Brain surgery before birth fixes abnormal blood vessel in fetus

For the first time, surgery has corrected an abnormal blood vessel in the brain of a fetus. The baby – who has a rare condition called vein of Galen malformation – was born without complications, indicating the procedure could safely treat infants.

Vein of Galen malformation forms before birth when arteries in the brain connect back to the organ’s central vein. This expands this vein and lets more blood rush through, placing pressure on the heart and lungs and depriving the brain of oxygen. Babies with the condition commonly develop heart failure and stroke-like symptoms within days of birth.

“There are a lot of patients we cannot help even with the best standard of care,” says Darren Orbach at Boston Children’s Hospital in Massachusetts. Before infants with this condition are born, the placenta helps mitigate some of the pressure. Once they are born, it may be too late to perform surgery. “They unfortunately pass away despite our best efforts, or they’re left with severe brain injuries,” he says.

Orbach and his colleagues conducted surgery to fix the malformation in a fetus at 34 weeks and 2 days gestation. MRI scans revealed that the central vein was greater than 14 millimetres in diameter. “When the width of the vein is 8 millimetres or larger, then we know with 90 per cent certainty that the baby is going to get very sick after birth,” says Orbach. “This was one of the more aggressive malformations we’ve ever seen.”

The woman carrying the fetus received spinal anaesthesia before the surgery and the fetus also received an anaesthetic via injection to prevent movement during the procedure. A needle was then inserted through the uterus. Ultrasound imaging helped aim it at the back of the fetus’s head, where the malformation was located.

The surgeons gently pushed the needle tip into the vein. A catheter placed through the needle was then used to insert special metal coils into the extra space created by the malformation. These coils decrease the amount of blood flowing through the vein. The surgery lasted under 2 hours.

An ultrasound one day later showed a 43 per cent decrease in the amount of blood pumped by the fetus’s heart. MRIs taken before and after the surgery also revealed the vein shrank by almost 5 millimetres in diameter. The baby was born prematurely two days later with no complications. She didn’t require heart medications or additional surgery.

“It was remarkable because these babies are usually so dramatically sick,” says Orbach. The infant, now 7 weeks old, still appears to be healthy, he says.

This surgery is a promising approach to preventing brain injury and death in infants with vein of Galen malformations who cannot be treated after birth, says Courtney Wusthoff at Stanford University in California. “The downside is that anytime you’re doing a fetal procedure, there is a risk of complications and, in particular, preterm birth,” she says.

“It’s obviously very exciting to have this result in the first patient, but it’s literally the first patient. We have to do the science and demonstrate that it works across patients,” says Orbach, who is planning to conduct the surgery in an additional 19 participants.