Jung-Hoon Park1,2, Tae-Hyung Kim3, Young Chul Cho1, Nader Bakheet1, Seung Ok Lee4, Seong-Hun Kim5, Kun Yung Kim6. 1. Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, Republic of Korea. 2. Department of Biomedical Engineering Research Center, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, Republic of Korea. 3. Department of Radiological Science, Kangwon National University, 346 Hwangjo-gil, Dogye-eup, Samcheok-Si, Kangwon-do, 25949, Republic of Korea. 4. Division of Gastroenterology, Department of Internal Medicine, and Research Institute of Clinical Medicine, Chonbuk National University, 20 Geonji-ro, Deokjin-gu, Jeonju, Chonbuk, 54907, Republic of Korea. 5. Division of Gastroenterology, Department of Internal Medicine, and Research Institute of Clinical Medicine, Chonbuk National University, 20 Geonji-ro, Deokjin-gu, Jeonju, Chonbuk, 54907, Republic of Korea. shkimgi@jbnu.ac.kr. 6. Department of Radiology, and Research Institute of Clinical Medicine of Chonbuk National University-Biomedical Research Institute, Chonbuk National University, 20 Geonji-ro, Deokjin-gu, Jeonju, Chonbuk, 54907, Republic of Korea. kky2kkw@gmail.com.
Abstract
PURPOSE: To compare the degrees of stent-induced tissue hyperplasia of balloon-expandable, biodegradable stents (BEBSs) with those of self-expandable metallic stents (SEMSs) in a rat urethral model. MATERIALS AND METHODS: A total of 20 rats were randomized into two groups. The BEBS group (n = 10) received a poly-l-lactic acid (PLLA) biodegradable stent. The SEMS group (n = 10) received a nitinol bare stent. All rats were killed eight weeks after stent placement. The degree of stent-induced tissue hyperplasia was assessed by comparing the results of retrograde urethrography and histologic examination between the two groups. RESULTS: Stent placement was technically successful in all rats. Two rats in the BEBS group were excluded due to procedure-related death. The mean luminal diameter of stented urethra on urethrograms was not significantly different at 4 and 8 weeks between the two groups. On histologic analysis, the percentage of granulation tissue area (p < 0.001) and the thickness of papillary projection (p < 0.001) were significantly higher in the BEBS group compared with the SEMS group. The inflammatory cell infiltration showed a clear tendency to significance (p = 0.050). There were no statistical differences in the number of epithelial layers and the thickness of submucosal fibrosis between the two groups. CONCLUSION: Formation of stent-induced tissue hyperplasia was significantly evident in the rat urethra with similar degrees between the BEBS and the SEMS. The BEBS was associated with a thicker papillary projection and larger granulation tissue area resulting from higher inflammation compared with the SEMS.
PURPOSE: To compare the degrees of stent-induced tissue hyperplasia of balloon-expandable, biodegradable stents (BEBSs) with those of self-expandable metallic stents (SEMSs) in a rat urethral model. MATERIALS AND METHODS: A total of 20 rats were randomized into two groups. The BEBS group (n = 10) received a poly-l-lactic acid (PLLA) biodegradable stent. The SEMS group (n = 10) received a nitinol bare stent. All rats were killed eight weeks after stent placement. The degree of stent-induced tissue hyperplasia was assessed by comparing the results of retrograde urethrography and histologic examination between the two groups. RESULTS: Stent placement was technically successful in all rats. Two rats in the BEBS group were excluded due to procedure-related death. The mean luminal diameter of stented urethra on urethrograms was not significantly different at 4 and 8 weeks between the two groups. On histologic analysis, the percentage of granulation tissue area (p < 0.001) and the thickness of papillary projection (p < 0.001) were significantly higher in the BEBS group compared with the SEMS group. The inflammatory cell infiltration showed a clear tendency to significance (p = 0.050). There were no statistical differences in the number of epithelial layers and the thickness of submucosal fibrosis between the two groups. CONCLUSION: Formation of stent-induced tissue hyperplasia was significantly evident in the rat urethra with similar degrees between the BEBS and the SEMS. The BEBS was associated with a thicker papillary projection and larger granulation tissue area resulting from higher inflammation compared with the SEMS.
Authors: Noor Buchholz; Alberto Budia; Julia de la Cruz; Wolfgang Kram; Owen Humphreys; Meital Reches; Raquel Valero Boix; Federico Soria Journal: Polymers (Basel) Date: 2022-04-19 Impact factor: 4.967