• Journal of the Korean Society of Radiology
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• v.14 no.4
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• pp.439-445
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• 2020

The purpose of this study was to investigate the feasibility of stent placement and the evaluation of tissue hyperplasia caused by bare metallic stent placement in a mouse colon model. In a pilot study, C57BL/6 mouse were used to verify diameter of colon. Mean diameter size was 4.05 mm. Twenty C57BL/6 mice were divided into two groups to assess differing stent diameters (Group A, 5 mm diameter; Group B. Group B, 4 mm diameter). Follow-up, 1-week fluoroscopic imaging, 4-week endoscopic imaging were obtained. Mice were sacrificed 4-week after stent placement. Microscopic findings were evaluated. Stent placement was technically successful except one mouse in Group A. Data from the mouse was omitted. During follow-up, five mice in Group A died within 7 days after stent placement, and one stent in Group B was migrated into the rectum. The incidence of stent-related complication was 60% and 10% between group A and Group B, respectively. Gross and Endoscopic findings showed tissue hyperplasia through the mesh, and all the stents had become incorporated into the wall of the colon. Microscopic findings were no statistically significant difference. colonic stent placement was technically feasible, and stent-induced tissue hyperplasia was evident in a mouse model. With stent large size, there was the highest incidence of colon perforation.

• Journal of the Korean Society of Radiology
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• v.16 no.5
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• pp.559-565
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• 2022

In this study, we intend to develop a granulation tissue formation model. As a pilot experiment, a contrast agent was injected into the pylorus in 3 rats, the normal pylorus lumen size was confirmed, and a stent was placed. Stent migration was confirmed in to the duodenum within 1 week. In this experiment, stent was sutured and fixed to induce granulation tissue formation after gastrostomy under a fluoroscopic guidance. Twenty rats were divided into Healthy Group / Gastrostomy Group. After anesthesia of the Gastrostomy Group, an abdominal incision was performed, and gastrostomy was performed under a fluoroscopic guidance, and a stent was placed into the pylorus. In order to prevent stent migration due to peristalsis, suture between the pylorus and the proximal end of the stent was performed. Postoperative behavior and weight changes were monitored daily. Four weeks after surgery, gastrointestinal fluoroscopy imaging was performed and rats were sacrifices. To evaluate the degree of granulation formation, the stent was sectioned transversely. Gastrostomy group was statistically significantly higher than Healthy Group in granulation area ratio (all p<.001). In conclusion, it is considered that the level of tissue overgrowth formation for preclinical evaluation of the pylorus stricture model through gastrostomy is appropriate as a research evaluation tool.