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.
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.
Cardiovasc Intervent Radiol. 2019 Sep;42(9):1343-1351. doi: 10.1007/s00270-019-02239-0. Epub 2019 May 13.
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.
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.
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.
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.
比较球囊扩张可降解支架（BEBS）和自膨式金属支架（SEMS）在大鼠尿道模型中的支架诱导组织增生程度。
将 20 只大鼠随机分为两组。BEBS 组（n=10）接受聚-L-乳酸（PLLA）可降解支架。SEMS 组（n=10）接受裸镍钛合金支架。所有大鼠在支架放置 8 周后处死。通过比较两组逆行尿道造影和组织学检查结果，评估支架诱导的组织增生程度。
所有大鼠的支架置入均技术成功。BEBS 组有 2 只大鼠因与手术相关的死亡而被排除。两组在尿道造影上的支架内尿道管腔直径在 4 周和 8 周时无显著差异。组织学分析显示，BEBS 组的肉芽组织面积百分比（p<0.001）和乳头状突起厚度（p<0.001）明显高于 SEMS 组。炎症细胞浸润有明显的显著趋势（p=0.050）。两组的上皮层数和黏膜下纤维化厚度无统计学差异。
大鼠尿道中支架诱导组织增生明显，BEBS 和 SEMS 之间的程度相似。与 SEMS 相比，BEBS 与更厚的乳头状突起和更大的肉芽组织面积相关，这是由于炎症反应更高所致。
