摘要
背景：天然丝素蛋白膜是较为理想的尿道缺损修复材料，其修复缺损尿道是否存在着长度问题，作者未查到确切的证实性资料。
目的：实验拟进一步观察丝素蛋白膜修复不同长度尿道缺损的效果。
设计、时间及地点：随机分组设计的动物对照实验，于2007-06/08在南方医科大学附属南方医院动物实验室完成。
材料：成年雄性比格犬14只，按随机数字表法分为3组，1.5 cm尿道缺损组（n=6），3.0 cm尿道缺损组（n =6），对照组(n =2)；丝素蛋白膜由浙江大学闵思佳教授惠赠，孔径150~250μm，孔隙率85％~95％。
方法：1.5 cm尿道缺损组和3.0 cm尿道缺损组：切开犬阴茎皮肤及皮下组织，游离出尿道海绵体，将尿道海绵体分别切除1.5，3.0 cm，再分别用1.5，3.0 cm丝素蛋白支架修复尿道缺损。对照组犬行尿道海绵体游离后即逐层缝合海绵体包膜、皮下组织及皮肤。
主要观察指标：术后6，12周逆行尿道造影，免疫组织化学染色观察尿道组织再生情况。
结果：1.5 cm尿道缺损组6只动物未见尿瘘及明显尿道狭窄梗阻，术后6周时修复区稍粗糙、不光滑，术后12周与对照组无明显差异；3.0 cm尿道缺损组6只动物均出现尿瘘或修复区管腔狭小、部分充盈缺损，术后6周和12周无明显差异。免疫组织化学染色证实1.5 cm尿道缺损组修复区腔面为尿道移行细胞覆盖；3.0 cm尿道缺损组修复区尿道外观呈苍白、致密坚硬且管腔狭小，免疫组织化学染色证实修复区腔面无尿道移行细胞覆盖。
结论：单纯丝素蛋白膜能修复1.5 cm短距离尿道缺损，对3.0 cm以上长距离缺损的修复效果不理想。
关键词：丝素蛋白膜；尿道；组织工程；生物材料

刘春晓，陈伟豪,郑少波，李虎林.丝素蛋白膜对犬不同长度尿道缺损的修复效果[J].中国组织工程研究与临床康复，2008，12(19):3613-3616 [www.zglckf.com/zglckf/ejournal/upfiles/08-19/19k-3613(ps).pdf]

Different lengths of dog urethral defects repaired with silk fibroin film

Abstract

BACKGROUND:Natural silk fibroin film may be a good way to repair urethral defect, but the confirmation of the repair effect requires the length difference is absent.
OBJECTIVE: To estimate the effect of different lengths of urethral defect repaired with silk fibroin film.
DESIGN, TIME AND SETTING: A randomized control animal experiment was carried out at the Animal Laboratory in Nanfang Hospital, Southern Medical University (Guangzhou, Guangdong, China) between June and August in 2007.
MATERIALS: Fourteen adult male dogs were randomly divided into three groups, experimental group of 1.5-cm defect (n =6), experimental group of 3.0-cm defect (n =6) and control group (n =2). Silk fibroin film was presented by Professor Min Si-jia from Zhejiang University (China), with the pore size of 150-250 μm and the porosity of 85%-95%.
METHODS: In two experimental groups, dog penis skin and subcutaneous tissue were excised to free cavernous body of urethra, and then two segmental defects of 1.5 cm and 3.0 cm were induced in the urethra of each dog. The defects were repaired with silk fibroin film with the corresponding lengths. Control group of two dogs underwent a sham operation.
MAIN OUTCOME MEASURES: Immunohistochemistry was used to observe the regeneration of urethra at weeks 6 and 12 after operation.
RESULTS: No fistulae were found among six animals in the experimental group of 1.5-cm defects, and serial urethrograms confirmed the maintenance of a wide urethral caliber without any signs of strictures. At week 12 postoperatively, there were no significant differences compared to the control group; fistula or strictures were observed in the 3-cm repair section of the experimental group. Silk fibroin film degraded completely at week 12, and the defect was repaired by mucous membrane of urethra and smooth muscle cells regularly in the 1.5-cm section. The cells were confirmed to be urethral epithelial cells analyzed with immunohistochemistry. Pale, dense and rigid appearance of the urethra was found in the 3-cm repair section, with the narrow cavity.
CONCLUSION: Silk fibroin film can repair a short-length defect within 1.5 cm, while it is unpredictable to repair defect longer than 3.0 cm only by the materials.

Liu CX, Chen WH, Zheng SB, Li HL.Different lengths of dog urethral defects repaired with silk fibroin film.Zhongguo Zuzhi Gongcheng Yanjiu yu Linchuang Kangfu 2008;12(19):3613-3616(China)
[www.zglckf.com/zglckf/ejournal/upfiles/08-19/19k-3613(ps).pdf]