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©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
Experimental model standardizing polyvinyl alcohol hydrogel to simulate endoscopic ultrasound and endoscopic ultrasound-elastography
Elymir S Galvis-García, Sergio Sobrino-Cossío, Arturo Reding-Bernal, Yesica Contreras-Marín, Karina Solórzano-Acevedo, Patricia González-Zavala, Rosa M Quispe-Siccha
Elymir S Galvis-García, Unidad de Endoscopía Gastrointestinal, Hospital General de México "Dr. Eduardo Liceaga", Mexico 06720, Mexico
Sergio Sobrino-Cossío, Unidad de Endoscopia y Fisiología Digestiva, Hospital Ángeles del Pedregal, Mexico 10700, Mexico
Arturo Reding-Bernal, Dirección de Investigación, Hospital General de México “Dr. Eduardo Liceaga”, Mexico 06720, Mexico
Yesica Contreras-Marín, Karina Solórzano-Acevedo, Unidad Profesional Interdisciplinaria de Biotecnología and Unidad de Investigación y Desarrollo Tecnológico, Instituto Politécnico Nacional and Hospital General de México "Dr. Eduardo Liceaga", Mexico 06720, Mexico
Patricia González-Zavala, Instituto de Investigaciones en Materiales and Unidad de Investigación y Desarrollo Tecnológico, Universidad Nacional Autónoma de México and Hospital General de México "Dr. Eduardo Liceaga", Mexico 06720, Mexico
Rosa M Quispe-Siccha, Unidad de Investigación y Desarrollo Tecnológico, Hospital General de México "Dr. Eduardo Liceaga", Mexico 06720, Mexico
Author contributions: Quispe Siccha RM established the design and concept of the study; Galvis García ES and Sobrino Cossío S executed the figures; Quispe Siccha RM, González Zaval P, Contreras Marín Y and Solórzano Acevedo K provided and validated the PVA phantoms; Sobrino Cossío S, Galvis García ES, Reding Bernal A and Quispe Siccha RM analyzed data from the literature, and Reding Bernal A performed the statistical analysis; Sobrino Cossío S and Quispe Siccha RM edited the first draft of the manuscript, which was critically discussed and revised in terms of intellectual content by Galvis García ES and Reding Bernal A; all authors discussed the statement and conclusions and approved the final version for publication.
Institutional review board statement: The study was reviewed and approved by the Science and Research Office of Hospital General de México “Dr. Eduardo Liceaga” (México) (Approval No. DI/12/11/04/017).
Informed consent statement: Patient details on ultrasound/elastography images have been removed to ensure anonymity.
Conflict-of-interest statement: There are no conflicts of interest to report.
Data sharing statement: No additional data are available.
STROBE statement: The authors have read the STROBE Statement-checklist of items, and the manuscript was prepared and revised according to the STROBE Statement-checklist of items.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Rosa M Quispe-Siccha, PhD, Academic Research, Research Scientist, Unidad de Investigación y Desarrollo Tecnológico, Hospital General de México "Dr. Eduardo Liceaga", Dr. Balmis 148, Doctores, Cuauhtémoc, Mexico 06720, Mexico.
rosa.quispe@gmail.com
Received: April 30, 2020
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
Processing time: 131 Days and 15.2 Hours
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 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).
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.
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.
