Abdominal Aortic Aneurysm: From Clinical Imaging to Realistic Replicas

Abstract

The goal of this work is to develop a framework for manufacturing nonuniform wall thickness replicas of abdominal aortic aneurysms (AAAs). The methodology was based on the use of computed tomography (CT) images for virtual modeling, additive manufacturing for the initial physical replica, and a vacuum casting process and range of polyurethane resins for the final rubberlike phantom. The average wall thickness of the resulting AAA phantom was compared with the average thickness of the corresponding patient-specific virtual model, obtaining an average dimensional mismatch of 180 μm (11.14%). The material characterization of the artery was determined from uniaxial tensile tests as various combinations of polyurethane resins were chosen due to their similarity with ex vivo AAA mechanical behavior in the physiological stress configuration. The proposed methodology yields AAA phantoms with nonuniform wall thickness using a fast and low-cost process. These replicas may be used in benchtop experiments to validate deformations obtained with numerical simulations using finite element analysis, or to validate optical methods developed to image ex vivo arterial deformations during pressure-inflation testing.

Soft 3D-Printed Phantom of the Human Kidney with Collecting System

“…However, these printed models are often made of hard plastic materials and lack interior cavity structures found in the target organ, such as the kidney’s collecting system. Recently, 3D printing and vacuum casting were combined to manufacture an abdominal aortic aneurism (AAA) model 5. A silicone outer mold and a wax inner mold were created based on a 3D-printed AAA artery, and the final phantom was molded in polyurethane resin that mimics the artery’s stress–strain behavior.…”

Method to simulate distal flow resistance in coronary arteries in 3D printed patient specific coronary models

“…Previous investigations [15][16][17][18] used phantoms from stiff photopolymers that lack compliance of arteries vital for device placement. To capture the flexible and compliant nature of the arteries, other investigators have followed similar approaches by fabricating a stiff 3D printed cast for silicone or polyurethane injection molding [19][20][21][22][23][24].…”

“…When combined with multi-material 3DP capability, this may allow development of vascular models where the mechanical properties of the anatomical structures might be replicated. A number of case studies have documented the feasibility of using 3DP vascular models where arterial wall mechanical properties such as compliance, stiffness, and hemodynamic pressure are preserved [20,21,25]. Another important application of the vascular phantoms are hemodynamics simulations where, in addition to the wall properties, special consideration must be paid to the boundary conditions, namely the inflow and outflow parameters.…”

A High-Fidelity Phantom for the Simulation and Quantitative Evaluation of Transurethral Resection of the Prostate

“…18 To lower the risk of surgical complications, it is promising to first perform surgical simulations, training and medical instrument testing on a phantom. Different phantom models have been developed and reported in the literature for many organs, such as blood vessel, 9 kidney, 1,22 brain, 15,24 prostate, 5,7,12,16 etc. For example, Weinstock et al built a brain phantom with realistic features for minimally invasive neurosurgery, using state-of-the-art 3D printing technology and special effects borrowed from the film industry.…”