异种膀胱无细胞基质替代尿道的研究

目的探讨异种膀胱无细胞基质(ACM)管状替代尿道的可行性。方法19只成年雄性新西兰白兔分成3组：A组3只，为假手术对照组；B组10只，切除一段1．0cm尿道；C组6只，切除一段3．5～4．0cm尿道，之后应用已经事先制备好的异种膀胱ACM制成相当长度的管状替代被切除的尿道。术后1、2、4、8、16周动态观察替代尿道的尿道上皮、平滑肌和血管的再生情况。结果所有实验动物在术后7d拔除尿管后都恢复了自主排尿，没有排斥、尿瘘、感染等并发症发生。组织学检查显示实验组术后2周尿道上皮再生良好，4周完全覆盖尿道内腔，术后8周平滑肌见于近吻合口处，平滑肌生长缓慢，观察期内未能覆盖全长尿道。尿道造影未见明显尿道狭窄和憩室。结论异种膀胱ACM是一种良好的尿道修复和替代的材料。

Experimental assessment of urethral substitution with xenogenic bladder acellular matrix graft

Objective To study the feasibility of urethral replacement using heterologous bladder acellular matrix graft.Methods Nineteen male white New Zealand rabbits weighing 2.5- 3.5 kg were assigned to one of three experimental groups.Three animals underwent sham operation in group A.A 1.0 cm long tubular urethral segment was excised in group B (n=10),and replaced with a 1.0 cm tubular acellular matrix graft placed on a 10F foley catheter.A 3.5- 4.0 cm long tubular urethral segment was excised in group C (n=6),and replaced with a 3.5-4.0 cm tubular acellular matrix graft placed on a 10F foley catheter.Specimens were analyzed with hematoxylin-eosin stains on the postoperative week 1,2,4,8 and 16.All animals underwent a retrograde urethrography before operation,and 4,8 and 16 weeks after operation.Results All animals could void independently postoperatively after removing urethral catheter at 7th day,and no other complications such as rejection,fistula,infection occurred.Histological analyses of the specimens indicated that the epitheial regeneration was satisfactory on the postoperative 2 week,and the urethra atrium was covered completely 4 weeks postoperatively in groups B and C.The muscle fiber bundles only were seen at the anastomotic sites in 8 weeks postoperatively.The muscle fiber bundles grew slowly,and didn't cover acellular matrix graft completely in 16 weeks postoperatively.Serial urethrography demonstrated that there were no obvious strictures,fistula and diverticula postoperatively in groups B and C.Conclosion The xenogenic bladder acellular matrix graft is a good urethral reconstruction material.