Neurogenic Lower Urinary Tract Dysfunction in Spinal Dysraphism: Morphological and Molecular Evidence in Children.

Spinal dysraphism, most commonly myelomeningocele, is the typical cause of a neurogenic lower urinary tract dysfunction (NLUTD) in childhood. The structural changes in the bladder wall in spinal dysraphism already occur in the fetal period and affect all bladder wall compartments. The progressive decrease in smooth muscle and the gradual increase in fibrosis in the detrusor, the impairment of the barrier function of the urothelium, and the global decrease in nerve density, lead to severe functional impairment characterized by reduced compliance and increased elastic modulus. Children present a particular challenge, as their diseases and capabilities evolve with age. An increased understanding of the signaling pathways involved in lower urinary tract development and function could also fill an important knowledge gap at the interface between basic science and clinical implications, leading to new opportunities for prenatal screening, diagnosis, and therapy. In this review, we aim to summarize the evidence on structural, functional, and molecular changes in the NLUTD bladder in children with spinal dysraphism and discuss possible strategies for improved management and for the development of new therapeutic approaches for affected children.

Myostatin Overexpression and Smad Pathway in Detrusor Derived from Pediatric Patients with End-Stage Lower Urinary Tract Dysfunction.

Cell therapies and tissue engineering approaches using smooth muscle cells (SMCs) may provide treatment alternatives for end-stage lower urinary tract dysfunction (ESLUTD). Myostatin, a negative regulator of muscle mass, is a promising target to improve muscle function through tissue engineering. The ultimate goal of our project was to investigate the expression of myostatin and its potential impact in SMCs derived from healthy pediatric bladders and pediatric ESLUTD patients. Human bladder tissue samples were evaluated histologically, and SMCs were isolated and characterized. The proliferation of SMCs was assessed by WST-1 assay. The expression pattern of myostatin, its pathway and the contractile phenotype of the cells were investigated at gene and protein levels by real-time PCR, flow cytometry, immunofluorescence, WES and gel contraction assay. Our results show that myostatin is expressed in human bladder smooth muscle tissue and in isolated SMCs at gene and protein levels. A higher expression of myostatin was detected in ESLUTD-derived compared to control SMCs. Histological assessment of bladder tissue confirmed structural changes and decreased muscle-to-collagen ratios in ESLUTD bladders. A decrease in cell proliferation and in the expression of key contractile genes and proteins, α-SMA, calponin, smoothelin and MyH11, as well as a lower degree of in vitro contractility was observed in ESLUTD-derived compared to control SMCs. A reduction in the myostatin-related proteins Smad 2 and follistatin, and an upregulation in the proteins p-Smad 2 and Smad 7 were observed in ESLUTD SMC samples. This is the first demonstration of myostatin expression in bladder tissue and cells. The increased expression of myostatin and the changes in the Smad pathways were observed in ESLUTD patients. Therefore, myostatin inhibitors could be considered for the enhancement of SMCs for tissue engineering applications and as a therapeutic option for patients with ESLUTD and other smooth muscle disorders.

Fetal surgery for spina bifida in Zurich: results from 150 cases.

PURPOSE: Over the past 10 years, over 150 fetal spina bifida surgeries were performed at the Zurich Center for Fetal Diagnosis and Therapy. This study looks at surrogates for success and failure of this approach. METHODS: We focused on key outcome parameters including hydrocephalus shunt rate at one year, bladder control at 4, independent ambulation at 3 years, and maternal, fetal, and neonatal complications. RESULTS: From the first 150 patients undergoing fetal surgery for spina bifida, 148 (98.7%) were included in the study. Maternal-fetal surgery was uneventful in 143/148 (97%) cases. Intraoperative problems included resuscitation in 4/148 fetuses (2.7%). 1/148 fetuses (0.7%) died on postoperative day 4. Maternal complications included chorioamniotic membrane separation in 22/148 (15%), lung embolism in 3/148 (2.1%), chorioamnionitis in 2/148 (1.4%), AV-block III and uterine rupture in 1/148 each (0.7%). 1/148 (0.7%) newborn death was recorded. Hindbrain herniation was identified preoperatively in 132/148 (90%) fetuses and resolved completely in 119/132 (90%). At one year, 39/106 (37%) children had required a CSF diversion. At 4 years, 4/34 patients (12%) had normal bladder control. At 3 years, 48/57 (84%) walked independently. CONCLUSION: A majority of patients benefitted from prenatal intervention, in that the shunt rate was lower and the rates of continent and walking patients were higher than reported with postnatal care.

Urological Outcome after Fetal Spina Bifida Repair: Data from the Zurich Cohort.

INTRODUCTION: Neurogenic lower urinary tract dysfunction (NLUTD) represents a severe burden for patients with open spina bifida (OSB). The effect of fetal OSB repair on the urological outcome remains unclear, as controversial data exist. The aim of this study was to further increment existing outcome data and to demonstrate that our earlier published positive preliminary results are not erratic. METHODS: Data from standardized urological follow-up appointments of patients with fetal OSB repair operated at our center were analyzed. Data were obtained from urodynamic studies (UDSs) and radiologic exams performed in the newborn (gestational age 37-39 weeks), at ages of 6, 12, 18, and 24 months, and then at yearly intervals. RESULTS: Of 82 patients (mean age 2.6 years, range 6 months to 7 years), 26 (32%) had a normal bladder function as demonstrated by UDSs. Of the 56 (68%) patients with NLUTD, 29 (51%) patients showed initially a normal UDS, but developed NLUTD in the follow-up, 19 (66%) of them spontaneously and another 10 (34%) in association with growth and development, or surgery of inclusion cysts. Radiologic abnormalities (upper tract dilatation and vesico-uretero-renal reflux) were seen in 15%, mainly patients with NLUTD. CONCLUSION: Our results add an important set of information to the existing body of evidence. The data reconfirm our earlier published favorable preliminary results and support other studies that show a possible benefit of prenatal OSB repair on the urological outcome, but they also demonstrate that the positive effect remains limited.

Inclusion Cysts after Fetal Spina Bifida Repair: A Third Hit?

INTRODUCTION: Fetal spina bifida repair (fSBR) has proven effective in the reversibility of hindbrain herniation, lower rate of shunt-dependent hydrocephalus, and independent ambulation. Besides distinct advantages, there are also concerns related to fSBR. One of these is the postnatal occurrence of inclusion cysts (IC). METHODS: In a prospective study, 48 children who underwent fSBR were followed up. Postnatal assessment included clinical examination, cystometry, and spinal MRI. Indication for IC resection was the evidence of a spinal mass on MRI in the presence of deteriorating motor or bladder function, pain, or considerable growth of the IC. RESULTS: Fourteen children (30%) developed IC, all within the first 2 years of life. Six children underwent IC resection; 4 children due to deteriorating function, 2 children due to doubling of the mass on MRI within 1 year. Following IC resection, 4/6 children (67%) demonstrated altered motor function and 6 children (100%) were diagnosed with neurogenic bladder dysfunction. CONCLUSIONS: Systematic follow-up of patients with a history of fSBR revealed a high incidence of IC. Whether these are of dysembryogenic or iatrogenic origin, remains unclear. Since both IC per se and IC resection may lead to loss of neurologic function, IC can be considered a "third hit".

Increased autophagy contributes to impaired smooth muscle function in neurogenic lower urinary tract dysfunction.

AIMS: To explore whether autophagy plays a role in the remodeling of bladder smooth muscle cells (SMCs) in children with neurogenic lower urinary tract dysfunction (NLUTD), we investigated the effect of autophagy in NLUTD in the paediatric population. METHODS: Bladder biopsies were taken from children with NLUTD and healthy donors as controls. Samples were labeled with the SMC markers calponin, smoothelin, and the autophagy proteins LC3, ATG5, and Beclin1. The contractile ability of bladder derived SMCs was investigated. RESULTS: ATG5 gene and protein was upregulated in NLUTD muscle tissue compared to normal bladder. NLUTD muscle exhibited a punctated immunostaining pattern for LC3 in a subset of the SMCs, confirming the accumulation of autophagosomes. Pronounced elevation of ATG5 in the SMC in NLUTD tissue was associated with a downregulation of the key contractile proteins smoothelin and calponin. Pharmacological blocking of autophagy completely stopped the cells growth in normal bladder SMCs. Inhibition of autophagy in the NLUTD SMCs, with already elevated levels of ATG5, resulted in a reduction of ATG5 protein expression to the basal level found in normal controls. CONCLUSIONS: Our study suggests that autophagy is an important factor affecting the remodeling of SMCs and the alteration of functionality in bladder smooth muscle tissue in the NLUTD. Since autophagy can be influenced by oral medication, this finding might lead to novel strategies preventing the deterioration of NLUTD muscle.

Prenatal myelomeningocele repair: Do bladders better?

AIMS: Prenatal myelomeningocele (MMC) repair has been proven to significantly reduce the need for hydrocephalus shunting and improve lower-extremity motor outcomes. The aim of this study was to evaluate the effect of prenatal MMC repair on the urological outcome. METHODS: All patients who underwent fetal MMC repair at our institution are followed prospectively. Assessments include medical history, renal and bladder ultrasound, voiding cystourethrogram and urodynamic study, need for clean intermittent catheterization (CIC) and anticholinergics, and the occurrence of urinary tract infections (UTI). RESULTS: Of the 30 patients who underwent prenatal MMC closure from December 2010 to December 2015, eight patients with a postnatal follow-up of at least 2 years were included in this study and compared with eight patients after postnatal MMC repair. The level of the bony spinal defect was similar in both groups. Urological evaluation at 2 years revealed normal bladder function in 50% after prenatal repair. Neurogenic bladder dysfunction requiring CIC and anticholinergic therapy was seen in 50% in the prenatal and in 100% in the postnatal group. Significant bladder wall thickening was found in 37.5% and 87.5%, respectively. Febrile UTIs occurred in 37.5% in the prenatal and 62.5% in the postnatal group during the observation period. CONCLUSIONS: Our data suggest a positive effect of prenatal MMC closure on lower urinary tract function. The long-term significance of these results remains unclear. Therefore, continued close monitoring of renal and bladder function are mandatory.

Stem Cells in Functional Bladder Engineering.

Conditions impairing bladder function in children and adults, such as myelomeningocele, posterior urethral valves, bladder exstrophy or spinal cord injury, often need urinary diversion or augmentation cystoplasty as when untreated they may cause severe bladder dysfunction and kidney failure. Currently, the gold standard therapy of end-stage bladder disease refractory to conservative management is enterocystoplasty, a surgical enlargement of the bladder with intestinal tissue. Despite providing functional improvement, enterocystoplasty is associated with significant long-term complications, such as recurrent urinary tract infections, metabolic abnormalities, stone formation, and malignancies. Therefore, there is a strong clinical need for alternative therapies for these reconstructive procedures, of which stem cell-based tissue engineering (TE) is considered to be the most promising future strategy. This review is focused on the recent progress in bladder stem cell research and therapy and the challenges that remain for the development of a functional bladder wall.

Multisystem neuroprosthetic training improves bladder function after severe spinal cord injury.

UNLABELLED: Severe spinal cord injury leads to neurogenic bladder dysfunction. We recently developed a multisystem neuroprosthetic training program that promotes plastic changes capable of restoring refined locomotion in rats with severe spinal cord injury. We investigated whether multisystem neuroprosthetic training would influence the development of posttraumatic bladder dysfunction. MATERIALS AND METHODS: Eight and 4 adult rats were randomly assigned to a spinal cord injury and an intact control group, respectively. Spinal cord injury consisted of 2 opposite lateral hemisections (T7 and T11), thus, interrupting all direct supraspinal input. After spinal cord injury 4 rats were subjected to a multisystem neuroprosthetic training program and 4 were not trained. At 8 weeks we performed urodynamics and evaluated kidney function using creatinine and cystatin C. Bladder investigation included morphological, histological and immunohistochemical evaluations. RESULTS: Bladder capacity increased threefold in trained and sevenfold in nontrained rats compared to intact rats. During filling we found a mean ± SEM of 2.7 ± 1.1 vs 12.6 ± 5.2 nonvoiding contractions in trained vs nontrained rats. Bladder morphology was similar in trained and intact rats. Nontrained rats showed detrusor hypertrophy, characterized by increased detrusor thickness and a decreased connective tissue-to-smooth muscle ratio. As labeled with protein gene product 9.5, general nerve density was significantly increased in trained and significantly decreased in nontrained rats. The relative proportion of neurofilament 200 positive afferent nerves was significantly lower in trained than in intact and nontrained rats. Neuropeptide Y positive fibers showed significantly lower density in nontrained rats. CONCLUSIONS: Multisystem neuroprosthetic training effectively counteracts the formation of neurogenic bladder dysfunction after severe spinal cord injury and might contribute to preserving bladder function and preventing long-term complications in patients with severe spinal cord injury.

Improved contractile potential in detrusor microtissues from pediatric patients with end stage lower urinary tract dysfunction.

Autologous cell-based tissue engineering has been proposed as a treatment option for end stage lower urinary tract dysfunction (ESLUTD). However, it is generally accepted that cells isolated from patient bladders retain the pathological properties of their tissue of origin and therefore need to be improved before they can serve as a cell source for tissue engineering applications. We hypothesize that human three-dimensional (3D) microtissues of detrusor smooth muscle cells (SMCs) are valuable ex vivo disease models and potent building blocks for bladder tissue engineering. Detrusor SMCs isolated from bladder wall biopsies of pediatric ESLUTD patients and healthy controls were expanded and cultured into 3D microtissues. Gene and protein analyses were performed to explore the effect of microtissue formation on SMC viability, contractile potential, bladder wall specific extracellular matrix (ECM) composition and mediators of ECM remodeling. Through microtissue formation, remodeling and intensified cell-cell interactions, the ESLUTD SMCs lost their characteristic disease phenotype. These microtissues exhibited similar patterns of smooth muscle related contractile proteins and essential bladder wall-specific ECM components as microtissues from healthy control subjects. Thus, the presented data suggest improved contractile potential and ECM composition in detrusor SMC microtissues from pediatric ESLUTD patients. These findings are of great relevance, as 3D detrusor SMC microtissues might be an appropriate cell source for autologous cell-based bladder tissue engineering.

Repeated Botulinum-A toxin injection in the treatment of neuropathic bladder dysfunction and poor bladder compliance in children with myelomeningocele.

AIMS: To evaluate the efficacy of intradetrusor injection of Botulinum-A toxin (BoNT/A) in children with neuropathic bladder dysfunction and poor bladder compliance, due to meningomyelocele. METHODS: We retrospectively reviewed the charts of 11 children (mean age 6.7 ± 5.3 years) with neuropathic bladder and poor bladder compliance (mean 7 ml/cmH(2) O) treated with intradetrusor injection of BoNT/A. After urodynamic evaluation a standardized injection was performed. The authors describe their results in 11 children after the first (5×) or repeated (6×) BoNT/A injections. Re-evaluation was performed 3 and 12 months after each injection. RESULTS: Three months after injection detrusor pressure decreased by 17% and bladder capacity increased by 33%. In all but 1 patient bladder compliance stayed poor. Twelve months after treatment patients still had an effect but the values were already reverting towards preoperative levels. With repeated injections we achieved a similar effect on capacity and detrusor pressure as after the first injection. Overall, bladder compliance normalized (>20 cmH(2) O) in only 1 patient. CONCLUSIONS: The results confirmed the positive temporary effect of BoNT/A on detrusor pressure and bladder capacity in children with myelomeningocele, even after repeated injections. Nevertheless, bladder compliance stayed severely pathological. Whether an earlier treatment may prevent poor bladder compliance is a yet unanswered question.

A rare case of symptomatic hydrometrocolpos in a 5y old female.

Late presentation of symptomatic hydrometrocolpos is uncommon. We present a 5 years old continent girl with prenatally diagnosed multicystic dysplastic left kidney and late-onset of lower abdominal pain. Investigations revealed a nonfunctioning left kidney with an ectopic ureter draining into the left hemivagina, and a vaginal duplication with an obstructed and urine-filled left hemivagina. Surgical therapy included resection of the vaginal septum and laparoscopic nephroureterectomy. Not only renal agenesis but also dysplasia or multicystic kidney may part of an OHVIRA syndrome. In girls with unilateral renal dysplasia, a duplication of the internal genitalia must always be considered.

Spheroids of Bladder Smooth Muscle Cells for Bladder Tissue Engineering.

Cell-based tissue engineering (TE) has been proposed to improve treatment outcomes in end-stage bladder disease, but TE approaches with 2D smooth muscle cell (SMC) culture have so far been unsuccessful. Here, we report the development of primary bladder-derived 3D SMC spheroids that outperform 2D SMC cultures in differentiation, maturation, and extracellular matrix (ECM) production. Bladder SMC spheroids were compared with 2D cultures using live-dead staining, qRT-PCR, immunofluorescence, and immunoblotting to investigate culture conditions, contractile phenotype, and ECM deposition. The SMC spheroids were viable for up to 14 days and differentiated rather than proliferating. Spheroids predominantly expressed the late myogenic differentiation marker MyH11, whereas 2D SMC expressed more of the general SMC differentiation marker α-SMA and less MyH11. Furthermore, the expression of bladder wall-specific ECM proteins in SMC spheroids was markedly higher. This first establishment and analysis of primary bladder SMC spheroids are particularly promising for TE because differentiated SMCs and ECM deposition are a prerequisite to building a functional bladder wall substitute. We were able to confirm that SMC spheroids are promising building blocks for studying detrusor regeneration in detail and may provide improved function and regenerative potential, contributing to taking bladder TE a significant step forward.

Predifferentiated Smooth Muscle-Like Adipose-Derived Stem Cells for Bladder Engineering.

Introduction: All organs of human body are a conglomerate of various cell types with multidirectional interplay between the different cells and the surrounding microenvironment, leading to a stable tissue formation, homeostasis, and function. To develop a functional smooth muscle tissue, we need to simulate and create a multicellular microenvironment. The multilineage adipose-derived stem cells (ADSCs), which can be easily harvested in large numbers, may provide an alternative cell source for the replacement of smooth muscle cells (SMCs) in cell-based detrusor bioengineering therapeutic approaches. The aim of this study was to investigate whether predifferentiated smooth muscle-like ADSC (pADSC) can support SMCs to generate stable smooth muscle tissue through remodeling of extracellular matrix (ECM) and factor secretion. Methods: Rat SMC and pADSC were mono- and cocultured in the cell ratios 1:1, 1:2, 1:3, and 1:5 (SMC-pADSC) and grown for up to 2 weeks in vitro. The expression of the SMC-specific markers alpha-smooth muscle actin, calponin, myosin heavy chain 11 (MyH11), and smoothelin was assessed, and cell proliferation and contractility were analyzed. Proteomic analysis of the secretome (cell-cell contact was compared with a noncontact transwell 1:1 coculture) and the cell pellets was performed, with the focus on ECM deposition and remodeling, integrin expression and growth factor secretion. Results: SMC and pADSC were strongly positive for all smooth muscle markers. After 1 and 2 weeks of culture, the 1:1 cell ratio developed a significantly higher number of smooth muscle organoids and improved contractility. These organoids were highly structured, consisting of an SMC core surrounded by a pADSC layer. The deposition of various EMC proteins, such as collagens 1a1, 1a2, 2a1, 3a1, 5a2, 6a2, 12a1, and fibrillin 1, was significantly increased. A decreased matrix metalloproteinase 3 (MMP3), MMP9 and MMP13 secretion, as well as increased tissue inhibitors of metalloproteinase 1 (TIMP1) and TIMP2 secretion were found in the contact coculture compared with the monoculture controls. Conclusion: SMC-pADSC 1:1 cocultures exhibit an improved cell proliferation, contractility, and organoid formation compared with all other ratios and monoculture, while retaining a stable phenotype that is comparable with the SMC monoculture. These effects are mediated by increased ECM deposition and tight ECM remodeling by the secreted MMP and TIMP. Impact statement Harvesting smooth muscle cells (SMCs) from diseased bladders represents a significant limitation for clinical translation of bladder Tissue Engineering. Our results suggest that autologous predifferentiated smooth muscle-like adipose-derived stem cell can substitute SMCs, and may be used in combination with SMCs to generate contractile detrusor muscle tissue for patients suffering from end-stage bladder diseases. We demonstrate a beneficial effect when using these cells in a 1:1 ratio with improved deposition of extracellular matrix (ECM) molecules and superior remodeling of the ECM by matrix metalloproteinases and decreased tissue inhibitors of metalloproteinase activity.

Detrusor bioengineering using a cell-enriched compressed collagen hydrogel.

OBJECTIVE: The gold standard for bladder regeneration in end-stage bladder disease is the use of intestinal tissue, which is however associated with significant long-term complications. Our study aims to bioengineer functional detrusor muscle combining bladder smooth muscle cells (SMC) and SMC-like adipose-derived stem cells (pADSC) in compressed collagen (CC) hydrogels and to investigate biocompatibility and tissue regeneration of such detrusor-equivalents in a rat detrusorectomy model. METHODS: Compressed collagen hydrogels seeded with 1 × 106 or 4 × 106 SMC alone or in combination with pADSC in a 1:1 ratio were investigated. Morphology, phenotype, and viability as well as proteomic secretome analysis were assessed in the 1:1 co-cultures and the respective monocultures. The hydrogels were implanted into rat bladders after partial detrusorectomy. Bladders were harvested 8 weeks after transplantation, and assessed for tissue morphology, detrusor regeneration, neo-vascularization and -innervation. RESULTS: Co-cultured cells exhibited native SMC morphology, high viability and proliferated to form microtissues in vitro. The pro-angiogenic factors angiogenin, vascular endothelial growth factor (VEGF)-A and -D were increased in the secretome of the pADSC samples. After 8 weeks of in vivo, the regenerated bladder wall showed a multilayered structure containing all bladder wall components. The overall performance of the bladder wall regeneration of CC seeded with 4 × 106 cells was significantly better than with 1 × 106 cells and the combination SMC:pADCS performed slightly better than SMC alone. CONCLUSION: Compressed collagen possesses an adequate regenerative potential to promote regeneration of bladder wall tissue in vivo. Seeded with a combination of pADSC and SMC this may well be the first step towards a functional bladder reconstruction especially in patients suffering of end-stage bladder diseases.

Determinants of success and failure of seromuscular colocystoplasty lined with urothelium.

PURPOSE: Seromuscular colocystoplasty lined with urothelium is a method of bladder augmentation that avoids incorporating intestinal mucosa into the urinary tract. Others have reported a repeat augmentation rate of 23%. We analyzed the results in 20 patients who underwent the procedure, as performed by one of us (RG), at 3 institutions. MATERIALS AND METHODS: After receiving institutional review board approval we retrospectively reviewed the charts of all patients operated on since 1998. Preoperative and postoperative bladder capacity at 30 cm H(2)O, expressed as the percent of expected capacity for age using the equation, bladder capacity in ml = (age +1) x 30, as well as prior, concomitant and subsequent bladder or bladder neck procedures, continence and the need for repeat augmentation were recorded. RESULTS: There were 20 patients, including 7 females, with a mean age at surgery of 9 years and a mean followup of 53 months. All patients had neurogenic bladder dysfunction. An artificial urinary sphincter was implanted at the time of seromuscular colocystoplasty in 10 patients, preoperatively in 6 and postoperatively in 1. A sling was used in 3 females. Patients were divided into 2 groups. The 15 group 1 patients underwent no concomitant procedure in the bladder and the 5 in group 2 underwent creation of a continent channel at seromuscular colocystoplasty. There were no failures of augmentation in group 1, in which bladder capacity increased from 60% of that expected for age to 100%. All patients were continent. Three of the 5 patients in group 2 required repeat augmentation. CONCLUSIONS: Seromuscular colocystoplasty lined with urothelium has proved to be an effective method to augment the bladder in patients who have an artificial urinary sphincter or who undergo simultaneous artificial urinary sphincter implantation. We do not recommend constructing a continent catheterizable channel at the time of seromuscular colocystoplasty lined with urothelium.

Long-term followup (37 to 69 years) in patients with bladder exstrophy treated with ureterosigmoidostomy: psychosocial and psychosexual outcomes.

PURPOSE: We describe the long-term psychosocial and sexual outcomes of patients born with bladder exstrophy treated with ureterosigmoidostomy at our institution. MATERIALS AND METHODS: Of 42 patients born with bladder exstrophy between 1937 and 1968, 28 were located, of whom 25 agreed to participate in this study. Evaluation consisted of studying pediatric and adult medical records, medical examination, and reports of sexual and social history. RESULTS: Four female and 21 male patients with a mean age of 50 years (range 39 to 67) were evaluated. Of the patients 21 (84%) were married or lived in a stable relationship, 6 (24%) had several children after normal conception and an additional 2 (8%) became parents with assisted reproductive technology. Nine patients (36%) reported no sexual activity or were unable to engage in sexual intercourse. All patients except 2 are professionally and socially successful. CONCLUSIONS: The long-term followup of this study of 37 to 68 years provides valuable information on patients who live with bladder exstrophy during a long period. Most followed patients who were born with bladder exstrophy and treated with ureterosigmoidostomy were able to lead satisfactory lives socially and professionally. However, at least 36% of the patients are severely restricted in their sexual lives.

Tissue Engineering in Pediatric Bladder Reconstruction-The Road to Success.

Several congenital disorders can cause end stage bladder disease and possibly renal damage in children. The current gold standard therapy is enterocystoplasty, a bladder augmentation using an intestinal segment. However, the use of bowel tissue is associated with numerous complications such as metabolic disturbance, stone formation, urine leakage, chronic infections, and malignancy. Urinary diversions using engineered bladder tissue would obviate the need for bowel for bladder reconstruction. Despite impressive progress in the field of bladder tissue engineering over the past decades, the successful transfer of the approach into clinical routine still represents a major challenge. In this review, we discuss major achievements and challenges in bladder tissue regeneration with a focus on different strategies to overcome the obstacles and to meet the need for living functional tissue replacements with a good growth potential and a long life span matching the pediatric population.

Pelvi-ureteric junction obstruction in duplex kidneys.

OBJECTIVE: To report our experience of 11 children with pelvi-ureteric junction obstruction (PUJO) in a duplex kidney and to review previous reports. PATIENTS AND METHODS: From 1995 to 2005 the second author (G.H.H.S.) performed 145 pyeloplasties in single-system kidneys and in 11 children with PUJO in a duplex kidney. Upper and lower pole obstructions were found in both complete and incomplete duplicated systems. Investigations included renal ultrasonography, renal scintigraphy, micturating cystography, cystoscopy and retrograde pyelography. Ten patients had surgery (eight dismembered pyeloplasties, one upper-pole heminephrectomy, one pyelo-ureterostomy). RESULTS: Three children had obstruction of the upper moiety and eight had obstruction of the lower moiety. Upper and lower pole obstructions were found in both complete and incomplete duplicated systems. CONCLUSION: Upper-pole obstruction in a duplex kidney is rare; the present series suggests that it is more common than previously reported.

Bladder regeneration through stem cell therapy.

INTRODUCTION: Impaired bladder function in children and adults often causes lifelong morbidity, as functional therapeutic approaches in this field are nonexistent. If reconstructive procedures are required, intestinal tissue is used as a gold standard for bladder repair. As this procedure is associated with significant long-term complications there is a strong clinical need for alternative sources of stable and reliable bladder tissue, of which stem cells are considered most promising. AREAS COVERED: This review focusses on the recent development in stem cell use for bladder bioengineering. Further, we discuss the importance of the microenvironment in stem cell differentiation, function and tissue regeneration and its effect on the development of functional bladder tissue. EXPERT OPINION: Functional bladder bioengineering requires a complex approach that involves the development of a multi-layered scaffold, with each layer offering a specific microenvironment for the generation and support of the respective cell type used in its redevelopment. The formation of cellular cross-talk within and between the layers is the key in this process. While autologous stem cells may provide a viable source of tissue for bladder reconstruction, their in situ activation combined with repair of the diseased microenvironment may offer better, more lasting solutions for functional bladder regeneration.