When Sally Wiley, an obstetrician-gynecologist from Texas, came to Brigham and Women’s Hospital (BWH) for a fetal cardiac intervention when she was 22 weeks pregnant, the other physicians in her practice were stunned.
Wiley recalls, “When I got back from Boston and told my colleagues what I’d done, they were incredulous. ‘You did what?’” Yet their reaction was understandable. Fetal cardiac interventions are fraught with challenges and risks.
In fetal cardiac surgery, there are actually two patients: the mother and the baby. But the patient in the mother’s womb can’t be directly touched or seen. And because the baby is bobbing in amniotic fluid, it can’t be completely immobilized. Its heart is the size of a grape. The left ventricle, a frequent target of fetal cardiac interventions, is smaller than a raisin.
Once the baby is correctly positioned for surgery—which can take as long as an hour—the procedure itself is usually over in 30 minutes. So while these operations aren’t time-consuming like a face or hand transplant, the stakes are incredibly high. And the procedure demands incredibly precise communication and teamwork.
Inside fetal cardiac surgery
Assisted by Carol Benson, MD, co-director of BWH’s High Risk Obstetrical Ultrasound Service, BWH surgeon Louise Wilkins-Haug, MD, PhD, gets the baby in the best position. Tracking the baby’s position, Benson uses ultrasound to guide Wilkins-Haug as she inserts a long, straw-like needle through a tiny incision in the mother’s belly, across the muscle of the uterus, and into the baby’s chest.
Even before entering the baby’s heart, Wilkins-Haug faces minimal margin for error. For a layperson, imagine threading a needle while it is moving, but with a life at stake. Nicking the blood vessels of the uterus or the amniotic sac in the wrong way could cause bleeding or contractions. Poking the baby’s rib instead of sliding between its ribs could push the baby out of position, or risk a catastrophic puncturing of the tiny heart.
Once Wilkins-Haug has placed the needle into the baby’s left ventricle, a fetal cardiac interventionist from Boston Children’s Hospital leans forward to thread a fine wire through the needle. The wire is attached to a balloon that the surgeon inflates once it reaches the malfunctioning or misshapen aortic valve. The balloon stretches the opening, and when the procedure is successful, the ultrasound images show the team that blood is surging through the newly widened opening across the aortic valve and exiting the left ventricle.
“That is the ‘Aha!’ moment,” says Wilkins-Haug. “Every time I see the blood flow across the open valve, it still amazes me.”
Photo Above: Sally Wiley credits the fetal heart surgery team at Brigham and Women's Hospital and Boston Children's Hospital with saving the life of her son Anders (left). (Photo courtesy of the Wileys.)