Her parents signed up for a clinical trial of an inute surgical treatment to see if doctors could intervene before any of these results materialized. It seems to have worked. The team behind the operation now plans to treat more fetuses in the same way. Other similar brain conditions could benefit from the same approach. For conditions like these, fetal brain surgery could be the future.
The baby’s condition, known as a malformation of the vein of Galen, was first noticed during a routine ultrasound at 30 weeks pregnant. The condition occurs when a vein connects to an artery in the brain. These two types of vessels have different functions and should be kept separate: arteries carry high-pressure flows of oxygenated blood from the heart, while thin-walled veins carry low-pressure blood to the other side.
When the two combine, high-pressure blood flow from an artery can stretch the thin walls of the vein. “Over time, the vein essentially pops like a balloon,” says Darren Orbach, a radiologist at Boston Children’s Hospital in Massachusetts, who treats babies born with the condition.
The resulting blood clot can cause serious problems for the baby. “It’s stealing blood from the rest of the circulation,” says Mario Ganau, a consultant neurosurgeon at Oxford University Hospitals in the UK, who was not involved in this particular case. Other parts of the brain can end up without oxygenated blood, causing brain damage and there is a risk of bleeding into the brain. The extra pressure on the heart to pump blood can lead to heart failure. And other organs can also suffer, especially the lungs and kidneys, says Ganau.
Fetuses with this condition are thought to be protected by the placenta to some extent. But that changes from the moment the umbilical cord is attached at birth. “Suddenly there’s this huge burden placed right on the newborn’s heart,” says Orbach. “Most babies with this disease will get very sick, very quickly.”
Several teams are trying to treat the disease before that happens, while the fetus is still inside the womb. Orbach is a member of one of those teams. He and his colleagues at Boston Children’s Hospital and Brigham and Women’s Hospital, also in Boston, registered a clinical trial in 2020 to test whether fetal brain surgery could help.
The girl’s mother was referred to Orbach’s clinical trial. On March 15, at 34 weeks, she underwent the experimental operation, a two-hour procedure that involved a number of medical professionals.
First, the mother received a spinal anesthetic to prevent her from feeling anything in the lower half of her body. However, she remained awake for the procedure, Orbach says. “She was wearing headphones and listening to music,” he says.