Nate Yamane pulmonary artery
Using CT scans of Nate’s heart, the team produced a 3D-printed model of the obstructed region of the heart.
A cardiologist working at the Los Angeles Children’s Hospital may have saved a child’s life after using 3D technology to repair his pulmonary artery.
Nate Yamane was born in June 2015 with tetralogy of Fallot (TOF) with pulmonary atresia, causing him to have trouble breathing straight from birth. The cause was a genetic abnormality resulting in a heart defect that obstructed the pulmonary artery, preventing blood travelling from the heart to the lungs.
After 18 months, LA Children’s Hospital cardiologists found evidence that a portion of Nate’s pulmonary artery, the same artery they had repaired once before, was narrowing once again. Pediatric Interventional Cardiologist, Frank Ing, MD decided a small stent was needed to keep the artery open. The size of the narrowing, roughly nine millimetres, meant the doctors would need to customise the stent to fit into the smaller space.
Using CT scans of Nate’s heart, the team produced a 3D-printed model of the obstructed region of the heart. Dr Ing was then able to fashion a smaller stent to fit precisely into the narrowed artery in the model. This replicated procedure gave Dr Ing the confidence that the stent would allow blood to flow through the narrowing artery.
“Imagine blood flowing in the artery like cars on the freeway, and it’s blocked,” said Dr Ing. “Cars exit and find an alternate route to its destination. Blood does the same, and in this case finds its way through collateral vessels to the lungs.”
Nate Yamane pulmonary artery
This replicated procedure gave Dr Ing the confidence that the stent would allow blood to flow through the narrowing artery.
After birth, however, these vessels need to be rebuilt quickly or the heart will fail. Using a surgical technique called unifocalisation, surgeons can repair the vessels by sewing them together.
At just one month old, Nate had already undergone two open heart surgeries and a catherisation procedure. In December 2015, Nate’s pulmonary arteries were found to be narrowed in both the right and the left branch. A balloon was used to open the right side, while a stent of about 15mm was inserted on the left side. Typically stents do not come that small, but Dr Ing carefully trimmed their smallest existing stent and folded it back on itself. From this Nate saw an immediate improvement in his blood flow, including a healthy drop in blood pressure.
Last month, Dr Ing was forced to insert an even smaller stent into Nate’s right pulmonary artery in CHLA’s catherisation lab. This surgery was streamed live from CHLA to an international audience of cardiologists, watching at the Pediatric and Adult Interventional Cardiac Symposium in Miami. With the new stent inserted, Nate again saw an immediate reaction – his oxygen levels improved overnight. Going forward, Nate will again require surgery, but since the start of the year has progressed well. He now weighs 21.5lbs.
“We did physical therapy and tried to fatten him up (after the first stent was inserted),” said Courtney Yamane, Nate’s mother. “(Now) he’s rolling around with energy and even took his first baby steps. There’s a big difference and a lot of improvement. We’re going in the right direction.”
