Operating in 3D

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UMCG doctors recently had a European first with the first successful pelvic reconstruction in 3D. However, the three musketeers of the 3D lab, as they call themselves jokingly, say that 3D provides revolutionary options for many other disciplines.

‘Out of the 28 departments at the UMCG, 26 indicated that 3D could help them in their treatment plans’, says Joep Kraeima, technical medical professional at the UMCG and one of the lab’s coordinators. ‘I work together as a team with my two fellow-musketeers, oral surgeon Max Witjes and computer scientist at radiology Peter van Ooijen. The 3D lab is a crucial hub where all our knowhow is combined and from where we can tend to all UMCG departments.’

One of the latest developments the 3D lab is currently working on is developing a 3D treatment of damaged neck and spinal vertebrae. This kind of surgery is a very precise matter. If you want to attach two vertebrae to each other, then the connecting piece not only needs to fit, but you also have only one chance to drill the screws into the vertebrae. And you have to do it, if possible, without hitting the spinal cord or other vital body parts.

Practice

It is easy to imagine how accurate you can do this if you can prepare the entire procedure, including connecting piece, holes and screws and can practice on a model. 3D is the start of a new era for diagnostics and treating a host of different conditions. It provides many benefits with respect to the usual CT scan, especially with respect to complex problems, such as heart conditions or complex bone fractures.

‘In two-dimensional images, it is often difficult to tell what the problem is exactly’, says Kraeima. ‘This new technology allows the surgeon to recognise the problem at a glance and make crucial decisions before operating.’

It means important decisions are made in advance, outside of the operating room and outside of the patient’s body. Whereas operating used to be a combination of manual work, experience and intuition, 3D now evolves the procedure in the operating room into a pre-set, detailed plan.

This has advantages for both patients and doctors: shorter times on the operating table, shorter anaesthesia times, less blood loss and better recovery. Moreover, patients also like to be able to see in advance what is going to happen to them.

The right place

Traditionally, a surgeon operates on the basis of a two-dimensional X-ray or CT scan. The surgeon can only see what exactly is going on when the patient is opened up and lying in front of them. At that moment, often under time pressure, the surgeon makes crucial decisions about what to do. ‘To connect two pieces of bone of a broken pelvis, for example, the surgeon needs to use a titanium plate’, Kaeima explains. ‘The plate must be bent into the right shape manually so it fits as exact as possible while the patient is still lying on the table.’

With the new method, a technical medical professional and an engineer will first reconstruct a broken pelvis, for example, on the computer and plan how best to fix it virtually. On the screen, they will make a digital model of a titanium plate that fits the broken bones exactly. They even design a mould that makes sure that all the screws end up in exactly the right place.

A 3D printer makes 3D models of the broken pelvis, the titanium plate and the mould. Eventually, the patient will have a custom-made titanium plate. So the moment the surgeon starts the operation, they already know exactly what they are going to do.

Pierced jaw

Oral surgeons have been using 3D for a longer time, for example to more accurately fix the holes in the jaw. Holes are often left in the jaw in the place where there used to be tumours. The surgeon fills this hole with a piece of bone, for instance from the calf bone. In the traditional method, the surgeon had to measure and saw the piece of calf bone in the right shape step by step during the operation.

The fact that the calf bone is straight and the jaw is curved makes it especially difficult to give the piece of bone the right shape. By visualising the jaw with the hole on the computer, you can print a 3D model of the jaw and saw and fit the piece used to fix the hole in advance.

Danger

There are also dangers with working in 3D. After all, it is still possible to make mistakes in a digital process. It is possible that you erroneously mistake something on the screen for a tumour. ‘That is why it is so important that the doctor knows everything there is to know of both the technology and the patient’, Kraeima emphasises. ‘It is not just a matter of clicking and dragging something on the screen. It is a very precise task and you should be fully aware of what you are doing.’

The 3D lab was established in 2015. Many projects are currently still in a testing phase, but in the MKA department (oral and maxillofacial surgery) 3D technology is being used on a daily base. Kraeima hopes this technology in the future will be a standard part of treatments that all patients can benefit from.

However, before 3D planned operations are covered by health insurance, the 3D lab must first prove that this technology results in a statistically significant advantage. This means that they need to show that the benefits for the patient and practitioner are worth the added costs. Surgeons who start using 3D are often swiftly convinced. Surgery is faster, more precise and more predictable.

‘It is difficult to express well-being in a financial value’, Kraeima says. ‘However, you can measure how well patients are recovering, for example. Patients who return frequently, for instance, because the puzzle pieces that do not exactly fit are bothering them cost more money in the long term than patients that heal without any complications.’

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