3 February 2021
Balázs Gasz is originally a cardiac surgeon, associate professor at the UPMS Department of Surgical Research and Techniques, while also the head of the Clinical Working Group of the UP 3D Centre; he is also the ambassador of the European Institute and Technology and the founder of “YourAnastomosis”, a start-up that develops medical engineering solutions. His career took a whole new direction when he became acquainted with 3D technology and, in general, with the possibility of approaching and solving medical problems with an engineering and technical approach. Let’s see why and how a cardiac surgeon will eventually become a biotechnologist 3D designer!
Written by Gábor Szabó
- The occasion of our conversation is that two chest correction, so-called Nuss procedures have recently been performed in Pécs, in the preparation of which 3D technology and you personally played a great role, unlike in the previous practice. Until now, in the case of these surgeries, the size and shape of the implanted prosthesis - a metal plate that corrects the shape of the chest - has been practically left to the intuition of the surgeon performing the surgery. At least so far.
- In the case of this intervention, it was unbelievable to me at first that the plate to be implanted was really bent by estimation. Of course, I have seen surgery like this before, although I am not a thoracic but a cardiac surgeon, I am aware of the protocol, but it is still surprising. I have been talking with Zalán (Dr. Zalán Szántó, the thoracic surgeon performing the surgery - ed.) for a long time about how this could be more predictable, more accurate and accordingly safer. We looked for more and more technical possibilities and now we got to the point that it is really precise and can be designed for each patient. Matro Kft. manufactures the prosthesis plate according to our design, provides the basis so that we can produce it quickly and reliably. By the way, this cooperation with them is incredibly good and smooth.
- You managed to achieve not only a small change, more precisely an improvement in the course of the intervention. For example, surgery takes 30 percent less time and the risk of complications from the sizing of the prosthesis is practically eliminated. Personally, what do you consider to be the most important result of these?
- The concept itself. The fact that we can design and produce this plate very precisely in advance, tailored to the individual, the patient. As a result, a discourse has been created, which I personally really enjoy, with the participation of the radiologist, the thoracic surgeon, the 3D designer, and the engineer, which studies what happens, what we do in a deeper context as well. A chest is a dynamic system with flexibility and ranges of movement. In addition to designing a plate for the two fixed states (inhalation and exhalation), we have now moved on and begun to examine how this chest changes in its dynamics because of the reconstruction. Moreover, not only the chest, but as a consequence the rest of the body - think about it, when a chest is lifted, the clavicles also move, the posture can change, and it would be good to know what effect this has on the structure as a whole. The good news is that it seems we can refine the procedure a lot but obviously we still need the experience of several similar interventions to get as much information as possible from the postoperative CT results.
- What is the input you are working with? How will there be a 3D image of the patient's chest?
- We work based on an imaging procedure - it can be a CT scan, but even an MRI scan too. In the present case, we receive the CT image of the chest. We have a well-established relationship with radiology, they already know what we need, what protocols to use to create the image, with which we will be able to work well - this plural means the UP 3D Centre. I would like to highlight Richárd Bakó, a young engineer who took this direction in his career and we are the ones who set to work on this with medical background and 3D modelling hobby. CT scans are then handled with a variety of software - originally, we tried these at home, like I said, this part was originally a hobby for all of us. The 3D Centre provided another opportunity because we were able to procure software in a targeted manner here. We need these to reconstruct the chest in space from the “slices” made by the CT and then model its operation with different algorithms. Software is also required for the necessary post-processing because what comes out raw from a CT is less usable for 3D design. Here we actually bent a plate - virtually - according to the line of the chest but we have already done several very similar modelling for other prostheses.
- From the CT image you create a “cleaned” 3D model to which you can design the desired prosthesis. Why will this be useful?
- Because this way it is characteristic of the patient, that is, it fits their body perfectly, it is specific to the given morphology. I would also like to point out that this can also reduce the time and burden of surgery.
- You have mentioned that you tried a lot of software. Were these software more specific to engineering or 3D image production?
- The question is interesting because each software is suitable for different things. Initially, there are segmentation software that we use to make 3D data from the CT. Then comes the really special part; perhaps here it can be said that experience and special knowledge matter because software used for engineering, i.e. parametric and organic modelling, had to be used as well. Now a hybrid solution has emerged - which works pretty well by the way - that takes a more holistic approach to the problem. We use software designed for sculpting or animation at the same time, the solutions used in technical design are very strongly present, and we must not forget the programmes designed for medical applications.
- That is, after each work phase, this model must be transferred to another software, in which the next step can then be performed on it?
- Yes, each software is good at something else, and this is how this workflow developed in the 3D Centre between us. We like to try new solutions or approaches anyway. On the one hand, the ready-made software packages on the market very often do not provide the solutions we need, and in many cases, they are not even available to us because of their price. Therefore, we rather combine the experience of our colleagues in connection with the software and we seem to be doing quite well.
- When I talked to the surgeon performing the surgery, based on what he said, it seemed that there could be special algorithms, but based on what you said, the special knowledge gathered here is important. Is there an algorithm that helps you, or is it in your head what to do?
- It is actually communication. We need to translate the problem to each other so that everyone understands from it the thing they are most familiar with. The starting point is a surgical problem, this must be understood by everyone in a way that they can talk about it with the others, then translate the problem to their own field so that we can then solve it together.
- Is that the end of this work?
- The continuation of this is that yes, we have now performed successful interventions, but it would be good to know what we have caused, we will indirectly look back at what we have triggered in the dynamics of the chest. It is also interesting as an area of research, it opens a new door, but it is always like that. What is even more interesting and important is that during and after we can perform finite element calculations, especially from a dynamic and structural, mechanical point of view; where such a plate bends, where it is loaded, whether material fatigue may occur, and what mechanical effects develop on the bony chest itself. Think about it, this is a pretty striking intervention even from an outside point of view that there was a dented chest that we corrected, and all this is held by a single plate. A new area and research direction for 3D technology and this type of method are that all this can be well modelled in a virtual simulation.
- How new is this approach in medical practice, or even in this type of surgery?
- The fact that we handled the problem at the system level and virtually studied and designed the intervention can really be considered a novelty. There are articles on the subject related to the traditional surgical procedure, its tracing, but it is experience written in a very sporadic and variable depth, and no one at this level and elsewhere has studied it in a way that the movement and flexibility of the chest are analysed as a dynamic model. As already mentioned, when we correct the chest, all the related joints move, even the clavicle, which we know from the fact that we also had a moving chest CT, so when we model this, we have to consider all this and that is where the plethora of consultations starts, through which we can actually tailor the intervention to the particular patient.
- Based on what has been said so far, it seems - at least to me - that even if you “laid” all this knowledge on the medical community, currently it is possible to perform this surgery in this form in Pécs only. Do you have any plans or motivation - if we have already talked about software - to replace this teamwork at some point with software made directly for this purpose and thus expand this special knowledge widely?
- We are definitely on this, but at the system level the issue is more complicated. Personally, I am uncertain that the centre of this would be in Pécs because there is a lot of work with it. Obviously, our basic idea is to have a know-how from this, but now I do not see the capacity on any side - whether financial or programming - to be able to make an instant software solution out of it in a short time. We are addressing the issue; we plan to start with NEAK first so that the individual prosthesis can become an individual funding or form of care. Not only in this case, but even in the case of other surgeries and if we see support then we can start in a more general direction. It takes a comprehensive structure and intent to offer a concise and focused solution, and I believe that so far, few people would understand that this product could have potential. Let us rejoice in these results for the time being but let us not rule out the possibility of this. Who knows, maybe someone who is interested will show up.
- Can the reduction of the possibility of error and the risk elements make this type of surgery "competitive" in terms of funding?
- Definitely, and if we are talking about increasing the efficiency of a surgical procedure or reducing the time of surgery, I see a lot of opportunities in the fields of orthopaedics, trauma, cardiac surgery, vascular surgery, otorhinolaryngology, neurosurgery, where similar procedures could take place every day, similarly in a way that is personalized to a particular patient, to problems that can be approached as a kind of surgical procedure standard. In the case of cardiac surgery, for example, time is a particularly critical factor, but even a separate discussion would be worth having about just how many things these solutions could be used for.
- Are there any examples of this in practice?
–In the case of craniotomies, for example, we have printed templates that can be used to solve a lot of things with the approved bone cement, thus we could avoid lengthy approval procedures for directly printed implants. We have a lot of paediatric traumatology cases where, for example, limb corrections are performed. We already have a system and protocol for this, which structures surgical planning solutions in a way that can be used in practice and education as well. The first step is when we print demonstration tools on which we present the pathology, and the second step is when doctors can practice the particular surgery on the demonstration tool. The third step is what we are now doing in the case of this surgery when designing an implant tailored to the individual. We are able to print the model and examine how the implant fits, and even during surgery we can see where it should go, and there is a fourth step when we look at the function in the virtual simulation and adjust the ideal solution accordingly. Returning to the example of cardiac surgery, when we have to close ventricular dilatation with a patch (when the ventricle is arched), its location and size are very important. An important question is how it is strained, what flow conditions are above it. Based on a dynamic heart model, we can then design the shape of the ideal patch. If I had to summarize what we are doing in a snapshot, then we can offer an individual therapeutic solution corresponding to the interpretation of the problem in any area. When we get to other universities to give a lecture on these, we never manage to list or tell the cases in an hour and a half, the list of cases we have already solved this way is so long.
- According to this, this requires people with special interests who, in addition to being doctors, can be said to be accidentally interested in 3D design and technology, while being able to make themselves understood with people working in the technical field. The university’s CBEI programme and initial Biomedical Engineering master’s training may serve to make it easier for anyone who wants to enter this field, but to what extent should a doctor be an engineer, and to what extent should an engineer be a doctor and how does 3D design come into play – for example in your case?
- I came across 3D as a hobby, and then I thought more and more about how to solve problems with its help. The defining experience was that these solutions then became technically valid, and the feeling came that this can really be done in the foreseeable future. Then it distracted me to such an extent that I started to deal with it the most. After that, it was natural that I got in touch with more and more engineers and software people who also started to believe in this and of course they became interested in what I was doing. Since this is a team, it is a whole other driving force, we have practically pushed each other along this path. It currently works at the 3D Centre where we design patient-specific things together.
Regarding Biomedical Engineering: we do not see how we are going to get into the picture yet but obviously we are completely open to tell what we are doing if the need arises, we will do our job until then. My experience as a teacher is that it provides a very interesting approach for both engineers and doctors and unleashes energy and potential on both sides. At the very least, this raises the possibility of forming an approach in interested people with engineering, IT, and medical degrees. Our lectures are received with great interest at the Óbuda University and SOTE and I am very confident that this kind of knowledge exchange will start here as well. 3D itself is only a very small slice of this, a useful tool with useful solutions to clinical problems. The most important part is rather how we can talk to each other as a doctor in the language of an engineer and vice versa. I think this is also the biggest problem abroad, so it would be a very promising step to build a training for this purpose.
- As a doctor, how difficult is it to understand engineers and how do you see it as a problem for them?
- It is very difficult. I think this is something that needs to be constantly learned.
- Is that due to the approach? The dichotomy of organic and mechanical?
- We simply interpret problems completely differently; we often talk about something different. And where the common ground is in the understanding only depends on one’s willingness to venture out of one’s own comfort zone and venture into the other’s field. This is where those crazy people come into play who start dealing with software as doctors and the engineers who want to understand medical problems in a way that they want to be involved in the solution too.
- Looking at it from a distance it seems — at least to me —that you are the first generation of professionals who did not learn what they are doing at school, but it came together from experience and will. As it has proven to be effective and useful, it may occur that it might be worthwhile to teach it to others, even in a graduate setting. I guess it takes no small effort for someone to go in a direction so completely different from what he was originally preparing for, even if it is within their area of interest. At least learning individually is always a bit more difficult, if perhaps more interesting.
- But it is fuller of experience, that is for sure. This could be the message for those interested in this direction: the joy of discovery. There is no greater experience than understanding things as a doctor, finding methods as an engineer, and then being able to offer a solution due to this.