https://www.bbc.co.uk/news/extra/PLNMqvmycN/conjoined-twins
The battle to separate Safa and Marwa
By Rachael Buchanan
It’s the rarest form of a rare condition - conjoined twins, fused at the head.
The BBC has been granted exclusive access to a ground-breaking series of operations in a British hospital to separate two sisters.
There is a crowd in the operating theatre. But the team of nearly 20 works as one.
Moving smoothly, every motion calculated. No signs of stress or tension, just hands methodically performing tasks.
But this is no routine operation. The shrouded shape of two small girls is picked out by the bright theatre lights. Safa and Marwa are joined at the head. Their brains are exposed as the surgeons work to separate a labyrinth of shared blood vessels.
But then the calm and peace of the theatre disappears, as anaesthetists raise the alarm.
The blood from Safa’s brain isn’t draining properly and she is shunting blood to her sister.
This puts strain on Marwa’s heart and she becomes dangerously unstable.
The anaesthetists call out commands, report vital signs and busy themselves trying to stabilise the girls.
"I think we need to shock," says one of them.
Pads are attached to Marwa’s chest in preparation.
The lead surgeon raises both hands so they can be clearly seen, and steps back.
Then everyone waits.
If they lose her, they may also lose Safa.
The birth
Zainab Bibi has already given birth to seven children - all of them at home. So when she becomes pregnant with twins, the plan is to do the same thing.
But after an ultrasound scan picks up a complication, she is advised to have them delivered in hospital.
It’s a difficult time for the family. Two months before the birth, Zainab’s husband died of a heart attack.
She is also told by the maternity team that the twins might be joined together. But there has been no mention of where on their bodies the join might be.
No-one, it seems, realises the full extent of the complications to come.
On 7 January 2017, the twins are delivered by Caesarean section at Hayatabad hospital in Peshawar, some 31 miles (50km) from her home in northern Pakistan.
The family are told that the girls are healthy.
But Zainab doesn’t meet the newborns immediately, because she needs to recover from the surgery.
It is the twins' grandfather Mohammad Sadat Hussain who finds out the truth first - the girls are what is called craniopagus twins, which means they are joined at the head. It is the rarest form of what is already a rare condition.
Their grandfather arrives on the maternity ward bearing the traditional gift of sweets for the nurses.
Still in mourning for the loss of his son, meeting his granddaughters is a bittersweet moment: “I was happy to see them, but I was thinking what am I going to do with them because of their joined heads?”
It is five days before Zainab is well enough to be introduced to her daughters, and she is given a photo of the twins to prepare her.
She says she instantly fell in love.
“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.”
They are named Safa and Marwa, after the twin hills in Mecca, Saudi Arabia, that play a central role in the Islamic ritual pilgrimage of Hajj.
After a month, the twins are discharged from hospital and the family agree that if it can be done, they should be separated.
A military hospital offers to perform the surgery but warns that one of the twins is likely to die. It is a risk their mother is unwilling to take.
Other options are explored, and when the twins are three months old, the family are put in touch with Owase Jeelani, a paediatric neurosurgeon at one of the world's leading children's hospitals, Great Ormond Street in London (GOSH).
By coincidence, he was born in the nearby region of Kashmir and immediately establishes a rapport with them.
After seeing scans of the girls, the surgeon is convinced they can be safely separated, but he wants to do it before they reach 12 months old, to get the best outcome.
The clock is ticking.
It is August 2018. The visas for the UK have already come through, but funding for the operations has not. This is not something the NHS in the UK would fund and Jeelani has raised only a small amount of the money needed to pay for the hospital care.
The girls are now 19 months old, well beyond the age that the GOSH team would like to operate. Any further delay might mean the separation becomes more dangerous, recovery more limited.
Jeelani urges the family to come to England immediately.
He remembers the moment they arrived: “They turned up in early August and at this point we only had a small amount of the money we needed. The kids were here and I must say I was really stressed. At this stage it felt like a personal responsibility.”
The twins’ uncle Mohammad Idrees and their grandfather are put up in a flat near the hospital. But Zainab will not be parted from her daughters, and prefers to sleep in their room.
Fused together
Conjoined twins develop from one fertilised egg and so are always identical.
There are two theories about why they are fused together - either the split into two embryos happens later than usual, and the twins only partially divide, or, following the split, parts of the embryos remain in contact and those body parts merge as they grow.
When it occurs, twins are more commonly connected at the chest, abdomen or pelvis.
Safa and Marwa’s particular commingled physiology presents a unique set of challenges for the GOSH team. The girls are joined at the top of their heads - crown to crown - facing opposite directions.
They have never seen each other’s faces.
Their skull is like a stove pipe, a long straight tube. Scans show that the girls have two distinct brains but these are misshapen. The right hemisphere of each brain is sticking up 90 degrees, projecting into the other twin's brain cavity.
This distorted shape will need correcting if the girls are to have near normal-shaped heads.
The surgical team's biggest concern is how to separate the complex shared network of veins and arteries. Each twin supplies the other with blood. Severing these connections carries a risk of starving the brain of nourishment and causing a stroke.
There are no official figures for the prevalence of craniopagus conjoined twins, but one estimate puts it at one in every 2.5 million births. Most do not survive beyond 24 hours.
Each case is unique, and separations of craniopagus twins have only been reported about 60 times since the first attempt in 1952.
Jeelani believes there could be up to six sets of craniopagus twins born worldwide each year who might be successfully separated.
Great Ormond Street Hospital is a world leader in this kind of surgery. Safa and Marwa will be their third set of craniopagus twins, more than any other centre. The team knows from experience that the best outcomes happen when the separation is staged over several operations, to allow for recovery in between.
As well as surgeons and nurses, the 100-strong team at GOSH involved with the care and separation of the twins includes bio-engineers, 3D modellers and a virtual reality designer.
Owase Jeelani and Prof David Dunaway
Jeelani will take the lead in separating the girls' brains and blood vessels, but it will be plastic surgeon Prof David Dunaway who will be responsible for rebuilding the girls' heads, and giving each of them a top to their skulls.
First operation
It's 08:00 on Monday 15 October 2018, and a team of nearly 20 gathers in theatre 10 at GOSH. Each member of staff identifies themselves and what their role will be.
"We have one case for the list today. Safa and Marwa. Two kids, one case," says Jeelani.
The twins’ slow journey to independence is about to begin.
The aim of this surgery - the first of three major operations - is to separate the twins' shared arteries.
Jeelani works his way through the plan one last time but everyone knows what they have to do. The team has been preparing for this day for months.
"We have been through everything in fine detail - rehearsed it repeatedly. This is the moment of truth and everything has to be perfect," says Dunaway.
Meanwhile on Bumblebee ward, the twins are being readied for theatre. Wearing identical surgical gowns, Safa and Marwa cry and twist restlessly.
Separating conjoined twins carries huge risks. One or both could die during surgery or be left with brain damage. The family understand the dangers, and have complete trust in the team.
“It is clearly very difficult to go through life when you are joined together like that, so it does make a persuasive case in favour of attempting the separation and the family are very clear on that,” says Jeelani.
Dunaway says the team has carefully assessed the ethical issues.
“Clearly I think life being separate is better than being joined together. If we felt there wasn't a very high chance that we could do it safely, we would think hard about whether we should do it at all. The whole team feels there's an excellent likelihood of a successful separation here.”
Jeelani is wearing surgical loupes, glasses fitted with magnifying scopes. He follows the marks he traced on the girls' shared skull, now shaved, and cuts through skin and bone.
Once the brains are exposed he swaps his surgical loupes for something far more powerful.
Standing 7ft high, the operating microscope dominates the theatre. It allows the neurosurgeon to examine the microstructure of the twins’ blood vessels.
It's now 14:30 and Jeelani announces: "The artery from Safa going to supply Marwa's brain has been clamped. Now we wait."
It’s a dangerous moment. Every time a connection is cut, there is a risk of brain damage. After five minutes the surgeon says the brain "doesn't look like it is too bothered", and carries on.
This painstaking procedure continues for several more hours as the shared arteries carrying oxygenated blood from one twin to the other are clamped and sealed.
Meanwhile, a second team, led by Dunaway, has set up shop a few feet from the main action.
Their task is to create a rigid frame from the three sections of skull, which can be detached in subsequent operations.
The curved bone pieces are held together with a network of metal mesh and screws.
Dunaway says this is a particular challenge given the twins' age: “Being older they are pretty active and so whatever we do has to be strong enough to resist the twisting and bending forces they will be putting on their heads."
As the team patiently tease Safa’s and Marwa's brains apart, they feed in a sheet of soft medical plastic to stop them reconnecting in between operations. A pulley system has been secured to the plastic to counteract the way a part of each brain sticks up into the other twin's skull. This will gradually ease the brains back into place.
Once the shared arteries are separated, the skull frame is re-attached. The operation has lasted 15 hours.
The girls are taken to intensive care. After two days, they are sent back to their usual home on Bumblebee ward - things are looking good.
With the girls’ brains enclosed in the watertight casing of dura, the skull fragments are jigsawed over the top of their now spherical heads. The individual pieces are secured in place with a lattice of disposable stitches, creating an archipelago of bone fragments.
The gaps have been seeded with bone cells, and in the coming months these should slowly close up leaving each sister with a complete skull.
The final task is to stretch the skin over the reconstructed skulls. There is just enough to make the join. Dunaway shakes his head in wonder. "Pretty amazing day isn't it?” he says.
At 01:30, after 17 hours in theatre, there is an emotional meeting between the two lead surgeons and the girls' family, who have been waiting in the hospital all day for news.
Speaking in Urdu, Jeelani tells Zainab that her daughters are finally separate.
Overcome, she kisses his hands and those of Dunaway.