Basic Study
Copyright ©The Author(s) 2024. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Apr 28, 2024; 30(16): 2272-2280
Published online Apr 28, 2024. doi: 10.3748/wjg.v30.i16.2272
Optimization of tracheoesophageal fistula model established with T-shaped magnet system based on magnetic compression technique
Miao-Miao Zhang, Jian-Qi Mao, Lin-Xin Shen, Ai-Hua Shi, Xin Lyu, Jia Ma, Yi Lyu, Xiao-Peng Yan
Miao-Miao Zhang, Yi Lyu, Xiao-Peng Yan, Department of Hepatobiliary Surgery, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an 710061, Shaanxi Province, China
Miao-Miao Zhang, Yi Lyu, Xiao-Peng Yan, Shaanxi Provincial Key Laboratory of Magnetic Medicine, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an 710061, Shaanxi Province, China
Jian-Qi Mao, Lin-Xin Shen, Zonglian College, Xi’an Jiaotong University, Xi’an 710061, Shaanxi Province, China
Ai-Hua Shi, National Local Joint Engineering Research Center for Precision Surgery & Regenerative Medicine, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an 710061, Shaanxi Province, China
Xin Lyu, Department of Pulmonary and Critical Care Medicine, The Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an 710004, Shaanxi Province, China
Jia Ma, Department of Surgical Oncology, Shaanxi Provincial People’s Hospital, Xi’an 710068, Shaanxi Province, China
Co-first authors: Miao-Miao Zhang and Jian-Qi Mao.
Co-corresponding authors: Xiao-Peng Yan and Yi Lyu.
Author contributions: Lyu Y and Yan XP designed and coordinated the study; Zhang MM, Mao JQ, Shen LX, Lyu X, Ma J, and Yan XP performed the research and acquired the data; Zhang MM, Mao JQ, and Shen LX analyzed the data; Zhang MM and Shi AH tested and analyzed the magnetic force; Zhang MM and Lyu X wrote the manuscript; Yan XP and Lyu Y conceived of the study and contributed to the study design, the interpretation of the results, and the critical revision of the manuscript; and all authors read and approved the final manuscript.
Supported by the Key Research & Development Program of Shaanxi Province of China, No. 2024SF-YBXM-447; Institutional Foundation of The First Affiliated Hospital of Xi’an Jiaotong University, No. 2022MS-07; Fundamental Research Funds for the Central Universities, No. xzy022023068; and Natural Science Foundation of Shaanxi Province, No. 2023-JC-QN-0814.
Institutional animal care and use committee statement: All procedures involving animals were reviewed and approved by the Experimental Ethics Committee of Xi’an Jiaotong University (Approval No. XJTUAE2023-2207).
Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article.
Data sharing statement: The authors declare that the data supporting the findings of this study are available within the article or from the corresponding authors upon request.
ARRIVE guidelines statement: The authors have read the ARRIVE Guidelines, and the manuscript was prepared and revised according to the ARRIVE Guidelines.
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: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Xiao-Peng Yan, MD, PhD, Associate Research Scientist, Department of Hepatobiliary Surgery, The First Affiliated Hospital of Xi’an Jiaotong University, No. 277 West Yanta Road, Xi’an 710061, Shaanxi Province, China. yanxiaopeng9966@163.com
Received: January 25, 2024
Revised: March 13, 2024
Accepted: April 8, 2024
Published online: April 28, 2024
Abstract
BACKGROUND

The magnetic compression technique has been used to establish an animal model of tracheoesophageal fistula (TEF), but the commonly shaped magnets present limitations of poor homogeneity of TEF and poor model control. We designed a T-shaped magnet system to overcome these problems and verified its effectiveness via animal experiments.

AIM

To investigate the effectiveness of a T-shaped magnet system for establishing a TEF model in beagle dogs.

METHODS

Twelve beagles were randomly assigned to groups in which magnets of the T-shaped scheme (study group, n = 6) or normal magnets (control group, n = 6) were implanted into the trachea and esophagus separately under gastroscopy. Operation time, operation success rate, and accidental injury were recorded. After operation, the presence and timing of cough and the time of magnet shedding were observed. Dogs in the control group were euthanized after X-ray and gastroscopy to confirm establishment of TEFs after coughing, and gross specimens of TEFs were obtained. Dogs in the study group were euthanized after X-ray and gastroscopy 2 wk after surgery, and gross specimens were obtained. Fistula size was measured in all animals, and then harvested fistula specimens were examined by hematoxylin and eosin (HE) and Masson trichrome staining.

RESULTS

The operation success rate was 100% for both groups. Operation time did not differ between the study group (5.25 min ± 1.29 min) and the control group (4.75 min ± 1.70 min; P = 0.331). No bleeding, perforation, or unplanned magnet attraction occurred in any animal during the operation. In the early postoperative period, all dogs ate freely and were generally in good condition. Dogs in the control group had severe cough after drinking water at 6-9 d after surgery. X-ray indicated that the magnets had entered the stomach, and gastroscopy showed TEF formation. Gross specimens of TEFs from the control group showed the formation of fistulas with a diameter of 4.94 mm ± 1.29 mm (range, 3.52-6.56 mm). HE and Masson trichrome staining showed scar tissue formation and hierarchical structural disorder at the fistulas. Dogs in the study group did not exhibit obvious coughing after surgery. X-ray examination 2 wk after surgery indicated fixed magnet positioning, and gastroscopy showed no change in magnet positioning. The magnets were removed using a snare under endoscopy, and TEF was observed. Gross specimens showed well-formed fistulas with a diameter of 6.11 mm ± 0.16 mm (range, 5.92-6.36 mm), which exceeded that in the control group (P < 0.001). Scar formation was observed on the internal surface of fistulas by HE and Masson trichrome staining, and the structure was more regular than that in the control group.

CONCLUSION

Use of the modified T-shaped magnet scheme is safe and feasible for establishing TEF and can achieve a more stable and uniform fistula size compared with ordinary magnets. Most importantly, this model offers better controllability, which improves the flexibility of follow-up studies.

Keywords: Magnetic surgery, Magnetic compression technique, Tracheoesophageal fistula, Magnet, Animal model, Beagles

Core Tip: The magnetic compression technique has been successfully used to establish animal models of tracheoesophageal fistula (TEF) in beagle dogs. However, for TEF, use of the common circular magnet shape is associated with poor homogeneity and poor controllability of model. In this study, we used a modified T-shaped magnet system to establish a TEF, and the results showed this approach could obtain a more stable and uniform fistula size compared with standard magnets. Most importantly, the proposed model offers better controllability, which improves the flexibility of subsequent studies.