人羊膜细胞外基质修复兔尿道缺损

目的 寻求较理想的尿道修复材料.方法 取健康孕妇剖宫产胎盘羊膜组织,无菌操作下脱细胞处理,制成人羊膜细胞外基质(HAECM),并用倒置显微镜观察脱细胞效果.另12只新西兰白兔分成二组,A组3只为对照组;B组9只为实验组.将实验组兔人为切除一段1 cm的尿道,做成尿道缺损模型,用已经制备好的HAECM制成长度1 cm、内径约2.5 mm的基质管修复被切除的尿道;对照组游离出尿道,正中切断后直接再逐层缝合.分别于术后4、12、16周取尿道标本进行大体观察和组织学检杳.结果 实验组兔的HAECM移植物无移位、脱落,除1例感染合并尿瘘、1例单纯尿瘘外余效果满意;对照组均顺利恢复.组织学检查显示术后4周新尿道恢复连续性;12周时新尿道组织基本上替代HAECM移植物,并可见少量血管和散在的尿道平滑肌再牛,术后16周移植区可见尿道平滑肌增多,排列较对照组欠规则.结论 人羊膜细胞外基质可以修复兔尿道部分缺损.     

兔骨髓间充质干细胞构建异种组织工程化尿道修复兔尿道缺损

目的 探索兔骨髓间充质干细胞为种子细胞构建异种组织工程化尿道修复兔尿道缺损的可行性.方法 60只兔随机数字法均分为实验组、对照组,实验组用种植有自体骨髓间充质干细胞的脱细胞猪尿道基质修复长约2 cm兔尿道缺损,对照组用脱细胞猪尿道基质修复.两组术后2、4、8、24周切取再造尿道标本,行组织学检查,术后24周行尿动力检查,比较差异.结果 实验组术后再造尿道腔面光滑,可见和正常尿道类似的组织结构.对照组血管和平滑肌形成较少,再造尿道腔面不如实验组光滑.实验组的术后最大尿道压(25±2)cmH2O与术前(24±3)cmH2O比较,差异无统计学意义(P＞0.05),对照组的术后最大尿道压(30±2)cmH2O与术前(24±2)cmH2O比较,差异有统计学意义(P＜0.05).结论 以兔骨髓间充质干细胞为种子细胞,脱细胞猪尿道基质为支架,构建组织工程化尿道,移植修复兔尿道缺损,可形成类似于正常尿道的组织结构.     

应用组织工程技术体外构建泌尿系细胞-支架复合结构

目的 探讨应用组织工程技术体外构建泌尿系细胞支架复合结构的可行性.方法 取健康处死猪的膀胱黏膜下层,经过物理和化学方法处理后形成膀胱黏膜下层无细胞基质,进行组织学和细胞毒性检测;收集原代兔膀胱尿路上皮细胞以及平滑肌细胞,经过体外培养扩增后分别接种于无细胞基质的两侧面,HE和免疫组织化学染色观察细胞在基质中的生长、粘附和扩增情况.结果 两种细胞可分别在膀胱黏下层无细胞基质的两侧面生长扩增,平滑肌细胞可向基质内部侵入.结论 膀胱无细胞基质适合膀胱平滑肌细胞及尿路上皮细胞生长,体外可形成类似膀胱壁的复层细胞组织工程结构.     

脂肪干细胞和血管内皮细胞共培养复合脱细胞基质材料修复兔尿道缺损的实验研究

目的本实验拟探讨应用脂肪干细胞(adipose-derived stem cells,ADSCs)和血管内皮细胞(vascular endothelial cells,VEC)体外共培养,联合脱细胞基质材料构建人工尿道修复兔尿道缺损的效果。方法体外分离培养、扩增获得兔脂肪干细胞和血管内皮细胞,分别将ADSCs、VEC以及二者共培养细胞群与脱细胞基质结合。将48只雄性成年新西兰兔阴茎腹侧尿道制作成缺损长度为2. 0 cm的动物模型,然后利用随机数字表法分为4组。无细胞对照组:单纯应用异种脱细胞基质修复组。ADSCs组:脂肪干细胞复合异种脱细胞基质手术修复组; VEC组:血管内皮细胞复合脱细胞基质手术修复组;ADSCs与VEC共培养组:ADSCs与VEC共培养后复合异种脱细胞基质手术修复组。分别于术后第1周、2周、4周、8周取各组实验动物的重建尿道组织,进行组织学及免疫组化观察分析。术后第8周观察各组动物排尿情况,记录有无尿瘘和尿道狭窄。结果体外培养扩增的ADSCs呈梭形生长,VEC形态多样,呈铺路石样;两者共培养7 d时部分细胞仍保持原有的梭形,另外一部分细胞呈多角形,巢样分布,14 d时观察可见细胞间存在许多相互连接的突触,并且部分细胞可融合成团块状。术后4周、8周分别对各组兔子尿道行免疫组织化学染色分析,可见ADSCs与VEC共培养组上皮血管内皮细胞因子(VEGF)、平滑肌肌动蛋白(a-SMA)明显多于无细胞对照组、ADSCs组、VEC组。术后8周无细胞对照组并发症发生率为75%(9/12),ADSCs组为41. 7%(5/12),VEC组为33. 3%(4/12),ADSCs与VEC共培养组为16. 7%(2/12),四组间差异有统计学意义(χ~2=8. 914,P 0. 05)。进一步两两比较发现,无细胞对照组与ADSCs与VEC共培养组相比差异有统计学意义(P 0. 0083)。无细胞对照组与ADSCs组、无细胞对照组与VEC组、ADSCs组与VEC组、ADSCs组与ADSCs和VEC共培养组及VEC组与ADSCs和VEC共培养组比较,差异均无统计学意义(P 0. 0083)。结论 ADSCs和VEC经体外共培养后可作为种子细胞应用于组织工程尿道的构建和尿道缺损的修复。VEC可诱导ADSCs向上皮细胞方向转变,并增加尿道组织血管的发生。     

小肠黏膜下层生物补片在腹裂修补术中的应用

目的 探讨小肠黏膜下层生物补片在腹裂修补术中的作用.方法 2010年6月至2015年5月,我们对20例腹裂患儿采用生物补片进行修复,其中12例采用小肠黏膜下层(SIS)生物补片一期修补腹壁缺损(SIS组),8例采用脱细胞真皮生物补片一期修补腹壁缺损(真皮组),与2006年6月至2010年5月收治的14例未用任何组织替代物、强行一期修补的腹裂患儿(对照组)的临床资料进行比较,观察胎龄、出生体重、出生至手术时间、缺损大小、暴露于腹腔外脏器情况、术后机械通气情况、术后开始进食时间、住院时间、切口感染、腹壁疝的发生率等指标.结果 三组患儿平均胎龄、出生体重、出生至手术时间、缺损大小、腹腔脏器脱出情况之间差异无统计学意义;SIS组12例患儿中仅2例患儿术后需机械通气,平均通气时间24 h,真皮组2例患儿需机械通气,平均通气时间19h,对照组10例患儿需机械通气,平均机械通气时间39 h,补片组机械通气的必要性和通气时长显著低于对照组,补片组中SIS组和真皮组机械通气的必要性和通气时长差异无统计学意义;SIS组和真皮组术后的开始进食时间分别是(186.5±37.7)h、(173.3±41.5)h,显著少于对照组开始进食时间(256.1±41.8)h;SIS组和真皮组的住院时间分别是(16.2±3.0)d、(15.1±2.2)d,显著少于对照组的住院时间(19.4±3.6)d;SIS组术后无切口感染发生,有2例术后3个月发生切口疝,1年后自行愈合,无需再次手术修补;真皮组术后3例发生切口感染、排异反应,经伤口换药、去除补片后瘢痕愈合,有2例术后5个月发生切口疝,2例约1年后逐渐自行愈合,无需再次手术修补;对照组5例发生切口感染,经换药后好转,3例切口裂开,蝶形胶布固定换药后瘢痕愈合,5例术后3个月发生切口疝,3例1年后逐渐愈合,2例2年后未愈合施行手术修补.结论 对腹壁缺损大、腹腔容积小的腹裂患儿可以采用一期补片修复的方式,以减少分期手术率、术后机械通气,降低术后腹腔压力,有利于肠道功能恢复;小肠黏膜下层(SIS)和脱细胞真皮组织补片均能用于修复腹壁缺损,但小肠黏膜下层在生物相容性、抗感染等方面优于脱细胞真皮组织.     

胎儿脐静脉脱细胞基质构建组织工程尿道

目的 探讨人脐静脉细胞外基质的制备及其在尿道重建中的应用.方法 采用酶消化、去污剂和渗透溶液方法制备人脐静脉细胞外基质(extracellular matrix,ECM).24只雄性白兔,随机分为A尿道ECM移植组,对照组B、C.A组切除尿道2.0 cm后用人脐静脉ECM修复,术后行组织学、尿流动力学和膀胱尿道造影评价尿道再生情况及功能.结果 经该法处理的人脐静脉细胞全部脱除.A组修复术后2周,脐静脉ECM有单层上皮细胞生长;4周管腔已被上皮细胞完全覆盖;8周可见人脐静脉ECM降解的微小碎片和平滑肌细胞生长,炎性细胞消失;16周尿道大体观、组织学检查均接近C组,平滑肌数量与C组差异无统计学意义(P>0.05),但排列欠规则.膀胱尿道造影无尿液外渗、尿道憩室形成;尿动力学A组与C组膀胱容量、最大尿道压分别与术前比较,差异均无统计学意义(P>0.05),B组无法置入测压管.结论 酶消化、去污剂和渗透溶液法是制备人脐静脉ECM较为理想的方法,人脐静脉ECM可作为尿道重建的良好支架材料.     

幼兔桡骨临界性骨缺损动物模型的建立

目的建立幼兔桡骨不同尺寸骨缺损模型,确定幼兔桡骨临界性骨缺损长度。方法选取健康3月龄雄性新西兰兔20只(2.2~2.5 kg),采用左右侧配对设计的方法在双侧桡骨中段分别制作15 mm及20 mm桡骨骨缺损模型,按骨缺损长度分为A组(15 mm)及B组(20 mm),每组各20侧。分别于术后第1天,术后第4、8、12周行CT检查,应用CT-Hedberg评分评估骨愈合情况。于术后12周处死所有实验兔,取出尺桡骨标本,通过大体观察及HE染色组织学观察分析缺损区骨愈合情况。结果术后实验兔均存活,术后第12周大体观察:A组19例(95%)桡骨断端有连续性骨痂生成,新生骨表面光滑,塑形良好;B组缺损断端髓腔封闭,缺损区由纤维组织填充。术后第12周CT图像可见A组皮质骨塑性完全,B组断端及缺损尺侧均有新骨生成,髓腔封闭。术后各时间点CT-Hedberg评分:A组(3.0±0.6,3.9±0.3,4.0±0.2)与B组(1.6±0.5,2.7±0.6,2.9±0.6)间差异有统计学意义(P0.05)。组织学结果:A组缺损已修复完全,新生骨组织内可见血管再生,B组缺损区由纤维组织填充。结论在进行幼龄兔骨缺损研究时,可选择3月龄雄性新西兰兔桡骨干构建20 mm长骨缺损。     

骨形成蛋白与肌瓣修复骨缺损的研究

采用羊胫骨缺损作为模型，分别植入肌瓣＋骨形成蛋白和肌瓣。植入后第１，２，３，４周分批将羊处死，并进行Ｘ线摄片和病理组织学检查。结果表明：植入肌瓣＋骨形成蛋白组术后第２周即在缺损边缘及中央出现大量新骨，于第４周基本由新骨充填；而单纯肌瓣植入组由缺损边缘少量新骨生长，术后第４周缺损由新骨部分充填。说明植入骨形成蛋白＋肌瓣能够较快地修复骨缺损。     

延长留置导尿管在减少尿道下裂术后尿道狭窄中的作用

目的 评价延长尿道下裂术后留置导尿管在减少尿道狭窄中的作用.方法 2011年2月至2012年2月采用管形包皮岛状皮瓣法治疗尿道下裂104例,年龄2～3岁,平均2.4岁.矫正阴茎下弯后成形尿道长度为3 cm,包皮岛状皮瓣的宽度为1.2 cm.术后第2天采用双盲法将患儿平均分为两组,A组术后6周拔除导尿管,B组术后2周拔除导尿管,比较两组拔管后尿道狭窄的发生情况.分别在术前和拔除导尿管后2周、4周和3个月测量患儿最大尿流率.结果 术后随访1～2年,平均1.5年.A组中术后出现尿瘘4例,B组6例.A组拔导尿管后2周和4周的最大尿流率分别为(11.3±3.4)ml/s和(10.8±2.5)ml/s,B组分别为(9.5±2.3)ml/s和(7.6±1.8)ml/s,两组比较差异均有统计学意义(P＜0.01).两组术前和拔导尿管后3个月最大尿流率比较差异均无统计学意义(P＞0.05).全部104例中有13例(12.5％)术后发生尿道狭窄.其中,A组术后有1例(1.9％)发生尿道狭窄;B组有12例(23.1％),两组比较,差异有统计学意义(P＜0.01).尿道狭窄发生时间为拔除导尿管后2～4周.A组术后出现尿道狭窄1例,再次留置导尿管4周后拔除导尿管未再发生尿道狭窄现象.B组术后出现尿道狭窄12例均行尿道扩张并留置导尿管,其中8例导尿管留置3～4周后拔除,未再出现尿道狭窄;4例于拔管后2～4周再次出现尿道狭窄,需再次留置导尿管3～4周.此4例拔除导尿管后,2例未再出现尿道狭窄现象,另2例在第3次拔除导尿管后4周和5周分别出现排尿困难现象,行狭窄段尿道劈开尿道造口术.结论 术后6周拔除导尿管与术后2周拔除导尿管比较,可有效地减少尿道狭窄的发生.术后最大尿流率检查可以帮助发现尿道狭窄现象的发生.     

人工生物膜修补狗尿道缺损的初步研究

目的 评价人工生物膜修补狗尿道缺损的效果,为临床寻找理想的尿道成形替代材料奠定基础.方法 以8只体重10～15 kg、年龄6～8个月的雄性狗为研究对象.静脉全麻下,分别对上述狗行阴茎前端尿道全层剥离切断术.形成长约5 cm的尿道缺损.接着用人工生物膜修补上述缺损,F10硅胶管作为尿道支架管.术后密切观察实验狗的排尿情况,并在2周～6个月期间取尿道标本,检查其修复情况.结果 1只狗在术后11 d将尿道支架管和人工生物膜咬脱,须行膀胱造瘘,病理检查显示其无尿道组织生长.4只狗在术后14～22 d将尿道支架管咬脱,3只狗的尿道支架管在术后30～46 d由人工拔除.后述的7只狗有6只排尿成线状、尿线较直;取尿道标本,大体上见尿道腔内面均形成一与正常尿道上皮层相连续的薄层结构;病理检查,其中1个标本取自术后16 d尿道,见纤维素性渗出物覆盖.无存活的移行上皮细胞团,其余6个标本分别取白术后39d、48d、60d、73d、162 d和181 d的尿道,均显示有正常的尿道上皮结构.结论 人工生物膜可作为修补尿道缺损的材料;为确保尿道缺损的顺利修复,尿道支架管至少保留2周;人工生物膜修复5cm长的尿道缺损需要超过1个月的时间.     

Is tubularization of the mobilized urethral plate a better alternative to tubularization of an incised urethral plate for hypospadias repair?

Introduction  Trial of a new procedure of hypospadias repair based on the incorporation of the entire available innate urethral tissue for the formation of neo-urethra in patients with hypospadias. Materials and methods  Fifteen consecutive children, nine with distal hypospadias and six with proximal hypospadias (all with severe chordee), whose parents consented to application of a new procedure of hypospadias repair, were the study subjects. This procedure is inspired by Cantwell Ransley procedure for epispadias repair and Snodgras procedure for hypospadias repair. The entire urethral plate was mobilized (i.e., lifted off the corpora) distal to the urethral meatus and was tubularized in two layers; inner urethral skin and outer spongiosal tissue, in Duplay fashion. The repair was reinforced with dartos vascularized flap. The skin incisions on the urethral strip are guided by the disposition of the spongiosal tissue underlying the urethral plate (rather than the conventional U-shaped incision on either side of hypospadiac urethral meatus). In the patients with proximal hypospadias with severe chordee urethral advancement was combined to achieve orthoplasty and a single stage hypospadias repair. The catheter was removed on tenth postoperative day. Results  Even in patients with proximal hypospadias with severe chordee, good single staged repair was achieved without resorting to dorsal plication that would have been necessary had any other methods based on the preservation of urethral plate was performed in these subjects. Therefore, the procedure was found to have an extended applicability to even those patients where tubularized incised urethral plate urethroplsty is not advised. All patients had good results (in 1 year follow-up), except in three early subjects of the series; two of whom developed minor urethrocutaneous fistulae (probably due to frank urinary leak secondary to repeated catheter blockade) and one developed partial glanular wound dehiscence. Conclusions  Though the authors have an initial limited experience with this procedure, the procedure is likely to have a promising future due to its versatility and utilization of the entire urethral tissue.     

下唇黏膜代尿道在尿道下裂治疗中的应用

目的 分析评估下唇黏膜代尿道在复杂性尿道下裂手术中的应用价值.方法 2006年3月至2009年10月共对24例复杂性尿道下裂患儿施行了下唇黏膜代尿道手术.年龄2岁3个月至14岁,平均7.2岁.其中以往手术失败14例,表现为阴茎周围残留大量不规则瘢痕,或膀胱黏膜代尿道后严重尿道狭窄和憩室.或严重阴茎海绵体弯曲残留,或尿道大段缺损伴膀胱造瘘术后等,尿道周围无其他组织如尿道板、皮肤等可用替代尿道.手术方法为先行阴茎整形,包括包皮和阴茎头,完全矫正海绵体弯曲,6个月后行下唇黏膜代尿道手术.会阴型尿道下裂10例,方法为先完全矫正阴茎弯曲和阴茎阴囊转位,同时利用原始尿道板将尿道外口从会阴延长至阴茎根部,6个月后行下唇黏膜代尿道.结果 所有病例均获满意效果,包括阴茎外观,即阴茎勃起时无明显弯曲、尿道开口位于阴茎头顶端、无包皮不规则瘢痕堆积、无排尿困难等.术后9例出现尿瘘,其中2例术后自愈,7例经一次修补后治愈.出现尿道狭窄6例,均经尿道扩张后痊愈.下唇取黏膜处均无术后出血.结论 下唇黏膜代尿道可作为尿道下裂治疗中最后选择的方法之一,具有黏膜切取方便,易存活,新尿道组织黏膜接近正常组织的优点,但并发症发生率仍较高.     

The novel use of small intestinal submucosal matrix for chest wall reconstruction following Ewing’s tumour resection

Chest wall reconstruction following major tumour resection remains a challenging problem in the paediatric population due to the need for growth and development following the repair. Synthetic non-biodegradable grafts and materials have led to asymmetrical growth and significant functional and cosmetic compromise. The ideal graft material should be biological non-immunogenic which enables natural healing and facilitates further growth. Ewing’s sarcoma is an uncommon primitive neuroectodermal tumour which rarely occurs in the ribs. However, recent improvements in management have produced a significantly improved survival; increasing the importance of chest wall reconstruction. We prospectively assessed the utilisation of Surgisis (an acellular collagen matrix) as a replacement graft in two children undergoing primary chest wall reconstruction following tumour resection. Surgisis is derived from porcine small intestinal submucosa (SIS) that serves as a template for tissue reconstruction and remodeling. The graft was well tolerated; there was no herniation and it allowed normal symmetrical chest movement and growth to occur. The properties of SIS allows natural collagen growth and compares favourably with marlex mesh and other forms of chest wall reconstruction. We believe its unique properties allow it to act as a suitable framework for chest wall reconstruction allowing chest wall growth and development.     

Urethral mobilization and meatal advancement: a surgical principle in hypospadias repair

A technique of urethral mobilization and advancement in hypospadias repair using the urethral elasticity to partially or completely bridge the defect in urethral length was employed in 56 children. In 46 with distal hypospadias it was the only procedure used. In 10 with proximal hypospadias, it was combined with other techniques. In distal hypospadias, no postoperative fistula occurred. Complications of the operation were 3 meatal stenoses that responded to dilatation, 1 urethral injury immediately repaired with no consequent fistula, and 1 chordee that was subsequently corrected. Of the 10 children with proximal hypospadias, 3 developed minor fistulae and 1 meatal stenosis. Urethral mobilization was found to be a safe and effective procedure in the management of hypospadias. It could be the only procedure required in distal hypospadias, or in combination with other procedures in proximal hypospadias. Accepted: 5 January 1999     

Blunt pediatric anterior and posterior urethral trauma: 32-year experience and outcomes

ObjectiveTo analyze our experience with delayed repair of pediatric urethral trauma.Materials and methodsFrom 1978 to 2007, 26 boys <18 years old (mean age 15.0) presented for delayed repair of urethral stricture after blunt trauma. Anterior and posterior urethral injuries were separately stratified.ResultsThere were 8 anterior and 18 posterior urethral strictures. All patients presented in a delayed fashion. Mean follow up of the anterior cohort was 2.9 years. All repairs were performed via a ventral onlay buccal graft or anastomotic approach. The mean follow up of the posterior cohort was 1.1 years, and all posterior urethral injuries were repaired via an anastomotic approach.Overall success for anterior stricture disease was 88.9% and for posterior stricture disease was 89.5%. All three urethroplasty failures responded favorably to internal urethrotomy; however, one failed anterior repair and one of the two failed posterior repairs required two internal urethrotomy operations for success. No secondary urethroplasty operations were required and ultimately all patients were voiding per urethra without need for urethral dilation.ConclusionDelayed, definitive repair of pediatric urethral trauma via open urethroplasty has a high success rate.     

Repair-oriented categorization of circumcision urethral injury in Benin city,Nigeria

BackgroundThe wide spectrum of circumcision urethral injury/fistula makes selection of appropriate repair methods challenging in sub-Saharan Africa. This paper reports on the outcome of repair-oriented categorization in a Nigerian center.MethodsConsecutive children presenting with circumcision urethral injury/fistula at the University of Benin Teaching Hospital were categorized into six repair-oriented groups in 2009–2011.Results21 children were treated. Except in 2 cases, early neonatal circumcision at an average age of 8 days (range 4–14 days) had been performed, the majority (52%) by paramedics at home. Categories of injury/fistula based on severity ranged from isolated fistula (38%) which required fistula excision and repair (category A) to severe ventral urethral/coronal/glanular avulsion (29%) which required urethral plate tubularization/ventral penile reconstruction (category F). Overall, successful first-stage repair was achieved in 19 (91%) children. Meatal stenosis (2), urethral stricture (1), which responded to serial dilatation, and minor urinary leakage (2), which was closed at second stage, were the post-repair complications. Adequate penile size and straight penis on erection were achieved in all cases. Cosmetic outcome was excellent in 16 (76%) cases, good in 4 (19%) and fair in 1 (5%).ConclusionRepair-oriented categorization, which could be useful to practitioners in similar settings, was satisfactory in managing urethral injury/urethrocutaneous fistula.     

尿道下裂术后严重并发症的治疗体会

探讨尿道下裂术后严重并发症的处理途径。方法收治尿道下裂术后严重并发症１３例,分别采用三种不同的处理方法：（１）简单尿瘘修补和／或尿道狭窄处切除吻合２例;（２）彻底切除阴茎腹侧瘢痕组织和病变尿道,充分矫正阴茎下曲后同时重建尿道４例;（３）彻底切除阴茎腹侧病变组织,充分伸直阴茎、尿道后移造口,二期重建尿道７例。     

In vivo bladder regeneration using small intestinal submucosa: experimental study

Significant side effects are correlated with bladder augmentation. Recently, small intestinal submucosa (SIS) has been proposed for clinical use. The efficacy of SIS bladder regeneration was studied in a porcine experimental model. Partial cystectomy (40–60% of bladder wall) was performed and replaced by SIS graft. Animals were planned to be killed at 2 weeks, 5 weeks and 3 months. Bladder capacity at 40 cmH₂O pressure and macroscopic graft morphology were assessed before and after SIS implant. Histological examination was carried out with computer assisted morphometric analysis for collagen/smooth muscle ratio. Student’s t test was adopted for statistical analysis. Two piglets died on the 9th and 10th post-operative day due to urinary peritonitis. The remaining piglets were killed after uneventful post-operative period at 5 weeks (two animals) and 3 months (two animals). The bladder capacity was reduced (−18%) at the 5 week follow-up and quite similar to the pre-operative volume (+2.5%) at the 3 months control. No diverticular formation, bladder calculi, mucus and urinary infection were found. The SIS graft resulted not significantly contracted. Histology at 10 days showed SIS membrane lined by transitional epithelium islands with some capillaries. At 5 weeks, transitional epithelium was fully covering the graft; new blood vessels and fibroblasts with smooth muscle cells were observed. At 3 months, the SIS was not evident. Two layers were defined: inner transitional epithelium, outer collagen with fibroblasts and muscular bundles. Computer assisted morphometric analysis showed collagen/muscle ratio 70/30% (normal bladder=56/44%, P<0.05). The SIS was effective as a scaffold for bladder wall regeneration in four out of six animals. Long-term studies are required to confirm the efficacy of the newly developed wall and for eventual clinical use.