Three-year-olds Bernardo and Arthur Lima underwent surgeries in Rio de Janeiro, with direction from Great Ormond Street Hospital in London.
The teams tested several methods for months using virtual reality projections of the twins, based on CT and MRI scans.
Noor ul Owase Jeelani, a surgeon, called it “space-age stuff.”
According to Gemini Untwined, the nonprofit Mr. Jeelani formed in 2018, it was one of the most difficult separation operations ever finished.
He said that for the first time, surgeons from several nations operated together in a “virtual reality room” while donning headsets.
The twins underwent seven operations, the last of which required approximately 100 medical staff and more than 27 hours of operating time.
Speaking about the VR aspect of the surgery, Mr. Jeelani told the PA news agency: “It’s just wonderful. It’s really great to see the anatomy and do the surgery before you actually put the children at any risk.
“You can imagine how reassuring that is for the surgeons.
“In some ways, these operations are considered the hardest of our time, and to do it in virtual reality was just really man-on-Mars stuff.”
He claimed that the boys’ anatomy was confounded by scar tissue as a result of prior unsuccessful attempts to separate them, and he was “really apprehensive” about the risky procedure.
After the 27-hour procedure, during which he only took four 15-minute breaks for food and water, Mr. Jeelani said he was “absolutely shattered,” but it was “wonderful” to see the family “over the moon” afterward.
The boys’ blood pressure and heart rates were “through the roof,” as it is with all conjoined twins following separation, he said, until they were reunited and touched hands four days later.
The twins will get six months of rehabilitation care as they continue their successful hospital recovery.
This was Mr. Jeelani’s sixth separation procedure with Gemini Untwined, after previously operating on twins from Pakistan, Sudan, Israel, and Turkey.
He led the procedure alongside Dr. Gabriel Mufarrej, head of pediatric surgery at Brazil’s Instituto Estadual do Cerebro Paulo Niemeyer.
As per BBC, Dr. Mufarrej said the hospital where he works has been caring for the boys for two-and-a-half years, and their separation will be “life-changing”.
“Since the parents of the boys came from their home in the Roraima region to Rio to seek our help two-and-a-half years ago, they have become part of our family here in the hospital. We are delighted that the surgery went so well.”
At almost four years old, Bernardo and Arthur are the oldest craniopagus twins – that is twins with a fused brain – to have been separated.
One in 60,000 births results in conjoined twins, and only 5% of those are craniopagus, according to the charity.