Surgeons at a leading London hospital faced the enormous challenge of separating the siblings’ brains, arteries and veins.

The operating theater is tense and hushed as medical experts work through a complex procedure, due to take many hours. Now in front of them are two 19-month-old girls, Safa and Marwa, who are incredibly unique. And right now their brains are exposed to air because the team is here to tease them apart.

For Safa and Marwa are twins of a particularly special kind: craniopagus. Almost unbelievably, their skulls grew together, and they share arteries and veins. What’s amazing is that as few as one in two-and-a-half million births come in the form of conjoined, craniopagus twins. But these two have already had some luck – most babies like them do not live for more than a day.

However, the twins now face an extremely complicated set of operations. Indeed, a team drawn from numerous medical disciplines have already put in hours of work to prepare for today. For they have been modeling, studying and caring for the siblings. And now the twins’ lives are in their hands at London’s Great Ormond Street Hospital.

But suddenly, the theater goes quiet, and the businesslike air is shattered: the anesthetists have spotted a problem. Yes, one of the twins is struggling to drain the blood from her brain. Worse still, she is now pumping it into her sister. And this extra blood is proving hard for the little girl’s heart to cope with. It’s a race against time.

An anesthetist says, “I think we need to shock.” So the pads come out, and the theater goes still as the head surgeon prepares to administer the electricity. What’s more, the team gets ready for the worst. In the next few seconds, the lives of both twins might end. The question is: can they overcome this crisis?

Now twins, Safa and Marwa Ullah, are natives of Pakistan. They hail from the town of Charsadda, near Peshawar, in the province of Khyber Pakhtunkhwa. And even though they are joined at the back of their heads, they are clearly their own people. Indeed, according to their mom, Safa is a bright, chatty girl, while Marwa keeps her cards close to her chest. Furthermore, they weren’t the first kids in the family.

In fact, mom Zainab Bibi had seven children before the girls. But even though that meant childbirth was not new for the 34-year-old, this time would be different. Firstly, the twins were delivered by cesarean in 2017, and Zainab was out of it. Moreover, she didn’t get to meet the girls until five days after their birth because she was recovering herself. But that’s not the main difference we’re talking about here.

Image: Great Ormond Street Hospital/PA Wire via Independent

You see, identical twins which are joined like Marwa and Safa are extremely rare. Although all conjoined twins come from a single egg, most are fixed together at the pelvis, belly or chest. Because they were melded at the crown, the twins had never been able to look each other in the eye. And their misfortune hadn’t been the first to befall the family.

Indeed, the girls’ immediate relatives had already been through a tough time. Tragically, their dad had passed during their mother’s pregnancy, suffering a heart attack. So their grandpa, himself still wrapped in grief for his son, welcomed them into the world. Naturally, he had mixed feelings, telling the BBC, “I was happy to see them, but I was thinking what am I going to do with them because of their joined heads?” However, the situation was different for mom.

That’s right, mother Zainab had no doubts about her feelings for the pair. In fact, she describes falling in love with them at first sight. She told the BBC, “They were very beautiful and they had nice hair with white skin. I didn’t even think about the fact they were joined. They are God-given.” In fact, the Muslim twins were named after the hills in Mecca that have great importance during the pilgramage of Hajj. But despite the clear affection for the two, the family knew that they couldn’t leave them how they were.

Yes, so they quickly agreed that the twins should be split, if possible. But although a military hospital pledged to try, it couldn’t promise that both girls would survive. Luckily, the family had another option: a U.K. neurosurgeon Owase Jeelani, who worked at Great Ormond Street Hospital and himself had Pakistani heritage. Furthermore, operating on craniopagus twins wasn’t unusual for him.

You see, along with plastic surgeon Prof.David Dunaway, Jeelani had already successfully separated two sets of craniopagus twins. And the most recent had been Sudanese girls Rital and Ritag Gaboura in 2011. Now they had the separation in several stages, a method that Jeelani’s team trusts in. And more importantly, the two are today healthy and happy. Given that success, the team expected to separate Marwa and Safa in four or five steps.

To do that, Jeelani would use a team of around 100 people. Staggeringly, they would include not just nurses and surgeons, but also specialists in 3D modeling, bio-engineering and even virtual reality. Setting out a protocol, Jeelani would lead the separation of brains and the arteries and veins that served them. While Dunaway had the responsibility of reshaping their heads and making them both skull tops. As we’ll see, however, it wasn’t going to be easy.

You’ve guessed it, this challenge looked more daunting, and much harder than the first two separations of craniopagus twins. As Dunaway explained to the BBC, “The first two cases were much more straightforward and we were lucky. But with this set we underestimated the complexity of the oblique brain joining. Also, they are older and I think older is really bad news.”

However, one thing working for the girls was that that technology had progressed dramatically since the 2011 Gaboura twins’ operation. In fact, the 3D software available could make incredibly detailed models of their brains and heads. Subsequently, these allowed the team to look at the unique issues the girls presented and practice ahead of the operations.

Indeed, Jeelani told the BBC what this meant to the team. He said, “To be able to see and visualize this and play with these models before the surgery makes an enormous difference to how we plan and do this operation.” And he outlined the task that faced them, “What we need to achieve is, in effect, to sort of untwist the brains. And that’s pretty difficult to do just in your head.”

What’s more, the team could use the 3D models to help produce guides for the staff concerning cutting. And it didn’t stop there. Jeelani found himself able to enter a virtual reality in which he could examine the tangled blood system of the twins. “This is clearly the way of the future,” he explained to the BBC. But as we’ll see, all of this expertise had to be paid for, somehow, by Marwa and Safa’s family.

And this kind of preparation, and the operation that followed, would not come cheap. Luckily, Murtaza Lakhani, a rich businessman from Pakistan, did not need asking twice for money. Touchingly, he had phoned the surgeons directly to learn about the girls first. He said, “The true reason for me helping them was because it was an operation that was going to save the lives of two children. For me it was an easy decision, it’s how you build the future.”

Now as operation day drew near, the team studied the twins’ scans. Although the girls had separate brains, they had askew shapes. Furthermore, the angle of each brain meant that they stuck into the other girl’s space. And the two brains shared blood vessels, connected with each other’s circulation. Consequently, any slip would risk giving the girls a stroke.

So early on a fall morning in October 2018, close to 20 staff came to the operating theater. Then, they got ready for the first of three operations that would separate Marwa and Safa. On this day in particular, the team would disentangle their shared arteries. But to get to the blood vessels meant that, first of all, three pieces of skull would need to be cut out.

Therefore, Jeelani gave the plan a final airing, not that anyone needed to hear it. That’s because there had been endless rehearsal for this moment. In fact, the team felt confident about the outcome, even though they knew nothing short of perfection would do. Dunaway expressed their feelings when he said, “The whole team feels there’s an excellent likelihood of a successful separation here.”

By 2:30 p.m. the artery that fed Marwa’s brain with Safa’s blood was stopped off with a clamp. Furthermore, the moment of truth had arrived for Jeelani, who now had to wait to see whether he could proceed. Although the twins’ lives hung in a delicate balance, Jeelani could soon give the green light. However, hours of work, clamping and sealing arteries, lay ahead.

While Jeelani’s team did that, Dunaway had put his guys into action. Yes, they began making a framework out of the three bits of skull that had been removed, held together with meshwork and screws. Given the twins’ age, this frame has to have the strength to cope with their level of movement and activity. What’s more, the new “skull top” has to be detachable for the follow up operations.

Now once the team had separated the twins’ brains, they slid a plastic sheet in between to keep them apart. Furthermore, to keep the brains in their “own” parts of the shared skull, the surgeons set up a pulley system. Finally, the operation ended more than 15 hours later with the remodeled skull being returned to its place.

But that didn’t end the surgery. Yes, the girls returned to their hospital bed, but a month later they came back for operation number two. And having disconnected the girls from each other’s arteries, the next step would be to separate their veins. Again, the risk of stroke would arise at each cut. And although the surgeons didn’t know it, danger was just around the corner.

You see, once the frame around their skulls was taken off, the twins began to bleed. And it turned out that Safa had some clots in the veins inside her neck. Now those prevented the easy draining of blood, and the consequence was that it was flowing into Marwa’s brain. Alarmingly, this had pushed up Marwa’s blood pressure, while Safa’s had plummeted.

So now Marwa’s life hung in the balance. As you’d expect, silence descended on the theater and the surgery team stopped suddenly to look at the monitors. At last, the moment had passed. But it was now obvious that Marwa would need to be given an important vein that the twins had in common. And Jeelani knew that his decision might seriously affect Safa.

In spite of this, no one disagreed with Jeelani, and the surgery continued. After 20 hours-plus, the plastic surgeon Juling Ong finally made the last sutures for the day. An elated Jeelani expressed his satisfaction with the day’s work. He told the BBC, “I am relieved. We thought we might lose Marwa at one point. But if they wake up as we hope they will, it’s gone well.”

However, the loss of the shared vein had badly affected Safa. And the terrible news left Jeelani reduced to tears. Furthermore, he had little energy after the exhausting surgery, and now had to digest that Safa had suffered a stroke. For two days, her family prayed desperately at her bedside, until at last she began to rally. Eventually, both twins came off their ventilators, and at last Jeelani too could breathe freely. But it didn’t mean the challenge was completely over.

No, because the team next had to change the tubular head that the girls shared, into two normal shaped heads. And top of the list of problems would be that there simply wasn’t enough skin. But Dunaway and Ong had an ingenious solution: little plastic bags slipped under the existing skin and pumped up with saline would help new skin to grow.

So finally, the day had come for the sisters to be split apart. More to the point, the medics had insisted on bringing this last operation forward because Marwa was still unwell. So four months after the first procedure, the girls were wheeled into the theater in February 2019. And for seven hours, the surgeons cut the last few connections between the twins. Then at last, a surgeon snipped the remaining brain membrane, and the team could actually separate Safa and Marwa.The surgery didn’t end there, though.

Image: Facebook/Great Ormond Street Hospital and Children’s Charity

Touchingly, each twin now had her own team, which would put together their new skull from pieces of the original. But the surgeons had to cross their fingers that the skin would have expanded enough for both heads. As the team prepared for this final stage, the leading surgeons enjoyed a brief moment of triumph with a handshake.

Mind you, putting the skulls together would still involve careful work. Indeed, Dunaway explained how it would be possible to make the new skulls out of the existing fragments. He told the BBC, “The skull is usefully designed in three layers: the inner and outer layers are very thick tough bone, but in between is like a honeycomb so you can split it. It is half the thickness but it means we should be able to cover nearly all the head with bone.”

Miraculously perhaps, the result was that the girls each now had a patchwork skull. And the surgeons joined the bits together with stitches that would melt away in time. In between the pieces sat bone cells that should grow to fill the spaces that had been left. Ultimately though, both girls would have their own round skull. One question remained, however. Had enough skin grown, as the surgeons had hoped for, to cover the skulls?

Well thankfully, the answer was yes: To the surgeons’ delight, sufficient skin had grown for the job. A happy Dunaway uttered to the BBC, “Pretty amazing day isn’t it?.” And early in the morning, 17 hours after going into surgery, Jeelani and Dunaway could finally meet with the twins’ family. Now they had been waiting the whole time for news about their daughters’ operation.

And given Jeelani is also from Pakistan, he gave them the good news himself in Urdu: Their daughters have now been separated. As a result, an emotional Zainab kissed both the surgeons’ hands in thanks. Now altogether, the girls had spent in excess of 50 hours in surgery. But now they had to recover. For five months, the hospital cared for them, adding skin grafts and giving them physiotherapy to teach them new skills.

In fact, each girl proved able to sit with their heads held high for the first time. To add to that, of course, they could also now see each other’s face. In a statement released to the media, Jeelani and Dunaway expressed their joy at the outcome. They wrote, “We are delighted we have been able to help Safa and Marwa and their family. It has been a long and complex journey for them, and for the clinical team looking after them.” But that wasn’t all.

Image: Great Ormond Street Hospital/PA Wire via Independent

Yes, the surgeons also praised the girls and their family. They wrote, “From our personal point of view, it has been great to get to know the girls and their family. Their faith and determination have been so important in getting them through the challenges they have faced. We are incredibly proud of them. We are also incredibly proud of the Great Ormond Street Hospital team responsible for their treatment and care over the past 10 months.”

Image: Great Ormond Street Hospital/PA Wire via Independent

What’s more, the two physicians wrapped things up with a complement for the huge team that they had led. They said, “From the surgical teams, scientists and engineers who helped us plan and perform the operations to the pediatricians, nursing staff, physiotherapists and occupational therapists, it has been a huge team effort and every single person has played a key part in helping Safa and Marwa.”

For her part, mom Zainab thanked the hospital and expressed delight at the separation. She told the Irish Independent, “We are extremely excited about the future.” And she had someone else she wanted to thank. She told the BBC, “I am very happy. With God’s grace I am able to hold one for an hour and then the other one. God has answered our prayers.”