A new oesophageal tube: assessment of collagen/vicryl composite membrane.

Collagen/vicryl composite membrane has been previously shown to be of use in an experimental model as a patch graft in the bladder and oesophagus. Attempts to use it as a circumferential tube graft have been unsuccessful due to the development of strictures at the site of anastomosis. We inserted a polytetrafluoroethylene (PTFE) stented collagen/vicryl bioprosthetic tube into rat omentum, which served as a vascular pedicle. Subsequent histology of the graft showed serial replacement of the bioprosthesis with host collagen and the development of a blood supply. In a second stage procedure, the bioprosthesis was anastomosed to the distal ileum and brought out on the skin to form a fistula. Squamous epithelium was subsequently identified growing the full length of the graft. Therefore, we have developed a vascularised bioprosthetic tube graft which will support the growth of unspecialised epithelium. This model could be of use in bridging congenital atresias or pathological strictures.     

An assessment of a collagen/vicryl composite membrane to repair defects of the urinary bladder in rabbits

Summary Collagen/vicryl (Polyglactin) composite membrane has been used to repair full-thickness defects in the urinary bladder of rabbits. The material has been shown to be biodegradable, prevent leakage of urine, and is readily replaced by collagenous scar tissue lined with a urothelium. Regeneration of smooth nuscle has been observed in the repair area of some animals. The results suggest that such a material may well be of use to urologists wishing to augment contracted bladders or in the repair of bladder fistulae in human subjects, thereby avoiding the use of bowel or other material e.g. omentum.     

The in-vitro assessment of a collagen/vicryl (polyglactin) composite film together with candidate suture materials for use in urinary tract surgery

Summary Collagen coated vicryl mesh has been incubated with a series of urine collections from healthy and stoneforming patients. For comparison, collagen film, vicryl mesh, and a number of absorbable and non-absorbable sutures were similarly tested. Incubation in rabbit urine were also included in the study. Deposition of urinary salts, estimated qualitatively by electron microcopy, were observed on the collagen vicryl composite in approximately two thirds of the urines tested including rabbit urine. Those urines from patients with a high calcium excretion in particular caused urinary deposits on the material. Similar results were obtained with collagen film although the latter was not tested in rabbit urine. Considerably less deposits of urinary constituents were found with other absorbable materials such as vicryl mesh, vicryl sutures, and chromic catgut, whereas a higher proportion of concretions were found with the nonabsorbable sutures. The results indicate that urinary salt deposition may be a problem associated with collagen based composite materials after prolonged exposure to urine. It must, however, be emphasised that great care should be exercised when extrapolating any results obtained in-vitro to the in-vivo situation.     

Cystoplasty using a resorbable polyglactin prosthesis covered by a free peritoneal flap

The bowel is not always suitable for cystoplasty. The use of a vicryl mesh lined with a peritoneal flap was investigated as material for partial replacement of the bladder. The procedure was performed on 20 rats divided into two groups. A partial cystectomy was first performed, then a cystoplasty was done using either a free peritoneal flap (group 1) or a vicryl mesh combined with a peritoneal flap (group 2). The results were evaluated using intravenous pyelography, macroscopic examination and histological analysis within one month. In group 1 (7 cases), there was one urinary fistula. In group 2 (13 cases), no fistula was observed but stones occurred in three cases. The histological analysis revealed good reconstruction of urothelium in both groups. Partial resorption of vicryl was observed at one month with organization of neo-muscular fibers. The vicryl prosthesis was well accepted and, when covered by a peritoneal flap, provided a strong and water-tight material for bladder replacement. The vicryl mesh increased the risk of stone formation in the presence of urinary tract infection.     

The use of a biodegradable collagen/vicryl composite membrane to repair partial nephrectomy in rabbits

Summary A composite membrane produced from collagen and vicryl mesh has been used to cover the kidney surface following partial nephrectomy in rabbits. The membrane readily held sutures, gave satisfactory haemostasis, and prevented leakage of urine. The experiments showed that the prosthesis biodegraded in less than twenty weeks. The only observed long-term effect of the material was thickening of the renal capsule. The results indicate that this membrane may be a suitable reparative materal for use in traumatised kidneys in humans.     

Some observations on the regeneration of smooth muscle in the repaired urinary bladder of the rabbit

The regeneration of smooth muscle appears to take place within the fibrous tissue characteristically found when a biodegradable collagen/Vicryl prosthesis is used to repair full thickness defects in the rabbit urinary bladder. The question of whether the central smooth muscle was the result of myoblastic differentiation in the fibrous tissue or arose from healthy pre-existing detrusor muscle was resolved by serial sectioning and specific staining. Only in situ transmutation, or differentiation, explains the morphology, and the results therefore strongly suggest that this central smooth muscle regenerated from within the repair area.     

The in vitro assessment of a collagen/vicryl (polyglactin) composite film together with candidate suture materials for use in urinary tract surgery

Summary A Vicryl (Polyglactin)/Collagen composite membrane has been developed for potential use in urinary tract surgery. The compatability of this membrane, together with its two individual components, collagen film and vicryl mesh, has been tested over a three week period in urine obtained from both healthy and from stone forming patients. The rate of degradation as indicated by changes in the mechanical strength was determined at regular intervals. In addition,absorbable suture materials such as plain catgut, chromic catgut, and vicryl were similarly tested; in the latter case, the breaking stress, and actual loss of weight of the material were compared. The whole series of experiments were then repeated in urine obtained from rabbits, the animal chosen for any future in vivo studies.     

Autologous chondrocyte implantation drives early chondrogenesis and organized repair in extensive full‐ and partial‐thickness cartilage defects in an equine model

Autologous chondrocyte implantation (ACI) has been used clinically for over 15 years and yet definitive evidence of chondrocyte persistence and direct impact on cartilage repair in full‐thickness lesions is scant and no data are available on ACI in partial‐thickness defects in any animal model. This study assessed the effect of chondrocytes secured using periosteal overlay in partial‐ and full‐thickness cartilage defects in the equine model. Paired cartilage defects 15 mm in diameter were made in the patellofemoral joint of 16 horse and repaired with ACI or periosteal flap alone. Response was assessed at 8 weeks by clinical, microradiographic, and histologic appearance, and by collagen type II immunohistochemistry, and proteoglycan and DNA quantification. ACI improved histologic scores in partial‐ and full‐thickness cartilage defects, including defect filling, attachment to the underlying subchondral bone, and presence of residual chondrocyte accumulations. For partial‐thickness defects chondrocyte predominance, collagen type II content, and toluidine stained matrix were enhanced, and attachment to the surrounding cartilage improved. DNA and PG content of grafted partial‐thickness defects was improved by chondrocyte implantation. Periosteal patches alone did not induce cartilage repair. This study indicated implantation of chondrocytes to cartilage defects improved healing with a combination of persisting chondrocyte regions, enhanced collagen type II formation, and better overall cartilage healing scores. Use of ACI in the more challenging partial‐thickness defects also improved histologic indices and biochemical content. The equine model of cartilage healing closely resembles cartilage repair in man, and results of this study confirm cell persistence and improved early cartilage healing events after ACI. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 29: 1121–1130, 2011     

复合生物支架胶原蛋白／壳聚糖及聚乙烯醇／丝胶在大鼠膀胱扩大手术中的应用

目的评价复合生物材料胶原蛋白／壳聚糖及聚乙烯醇／丝胶在膀胱扩大手术中的效果及町行性。方法雌件大鼠21只随机分为3组,即膀胱扩大手术组（实验组：修补材料为胶原蛋白／壳聚糖＋聚乙烯醇／丝胶）;膀胱部分切除组（对照组）和非手术组（平行对照组）。所有3组实验动物在术后7d、21d、42d进行膀胱容量测定,并取材观察其形态学及组织学改变。结果接受膀胱扩大手术的大鼠,术后各时间点的膀胱容量均明显高于其他两组。大体检查见膀胱血管纹理清晰,修补部位与正常膀胱无明显分界,结石发生率为71．4％。镜下组织学检查发现：术后7d时,支架外层大量炎症细胞浸润,组织结构无法分清。术后42d时,支架内层上可见泌尿上皮呈多层排列,黏膜下层增厚明显,但平滑肌层相对稀疏且排列欠规则。结论复合生物支架胶原蛋白／壳聚糖＋聚乙烯醇／丝胶能成功应用于大鼠膀胱扩大手术,但仔在膀胱平滑肌层再生情况不佳、成石率较高的缺点,有待进一步研究改善。     

Repair of spinal dural defects with vicryl (polyglactin 910) mesh

This study examined and compared the effectiveness of woven vicryl (polyglactin 910) mesh and lyophilized cadaver dura (Lyodura) for the repair of spinal dural defects. A woven vicryl mesh was used to repair spinal dural defects in 16 mongrel dogs. As an internal control, all animals had a separate dural incision that was closed with 9-0 vicryl suture. Animals were killed, and results were evaluated at 4, 8, 12, and 24 weeks. The repair of dural defects was achieved in all animals, and there were no cases of pseudo-meningocele formation, cerebrospinal fluid leakage, or postoperative infection. The vicryl mesh served as a latticework for formation of a neodural membrane. Inflammatory or reactive response to vicryl mesh was minimal, and no adhesion to underlying neural structures was noted. The neodural membrane formed in the animals in which lyophilized dura was employed was usually thicker than those in which vicryl mesh was used and was associated with thick arachnoid-neural adhesions in two of eight animals. We believe vicryl mesh is a suitable dural substitute and offers promise for use in clinical situations.     

Influence of hyaluronic acid on wound healing using composite porcine acellular dermal matrix grafts and autologous skin in rabbits

This study aims to explore the influence of hyaluronic acid (HA) on wound healing during xenogeneic porcine acellular dermal matrix (PADM) composite skin grafting. The results will facilitate the development of methods for improving graft contracture and poor elasticity of composite transplantation. Exogenous HA was added to composite PADM grafts and to thin autologous skin grafts during rabbit full‐thickness skin wound repair. The influence of HA on wound healing was evaluated according to its contracture rate and its expression of collagen types I and III. The possible mechanism was then explored based on HA metabolism and vascularisation in the skin graft. The results show that exogenous HA relieves graft contracture on rabbit wound surfaces, increases collagen I and III expression and decreases the ratio between collagen types. HA stimulates the generation of more CD44 receptors to strengthen its enzymolysis. The resulting metabolites promote the vascularisation of the wound surface, which are conducive for mitigating graft contracture, and further improve the composite grafting effect.     

Experimental Urinary Bladder Reconstruction Using a Synthetic Poly (α-amino acids) Membrane

Abstract: Biodegradability of the poly (ε-benzyloxycarbonyl-L-lysine) membrane was tested for use as a biodegradable graft for the reconstruction of rabbit urinary bladder. Rabbit urinary bladder was exposed through a midline incision under general anesthesia and segmental resection with full thickness was done, with replacement by this synthetic membrane. The membrane was gradually reabsorbed, serving as a framework of support for regeneration of normal bladder tissues. Follow-up study at 1 year revealed no urinary tract complications, such as bladder stones or urinary tract infection. Also, no disturbance of renal function was demonstrated. Bladder capacity remained within normal limits and bladder functions were almost normal. These results indicate that biodegradable membrane may be well suited to this clinical use.     

Preliminary development of a collagen membrane for use in urological surgery

Summary A series of experiments have been carried out in-vitro in order to assess the possibility of using a collagen membrane in the repair of various sections of the urinary tract following operative surgery such as the removal of a stone from the ureter. The collagen film has been tested for its compatability with urine, its ability to prevent leakage of fluid in a simulated wound in-vitro and for its ability to withstand any degradative effect of liver and kidney homogenates. The material was not significantly degraded by either urine or by tissue homogenates and was able to prevent leakage of fluid under the experimental conditions employed. Although some slight build-up of calcium and some trace elements took place after incubation in urine over a six-day period this was not significant. On the basis of the results obtained it has been decided to proceed to in-vivo trials on rabbits using the collagen membrane. The possibility of using such a material in partial nephrectomy operations is discussed.     

Laparoscopic management of mesh migration into urinary bladder following laparoscopic totally extraperitoneal inguinal hernia repair—A case report

Introduction and importanceMesh migration into urinary bladder is one of the rare complications following inguinal hernia repair (Laparoscopic/Open). On reviewing the literature, erosion of mesh following inguinal hernia repair has been into the urinary bladder in most of the cases, and the erosion may occur as early or late complication. It may occur as a result of improper suturing, inadequate fixation or foreign body reaction. The most common presentation is recurrent urinary tract infection and haematuria and may mimic bladder malignancy.Case presentationA 38-year male presented with recurrent UTI and mimicked to have bladder malignancy on CT scan. On Cystoscopy, mesh along with tackers is visualized within the bladder lumen. A diagnosis of Mesh migration into bladder following laparoscopic inguinal hernia repair was made. The Patient underwent Complete laparoscopic removal of mesh with partial cystectomy, per urethral and suprapubic catheter were placed. The patient made a good recovery without any post-operative complications. On follow-up, Patient underwent Fluoroscopy to look for urinary leakage, and suprapubic catheter removal was done. Patient is asymptomatic on follow-up.Clinical discussionMesh migration into bladder is one the rare complications following laparoscopic hernia repair. Proper preoperative evaluation is necessary to determine whether mesh is free floating in the bladder lumen or adherent to bladder wall. This will help in deciding the surgical technique for route of extraction.ConclusionA case of mesh migration into the bladder can be easily managed by laparoscopic TAPP approach and it is better approach compared to other techniques.     

Role of type III collagen in bladder filling

The function of the urinary bladder is to store urine at low pressure and expel it periodically. To accomplish this, it must have the appropriate structural properties to accommodate slow but continuous volume changes. While much is presently known about the functional measurements of compliance, relatively little is known about the structural basis of compliance. In the present study, immunohistochemistry has been used to localize type III collagen fibers in the bladder wall at different intravesical volumes. To improve the resolution of these fibers, confocal microscopy was utilized to determine the changes in type III collagen fiber orientation and correlate them with the degree of mechanical distension of the bladder wall at partial and full capacity. We demonstrate that there were significant changes in both the orientation and conformation of type III collagen fibers during bladder filling. These observations support the view that volume accommodation in the bladder is achieved by changes in the arrangement of type III collagen. These data suggest that abnormal deposition or arrangement of type III collagen fibers can have an impact on normal bladder function. Neurourol. Urodyn. 17:135–145, 1998. © 1998 Wiley-Liss, Inc.     

Paracrine effect of transplanted rib chondrocyte spheroids supports formation of secondary cartilage repair tissue

The study's objective was to investigate if transplanted chondrocyte or periosteal cell spheroids have influence on ingrowing bone marrow‐derived cells in a novel cartilage repair approach in miniature pigs. Autologous rib chondrocytes or periosteal cells were cultured as spheroids and press‐fitted into cavities that were milled into large, superficial chondral lesions of the patellar joint surface. Within the milled cavities, the subchondral bone plate was either penetrated or left intact (full‐thickness or partial‐thickness cavities). The transplantation of chondrocyte spheroids into full‐thickness cavities induced the formation of additional secondary repair cartilage that exceeded the original volume of the transplanted spheroids. The resulting continuous tissue was rich in proteoglycans and stained positive for type II collagen. Cell labeling revealed that secondarily invading repair cells did not originate from transplanted spheroids, but rather from arroded bone marrow. However, secondary invasion of repair cells was less pronounced following transplantation of periosteal cells and absent in partial‐thickness cavities. According to in vitro analyses, these observations could be ascribed to the ability of chondrocyte spheroids to secrete relevant amounts of bone morphogenetic protein‐2, which was not detected for periosteal cells. Transplanted chondrocyte spheroids exert a dual function: they provide cells for the repair tissue and have a stimulatory paracrine activity, which promotes ingrowth and chondrogenesis of bone marrow‐derived cells. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res     

New onset vesicovaginal fistula after transurethral collagen injection in women who underwent cystectomy and orthotopic neobladder creation: presentation and definitive treatment

PURPOSE: We present our experience with collagen injection for treating urinary incontinence after cystectomy and orthotopic bladder substitution in women. We discuss the efficacy of collagen injection, specific complications and subsequent definitive therapy. MATERIALS AND METHODS: We performed cystectomy and orthotopic bladder substitution in 2 women for muscle invasive transitional cell carcinoma of the bladder. In each case new onset stress urinary incontinence developed after surgery that was refractory to conservative therapy. Intrinsic sphincter deficiency was diagnosed in each patient by video urodynamic studies. Initial treatment involved transurethral collagen injections but subsequent intervention was required due to resultant complications and primary therapy inefficacy. RESULTS: Collagen (3.5 cc per session) was injected in 1 case at 2 treatment sessions and in the other at 3. Incontinence symptoms did not significantly improve in either patient and a new onset vesicovaginal fistula developed 2 days and 1 month after collagen injection, respectively. Subsequently in each case 1-stage transvaginal primary fistula repair was done in multiple layers with a pubovaginal sling procedure. Six months after repair there has been no recurrent fistula and the women remain hypercontinent, requiring intermittent self-catheterization. They are satisfied with their eventual lower tract function and overall outcome. CONCLUSIONS: Collagen injection for type 3 stress urinary incontinence after cystectomy and orthotopic bladder replacement in women may not be as effective and innocuous as in patients with a native bladder. Initial treatment with a pubovaginal sling procedure should be considered.     

The sandwich omental flap for abdominal wall defect reconstruction.

We present a case of a large full thickness abdominal wall defect following excision of a huge basal cell carcinoma, uniquely reconstructed with a sandwich omental flap, vicryl/prolene (vypro II) mesh and split thickness skin graft.     

Distribution of collagen XII and XIV in the bladder wall of the male rat with outlet obstruction

PURPOSE: Our previous studies indicate that neonatal estrogenization with diethylstilbestrol (neoDES) of male mice and rats causes partial outlet obstruction. In the present study, type XII and XIV collagens were localized in the bladder to study their role in the development of obstruction. MATERIALS AND METHODS: The bladder sections immunostained with smooth muscle specific a-actin antibody were double labeled either with collagen type XII or type XIV antibodies. The specimens were then analyzed with conventional and confocal fluorescence microscope. RESULTS: Type XII and XIV collagens were not evenly distributed in the bladder. Further, in neonatally estrogenized rats collagen XIV appeared inside smooth muscle fascicles. CONCLUSIONS: Non-overlapping distributions of collagen XII and XIV suggest their different roles in the urinary bladder. Penetration of collagen XIV inside smooth muscle fascicles may have a role in the development of DES-induced partial outlet obstruction.     

Sonographic measurement of detrusor muscle thickness in healthy children

The aim was to measure detrusor thickness in healthy children, using high frequency ultrasonography, to determine normal values that could be used for the evaluation of pathological bladder conditions. Ultrasound (US) was performed in 62 children (38 boys, 24 girls, 20 months – 18 years, mean 8.4±4.5 years) with the absence of clinical or laboratory pathological changes of the urinary tract. The detrusor thickness was measured at the posterior, anterior and lateral bladder walls, and the average thickness was calculated for each bladder wall in every child. The mean detrusor thickness was 1.17±0.45 mm (range 0.4–2.8 mm) for the anterior bladder wall, 1.25±0.45 mm (range 0.5–3.0 mm) for the posterior bladder wall, 1.18±0.44 mm (range 0.4–2.9 mm) for the left lateral wall, and 1.19±0.45 mm (range 0.4–2.8 mm) for the right lateral wall. There was a significant correlation of mean detrusor thickness with age. Using high-frequency US transducers it was possible to measure the detrusor thickness of the anterior and posterior bladder walls in all children. The mean normal detrusor thickness is 1.2±0.45 mm (range 0.4–3 mm) when the bladder is full. Future studies should evaluate this method in children with functional, neuropathic and anatomical dysfunctions of the lower urinary system. Received: 5 June 2001 / Revised: 29 August 2001 / Accepted: 29 August 2001