If the separation of conjoined twins results in death, who should die?

In early August 2022, media around the world reported that a team of more than 100 medical staff had performed a complex operation to separate conjoined twins conjoined in the skull.

Three-year-old twins Arthur and Bernardo Lima were born in rural northern Brazil in 2018, fused at the top of their heads, and they share vital cerebral blood vessels. The surgical team spent months practicing the separation procedure using virtual reality models based on CT and MRI scans of the twins.

Then what the surgeon called Noor Al-Awwas Al-Jilani.Things in the space ageSurgeons at the Institut Estadual do Cérebro Paulo Niemeyer in Rio de Janeiro performed seven surgeries on the twins, over 27 hours from the time of surgery, with the help of their colleagues at Great Ormond Street Hospital in London. The two teams, more than 9,000 kilometers apart, performed The operation – said to be the most complex of its kind ever – was successful, and the twins are now beginning a six-month rehabilitation in hospital.

Great Ormond Street surgeons performed similar procedures in 2006 and 2011. In 2019, they operated on two-year-old sisters. Safa and Marwa Allahafter using virtual reality for the first time to create a replica of the skulls, brains and cerebrovascular systems of twins.

Date of separation of conjoined twins

conjoined twins Rare, occurring in about 1 in 50,000 births, craniofacial twins – which fuse in the skull and share brain tissue – account for 2% to 6% of these with an incidence of 1 in 2.5 million births. It is believed that 50 are born each year; Of these, 40% are stillborn, and a third die within a day of birth. About a quarter of them are alive and are being considered for surgical separation.

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The oldest known description of craniofacial twins appears in Sebastian Munster Cosmography Universalis. The Latin version, published in 1559, includes a brief reference to two twin girls born at Bierstadt in September 1495, who are joined at the forehead. It also contains wooden pieces that show the girls standing with their heads facing each other. These twins reportedly lived until the age of ten, at which point one of them died and was separated from the other; The second died shortly thereafter. In addition to being the first reported case, this appears to be the first recorded case of separation, also notable for the longevity of the twins.

Cranial twins can generally be divided into ‘partial’ and ‘complete’ types, depending on how well their skulls are fused, with total craniofacial twins being considered to share a single skull. The exact point of attachment is variable but most commonly occurs in the parietal bone at the back of the skull.

The successful separation of craniofacial twins was not heard of until relatively recently. The first recorded case of both twins surviving more than a few hours after separation was published in the early 1950s, in which case one of the twins died a month after the operation without regaining consciousness. Since then, advances in brain imaging and neurosurgical techniques have greatly increased the likelihood of a successful outcome after a separation.

It’s unclear exactly how conjoined twins form. Aristotle claimed that “most of it is due to embryos growing together,” but early embryologists traditionally explained this as the result of an incomplete division event at about two weeks of gestation, when the embryo was still a small mass of identical cells. Recently, it has been suggested that craniofacial twins occur as a result of the fusion of two separate fetuses four weeks before and before gestation. nervous – ie the folding of the neural plate to form the neural tube – finished.

annoying moral dilemma

Conjoined twins lift a lot Ethical challenges and philosophical questions. For example, is it morally acceptable to sacrifice one life to save another? And if the separation is performed in the first years of life, it will be done without the patient’s independence and informed consent.

Twenty-two years ago, the births of Gracie and Rosie Attard were given to the judges of the British High Court”Their hardest case ever. The twins were conjoined in the abdomen and shared an aorta. Doctors believe that if separated, one would die instantly, while the other would have a 94% chance of surviving; if they were not separated, both were likely to die within six months.

The girls’ parents did not agree to the separation for religious reasons and were “happy with God’s will to decide what happens,” but were also content to leave the decision to the court. The three judges involved in the case agreed that it would be legal to separate them. After a 20-hour operation, Gracie survived and Rosie died, as expected.

common consciousness

Conjoined twins also raise fascinating questions about self-identity and awareness. If conjoined twins share brain tissue, can they also share conscious experience? Canadian twins Krista and Tatiana Hogan, who were born in 2006 and still conjoined at the skull, offer some clues.

An electroencephalogram (EEG) done on the twins when they were two years old showed that bright light in one of the couple’s eyes elicited a response in the visual cortex in the other. Brain scans also showed that their brains were attached to a thin piece of tissue, which neurosurgeon Douglas Cochran of British Columbia Children’s Hospital called “mulch bridge. “

The thalamus is a deep brain structure that processes sensory information before transmitting it to the cerebral cortex and may play a role in conscious perception. So Cochrane believes that twins share feelings and emotions. Anecdotal evidence of this comes from notes made by their families. as stated in New York Times Magazine“The family … suspected that even when the girl’s vision was far from the TV, she was laughing at the pictures flashing before her sister’s eyes. They also believe that the sensual exchange extends to the girls’ taste buds: Krista loves ketchup, Tatiana does not, and he Something the family discovered when Tatiana tried to get the spice out of her tongue, even when she wasn’t eating it.”

According to the CBC documentary inseparableThe twins also share engine control. Krista and Tatiana Hogan share the senses of touch, taste, and even control of each other’s limbs. Tatiana can see from both Krista’s eyes, while Krista can only see from one of Tatiana’s eyes… Tatiana controls three arms and a leg, while Krista controls three legs and an arm. They can also switch to self-control in their limbs.”

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