• Israel Two Siamese babies can see their faces after a successful operation

  • United Kingdom 50 hours of operation to separate two Siamese conjoined by the skull

Brazilian Siamese children joined at the head were separated in an intervention whose responsible doctors described this Monday as the

most complex surgery of its kind,

for which they prepared using virtual reality.

Arthur and Bernardo Lima were born in 2018 in the state of Roraima, in northern Brazil, as craniopagus twins, an extremely rare condition in which the

brothers are fused at the skull.

Joined on top of their heads

for almost four years,

most of which was spent in a Rio de Janeiro hospital equipped with a custom-made bed, the brothers can now look at each other's faces for the first time, after

nine operations .

culminating in a 23-hour marathon surgery.

The

London-based medical charity Gemini Untwined,

which helped carry out the procedure, described it as "the most challenging and complex separation to date", given that the children shared several vital veins.

The Siamese Bernardo and Arthur Lima united by the skull. Gemini Untwined

"The twins had

the most severe and difficult version of the condition,

with the highest risk of death for both," said neurosurgeon Gabriel Mufarrej, of the Paulo Niemeyer State Brain Institute (IECPN) in Rio, where the procedure was performed.

For Mufarrej, it was the "most difficult surgery of (his) career," he told AFP.

"We are very satisfied with the result, because

no one else believed in this surgery at first

, but we always believed there was a possibility," Mufarrej added in a statement.

Medical team of 100 professionals

Members of the medical team, which included nearly 100 professionals, prepared for the delicate

final stages of surgery on June 7 and 9 with the help of virtual reality,

Gemini Untwined said.

Using brain scans to create a digital map of the children's shared skull, surgeons trained together in Rio and London with trial surgery performed in virtual reality.

British neurosurgeon Noor ul Owase Jeelani, lead surgeon for Gemini Untwined, called the virtual reality prep session

"space-age stuff."

"It's just wonderful, it's great to see the anatomy and do the surgery before putting the children at risk," he told Britain's PA news agency.

"You can imagine how reassuring that is for surgeons... Doing it in virtual reality was really a man on Mars thing," Jeelani added.

Pictures and videos released by medical staff showed the boys lying side by side in a hospital bed after surgery, with

little Arthur reaching out to touch his brother's hand.

Through tears, the children's mother, Adriely Lima, described the family's relief.

"We have been

living in the hospital for almost four years," he

said.

The children are still recovering and may need more procedures as they get older, doctors said.

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