For the last 30 years, Dr. Abdullah al-Rabeeah, a pediatric surgeon and adviser to the Saudi Royal Court, has spearheaded a program that separates conjoined twins who were born to poorer families from around the world.
In November, he successfully completed his 48th surgery on a set of conjoined twins, Ahmed and Muhammed, from Libya.
Al-Rabeeah has separated so many children that even his identical, non-conjoined twin daughters speculated he might have operated on them.
"When (my twins) were three or four -- I can't remember -- they were seeing in the news that I was separating twins. So they asked their mother, 'Mom, when did dad separate us?'" he said, laughing.
'Based on science and humanity'
Housed at the King Abdullah Specialist Children's Hospital in Riyadh, al-Rabeeah's program receives much of its funding from royal and Islamic charities. Saudi Arabia's King Salman and Crown Prince Mohammed bin Salman approve each individual operation with the Saudi government footing the bill.
"We pay for the travel and expenses," al-Rabeeah told ABC News about the patients who have come from 21 countries. "It has nothing to do with geography, religion or politics. It's based on science and humanity."
Al-Rabeeah first operated on conjoined twins in the early 1990s. As his practice grew, he also rose in the ranks of the Saudi government serving as health minister and director of the King Salman Humanitarian Aid and Relief Centre.
As his public service portfolio increased, he still made time for his medical program for conjoined twins.
"Even when I was minister of health, I continued to do my surgeries because I believe even if I do it on the weekends, it is something (that) can help people. Humanity is part of medicine," he said.
While many scientific journals have not reported on the program, al-Rabeeah says his program has separated nearly one hundred patients, with ninety still living as of 2019.
Conjoined twins are rare. According to researchers from the University of Minnesota, the phenomenon is only found in about 1 in 200,000 births. Occurrences are higher in Southeast Asia and Africa, where the rate is 1 in 25,000, because of an increased rate of identical twins.
Arguably, the most famous conjoined twins were Chang and Eng Bunker, who lived during the 19th Century. Born in Thailand, they moved to the United States and the pair eventually toured the carnival circuit popularizing the term "Siamese twin."
Dr. Oren Tepper, director of Craniofacial Surgery at Montefiore Health System in New York City who has operated on three twins conjoined at the head, said the decision to separate is dependent on "what vital structures are shared."
"When they share (vital structures), you can't simply just separate them," he told ABC News, "they need to be able to tolerate being independent."
Separation surgery methods depend on each patient. "Separating the organs that they've shared requires usually a specialist in whatever area you're talking about," Tepper said. "If they share a brain, you're going to need a neurosurgeon involved. If they share a heart, lung, it's going to be a cardiac or thoracic surgeon."
From a small Libyan hospital to Riyadh
Ahmed and Muhammed's journey to Riyadh began with an email.
The twins' family knew before their birth that the brothers would be conjoined. Although they considered abortion, the parents decided to carry the pregnancy to term.
On June 26, Ahmed and Muhammed were born through cesarean section in a small Libyan hospital. Conjoined at the abdomen and pelvis, the brothers shared a third leg, bowels and urinary organs.
The twins underwent a colostomy -- an operation to bypass a damaged part of the colon -- but Libyan doctors told their parents that no one in war-torn Libya could perform what would be a risky separation surgery.
The parents began making appeals through traditional and social media. Then their father found al-Rabeeah's program online.
Al-Rabeeah said their father wrote to him saying, he had a set of twins and he was searching for any country to help them.
"So I immediately responded to him to provide me with details and reports," al-Rabeeah told ABC News.
After reviewing their records with his colleagues they decided they wanted to help the family, al-Rabeeah said. They presented the case to the crown prince, who "immediately directed me to bring them and the government would totally finance them."
The last two centimeters
After arriving in Riyadh, Ahmed and Muhammed undertook a detailed medical evaluation. Al-Rabeeah's team estimated the complex surgery would take about 14 to 15 hours and require approximately 35 surgeons and nurses.
"We told the parents there is a 30% risk of either a major complication or loss of life because of the crossing of major organs," al-Rabeeah said.
Still, the parents agreed to continue with the surgery.
At 7:45 a.m. on Nov. 14, the operation began. After receiving anesthesia and undergoing further tests, the twins had their intestines separated.
"That took about an hour and a half," al-Rabeeah said, "then we separated the bowel to give each one of them an appropriate amount based on their blood supply to ensure that they can survive."
Next, the pediatric urology and orthopedic teams worked to separate Ahmed and Muhammed's internal and genital organs, and al-Rabeeah explained they have to split the pelvis from the front and from the back.
The tensest and most emotional moment comes near the end of the surgery.
"In the last two centimeters, there is a silence in the room and we count from five to zero when the bodies are separated into two," he said.
"And that moment, the parents are informed, they can see it live. There is a big emotion between all the surgical team that this is the first time when the twins are put on two separate tables for the first time in their lives," he added.
'Hugging me like a father'
Ahmed and Muhammed's procedure was the 48th operation on conjoined twins conducted by al-Rabeeah. While unfamiliar with the Saudi pediatric surgeon's program, Tepper acknowledged that this is a high number.
Al-Rabeeah said that in each surgery one of the most difficult components is dealing with the emotional weight of operating on patients who are frequently under the age of 1.
"You stay with (the families) for weeks before the surgery," he said. "So there is a lot of emotion, lots of bonding. And I must admit, it's not easy. But, with time you can build on it."
"You cannot, for example, salvage a twin at the risk of the other except in few conditions when one of the twin's life is dependent on the other, which we call almost like a parasitic twin," he said. "It was not an easy surgery, but we knew ahead of time that it's going to happen. But we managed to save a beautiful girl. Her name is Haneen. She recovered well."
He has remained in touch with many of his former patients.
"I separated (Polish twins) in 2005," al-Rabeeah told ABC News. "I happened to visit Poland this year … and when (the twins) saw me -- they are now, as you could imagine, 15 years of age -- they're coming, running and hugging me like a father. I really cannot believe how my tears came down. So both of them were crying and I was crying. It was really emotional."
'I'm crying because I'm happy'
On two tables, Ahmed and Muhammed each had their own set of doctors to reconstruct their small, separated bodies. Surgeons recreated bowels, urinary systems and genital organs for each twin.
After over three and a half hours, the twins went from the operating room to the intensive care unit. The operation was successful and both are now recovering.
Once the surgery ended, al-Rabeeah let the parents walk into the room.
"(The twins' father) came and tried to kiss my hand. I refused, so he hugged me. And while he's going to his child, which is Ahmed, he just fell into a big cry. And we have to rub his back and tell him that they're OK, they're stable. He said, 'I'm crying because I'm happy," al-Rabeeah recounted.
The babies would stay in the pediatric intensive care unit for around two weeks before doctors remove the artificial respirator to start their feeding. Once Ahmed and Muhammed are stable, they will be taken to the pediatric surgical ward for further rehabilitation.
The twins are expected to be in recovery for eight to 12 weeks.
After the twins moved to the ICU, al-Rabeeah left the hospital for home. He said his family prepared a celebratory dinner for him.
The emotions and intensity of a separation surgery often keeps him awake late into the night.
"But I sleep really happy that I have managed to draw a smile on the face of a family that has been under stress and big suffering. For them now to smile ... is a really happy feeling," he said.