Fabrication of deformable patient-specific AAA models by material casting techniques

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Fluid Dynamics

Background:

• Abdominal Aortic Aneurysm (AAA) poses life-threatening risks if untreated.
• Patient-specific AAA models are crucial for in-vitro hemodynamic studies, surgical planning, and intervention testing.
• Current additive manufacturing methods struggle to provide the necessary flexibility and transparency for AAA models.

Purpose of the Study:

• To investigate and present casting techniques for fabricating patient-specific, deformable abdominal aortic aneurysm (AAA) models.
• To overcome limitations of direct additive manufacturing for AAA model creation.
• To produce AAA models suitable for advanced in-vitro hemodynamic investigations.

Main Methods:

• Two patient-specific AAA geometries were used to fabricate 3D models via material casting.
• Investigated lost molds and lost core casting approaches for manufacturing deformable AAA models.
• Acquired manufactured models using MRI, CT, ultrasound, and Particle Image Velocimetry (PIV); compared CT data to reference models for accuracy assessment.

Main Results:

• Both lost molds and lost core casting techniques successfully produced deformable AAA models.
• Lost molds casting yielded superior surface finish but was more expensive and time-consuming.
• Lost core casting was more affordable, allowed mold reuse, but resulted in a poorer surface finish.

Conclusions:

• Lost molds and lost core casting are viable methods for creating patient-specific, deformable AAA models.
• These models are suitable for in-vitro hemodynamic investigations, including PIV and medical imaging.
• Casting techniques offer a solution for producing AAA models with desired flexibility and transparency.