In 1962, the Harvard School of Public Health made a critical loan to Boston Children’s Hospital: the Harvard hyperbaric chamber. It established a new approach to pediatric heart surgery at Boston Children’s.
For many children — including a premature infant named Janet, born in 1964 with a heart murmur — the hyperbaric chamber would prove to be life-saving.
At that time, before the invention of the heart-lung bypass machine, hyperbaric chambers offered a way to operate on infants more safely. That’s because hyperbaric oxygenation, coupled with the effects of increased pressure on the respiratory system, seemed to give infants a better chance of surviving heart surgery.
A better environment for heart surgery
Led by William Bernhard, MD, the hyperbaric team at Boston Children’s was able to operate on more than 120 infants who needed corrective heart surgery. According to a 1965 Boston Children’s press release, “on many occasions at surgery, [Bernhard] has seen a cyanotic (blue) heart, berating feebly during normal operating conditions, suddenly turn pink and beat robustly when the chamber pressure was raised…”
Oxygenators, used during heart surgery at that time, were not suitable for use on patients weighing less than 45 lbs. But inside the hyperbaric chamber, a mask or breathing tube could supply 100 percent oxygen to the infant. The high atmospheric pressure within the chamber caused dense saturation of oxygen molecules within an infant’s body tissues. Therefore, hyperbaric oxygenation allowed the team to stop the heart and blood circulation for a precious few minutes in which Bernhard could quickly correct cardiac defects.
Such was the case with Janet. She was born with a life-threatening condition called aortic valve stenosis, which blocks blood flow across the aortic valve.
The hyperbaric chamber’s impact
Janet’s condition was first discovered when she was 1 month old and her pediatrician heard a heart murmur.
“She quickly deteriorated to the point where she was heading toward heart failure,” says Janet’s mother, Barbara Bombaci. “It was then, at 6 months old and only weighing 8 pounds, that she underwent a catheterization process at Boston Children’s. But she was so weak that her heart stopped and she had to be resuscitated.”
The very next day after Janet’s resuscitation, with no time to lose, she went into the hyperbaric chamber for surgery with Bernhard’s team.
“Dr. Bernhard performed a surgery in two a half minutes that opened up her aortic valve,” says Barbara.
After surgery in the hyperbaric chamber, Janet remained in intensive care for weeks.
“Back in those days, you couldn’t see your child if they were in intensive care. It was overwhelming to not be able to see her right after the surgery,” says Barbara. “Medicine has made a lot of progress since then to include families in the treatment process, and that’s a good thing.”
Today, Janet is 53 years old and still receives a heart check-up at Boston Children’s, once every five years, through the Boston Adult Congenital Heart Program (BACH).
The evolving frontier of heart surgery innovation
The same year as Janet’s surgery, seeing the hyperbaric chamber’s positive impact, the National Heart Institute (today the National Heart, Lung and Blood Institute) gave Boston Children’s a $350,000 grant — the equivalent of $2.8 million today — to launch a Hyperbaric Research Unit and build a bigger pressure chamber that could simulate the atmospheric pressure of 132 feet below sea level.
It was built in East Boston by Vacudyne Corporation and its subcontractor, Hodge Boilerworks. It weighed 53 tons and consisted of two main compartments.
The first compartment, a ball-shaped chamber 16 feet in diameter, was used as the hyperbaric operating room. It was big enough to fit a patient and a 12-member surgical team.
The second compartment, a 27-foot long section, was used for treatment and recompression (to alleviate decompression illness). Portholes allowed for viewing of both chambers and a closed-circuit television camera enabled a chamber technician to closely monitor the operating team from the control area.
The Boston Children’s hyperbaric chamber remained in use until 1974, when rapidly advancing innovations such as the heart-lung bypass made it safe to operate on infants in normal operating rooms. Today, Bernard is Professor of Surgery, Emeritus, at Boston Children’s.
More recently, Boston Children’s cardiac surgeons and researchers have developed a soft robot that aids failing hearts, use of umbilical shunts in heart surgery, mitochondrial transplantation and a minimally-invasive, UV-light-enabled catheter that can fix holes in the heart.
But back in 1964, it was the cutting-edge hyperbaric chamber gave infants a special chance at having corrective heart surgery.
“At that time, it was pretty standard to try and wait for children to get to be 7 or 8 years old before having heart surgery,” Barbara recalls. “But Janet couldn’t wait. She wouldn’t be here today without the surgery that Dr. Bernhard performed.”