Aortic aneurysm: construction of a life-size model by rapid prototyping

Development of new endovascular techniques for repair of abdominal aortic aneurysm (AAA) requires the use of experimental models. Stereolithography is a rapid prototyping technique used in industry to prototype parts during the design phase. A stereolithography apparatus (STL) employs laser technology to build a digital model layer by layer with photopolymer resin. The purpose of this study was to use this technology to produce a life-size AAA model. Data were acquired by CT scan and stored in DICOM 3 format. Specifically designed software was used for 3-D imaging and conversion of data to a standard STL format. Two replicas were made: one to scale and the other 3 mm larger. The final model was made by pouring silicone rubber or polyurethane into the mold over the life-size model so as to obtain a sturdy, life-size, soft, transparent plastic casting. Arterial models made for living subjects with these rapid prototyping techniques can be used to simulate surgical procedures, calibrate imaging modalities, and design new stent grafts.