Radiofrequency ablation via an implanted self-expandable metallic stent to treat in-stent restenosis in a rat gastric outlet obstruction model

Dong-Sung Won; Yubeen Park; Chu Hui Zeng; Dae Sung Ryu; Ji Won Kim; Jeon Min Kang; Song Hee Kim; Hyung-Sik Kim; Sang Soo Lee; Jung-Hoon Park

doi:10.3389/fbioe.2023.1244569

Radiofrequency ablation via an implanted self-expandable metallic stent to treat in-stent restenosis in a rat gastric outlet obstruction model

Front Bioeng Biotechnol. 2023 Sep 6:11:1244569. doi: 10.3389/fbioe.2023.1244569. eCollection 2023.

Authors

Dong-Sung Won^#¹, Yubeen Park^#^{1

2}, Chu Hui Zeng¹, Dae Sung Ryu^{1

2}, Ji Won Kim^{1

2}, Jeon Min Kang¹, Song Hee Kim^{1

2}, Hyung-Sik Kim³, Sang Soo Lee², Jung-Hoon Park¹

Affiliations

¹ Biomedical Engineering Research Center, Asan Institute for Life Sciences, Asan Medical Center, Seoul, Republic of Korea.
² Department of Gastroenterology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
³ Department of Mechatronics Engineering, School of ICT Convergence Engineering, College of Science and Technology, Konkuk University, Chungju, Republic of Korea.

^# Contributed equally.

Abstract

Background: In-stent restenosis caused by tissue hyperplasia and tumor growth through the wire meshes of an implanted self-expandable metallic stent (SEMS) remains an unresolved obstacle. This study aimed to investigate the safety and efficacy of SEMS-mediated radiofrequency ablation (RFA) for treating stent-induced tissue hyperplasia in a rat gastric outlet obstruction model. Methods: The ablation zone was investigated using extracted porcine liver according to the ablation time. The optimal RFA parameters were evaluated in the dissected rat gastric outlet. We allocated 40 male rats to four groups of 10 rats as follows: group A, SEMS placement only; group B, SEMS-mediated RFA at 4 weeks; group C, SEMS-mediated RFA at 4 weeks and housed until 8 weeks; and group D, SEMS-mediated RFA at 4 and 8 weeks. Endoscopy and fluoroscopy for in vivo imaging and histological and immunohistochemical analysis were performed to compare experimental groups. Results: Stent placement and SEMS-mediated RFA with an optimized RFA parameter were technically successful in all groups. Granulation tissue formation-related variables were significantly higher in group A than in groups B-D (all p < 0.05). Endoscopic and histological findings confirmed that the degrees of stent-induced tissue hyperplasia in group D were significantly lower than in groups B and C (all p < 0.05). Hsp70 and TUNEL expressions were significantly higher in groups B-D than in group A (all p < 0.001). Conclusion: The implanted SEMS-mediated RFA successfully managed stent-induced tissue hyperplasia, and repeated or periodic RFA seems to be more effective in treating in-stent restenosis in a rat gastric outlet obstruction model.

Keywords: gastric outlet obstruction; granulation tissue; radiofrequency ablation; self-expandable metallic stent; tissue hyperplasia.

Grants and funding

This work was supported by the Korea Medical Device Development Fund grant funded by the Korean government (the Ministry of Science and ICT; the Ministry of Trade, Industry, and Energy; the Ministry of Health and Welfare, Republic of Korea; and the Ministry of Food and Drug Safety; project number: RS-2023-00238092). This work was also supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT) (2022R1C1C1003205). MSIT: Ministry of Science and ICT.