How a 3D printed aorta helped surgeons replace a 'ticking time bomb' inside a man's chest

Australia Broadcast Center

a day ago

Surgeons have replaced most of a man's aorta in a life-saving operation after scans revealed he was walking around with a "ticking time bomb" inside his chest.
The Queensland man's aorta, the biggest blood vessel in the body, had ballooned to about four times the usual size, leaving it in danger of rupturing — a medical emergency likely to have cost him his life.
Doctors used a life-sized 3D printed model of the man's dangerously enlarged aorta to prepare for the high-stakes surgery at The Prince Charles Hospital, on Brisbane's northside, last month.
In their most complicated anatomical model so far, engineers and industrial designers developed the replica at Brisbane's Herston Biofabrication Institute, using computer software and scans of the patient to guide them.
It then took a cutting-edge printer almost four days to create the 3D reproduction, allowing the medical specialists to better plan for the operation on the man, aged in his late 50s, because it gave them a deeper insight into his anatomy before they put scalpel to skin.
Without it, they would have had to rely on two-dimensional scans.
The cane-shaped aorta starts at the heart's main pumping chamber, then travels upwards and curves over the heart in what's known as the aortic arch, before descending through the chest, down through the abdomen and ending near the navel.
It delivers oxygen-enriched blood to the body.
Vascular surgeon Samantha Peden said the diameter of the patient's aorta at the arch was about 8 centimetres, compared to the average size of 2-3cm.
His had stretched way beyond normal size because of a disorder with his connective tissue, a condition which is yet to be definitively diagnosed.
He had surgery in 2017 to repair a tear of the aorta, but the artery continued to expand over time, to the point it needed to be replaced as the wall thinned.
"The risk is, if you leave it, it can rupture. Most patients would die," Dr Peden said.
The operation itself was not without significant danger.
During the procedure, the patient's body had to be cooled so he could be put under circulatory arrest — a condition which involves temporarily stopping the heart to prevent it from pumping blood throughout the body.
Blood flow is stopped for about 20 minutes.
"They can wake up with a stroke or they might not wake up," Dr Peden said.
Paraplegia, kidney and liver failure are also possibilities.
In the nine-hour procedure, a team of vascular and heart surgeons, operating in tandem to reduce the length of the surgery, replaced the patient's upper aorta with a synthetic graft made from material Dr Peden describes as akin to flexible, waterproof jackets.
Almost three weeks later, the patient is still in hospital but out of intensive care, and preparing for intensive rehabilitation.
"He's recovering really well, hasn't had any major complications, so we're all really happy with his progress," Dr Peden said.
"There's no evidence of paraplegia. He's got full function to his arms and legs.
The man will have the lower part of his aorta replaced later this year.
Dr Peden likened the operation to "fancy plumbing", but it's a highly specialised procedure only carried out in about "five or six" centres across Australia and New Zealand because of its complexity.
The Prince Charles Hospital team performs just six full aortic replacements on average a year.
Industrial designer Liam Georgeson, who is based at the Herston Biofabrication Institute, worked on the 3D model of the patient's aorta using a digital anatomy printer.
"It has the ability to print many different materials into the one print," Mr Georgeson said.
The former electrician said the institute was working with vascular surgeons to develop patient replicas of blood vessels connected to pumps, designed to copy the rhythmic pumping action of the heart.
This allows surgeons to practise on models with simulated blood flow before operating on a patient.