Tunica albuginea acellular matrix graft for penile reconstruction in the rabbit: a model for treating Peyronie's disease

OBJECTIVE: To evaluate the use of an acellular matrix graft of the tunica albuginea for functional penile reconstruction in severe cases of Peyronie's disease. MATERIALS AND METHODS: In 18 rabbits, an acellular matrix graft of the tunica albuginea was used to cover a 4 x 8 mm tunical defect, and six animals each were killed 1, 3 and 6 months later; four unoperated animals served as histological controls. Before death an erection was induced by papaverine, with the quality classified on a scale of 0-5, and cavernosography performed. After death the penis was prepared for histological study, and the cell number, collagen and elastic fibre content evaluated in the regenerated matrix, and in control specimens and four unimplanted matrices. RESULTS: Of 18 experimental animals, 11 had normal erections before death, four had slight penile deviation and three developed no erection. Failure was caused by severe postoperative haematoma, resulting in scar tissue. There was no graft rejection. Histologically there was no difference between natural and regenerated tunica. The collagen content and cell number were not significantly different in regenerated and control samples. There were significantly fewer elastic fibres in the unimplanted grafts and the 1-month group, but in later samples this difference was no longer evident. CONCLUSION: The homologous acellular matrix graft of the tunica albuginea warrants further evaluation as an alternative treatment in Peyronie's disease, despite some postoperative failures. The advantage of this orthotopic biomaterial is its rapid integration, with no rejection.     

Homologous bladder augmentation in dog with the bladder acellular matrix graft

OBJECTIVE: To determine the functional potential and antigenicity of the homologous bladder acellular matrix graft (BAMG) in a dog model. MATERIALS AND METHODS: Seven mongrel dogs underwent partial cystectomy (20-50%) and grafting with an equal-sized BAMG; two control animals underwent partial cystectomy (40%) only. The dogs were killed after 30 (one), 120 (one) and 210 days (five dogs). Blood samples were obtained before and at 1, 2, 4, 7, 14, 30, 90 and 210 days after surgery. The dogs underwent cystography, intravenous pyelography and ultrasonography before and after surgery, and on the day they were killed, with cystoscopy carried out just before death. The grafted tissue was assessed using routine and immunohistochemical techniques. RESULTS: All the dogs survived surgery; a complete blood cell count, chemical panel and white blood cell count showed no significant difference between the experimental and control animals. Cystography, cystoscopy and ultrasonography revealed no pathological changes in the upper urinary tract. After 7 months, the mean bladder capacity in the augmented dogs was significantly higher (P = 0.035) than in the controls (264 vs 172 mL). Histological evaluation showed an invasion of all bladder wall components during the first month; at 7 months, the morphological examination showed essentially complete regeneration. CONCLUSION: In this dog model, the potential of the BAMG as a bladder augmentation graft was confirmed, having minimal antigenicity with maximal acceptance. The reconstructed bladder matched the morphological and functional properties of the normal bladder.     

Time dependent smooth muscle regeneration and maturation in a bladder acellular matrix graft: histological studies and in vivo functional evaluation

PURPOSE: We evaluated the time dependence of smooth muscle regeneration and restoration of in vivo functional properties in bladder augmented with a bladder acellular matrix graft. MATERIALS AND METHODS: A total of 45 Sprague-Dawley rats underwent augmentation cystoplasty with a bladder acellular matrix graft. Two rats each were sacrificed at various intervals within the first 21 days and 6 each were sacrificed at 4, 8 and 12 weeks. This second group underwent preoperative and postoperative assessment of bladder function, including cystometry, electrostimulation and stimulation with ice water, potassium and carbachol, as well as labeling of the bladder wall by the injection of fluorescent microspheres. After sacrifice slides of the bladders prepared for hematoxylin and eosin, trichrome, KI67, vimentin, desmin, smooth muscle specific alpha-actin and fluorescent microspheres were evaluated. RESULTS: Within 2 weeks the number of cells in the matrix as well as the proliferation index increased rapidly and then decreased gradually. Erythrocytes and inflammatory cells were found in the matrix within 2 to 4 days, followed by fibroblasts. A bladder host-to-matrix shift was evident by the appearance of microspheres in the matrix. Cell marker expression indicated the early appearance of vimentin and alpha-actin within the first 10 days. Distinct desmin expression was observed later, when the first smooth muscle cells were recognized. Functional evaluation revealed restored bladder function at 12 weeks. CONCLUSIONS: The time dependent increase of muscle cell markers during smooth muscle cell regeneration in a bladder acellular matrix graft is concordant with the progressive restoration of bladder function. These results may support the bladder acellular matrix graft concept for clinical application.     

应用异体脱细胞尿道基质修复尿道缺损

目的探讨应用同种脱细胞尿道基质修复尿道缺损的可行性。方法将14只雄性新西兰兔分为两组，切除实验组长约1.0～1．5cm的尿道，用相应长度脱细胞尿道基质修复；对照组行假手术。术后行尿道造影并取尿道标本作病理检查。结果12只实验兔的脱细胞基质移植物没有移位。除2例狭窄、2例尿瘘外，其余满意效果。病理检测示，术后3周尿道管腔上皮化，6个月基质中平滑肌及血管再生明显。结论同种脱细胞尿道基质材料可以修复兔尿道部分缺损。     

脱细胞基质在尿道组织工程中的应用

脱细胞基质是经过物理化学方法 脱去组织中抗原成分且富含胶原的一种材料,在尿道修复和重建中,显示了极其广泛的应用前景.     

The bladder acellular matrix graft in a rat chemical cystitis model: functional and histologic evaluation

PURPOSE: We investigated the feasibility of augmentation in a diseased bladder with a bladder acellular matrix graft. MATERIALS AND METHODS: In 50 female Sprague-Dawley rats chemical cystitis was induced by intravesical instillation of HCl repeated monthly to maintain chronic inflammation. Urodynamic studies were performed in all rats 1 week after the induction of chemical cystitis and repeated at sacrifice. The 29 rats in the experimental group underwent partial cystectomy (50% or greater), followed by bladder acellular matrix graft augmentation, while the 21 controls underwent monthly HCl instillation only. The rats were sacrificed at 2 weeks, 1, 2 and 3 months, respectively. The bladder was removed and examined for histological changes. RESULTS: Urodynamic studies showed that bladder capacity and compliance were significantly higher in the grafted than in the control group (p = 0.008 and 0.006, respectively, at 3 months). Histological studies revealed urothelial and smooth muscle regeneration within the bladder acellular matrix graft at 1 month and nerve regeneration at 3. The number of mast cells was significantly lower in the grafted region than in the host bladder of all grafted rats (p <0.001). CONCLUSIONS: In this rat chemical cystitis model bladder augmentation with a bladder acellular matrix graft led to functional and histological improvement over diseased host bladder.     

口腔黏膜细胞与膀胱黏膜下脱细胞基质复合物构建组织工程化尿道的实验研究

目的 探讨以兔口腔黏膜细胞与同种异体膀胱黏膜下脱细胞基质(BAMG)复合物构建组织工程化尿道的可行性.方法 新西兰雄性兔24只,距尿道外口2.0 cm剥离尿道黏膜(2.0 cm×0.8 cm)后,随机分实验组和对照组,每组12只.切取实验组兔口腔黏膜组织分离细胞,在有灭活的3T3细胞培养皿上进行培养扩增,将培养获得的第2代口腔黏膜细胞种植于BAMG(2.2 cm×1.0 cm)上,植入实验组兔尿道缺损区域;对照组单纯采用无细胞植入的BAMG修复尿道.分别于术后1、2、6个月观察动物排尿情况,行尿道造影,8 F尿管插管确定有无狭窄;随后处死实验兔,取修复段尿道黏膜组织行组织学检查.结果 细胞培养获得的口腔黏膜细胞形态均一,生长良好;组织形态学、扫描电镜观察见口腔黏膜细胞与BAMG具有良好的相容性.实验组兔术后1、2、6个月伤口愈合良好、排尿通畅,无尿瘘发生,组织学和尿道造影检查显示带细胞修复的尿道形态完整、清晰宽敞,无狭窄发生;术后6个月植入的口腔黏膜细胞仍然存在,并明显扩增.对照组兔则出现排尿困难、尿道狭窄,光镜下发现黏膜及黏膜下存在严重的炎症反应.结论 兔口腔黏膜细胞与同种异体BAMG复合后,可成功用于尿道缺损的修复,构建组织工程化尿道.     

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。     

Homologous acellular matrix graft for vaginal repair in rats: a pilot study for a new reconstructive approach

The purpose of this paper is to investigate using an acellular matrix graft of vagina (VAMG) or bladder (BAMG) in vaginal reconstruction. In 18 rats, vaginal length was measured and a hysterectomy performed. In three control animals, the vaginal stump was closed. In eight rats, the vagina was augmented with a VAMG; in seven, a BAMG was used. After 2-12 weeks, the animals were sacrificed, the vaginal length was reevaluated, and the vaginas were prepared for histologic evaluation. In the controls, the vagina was markedly shorter postoperatively. In the grafted animals, vaginal length was not significantly less than preoperative values with either matrix. Epithelialization, vascularization, and alpha-actin expression in the grafts were consistently observed. Regeneration appeared to be slightly greater in the organ-specific vagina matrix. With either matrix, however, although the vaginal stump remained open, the grafts lost most of the lumen. Vaginal reconstruction with a vagina acellular matrix graft is technically feasible. If further experiments can address the problem of luminal collapse - with, for instance, tissue expanders in the matrix - this technique may offer an alternative to the complex therapeutic options currently available.     

Bladder acellular matrix graft: in vivo functional properties of the regenerated rat bladder

The purpose of this study was to determine whether the rat urinary bladder augmented by an acellular matrix graft can restore the bladder's low-pressure reservoir function and preserve normal micturition. After partial cystectomy (>50%) and grafting with the bladder acellular matrix graft (BAMG), storage and voiding functions were monitored in 20 rats by means of a specially designed “micturition cage,” leak-point cystography, and cystometry. After 4 months, sections (n = 6) were examined histologically to evaluate regeneration of bladder wall components within the BAMG. Bladder capacity and compliance increased progressively and were significantly higher in the grafted animals than in controls (partial cystectomy only), and volumes per void were significantly higher than in either control or normal animals. At 4 months, the regenerated urothelium, smooth muscle, blood vessels and nerves within the BAMG were qualitatively identical to normal bladder wall. Augmentation cystoplasty with the homologous BAMG leads to morphologic and functional rat bladder regeneration, thus enhancing low-pressure reservoir function and preserving normal micturition. Received: 27 May 1998 / Accepted: 20 October 1998     

Two cases of female urethral reconstruction with acellular porcine urinary bladder matrix

Introduction and hypothesis

Female urethral reconstruction via the traditional routes can be limiting for various reasons. Current literature on the use of acellular biologic grafts derived from viscera for female urethral reconstruction is limited. We present two cases of women with complete loss of their posterior urethra presenting for urethral reconstruction.

Methods

Two cases of urethral reconstruction using acellular porcine urinary bladder matrix (UBM), along with labial fat pad transposition and biologic pubovaginal sling are presented.

Results

In both cases the UBM graft showed successful conversion to what appeared to be normal urethral mucosa. One woman showed significant improvement in continence and the other showed complete continence.

Conclusions

Female urethral reconstruction using acellular porcine UBM is a viable option for patients who have lost a significant portion of their urethra. Both cases demonstrated transition of the graft into the posterior wall of the urethra with significant improvement in continence. Further studies are needed to confirm that acellular porcine UBM can transform to urethral mucosa in women requiring urethral reconstruction.

     

脱细胞尿道及其海绵体基质制备的实验研究

目的 探索脱细胞尿道及其海绵体基质的制备方法。方法取健康壮年兔完整尿道及其海绵体组织，以Triton-X100与NH3H2O联合提取法进行脱细胞处理。标本做HE染色，组织学观察分析脱细胞效果。结果脱细胞处理11天后，成功获得脱细胞及其海绵体基质，所得基质外观良好。HE染色观察无细胞存在。弹力纤维排列规整，间隙较大，结构无破坏。结论利用Triton-X100与NH3H2O联合提取法可成功制备完整无细胞尿道及其海绵体基质，为尿道再造修复提供崭新思路。     

脱细胞尿道及其海绵体基质制备的实验研究

目的探索脱细胞尿道及其海绵体基质的制备方法.方法取健康壮年兔完整尿道及其海绵体组织,以Triton-X 100与NH3H2O联合提取法进行脱细胞处理.标本做HE染色,组织学观察分析脱细胞效果.结果脱细胞处理11天后,成功获得脱细胞及其海绵体基质,所得基质外观良好.HE染色观察无细胞存在,弹力纤维排列规整,间隙较大,结构无破坏.结论利用Triton-X 100与NH3H2O联合提取法可成功制备完整无细胞尿道及其海绵体基质,为尿道再造修复提供崭新思路.     

The application of tissue-engineered preputial matrix and fibrin sealant for urethral reconstruction in rabbit model

Background

To introduce the role of fibrin sealant and preputial acellular matrix (PAM) as a new source of inert collagen matrix for urethral reconstruction.

Methods

A ventral urethral segmental defect was created in 24 male rabbits divided into four groups. In group 1 (G1), urethrotomy was closed in layers. In group 2 (G2), closure was followed by applying fibrin sealant. In groups 3 (G3) and 4 (G4), urethroplasty was performed with a patch graft of PAM, and in G4, fibrin sealant was also applied. Serial urethrography was performed before and after the operation. Then, the animals were euthanized, and their urethra was excised 1, 3, and 9 months postoperatively for further electron microscopic examination, terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) technique, and immunohistochemical (IHC) staining with CD34, CD31, desmin, SMA, and α-actin.

Results

In G1 and G2, the fistula repair failed in all the time points. In G3 and G4, serial urethrography confirmed the maintenance of a wide urethral caliber without signs of strictures or extravasations. Satisfactory vascularity was observed in G3 and G4 during the whole study, which was more significant in G4 after 9 months of follow-up. The presence of a complete transitional cell layer was confirmed over the graft in G3 and G4 in all time points. IHC staining confirmed the effectiveness of fistula repair in G3 and G4, 3 months postoperatively.

Conclusion

This rabbit model showed that PAM combined with fibrin sealant may herald a reliable option for repairing segmental urethral defects.     

口腔粘膜游离移植再造尿道

目的：探讨采用口腔粘膜游离移植，对局部缺乏组织的尿道下裂行尿道再造的方法。方法：1998－2001年对25例患者应用口腔粘膜游离移植再造阴茎段尿道，半年后吻合瘘口。结果：1例一期术后并发感染，愈后无尿道狭窄，所有病例二期吻合瘘口后，再造尿道通畅。结论：口腔粘膜丰富的网状毛细血管网、韧厚的上皮层和相对较薄的皮下板层结构是移植成功的关键。以口腔粘膜游离移植行尿道再造是一种可行的方法。     

异种真皮去细胞基质在尿道重建中的临床应用

目的 观察异种真皮来源的去细胞基质移植物(acellular matrix graft,ACMG)作为尿道狭窄重建手术替代材料应用于临床的安全性与有效性.方法 将ACMG作为尿道重建的替代材料,观察尿路上皮细胞能否长入并形成通畅的新尿道以及有无排斥反应.采用ACMG治疗尿道狭窄病例10例,年龄20 ～ 62,平均36岁.狭窄长度3.0 ～15.0 cm,平均6.9 cm.术时采用狭窄段切除后ACMG尿道套入术或狭窄段切开后ACMG补片尿道修补术,术后6个月拔除尿管,观察该ACMG在人体中有无排斥反应及ACMG辅助尿道重建术的治疗效果. 结果 10例患者拔除尿管后均恢复排尿,尿道造影及尿道镜检查可见术后尿道连续性好,腔内黏膜连续.随访至术后18个月,出现尿道狭窄2例,经尿道内切开扩张后恢复正常排尿,其余患者均可通过尿道正常排尿. 结论 异种真皮ACMG应用于尿道成形术中具有生物相容性良好、能从解剖上和功能上修复尿道的优点,适用于复杂、长段尿道狭窄病例的成形手术.