[3D Printing News] 3D-printed liver model used for preoperative planning

[3D Printing News] 3D-printed liver model used for preoperative planning

3D printing has significant advantages in providing preoperative planning for the medical field. However, the high cost of industrial-grade printers, not to mention the difficulty in obtaining the necessary software, makes it a challenging area.
Therefore, it has not been widely used.
Jan Witowski, along with a research group at the Jagiellonian University, has developed a method to create human liver models using a desktop 3D printer for use before complex surgeries. Preoperative models (or known preoperative guidelines) are particularly useful in surgeries requiring accurate anatomical visualization.
They believe that superior imaging techniques offer several benefits, such as shorter surgery and recovery times, reduced blood loss, and better excision margins.

Challenges faced by doctors

When performing laparoscopic resection of the liver, it is crucial to be able to see where the tumor is located and where nearby blood vessels are situated. This reduces the risk of excessive blood loss during the procedure.
This is a minimally invasive procedure, and surgeons are keen to explore new ways to improve surgical preparation. However, according to the latest literature, only 10 doctors worldwide use 3D printing as part of their preparation process. The biggest question is, what exactly is preventing them from using this technology?


In his paper, Witowski points out that the main reason why surgeons have traditionally not used 3D printing is cost.
Industrial-grade 3D printers cost over $200,000 and are rarely used by professionals in medical institutions.
Furthermore, the software for detailed subdivisions costs thousands of dollars, and these are costs that few practitioners are willing to bear. Until recently, most liver models were created using material spraying (Polyjet, Multijet) , with each model costing as much as $5,000.
Another significant factor preventing surgeons from adopting 3D printing technology is time. Developing a model using an industrial-grade 3D printer takes four to seven days.
Outsourcing will take longer.
Witowski also emphasized the inappropriateness of SLA and SLS because surgeons would lose the ability to visualize the substance (the external shape of the liver). His goal was to provide an alternative using an FDM printer and silicone, which would reduce manufacturing costs slightly while retaining all the details needed to improve the surgical procedure.

Use the Ultimaker 3D printer to create a liver model

Using a desktop 3D printer to 3D print a liver model reduces all time by approximately 60-100 hours. The price is also quite low. Witowski uses diagrams to illustrate how it works.
The 52-year-old female patient first underwent laparoscopic colorectal resection, and two years later underwent laparoscopic right hemihepatectomy (second hepatectomy).
When CT scans show a single metachronous metastasis.
Her CT scan clearly showed its cross-sectional structure, and then the virtual model was converted into an STL file and printed in 3D.
For 3D printing, Witowski used Blender, Meshmixer, and Ultimaker Cura, as well as an Ultimaker 2+ 3D printer .



Model development phase

Model development consists of four key stages: object segmentation, common 3D model computer processing, slicing and printing, and finally curing with silicone before finishing and assembly.
The total printing time ranges from 60 to 100 hours, depending on the size of the model, the number of parts, the printing accuracy, and the type of printer. In this case, 72 hours of printing is required, and due to the interchangeable materials and the size of the printing platform, it must be performed over six print jobs.
Post-treatment is important to maximize the smoothness of the silicone surface and prevent cloudiness. Sand the model with 100-300 grit sandpaper, then wash with water and let it dry. Apply self-leveling resin XTC-3D and wait for it to cure for about 3 hours until the resin is dry. Repeat this process to ensure the surface is smooth enough for use in silicone casting.
The multi-part structure is bonded together using a common cyanoacrylate-based adhesive, and then the joint areas are protected with insulating tape and modeling putty. This prevents silicone leakage during the casting stage.
Thanks to Ultimaker, Witowski was able to create a transparent, full-size liver model, showing blood vessels and malignant metastases of colorectal cancer, for under $150. This was achieved through a combination of 3D printing and silicone molding.

Desktop 3D printers like Ultimaker can be placed in hospitals immediately and generate physical models of patients' anatomy within hours or days.
This allows surgeons to touch and feel the model, making the surgical planning process more realistic.

Jan concluded, "I chose Ultimaker because of its reliability. I need a printer that doesn't let me down when I'm printing over 20 hours a day . I truly believe that using low-cost printing is a huge step towards personalized medicine. I will definitely continue to use Ultimaker."
This is especially true for high-impact projects that require timely results.



Cost and time

The estimated cost of creating models using traditional techniques is approximately $1,000 for a liver model and $500 for a kidney model.

Cost comparison between manufacturing methods

Since Witowski does not require additional personnel (experts, technicians, computer graphics, etc.) to perform the task, the labor and other costs associated with operating the 3D printer are disregarded.
Using the FDM method, this model can be created in five days.
Surgeons can then explore the model using sight and touch, helping them create a surgical plan.

Wider influence

Jagiellonian University employs 3D printing technology in departments such as vascular surgery, cardiac surgery, and urology. It has established the largest 3D printing research center in Poland and provides consultation services to doctors nationwide.
Jan and his team have proven that 3D printing is not just a trend, but a real medical tool. The department is excited to further collaborate with FDM technology while exploring its broader benefits.
Surgical guidance and training of medical students to demonstrate models to patients provides doctors and patients with greater mutual understanding and reassurance.

"I firmly believe that using low-cost printing is a major step towards personalized medicine." .

Recently, Jan and his team printed a pulmonary artery model for cardiologists in Otwock, Poland, for use in pulmonary balloon angioplasty—a procedure to widen narrowed or blocked arteries or veins. The report shows that using these models reduced surgical time, improved short-term outcomes, and facilitated significant planning.

It may only be a matter of time before desktop 3D printing technology is more widely adopted in medical practice and yields the greatest benefits.

Disclaimer: Ultimaker 3D printers are designed and manufactured for commercial environments using Ultimaker engineered thermoplastics for fused deposition modeling.
The combination of precision and speed makes the Ultimaker 3D printer the perfect machine for conceptual models, functional prototypes, and small-batch production. While we have achieved a very high level of performance in replicating 3D models using the Ultimaker Cura, users still have a responsibility to validate the application of the printed objects, particularly in the areas of medical devices and aerospace .

Original link: https://ultimaker.com/en/stories/39791-3d-printing-a-cost-effective-personalized-liver-model-for-preoperative-planning