Abstract
Henry Pinchbeck, Michael Richard and Rafael Guerrero speak to Freya Leask, Publisher. Henry Pinchbeck is the CEO of 3D LifePrints (Liverpool, UK), a 3D technology company supplying 3D printing services to the medical sector including the NHS, private hospitals, universities and medical training centers. It is has a 3D printing facility embedded in the Innovation Hub at Alder Hey Children's Hospital (Liverpool, UK). One of the main services is the provision of high quality 3D printed anatomical models from patient data to assist surgeons in planning their procedures, discussing the treatment with their patients and for training and simulation purposes. Michael Richard is 3D LifePrints’ Head of Engineering and has previously worked on 3D LifePrints’ humanitarian projects in South Africa and Kenya. Mr Rafael Guerrero is a Consultant Pediatric Cardiac Surgeon, Chief of Cardiac Surgery at Alder Hey Children's Hospital and the Director of Cardiac Services in the North West of England.
To learn more about how 3D LifePrints supports surgeons at Alder Hey Children's Hospital, visit 3DMedNet to watch a series of video interviews with Henry, Michael and Rafael.
What is 3D LifePrints?
Henry Pinchbeck (HP): I founded 3D LifePrints with Paul Fotheringham and Mike Richard back in 2013, at which time it was a humanitarian venture. We started 3D printing prosthetic limbs in East Africa and we brought the same skill set when we came to the NHS, working with a basic set of technologies but producing some very hi-tech results.
You're embedded in the Innovation Hub at Alder Hey Children's Hospital. What is the Innovation Hub & how are you supporting surgeons at the hospital?
HP: Alder Hey's Innovation Hub brings people together; it brings together small companies, big companies, clinicians and scientists to innovate together, and produce new and exciting ways of delivering healthcare. What we do at Alder Hey is provide solutions to the surgeon's problems; that could be anything from something as simple as an anatomical model for them to plan their surgery to something as complicated as a face mask for a burns victim.
What surgical challenges can 3D printing assist with?
Rafael Guerrero (RG): The challenge that we have as children's heart surgeons, is facing multiple malformations of very small hearts in newborn babies, infants and children. This requires performings very complex, high risk surgical procedures. The heart could simply have a hole in the heart, or it could be upside down with the arteries and veins connected to the wrong places. Because we are working with tiny hearts, which are probably as small as a strawberry, you are not always able to visualize them properly during an operation.
At the moment we rely on x-rays, angiograms, CT scans, MRI and echocardiograms. However, if we can print this information and analyze the different malformations, I can do three things: I can plan my operation better, I can explain the procedure to the parents of the patients in a better way and obviously I can teach and train other people better.
For example, I had a case of truncus arteriosus with interrupted aortic arch. This rare malformation, in which a single blood vessel comes out of the right and left ventricles instead of the normal two, could be lethal; without treatment, patients will not survive the first weeks of life. It's so rare, there are probably less than 5 cases per year in the UK. In this operation, we need to stop the heart, open two of the main chambers of the heart and place a small patch inside to divert the blood in the right direction. We then need to disconnect the arteries that are not in the right position, and enlarge and reconnect the main artery of the body, the aorta. Having the 3D model allows us to have a better idea before doing the operation of how it looks inside so we can plan ahead. It also allows us to train the trainees on how it should be done.
Often, the diagnostics are done antenatally so we would know something wasn't right before the baby was even born. As soon as they are born, the malformation will be confirmed by another scan. With 2 days of the baby being born, we could have the scan data needed to produce the 3D model.
How do the patients react when they can see a model of what's wrong with them?
RG: The parents are incredibly welcoming because now they can actually understand what is wrong with their babies. They are quite stunned about the size of the hearts that we need to deal with and perform complex reconstructions; they never realize it is so small.
How has 3D technology changed how you train new surgeons?
RG: Congenital heart malformations are rare and complex so you can't use alternative such as animal models. There is no other way to train junior surgeons except in real life, with a real patient. This could be a steep learning curve, which requires very close supervision by the consultants supervising the trainees. They work together until they gain the skills to perform the operation and use drawings to illustrate the procedure but it is impossible to create a model of this type on a piece of paper. A 3D model makes a difference as it allows them to hold these tiny malformed hearts in their hands and examine them (without the pressure of real life). In addition, if the right material is used for printing, they are able to perform or practice the procedure before the actual operation.
What happens when you receive patient data to make a 3D model from?
Mike Richard (MR): At the heart of each 3D print is the scan which it was obtained from, which will normally be from CT scans or from MR scans. Our segmentation process starts by identifying specific Hounsfield unit ranges within the scan data. Parts of the scan, such as bone or contrasted blood, will show up as a very high Hounsfield unit range. This allows you to segment out very complex ventricular data, bone data and metal work within the scan.
How long does it take to turn a patient scan into a model?
MR: On average, it takes three to four hours of human time spent with the software to get the scans to a point where they are ready to then either to be 3D printed or to be reviewed with the team. In cases where the imaging isn't exactly ideal, this can go onto a day or even several days.
What are the challenges in making pediatric models?
HP: Children are certainly tricky when it comes to 3D printing. Their anatomy is smaller, the detail level is greater and you can't use as heavy a radiation dosage when scanning. This means we tend to work with worse data but the surgeons demand better results.
MR: In imaging, particular pediatric imaging, there are a number of challenges you can come across. Some scans, like MR scans, can take a long period of time, and small children moving around in the scanner can sometimes lead to a loss of detail on the scan, or a blur, which will eventually affect the 3D model. Another challenge is when there is metal work or devices that have been implanted into the patient previously. These can sometimes interfere with the scanning and cause artifacts in your CT or MR scan which then gets translated onto the 3D print. Steps can be taken to reduce that from a scanning perspective, but it often just ends up being a lot of manual time spent removing the artifact throughout the specific areas that the surgeons and the hospital needs to see.
Do you think this time will reduce as software or scans get better?
MR: This will absolutely gradually reduce, through the kind of revolution that 3D printing is undergoing throughout the world. In the medical field especially, there are radiology teams which are developing specific sequences which results in a better scan, leading to something easier to look at and a better model which will be even more helpful to the teams looking at them.
How does the material the 3D model is made of vary depending on the application?
MR: There are three categories where the models are used. The first is for doctor–patient communications. This can be a very basic, often single color model, which would purely be used for the doctor to communicate to the patient, and, in the case of pediatric medicine, their parents. This can be very useful in educating them as to the procedure they plan to undertake and helping the patient understand their conditions more fully.
The second major use for 3D printed models is for education. This could be training the next generation of doctors and surgeons. These educational models could be as basic as anatomy models, showing different pathologies for the different surgical fields, or they could be as advanced as specific surgical simulation models where you can teach and reenact specific surgical procedures on a specific surgical model. In this case, you'd be looking to match the material with specific tissue densities and properties.
For this category, and the third field, for preoperative assessment and planning, you'd also be working with a whole range of materials. For soft tissues, we often look towards more flexible materials. These can be thermoplastic polyurethanes on the lower end of the fused deposition modeling (FDM) printing scale such as FilaFlex, which, when printed thin enough, can mimic or semi-mimic softer tissues within the body. Some more advanced materials include some PolyJet materials, such as the Tango™ range. However, with the up-and-coming silicon printing technology, which is becoming more popular, we can mimic a whole range of soft tissues in the body, building up very realistic cardiac and renal models which can be accurately cut and sutured. All sorts of specific procedures can be actually practiced on these models due to their real likeness to actual soft tissue in the body.
For bones, at the lower end of the printing scale, we can look towards materials such as woodfill. When printed under the correct settings, woodfill mimics bone quite closely, especially how it reacts under a saw or a drill. On the higher end of the scale, we can look at some of the selective laser sintering (SLS) powders such as nylon.
What methods of 3D printing do you utilize to produce the models?
HP: We use all different sorts of technology; we use FDM technology, SLS technology, stereolithography (SLA) technology and PolyJet technology. One of our most recent additions is a Stratasys Objet Prime which has allowed us to print in a wider variety of different materials and has really increased the scope of the type of models and devices we can make for the surgeons here but still at a reasonable cost.
What are 3DLifePrints’ plans for the next 5 years?
HP: I see what we do here in Liverpool as a template for what we can do around the country. We recently opened a hub in Oxford and we have other embedded hubs in Liverpool Heart and Chest Hospital and in the Liverpool Royal Hospital (both Liverpool, UK). I see this as something that can be utilized nationally as a way of bringing 3D printing from the academic sphere to the commercial sphere.
How do you think the use of 3D printing will change & evolve in the next few years?
RG: I think that the way we evolve is that several specialties, not just heart surgeons but brain, plastic or spine surgeons, for example, will be using these 3D models more and more often to help them with the final diagnosis, in particularly in more complex cases. In the future, I foresee that surgeons will be able to order a 3D printed model in the same way that I order an x-ray, a CT scan or an echocardiogram. The next thing will be for funding to become available for 3D printing to allow it to become just another source of imaging of the body.
Disclaimer
The opinions expressed in this interview are those of Henry Pinchbeck, Michael Richard and Rafael Guerrero and do not necessarily reflect the views of Future Medicine Ltd.
Financial & competing interests disclosure
The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.
No writing assistance was utilized in the production of this manuscript.