Details:
Development and study of innovative endovascular balloon system for the local administration of innovative drug.
Funding
The Clever Balloon project was co‐financed by the European Union and Greek national funds through the Operational Program Competitiveness, Entrepreneurship and Innovation, under the call RESEARCH – CREATE – INNOVATE (project code: Τ2ΕΔΚ-03677)
Technology used
- Ansys Spaceclaim 2023R1
- Ansys Explicit Dynamics 2023R1
- Ansys Workbench 2023R1
- Ansys CFX 2023R1
- Ansys CFD-POST 2023R1
Challenge:
SIMTEC has tackled two challenges: (a) modeling the mechanical behavior of the balloon and the induced stresses and strains in the balloon as well as in the arterial wall, quantities related to the strength levels of the balloon material and to the damages in the arterial wall that contribute to restenosis phenomena, respectively; (b) modeling drug release based on diffusion mechanisms within the arterial tissue. More specifically, the effect of the drug will be studied as the rate of diffusion depends on the rate of expansion, so that we can evaluate and optimize the amount of drug that should be contained in the balloon.
Solution:
In collaboration with the UOI, SIMTEC has conducted three-dimensional representations of several arterial walls and modeled the behavior of the balloon during drug deployment and release. The arterial wall has been reconstructed, including different types of atheromatous plaques (calcified and non-calcified), based on imaging data from animal studies.
To enhance the realism of the balloon deployment process and its shape, SIMTEC modeled the folding and pleating of the balloon. This modeling result was used to simulate balloon inflation in various artery sets. SIMTEC then simulated balloon inflation in each artery individually and assessed the stress, strain, and deformation on both the balloon and the arteries. Additionally, SIMTEC evaluated the surface contact between the balloon and the arteries.
Since the balloon was coated with a drug, SIMTEC conducted drug delivery CFD simulations to calculate drug diffusion on the artery wall for each individual artery.
Balloon folding process
Balloon inflation process
Balloon pleating process
Based on the computational study of induced stresses and strains, we concluded that the balloon is a safe method for treating coronary artery disease, as it withstood high pressures and remained intact. A larger diameter balloon fitted precisely to the uneven arterial wall without causing injury. The balloon’s performance matched the compliance chart provided by the company, confirming the accuracy of the expansion model.
Different computational models for drug release and absorption by arterial tissue were designed and executed. Simulations of drug release for Everolimus, Sirolimus, and their various concentrations, based on diffusion mechanisms, were conducted according to the Clinical Trials data. The results showed rapid drug release within 60 seconds due to the high drug concentration in the balloon’s cellulose coating, which led to large pore formation and rapid diffusion.
Comparative analysis indicated that Sirolimus released more slowly compared to Everolimus, up to 5 times slower. High Dose Everolimus and standard Everolimus showed no difference in release rate, only in the total amount released, aligning with the expected threefold concentration difference.
