Copyright
©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
Establishing a rabbit model of perianal fistulizing Crohn’s disease
Shuang-Shuang Lu, Wen-Jia Liu, Qiu-Ya Niu, Chun-Yan Huo, Yu-Qing Cheng, En-Jing Wang, Rong-Nan Li, Fang-Fang Feng, Yi-Ming Cheng, Rong Liu, Jin Huang
Shuang-Shuang Lu, Wen-Jia Liu, Qiu-Ya Niu, Chun-Yan Huo, Yu-Qing Cheng, En-Jing Wang, Rong-Nan Li, Fang-Fang Feng, Yi-Ming Cheng, Jin Huang, Gastroenterology Center, The Affiliated Changzhou Second People's Hospital of Nanjing Medical University, Changzhou 213000, Jiangsu Province, China
Shuang-Shuang Lu, Wen-Jia Liu, Yu-Qing Cheng, Rong-Nan Li, Fang-Fang Feng, Yi-Ming Cheng, Jin Huang, Graduate School, Dalian Medical University, Dalian 116044, Liaoning Province, China
En-Jing Wang, Graduate School, Nanjing Medical University, Nanjing 210000, Jiangsu Province, China
Rong Liu, Jin Huang, Medical Statistics Center, Changzhou University, Changzhou 213000, Jiangsu Province, China
Author contributions: These authors contributed to this work. Huang J and Niu QY conceived the concept; Lu SS designed the method; Lu SS completed the entire study with the help of Liu WJ, Huo CY, Li RN, Wang EJ, Feng FF, Liu R and Cheng YM; the histological sections were completed with the help of Cheng YQ and Huo CY; endoscopy was performed by Huang J and Niu QY; Lu SS, Huang J and Liu WJ discussed the results and revised the manuscript.
Institutional review board statement: This study was approved by the Institutional Review Board of Changzhou University (No. 2019102510).
Institutional animal care and use committee statement: All animal experiments conformed to the internationally accepted principles for the care and use of laboratory animals.
Conflict-of-interest statement: The authors have nothing to disclose.
Data sharing statement: No additional data are available.
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: Jin Huang, PhD, Professor, The Affiliated Changzhou Second People's Hospital of Nanjing Medical University, No. 68 Gehu Road, Wujin District, Changzhou 213000, Jiangsu Province, China. hj042153@hotmail.com
Received: November 25, 2021
Peer-review started: November 25, 2021
First decision: January 11, 2022
Revised: January 18, 2022
Accepted: March 6, 2022
Article in press: March 6, 2022
Published online: April 21, 2022
BACKGROUND
Crohn's disease (CD) is a chronic nonspecific intestinal inflammatory disease. The aetiology and pathogenesis of CD are still unclear. Anal fistula is the main complication of CD and is a difficult problem to solve at present. The main limitation of developing new therapies is bound up with the short of preclinical security and effectiveness data. Therefore, an ideal animal model is needed to establish persistent anal fistula and an inflamed rectal mucosa.
AIM
To improve the induction method of colitis and establish a reliable and reproducible perianal fistulizing Crohn’s disease animal model to evaluate new treatment strategies.
METHODS
Twenty male New Zealand rabbits underwent rectal enema with different doses of 2,4,6-trinitrobenzene sulfonic acid to induce proctitis. Group A was treated with an improved equal interval small dose increasing method. The dosage of group B was constant. Seven days later, the rabbits underwent surgical creation of a transsphincteric fistula. Then, three rabbits were randomly selected from each group every 7 d to remove the seton from the fistula. The rabbits were examined by endoscopy every 7 days, and biopsy forceps were used to obtain tissue samples from the obvious colon lesions for histological analysis. The disease activity index (DAI), colonoscopy and histological scores were recorded. Perianal endoscopic ultrasonography (EUS) was used to evaluate the healing of fistulas.
RESULTS
Except for the DAI score, the colonoscopy and histological scores in group A were significantly higher than those in group B (P < 0.05). In the ideal model rabbit group, on the 7th day after the removal of the seton, all animals had persistent lumens on EUS imaging, showing continuous full-thickness high signals. Histological inspection of the fistula showed acute and chronic inflammation, fibrosis, epithelialization and peripheral proctitis of the adjoining rectum.
CONCLUSION
The improved method of CD colitis induction successfully established a rabbit perianal fistula CD preclinical model, which was confirmed by endoscopy and pathology.
Core Tip: In this work, we improved the method of Crohn's disease (CD) colitis induction and successfully established a rabbit perianal fistula CD preclinical model, which was confirmed by endoscopy and pathology. The anatomy of this mid- to large-sized animal can simulate the human intestinal environment and tolerate examination and operation. This model may be used to assess perianal fistulizing CD treatments and their effectiveness.
