新型药物缓释尿道支架修复创伤性尿道狭窄

New biodegradable paclitaxel-eluting stents for repair of traumatic urethral stricture

目的 评估新型生物可降解紫杉醇缓释尿道支架修复创伤性尿道狭窄的可行性和有效性.方法 选取25只成年新西兰雄兔,按随机数字表法抽取其中20只为实验组,利用自行设计的爆炸装置成功构建创伤性尿道狭窄动物模型后,外科手术直视下置入生物可降解紫杉醇尿道支架.其余5只为正常对照组.分别在术后4,8,12周时通过尿道镜、逆行尿道造影和组织学检查评估药物支架修复创伤性尿道狭窄的效果.结果 实验组所有支架均在直视下成功置入原狭窄段尿道,术后未发生支架移位、结石形成.尿道镜观察显示,实验组8周时可见支架已经部分降解,12周时支架大部分已经降解,并且随尿液排出,修复后的尿道黏膜肉眼观察与正常尿道黏膜无明显差异.逆性尿道造影显示,实验组修复后的尿道腔恢复通畅,未见狭窄征象.组织学结果显示,实验组药物支架修复后的尿道上皮与正常结构基本一致,未见瘢痕形成征象.结论 新型生物可降解紫杉醇缓释尿道支架具有良好的生物相容性,能更有效地修复兔创伤性尿道狭窄.

Objective To evaluate the feasibility and effect of the new biodegradable paclitaxel-eluting stents in treatment of traumatic urethral stricture.Methods Twenty-five adult New Zealand rabbits were divided into study group （n =20） and control group （n =5） according to the random number table.In study group,rabbit models of traumatic urethral stricture were developed by self-designed explosive devices.All the stents were inserted under direct vision.Reparative results were evaluated by urethroscopy,retrograde urethrogram and histological examinations at postoperative 4,8,and 12 weeks.Results In study group all the stents were smoothly inserted into the strictured urethra without the occurrence of stent migration and lithogenesis.Urethroscopy showed that the stents in study group were partially degraded at 8 weeks,mostly degraded at 12 weeks and discharged with the urine.And from the naked eye,there was no distinct difference between the repaired and normal urinary mucosa.Retro^ade urethrogram demonstrated the stents restored urethral patency.Histological examinations showed the stents minimized stent-related inflammatory reactions,uroepithelial hyperplasia and scar formation.Conclusion New biodegradable paclitaxel-eluting stents exhibiting good biocompatibility are more effective to repair urethral stricture in rabbits.