LOS ANGELES - Oliver's dad vividly remembers his son's birth.
"I remember probably most vividly was the doctor saying to me, 'Alright, Dad, get your camera ready.' Pretty shortly thereafter, that's when sort of the air was taken out of the room," Peter Heilbron described.
Oliver was born with a large, soft cystic mass under his armpit.
"It was so large that his, his arm was completely elevated up over his head, and it was stuck in that position," he said.
The 12-ounce mass was a lymphatic malformation.
"When a lymphatic malformation develops those, instead of those lymphatic channels developing as tiny little tubes, they develop like little bubbles or balloons," explained Dr. Dean Anselmo, a pediatric surgeon and co-director of the Vascular Anomalies Center at Children's Hospital Los Angeles.
Anselmo is one of the few in the country that uses sclerotherapy for vascular malformations.
"I kind of describe it like if you put super glue inside a balloon and then try to fill it up with water," he said. "It can't, it won't fill up."
Using a needle, doctors injected a special medication into the cyst that causes the wall to collapse. Oliver has been left with a surgical scar that's barely visible and full use of his right arm.
"So, there are days where I look at him and I see his tiny little remnant of a scar, and I'm like, 'I can't believe that this is that.' That is not how he was born," said Jennifer Heilbron.
These types of malformations develop between four and six weeks of gestation and often cannot be seen during a prenatal ultrasound.
Twenty years ago, this story may have a different ending for Oliver. Surgeons would have immediately cut off the cyst, often leading to a recurrence of the malformation or causing problems that could last a lifetime.
Children's Hospital Los Angeles is one of 10 multi-disciplinary vascular anomaly centers in the United States. Luckily, the Heilbrons live less than an hour away.