Researchers at Washington State University have developed a 3D-printed heart model that contracts and beats. The model can help surgeons and medical students practise heart surgery on a realistic simulation of the human heart.
The synthetic model replicates the entire left half of the heart and responds dynamically to procedures. The researchers even performed a valve repair on the model, with ultrasound imaging and sensors confirming that the repair was successful. The results of the research have also been published in Advanced Materials Technologies.
Realistic simulation of a beating heart
According to Kaiyan Qiu, lead researcher of the study, the model offers significant advantages for surgical training. ‘It is very useful for doctors and surgeons to practise while the heart is still beating, especially in minimally invasive surgery.’
According to the researchers, the model is the first fully synthetic system that can mimic the entire left side of the heart without the use of animal models. ‘In our case, this model is the first fully synthetic model that mimics the entire left side of the heart without the aid of animal models. We were able to integrate both the anatomical features and the dynamic functions,’ said Qiu.
Surgical training without laboratory animals
Cardiovascular disease is a major cause of death worldwide. In the United States, approximately 800,000 patients undergo heart surgery each year. In addition to major surgical procedures, many minimally invasive procedures are also performed, for example to repair heart valves.
Training for such procedures often takes place using animal models or cadavers. However, these are not patient-specific and usually cannot be reused. Alternatively, doctors can practise the procedures virtually using computer simulations.
According to Alejandro Guillen Obando, existing synthetic models also have limitations. ‘There are other synthetic models that are usually cast in a mould. A major disadvantage of these is that they cannot properly replicate some of the more complex curves found in the heart.’
Detailed anatomy
For the new model, the researchers used a scan of a real heart to 3D print a replica of the left half of the heart. This side of the heart is under the highest pressure and pumps oxygen-rich blood through the body.
The model contains an atrium, ventricle and mitral valve and has a soft structure similar to heart tissue. Small pneumatic actuators cause the model to contract and pump blood through the system. In addition, thread-like structures have been added to mimic the movement of the mitral valve.
During the simulations, an artificial blood fluid flows through the model. Sensors record, among other things, the “blood pressure” in the heart chambers. According to Guillen Obando, the 3D printing technique used makes it possible to create more complex shapes. ‘Our layered approach to 3D printing makes it possible to add more curvature and give the heart chambers a more realistic shape.’
Test with mitral valve repair
To test the model, the researchers first printed a defective mitral valve. They then performed a repair using a tool similar to existing medical devices.
The sensors in the model showed that blood pressure in the left ventricle increased after the procedure, indicating that the valve was closing properly again. Ultrasound also showed that the artificial blood was no longer flowing back into the heart chamber.
Next step: a fully 3D-printed heart model
The researchers have now filed a provisional patent application and are working on the next step: a fully 3D-printed heart model with four chambers and four valves.
In addition, they want to further develop the model for patient-specific preoperative training in collaboration with doctors and students. This would make it possible to realistically practise different heart valve conditions in advance before performing surgery on a patient.
3D-printed heart model in the Netherlands
Since 2023, the Dutch Catharina Heart and Vascular Centre has been using a 3D printer to create realistic silicone models (in Dutch) of patients' hearts in order to better prepare for complex heart surgery. The models are based on scans of the heart and are an accurate copy of the patient's anatomy. Whereas plastic was previously used, doctors now make silicone models that are more flexible and more similar to real organ tissue.
Surgeons can use the model to determine the best surgical strategy in advance and plan the course of the procedure. In addition, the 3D heart helps to explain the condition and treatment options to patients. According to the doctors involved, the tangible model makes the conversation in the consulting room clearer and helps patients to better understand their situation.
