model was designed so it could be taken apart and put back together during the surgical planning process. Detailed CT imaging and 3D printing technology had been used for the first time in the surgical planning for the separation of conjoined twins. After the 26 hour surgery, consisting of 24 clinicians, 12 surgeons, 6 anesthesiologists and 8 surgical nurses, the twin girls had finally been separated and were stable. The 3D model was an excellent source of information and there were no major differences between the 3D model and the twins actual anatomy. The doctors expect the combination of CT imaging and 3D printing to become a standard of preparation for separation of conjoined twins. They also found that not only did the model help in assisting them prepare for surgery, but it helped the twins parents understand the process too. The twins returned home in May 2015 and are doing well.
Because conjoined twins are so rare, it is hard for researchers and doctors to learn more about them. As time goes on, the main goal is to keep saving lives, and to find ways to save more. Medical and technological advances have significantly helped with the lives of conjoined twins. Although it is nowhere near where researchers want it to be, separation surgeries have definitely improved. Researchers hope that one day they will have enough information to know what causes the fertilized egg to not completely divide and that they can find a way to fix the problem before it starts.
Do you think that researchers are doing enough to help prevent conjoined twins?
Could the probability of conjoined twins have to do with living of Africa and India?
What do you think the separation surgeries will look like 10 years from now?