Experimental model standardizing polyvinyl alcohol hydrogel to simulate endoscopic ultrasound and endoscopic ultrasoundelastography

BACKGROUND Endoscopic ultrasound(EUS)and endoscopic ultrasound elastography(EUS-E)simulation lessens the learning curve;however,models lack realism,diminishing competitiveness.AIM To standardize the mechanical properties of polyvinyl alcohol(PVA)hydrogel for simulating organs and digestive lesions.METHODS 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).RESULTS 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 EUSgraphically 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).CONCLUSION 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.