Arthur and Bernardo Lima were born in 2018 in Roraima, in Brazil’s far north, joined at the crown — craniopagus twins who shared part of the brain and the principal vein that returns blood to the heart. It is among the rarest and most lethal forms of conjoined twinning. Their parents, Adriely and Antonio Lima, brought them to the Instituto Estadual do Cérebro Paulo Niemeyer in Rio de Janeiro. For more than two years the boys lived on a custom bed. Other centres had called separation impossible. At nearly four they would be the oldest craniopagus twins with fused brain tissue ever taken apart.

Rio’s team, led locally by neurosurgeon Gabriel Mufarrej, asked London charity Gemini Untwined and Great Ormond Street paediatric neurosurgeon Noor ul Owase Jeelani for help. Surgeons in two countries put on VR headsets and stood in the same digital operating room, walking through CT- and MRI-based maps of the shared skull before anyone opened skin. Scar from earlier incomplete attempts made the anatomy worse. Staged operations — sources count seven to nine — slowly rerouted circulation so each brain could grow its own venous return. The last two sessions alone ran more than 33 hours; the final marathon is widely reported at about 27 hours, with a team of nearly 100 and only brief breaks. Both boys survived. For the first time they could look at each other’s faces.

Rehabilitation followed. By Christmas 2022 they were home in Roraima, no longer a single patient. Adriely said she still cried every day from seeing them both in the room. The photographs that spread afterward — space-themed birthday shirts, then two laughing boys on a sofa — skip the bandages and the ventilator. What they do not skip is the point of the VR rehearsals: the operation was rehearsed until the risk, which remained enormous, was at least a known risk.

Sources
Gemini Untwined case page for Arthur and Bernardo
Washington Post and AFP coverage of the August 2022 announcement
BBC / The Telegraph / The Times interviews with Noor ul Owase Jeelani
G1 Roraima, first Christmas at home (December 2022)
Estadão and Instituto Estadual do Cérebro Paulo Niemeyer contemporaneous reports