尿道细胞外基质在兔尿道重建中的应用

目的 评价尿道细胞外基质作为一种生物材料重建尿道的效果. 方法 切取新西兰兔的尿道制备尿道细胞外基质.手术切除实验组1～1.5 cm的尿道片段后用细胞外基质修复缺损,采用ELISA法检测术前、术后12、24及48 h血清TNFα的水平,评估术后兔的免疫反应状态.术后10d和3、6、24周取修复段尿道,行组织学观察并做尿道造影、尿道镜及尿流动力学检查. 结果 术后实验组血清TNFα水平较对照组略有升高,但无统计学意义(P>0.05).术后10 d,上皮细胞开始从边缘向细胞外基质移行并出现新生小血管;3周上皮细胞覆盖细胞外基质的整个管腔;6周出现排列不规则的平滑肌纤维;24周平滑肌数量明显增多,成束状排列.尿道造影、尿道镜及尿流动力学检测检查显示,尿道基质管壁光滑,排尿通畅. 结论 尿道细胞外基质是一种安全有效的尿道重建材料.

Reconstruction of rabbit urethra using urethral extracellular matrix

Objective To evaluate the feasibility of reconstruction of rabbit urethra using urethral extracellular matrix. Methods Extracellular matrix was obtained from the urethra of 20 donor New Zealand rabbits. In experimental group, 20 rabbits underwent segmental urethal resection(about 1.0 to 1.5 cm in length) and the defects were replaced by a tube of extracellular matrix. The serum TNFα was detected by ELISA to assess the immunity response preoperatively and 12、24、48 h postoperatively. The regenerated urethral segments were taken for histolngic and pathologic study 10 days, 3 weeks, 6 weeks and 24 weeks after operation. The urodynamics,urethroscopy and urethrography were also performed. Results The serum TNFa in experiment group slightly rised, with no significant difference when compared with that in control group. 10 days after operation, epithelial cell migrated into the extracellulur matrix from two ends, and small vessels were also found. 3 weeks later, several layers of urothelium covered the whole surface of the matrix tube. 6 weeks later, the irregularly arranged smooth muscle fibers were fist observed by Van Giesen staining. 24 weeks after operation, the smooth muscle cells increased, the appearance of the regenerated urethra segments were very similar to normal urethral wall components. The urethrography and urodynamic evaluation revealed no difference between the normal and the regenerated urethal tube. Conclusions The urethral extracellular matrix might be an ideal replacment material for urethral defect.