Published online Sep 14, 2020. doi: 10.3748/wjg.v26.i34.5169
Peer-review started: April 30, 2020
First decision: May 15, 2020
Revised: July 27, 2020
Accepted: August 15, 2020
Article in press: August 15, 2020
Published online: September 14, 2020
Endoscopic ultrasound (EUS) and endoscopic ultrasound elastography (EUS-E) simulation lessens the learning curve; however, models lack realism, diminishing competitiveness.
To standardize the mechanical properties of polyvinyl alcohol (PVA) hydrogel for simulating organs and digestive lesions.
PVA hydrogel (Sigma Aldrich, degree of hydrolysis 99%) for simulating EUS/EUS-E lesions was investigated in Unidad de Investigación y Desarrollo Tecnológico at Hospital General de México “Dr. Eduardo Liceaga”, Mexico City. We evaluated physical, contrast, elasticity and deformation coefficient characteristics in lesions, applying Kappa’s concordance and satisfaction questionnaire (Likert 4-points).
PVA hydrogel showed stable mechanical properties. Density depended on molecular weight (MW) and concentration (C). PVA bblocks with the greatest density showed lowest tensile strength (r = -0.8, P = 0.01). Lesions were EUS-graphically visible. Homogeneous and heterogeneous examples were created from PVA blocks or PVA phantoms, exceeding (MW2 = 146000-186000, C9 = 15% and C10 = 20%) with a density under (MW1 = 85000-124000, C1 = 7% and C2 = 9%). We calculated elasticity and deformation parameters of solid (blue) areas, contrasting with the norm (Kappa = 0.8; high degree of satisfaction).
PVA hydrogels were appropriate for simulating organs and digestive lesions using EUS/EUS-E, facilitating practice and reducing risk. Repetition amplified skills, while reducing the learning curve.
Core Tip: Endoscopic ultrasound (EUS)/EUS-elastography simulation reduces the learning curve. In this study, the mechanical properties of polyvinyl alcohol (PVA) hydrogel were standardized to simulate digestive organs and lesions. PVA hydrogels with stable mechanical properties were obtained; the density depended on the molecular weight (MW) and concentration (C), and the PVA hydrogels with the highest density showed less tensile strength. All lesions were visible by EUS/EUS-elastography; those that were homogeneous and heterogeneous were created with hydrogels of higher density (MW2, C9 and C10) and lower density (MW1, C1 and C2), respectively. In conclusion, PVA hydrogels are appropriate for simulating organs and digestive lesions, facilitating practice and reducing risk.