Prevalence of high-risk bladder categorization with prenatal and postnatal myelomeningocele repair types.

INTRODUCTION: Urologic substudies of prenatal myelomeningocele (MMC) closure have focused primarily on continence without significant clinical benefit. Fetoscopic MMC repair (FMR) is a newer form of prenatal intervention and touts added benefits to the mother, but urological outcomes have yet to be analyzed. We set out to focus on bladder safety rather than continence and examined bladder outcomes with different prenatal MMC repairs (FMR and prenatal open [POMR]) and compared bladder-risk-categorization to traditional postnatal repair (PSTNR). METHODS: An IRB-approved retrospective analysis of all patients undergoing all forms of MMC repairs with inclusion and exclusion criteria based on the MOMS trial was performed. Bladder safety assessment required initial urodynamic studies (UDS), renal bladder ultrasound (RBUS), and/or voiding cystourethrogram (VCUG) within the 1st year of life. Follow-up analyses within the cohorts required follow-up studies within 18 months after initial evaluations. Outcomes assessed included bladder-risk-categorization based on the CDC UMPIRE study (high, intermediate, and safe), hydronephrosis (HN), and vesicoureteral reflux (VUR). A single reader evaluated each UDS. RESULTS: Initial UDS in 93 patients showed that the prevalence of high-risk bladders were 35% FMR versus 36% PSTNR and 60% POMR. Follow-up UDS showed only 8% of FMR were high-risk compared to 35% POMR and 36% PSTNR. Change from initial to follow-up bladder-risk-category did not reach significance (p = .0659); however, 10% PSTNR worsened to high-risk on follow-up, compared to none in either prenatal group. Subanalysis of follow-up UDS between the prenatal cohorts also was not significant (p = .055). Only 8% of FMR worsened or stayed high-risk compared to 35% with POMR (p = .1). HN was significantly different at initial and subsequent follow up between the groups with the least in the FMR group. CONCLUSIONS: Early outcome UDS analyses demonstrated lower incidence of high-risk bladders in FMR patients with a trend toward clinically significant improvement compared to POMR in regard to all evaluated metrics. Larger, prospective, confirmatory studies are needed to further evaluate the potential benefits on FMR on bladder safety and health.

Patient and Caregiver Attitudes toward Disorders of Sex Development Nomenclature.

PURPOSE: The medical terminology applied to differences/disorders of sex development has been viewed negatively by some affected individuals. A clinical population of patients with differences/disorders of sex development and their caregivers were surveyed regarding current nomenclature, hypothesizing that those unaffiliated with support groups would have more favorable attitudes. MATERIALS AND METHODS: We recruited English and Spanish speaking patients 13 years old or older with differences/disorders of sex development and their caregivers at 5 national tertiary care clinics from July 2016 to December 2018. No diagnoses were excluded. Participants completed a survey rating terminology commonly applied to differences/disorders of sex development. Responses were compared between subgroups, including members vs nonmembers of a support group. RESULTS: Of 185 potential participants approached 133 completed the survey (72% response rate). Congenital adrenal hyperplasia (33%) was the most common diagnosis. "Variation of sex development" was the most liked term (37%) but was not liked more significantly than "disorders of sex development" (27%, p=0.16). No term was liked by a majority of respondents. "Disorders of sex development" (37%) and "intersex" (53%) were the only terms most frequently viewed unfavorably. Support group members were significantly more likely to dislike the term "intersex" (p=0.02) and to like "variation of sex development" (p=0.02). CONCLUSIONS: A clinical population of patients and their caregivers had generally neutral attitudes toward nomenclature applied to differences/disorders of sex development. Members of a support group had clearer terminology preferences. "Variation of sex development" was the most liked term, and "disorders of sex development" and "intersex" were the most disliked. No term was liked by most respondents, and no clear alternative to the present nomenclature was identified.

Interrater Reliability in Interpretation of Neuropathic Pediatric Urodynamic Tracings: An Expanded Multicenter Study.

PURPOSE: Urodynamic findings often guide treatment for neuropathic bladder and are reported as objective data points in multi-institutional trials. However, urodynamic interpretation can be variable. In a pilot study pediatric urologists interpreting videourodynamics exhibited only moderate agreement despite similar training and practice patterns. We hypothesized the pilot study variability would be replicated in a multi-institutional study. MATERIALS AND METHODS: We developed an anonymous electronic survey that contained 20 scenarios, each with a brief patient history, 1 urodynamic tracing and fluoroscopic imagery. All videourodynamics were completed during routine care of patients with neuropathic bladder at a single institution. Pediatric urologists from Centers for Disease Control and Prevention Urologic Protocol sites were invited to complete an interpretation instrument for each scenario. Fleiss kappa and 95% confidence limits were reported, with Fleiss kappa 1.00 corresponding to perfect agreement. RESULTS: The survey was completed by 14 pediatric urologists at 7 institutions. Substantial agreement was seen for assessment of fluoroscopic bladder shape (Fleiss kappa 0.73), while moderate agreement was observed for assessment of bladder safety, end filling detrusor pressure and bladder capacity (Fleiss kappa 0.50, 0.56 and 0.54, respectively). Fair agreement was seen for electromyographic synergy and presence of detrusor overactivity (Fleiss kappa 0.21 and 0.35, respectively). CONCLUSIONS: Experienced pediatric urologists demonstrate variability during interpretation of videourodynamic tracings. Subjectivity of assessment of electromyographic activity and detrusor overactivity was confirmed in this expanded study. Future work to improve the reliability of videourodynamic interpretation would improve the quality of clinical care and the quality of multi-institutional studies that use urodynamic data points as outcomes.

Evidence-Based Management of Patients with 45,X/46,XY Gonadal Dysgenesis and Male Sex Assignment: from Infancy to Adulthood.

45,X/46,XY gonadal dysgenesis is a disorder of sexual differentiation with a wide clinical presentation, ranging from Turner-like females to individuals with genital ambiguity to azoospermic but otherwise normal-appearing males. Hence, patients can be assigned female or male sex. Female patients are managed according to the Turner Syndrome Guidelines, whereas males are managed on a case-by-case basis. Male patients present with multiple medical challenges: undervirilization, hypogonadism, gonadoblastoma risk, and short stature. Many require surgeries and hormonal treatments that are time-sensitive and irreversible. Nonetheless, these therapeutic decisions are made without evidence-based guidelines. This review describes the medical concerns and possible interventions in male patients with 45,X/46,XY dysgenesis for each stage of development. Interventions should be addressed within a patient-centered framework by a multidisciplinary team and after thorough discussion with the family. We use the GRADE system to appraise the existing evidence and provide recommendations based on the available evidence.

Translating pediatric urodynamics from clinic into collaborative research: Lessons and recommendations from the UMPIRE study group.

Pediatric patients present unique challenges in the performance and interpretation of urodynamic studies. Interpretation of urodynamics to guide clinical management at an institutional level is accepted as reliable. Challenges arise however when multi-site collaborations incorporate urodynamics into study design to determine primary or secondary outcomes or to direct decision-making. Although standardized terminology has been established by ICCS, the application of this shared language to performance and interpretation of pediatric urodynamics to across multiple sites may not be intuitive or reliable. With a primary goal of defining the care necessary to protect future renal function, the UMPIRE protocol (Urologic Management to Preserve Initial REnal function) utilizes a urodynamics-based risk stratification to determine medical management for infants with myelomeningocele. Iterative changes in the protocol are based upon the clinical progress of the enrolled children. Despite a team experienced in subtleties of urodynamics and despite efforts to minimize variability across sites, the UMPIRE study group identified several areas in which the language of urodynamics required additional clarification or creation of more explicit definitions to standardize performance and interpretation across sites. This article reviews the foundations of current urodynamics practice, describes limitations and challenges unique to pediatric studies, and the shares the humble lessons learned by the UMPIRE study group on their journey toward standardized urodynamic language for management of infants and children with myelomeningocele.

Urodynamic characteristics of neurogenic bladder in newborns with myelomeningocele and refinement of the definition of bladder hostility: Findings from the UMPIRE multi-center study.

INTRODUCTION: Infants with myelomeningocele are at risk for chronic kidney disease caused by neurogenic bladder dysfunction. Urodynamic evaluation plays a key role to risk stratify individuals for renal deterioration. OBJECTIVE: To present baseline urodynamic findings from the Urologic Management to Preserve Initial Renal function for young children with spina bifida (UMPIRE) protocol, to present the process that showed inadequacies of our original classification scheme, and to propose a refined definition of bladder hostility and categorization. STUDY DESIGN: The UMPIRE protocol follows a cohort of newborns with myelomeningocele at nine children's hospitals in the United States. Infants are started on clean intermittent catheterization shortly after birth. If residual volumes are low and there is no or mild hydronephrosis, catheterization is discontinued. Baseline urodynamics are obtained at or before 3 months of age to determine further management. Based on protocol-specific definitions, urodynamic studies were reviewed by the clinical site in addition to a central review team; and if necessary, by all site urologists to achieve 100% concurrence. RESULTS: We reviewed 157 newborn urodynamic studies performed between May 2015 and September 2017. Of these 157 infants, 54.8% were boys (86/157). Myelomeningocele closure was performed in-utero in 18.4% (29/157) and postnatally in 81.5% (128/157) of newborns. After primary review, reviewers agreed on overall bladder categorization in 50% (79/157) of studies. Concurrence ultimately reached 100% with further standardization of interpretation. We found that it was not possible to reliably differentiate a bladder contraction due to detrusor overactivity from a volitional voiding contraction in an infant. We revised our categorization system to group the "normal" and "safe" categories together as "low risk". Additionally, diagnosis of detrusor sphincter dyssynergia (DSD) with surface patch electrodes could not be supported by other elements of the urodynamics study. We excluded DSD from our revised high risk category. The final categorizations were high risk in 15% (23/157); intermediate risk in 61% (96/157); and low risk in 24% (38/157). CONCLUSION: We found pitfalls with our original categorization for bladder hostility. Notably, DSD could not be reliably measured with surface patch of electrodes. The effect of this change on future renal outcomes remains to be defined.

Testosterone versus hCG in Hypogonadotropic Hypogonadism - Comparing Clinical Effects and Evaluating Current Practice.

Background. Gonadotropin therapy is not typically used for pubertal induction in hypogonadotropic hypogonadism (HH), however, represents a promising alternative to testosterone. It can potentially lead to the maintenance of future fertility in addition to testicular growth. We compared the pubertal effects of human chorionic gonadotropin (hCG) versus testosterone in adolescent males with HH. We evaluated the current practice, among pediatric endocrinologists, to identify barriers against gonadotropin use. Methods. In this retrospective review, we compared the effect of testosterone versus hCG therapy on mean testicular volume (MTV), penile length, growth velocity, and testosterone levels. We surveyed pediatric endocrinologists at our center, using RedCap. Results. Outcomes were assessed in 52 male patients with HH (hCG, n = 4; T, n = 48) after a mean treatment duration of 13.4 (testosterone) and 13.8 months (hCG; P = .79). Final MTV was higher with hCG (8.25 mL) than testosterone (3.4 mL; P < .001). The groups did not differ in penile length, growth velocity, or testosterone levels. Survey results showed that more than half the providers were aware of the benefits of gonadotropins, however, 91% were uncomfortable prescribing hCG. Commonly reported barriers to prescribing hCG were lack of experience (62%) and insurance coverage concerns (52%). Conclusions. Larger testicular volume predicts faster induction of spermatogenesis. Since hCG promoted better testicular growth, compared to testosterone, it may potentially improve future fertility outcomes in HH patients. Our results identify an opportunity to improve current practice among pediatric endocrinologists worldwide and reduce barriers to prescribing gonadotropins in the adolescent population.

The National Spina Bifida Patient Registry: A Decade's journey.

BACKGROUND: The National Spina Bifida Patient Registry (NSBPR) was established in 2008, as a partnership between the CDC and spina bifida (SB) clinics throughout the United States. The purpose of this study is to explore the initial work of this project through a literature review of published studies from the NSBPR and provide a description of how this body of literature has developed overtime. METHODS: We included studies indexed in MEDLINE by means of PubMed from January 2009 through April 2018. Included articles were appraised to identify key themes relevant to SB demographics, interventions, and outcomes. Additionally, information regarding objectives, hypotheses, and results of each study was summarized. RESULTS: We identified 13 articles meeting inclusion criteria. These publications described findings or explored associations using NSBPR variables. They were grouped into four categories: general characteristics (4 studies), mobility and skin injury (2 studies), bowel continence (3 studies), and bladder continence (5 studies). CONCLUSIONS: The NSBPR represents one of the largest described clinical samples of individuals living with SB. The first decade of studies have focused primarily on descriptive analyses and on identifying predictors of clinical outcomes. These initial results may help develop interventions (including culturally appropriate initiatives), be a resource for developing international evidence-based standards of care and best-practices, and lead to improved outcomes for individuals living with SB globally. Additionally, the results underscore the strengths of the NSBPR's design and highlight the potential breadth of research topics that could be addressed in the future.

Surgical interventions and anesthesia in the 1st year of life for lower urinary tract obstruction.

BACKGROUND: Patients with a prenatal diagnosis of lower urinary tract obstruction (LUTO) may undergo prenatal interventions, such as vesicoamniotic shunt (VAS) placement, as a temporary solution for relieving urinary tract obstruction. A recent FDA communication has raised awareness of the potential neurocognitive adverse effects of anesthesia in children. We hypothesized as to whether a prenatal LUTO staging system was predictive of the number of anesthesia events for prenatally diagnosed LUTO patients. METHODS: We retrospectively reviewed the prenatal and postnatal clinical records for patients with prenatally diagnosed LUTO from 2012 to 2015. Patients were stratified by prenatal VAS status and by LUTO disease severity according to Ruano et al. (Ultrasound Obstet Gynecol. 2016). RESULTS: 31 patients were identified with a prenatal LUTO diagnosis, and postnatal records were available for 21 patients (seven patients in each stage). When combining prenatal and postnatal anesthesia, there was a significant difference in the number of anesthesia encounters by stage (1.6, 3.7, and 6.7 for Stage I, II, and III respectively, p = .034). Upon univariate analysis, higher gestational age (GA) at birth was associated with a decreased number of anesthesia events in the first year (p = .031). CONCLUSIONS: The majority of infants with prenatally diagnosed LUTO will undergo postnatal procedures with general anesthesia exposure in the first year of life. Patients with higher prenatal LUTO severity experienced a higher number of both prenatal and postnatal anesthesia encounters. In addition, higher GA at birth was associated with fewer anesthesia encounters in the first year. LEVEL OF EVIDENCE: This is a prognostic study with Level IV evidence.

Evaluating Outcomes of Differential Surgical Management of Nonfunctioning Upper Pole Renal Moieties in Duplex Collecting Systems.

OBJECTIVE: To evaluate the management and clinical outcomes of nonfunctioning upper pole moieties treated with either upper pole heminephrectomy or upper pole preservation with lower ureteral reconstruction at a single tertiary institution. METHODS: After Institutional Review Board (IRB) approval, patients with duplicated systems undergoing upper pole heminephrectomy, ureteroureterostomy, or common sheath ureteral reimplantation from 2012-2017 were identified. Only patients with a nonfunctioning upper pole moiety on ultrasound or renal scan were included. Patients undergoing upper pole heminephrectomy were compared to those undergoing upper pole preservation with respect to demographics, anatomic variations preoperatively, and postoperative outcomes. RESULTS: Twenty-seven (57%) patients underwent upper pole preservation with lower ureteral reconstruction; 20 (43%) patients underwent upper pole heminephrectomy. Patients undergoing lower ureteral reconstruction were older (1.63 vs 2.76 years, P = .018) and more commonly presented with lower pole vesicoureteral reflux (67% vs 25%, P = .008). No significant difference in postoperative complications was seen between the two groups. After ureteroureterostomy, one patient developed new onset symptomatic reflux to the upper pole requiring intravesical reimplantation. In the heminephrectomy group, 4 of 11 patients with ureteroceles had ureterocelectomy with concomitant lower pole reimplantation. After heminephrectomy, two additional patients required further interventions: ureterocele excision and transurethral polyp excision. CONCLUSION: For patients with nonfunctional upper poles, lower tract reconstruction is a safe alternative to upper pole heminephrectomy. No significant difference in outcomes was seen. Considering that nearly 1 of 3 of patients with upper pole heminephrectomy required additional lower urinary tract procedures, pursuing upper pole preservation with lower urinary tract reconstruction may be favorable.

Vesicoamniotic Shunting Improves Outcomes in a Subset of Prune Belly Syndrome Patients at a Single Tertiary Center.

Objective: Review outcomes of Prune Belly Syndrome (PBS) with the hypothesis that contemporary management improves mortality. Methods: A retrospective chart review of inpatient and outpatient PBS patients referred between 2000 and 2018 was conducted to assess outcomes at our institution. Data collected included age at diagnosis, concomitant medical conditions, imaging, operative management, length of follow-up, and renal function. Results: Forty-five PBS patients presented during these 18 years. Prenatal diagnoses were made in 17 (39%); 65% of these patients underwent prenatal intervention. The remaining patients were diagnosed in the infant period (20, 44%) or after 1 year of age (8, 18%). Twelve patients died from cardiopulmonary complications in the neonatal period; the neonatal mortality rate was 27%. The mean follow-up among patients surviving the neonatal period was 84 months. Forty-two patients had at least one renal ultrasound (RUS); of the 30 patients with NICU RUSs, 26 (89%) had hydronephrosis and/or ureterectasis. Of the 39 patients who underwent voiding cystourethrogram (VCUG), 28 (62%) demonstrated VUR. Fifty-nine percent had respiratory distress. Nine patients (20%) were oxygen-dependent by completion of follow up. Thirty-eight patients (84%) had other congenital malformations including genitourinary (GU) 67%, gastrointestinal (GI) 52%, and cardiac 48%. Sixteen patients (36%) had chronic kidney disease (CKD) of at least stage 3; three patients (7%) had received renal transplants. Eighty-four percent of patients had at least one surgery (mean 3.4, range 0-6). The most common was orchiopexy (71%). The next most common surgeries were vesicostomy (39%), ureteral reimplants (32%), abdominoplasty (29%), nephrectomy (25%), and appendicovesicostomy (21%). After stratifying patients according to Woodard classification, a trend for 12% improvement in mortality after VAS was noted in the Woodard Classification 1 cohort. Conclusions: PBS patients frequently have multiple congenital anomalies. Pulmonary complications are prevalent in the neonate while CKD (36%) is prevalent during late childhood. The risk of CKD increased significantly with the presence of other congenital anomalies in our cohort. Mortality in childhood is most common in infancy and may be as low as 27%. Contemporary management of PBS, including prenatal interventions, reduced the neonatal mortality rate in a subset of our cohort.

Corrigendum: Vesicoamniotic Shunting Improves Outcomes in a Subset of Prune Belly Syndrome Patients at a Single Tertiary Center.

[This corrects the article DOI: 10.3389/fped.2018.00180.].

Evaluating Natural History and Follow Up Strategies for Non-obstructive Urolithiasis in Pediatric Population.

Objective: While small non-obstructive stones in the adult population are usually observed with minimal follow-up, the same guidelines for management in the pediatric population have not been well-studied. We evaluate the clinical outcomes of small non-obstructing kidney stones in the pediatric population to better define the natural history of the disease. Methods: In this IRB-approved retrospective study, patients with a diagnosis of kidney stones from January 2011 to March 2017 were identified using ICD9 and ICD10 codes. Patients with ureteral stones, obstruction, or stones >5 mm in size were excluded. Patients with no follow-up after initial imaging were also excluded. Patients with a history of stones or prior stone interventions were included in our population. Frequency of follow-up ultrasounds while on observation were noted and any ER visits, stone passage episodes, infections, and surgical interventions were documented. Results: Over the 6-year study period, 106 patients with non-obstructing kidney stones were identified. The average age at diagnosis was 12.5 years and the average stone size was 3.6 mm. Average follow-up was 17 months. About half of the patients had spontaneous passage of stones (54/106) at an average time of 13 months after diagnosis. Stone location did not correlate with spontaneous passage rates. Only 6/106 (5.7%) patients required stone surgery with ureteroscopy and/or PCNL at an average time of 12 months after initial diagnosis. The indication for surgery in all 6 cases was pain. 17/106 (16%) patients developed febrile UTIs and a total of 43 ER visits for stone-related issues were noted, but no patients required urgent intervention for an infected obstructing stone. Median interval for follow-up was every 6 months with renal ultrasounds, which then was prolonged to annual follow up in most cases. Conclusions: The observation of pediatric patients with small non-obstructing stones is safe with no episodes of acute obstructive pyelonephritis occurring in these patients. The sole indication for intervention in our patient population was pain, which suggests that routine follow-up ultrasounds may not be necessary for the follow-up of pediatric non-obstructive renal stones ≤5 mm in size.

Early postnatal bladder function in fetoscopic myelomeningocele repair patients.

PURPOSE: Prenatal repair of myelomeningocele (MMC) via hysterotomy has demonstrated neurosurgical and motor benefits, when compared to postnatal repairs. Urologic benefits, however, remain to be seen. The purpose of this study was to review early postnatal bladder function in patients undergoing a novel endoscopic approach for MMC repair using an exteriorized uterus. METHODS: A prospective urologic assessment of patients undergoing fetoscopic MMC repair and receiving subsequent care at our facility, was performed. Patients were managed and urodynamic studies risk-stratified according to the Centers for Disease Control and Prevention Urologic and Renal Protocol for the Newborn and Young Child with Spina Bifida. RESULTS: Fetoscopic MMC repair was performed in 14 patients. No patients had hydronephrosis or bladder thickening at birth. Detrusor overactivity was observed in nine (64.3%) patients. Impaired compliance was seen in eight (57.1%) patients. No patients had a detrusor leak point pressure of > 40 cm H2O or evidence of detrusor sphincter dyssynergia. Three (21.4%) patients had vesicoureteral reflux, seven (50.0%) had an open bladder neck, and none had trabeculated bladders. CONCLUSION: In this early experience with fetoscopic MMC repair, postnatal bladder function does not appear to be any worse than that of previously reported prenatal or postnatal closures.

Inosine Improves Neurogenic Detrusor Overactivity following Spinal Cord Injury.

Neurogenic detrusor overactivity and the associated loss of bladder control are among the most challenging complications of spinal cord injury (SCI). Anticholinergic agents are the mainstay for medical treatment of detrusor overactivity. However, their use is limited by significant side effects such that a search for new treatments is warranted. Inosine is a naturally occurring purine nucleoside with neuroprotective, neurotrophic and antioxidant effects that is known to improve motor function in preclinical models of SCI. However, its effect on lower urinary tract function has not been determined. The objectives of this study were to determine the effect of systemic administration of inosine on voiding function following SCI and to delineate potential mechanisms of action. Sprague-Dawley rats underwent complete spinal cord transection, or cord compression by application of an aneurysm clip at T8 for 30 sec. Inosine (225 mg/kg) or vehicle was administered daily via intraperitoneal injection either immediately after injury or after a delay of 8 wk. At the end of treatment, voiding behavior was assessed by cystometry. Levels of synaptophysin (SYP), neurofilament 200 (NF200) and TRPV1 in bladder tissues were measured by immunofluorescence imaging. Inosine administration decreased overactivity in both SCI models, with a significant decrease in the frequency of spontaneous non-voiding contractions during filling, compared to vehicle-treated SCI rats (p<0.05), including under conditions of delayed treatment. Immunofluorescence staining demonstrated increased levels of the pan-neuronal marker SYP and the Adelta fiber marker NF200, but decreased staining for the C-fiber marker, TRPV1 in bladder tissues from inosine-treated rats compared to those from vehicle-treated animals, including after delayed treatment. These findings demonstrate that inosine prevents the development of detrusor overactivity and attenuates existing overactivity following SCI, and may achieve its effects through modulation of sensory neurotransmission.

The use of bi-layer silk fibroin scaffolds and small intestinal submucosa matrices to support bladder tissue regeneration in a rat model of spinal cord injury.

Adverse side-effects associated with enterocystoplasty for neurogenic bladder reconstruction have spawned the need for the development of alternative graft substitutes. Bi-layer silk fibroin (SF) scaffolds and small intestinal submucosa (SIS) matrices were investigated for their ability to support bladder tissue regeneration and function in a rat model of spinal cord injury (SCI). Bladder augmentation was performed with each scaffold configuration in SCI animals for 10 wk of implantation and compared to non-augmented control groups (normal and SCI alone). Animals subjected to SCI alone exhibited a 72% survival rate (13/18) while SCI rats receiving SIS and bi-layer SF scaffolds displayed respective survival rates of 83% (10/12) and 75% (9/12) over the course of the study period. Histological (Masson's trichrome analysis) and immunohistochemical (IHC) evaluations demonstrated both implant groups supported de novo formation of smooth muscle layers with contractile protein expression [α-smooth muscle actin (α-SMA) and SM22α] as well as maturation of multi-layer urothelia expressing cytokeratin (CK) and uroplakin 3A proteins. Histomorphometric analysis revealed bi-layer SF and SIS scaffolds respectively reconstituted 64% and 56% of the level of α-SMA+ smooth muscle bundles present in SCI-alone controls, while similar degrees of CK+ urothelium across all experimental groups were detected. Parallel evaluations showed similar degrees of vascular area and synaptophysin+ boutons in all regenerated tissues compared to SCI-alone controls. In addition, improvements in certain urodynamic parameters in SCI animals, such as decreased peak intravesical pressure, following implantation with both matrix configurations were also observed. The data presented in this study detail the ability of acellular SIS and bi-layer SF scaffolds to support formation of innervated, vascularized smooth muscle and urothelial tissues in a neurogenic bladder model.

Bladder tissue regeneration using acellular bi-layer silk scaffolds in a large animal model of augmentation cystoplasty.

Acellular scaffolds derived from Bombyx mori silk fibroin were investigated for their ability to support functional tissue regeneration in a porcine model of augmentation cystoplasty. Two bi-layer matrix configurations were fabricated by solvent-casting/salt leaching either alone (Group 1) or in combination with silk film casting (Group 2) to yield porous foams buttressed by heterogeneous surface pore occlusions or homogenous silk films, respectively. Bladder augmentation was performed with each scaffold group (6 × 6 cm(2)) in juvenile Yorkshire swine for 3 m of implantation. Augmented animals exhibited high rates of survival (Group 1: 5/6, 83%; Group 2: 4/4, 100%) and voluntary voiding over the course of the study period. Urodynamic evaluations demonstrated mean increases in bladder capacity over pre-operative levels (Group 1: 277%; Group 2: 153%) which exceeded nonsurgical control gains (144%) encountered due to animal growth.In addition, animals augmented with both matrix configurations displayed increases in bladder compliance over pre-operative levels(Group 1: 357%; Group 2: 338%) similar to growth-related elevations observed in non-surgical controls (354%) [corrected]. Gross tissue evaluations revealed that both matrix configurations supported extensive de novo tissue formation throughout the entire original implantation site which exhibited ultimate tensile strength similar to nonsurgical counterparts. Histological and immunohistochemical analyses showed that both implant groups promoted comparable extents of smooth muscle regeneration and contractile protein (α-smooth muscle actin and SM22α) expression within defect sites similar to controls. Parallel evaluations demonstrated the formation of a transitional, multi-layered urothelium with prominent cytokeratin, uroplakin, and p63 protein expression in both matrix groups. De novo innervation and vascularization processes were evident in all regenerated tissues indicated by synaptophysin-positive neuronal cells and vessels lined with CD31 expressing endothelial cells. Ex vivo organ bath studies demonstrated that regenerated tissues supported by both silk matrices displayed contractile responses to carbachol, α,ß-methylene-ATP, KCl, and electrical field stimulation similar to controls. Our data detail the ability of acellular silk scaffolds to support regeneration of innervated, vascularized smooth muscle and urothelial tissues within 3 m with structural, mechanical, and functional properties comparable to native tissue in a porcine model of bladder repair.

Evaluation of biomaterials for bladder augmentation using cystometric analyses in various rodent models.

Renal function and continence of urine are critically dependent on the proper function of the urinary bladder, which stores urine at low pressure and expels it with a precisely orchestrated contraction. A number of congenital and acquired urological anomalies including posterior urethral valves, benign prostatic hyperplasia, and neurogenic bladder secondary to spina bifida/spinal cord injury can result in pathologic tissue remodeling leading to impaired compliance and reduced capacity(1). Functional or anatomical obstruction of the urinary tract is frequently associated with these conditions, and can lead to urinary incontinence and kidney damage from increased storage and voiding pressures(2). Surgical implantation of gastrointestinal segments to expand organ capacity and reduce intravesical pressures represents the primary surgical treatment option for these disorders when medical management fails(3). However, this approach is hampered by the limitation of available donor tissue, and is associated with significant complications including chronic urinary tract infection, metabolic perturbation, urinary stone formation, and secondary malignancy(4,5). Current research in bladder tissue engineering is heavily focused on identifying biomaterial configurations which can support regeneration of tissues at defect sites. Conventional 3-D scaffolds derived from natural and synthetic polymers such as small intestinal submucosa and poly-glycolic acid have shown some short-term success in supporting urothelial and smooth muscle regeneration as well as facilitating increased organ storage capacity in both animal models and in the clinic(6,7). However, deficiencies in scaffold mechanical integrity and biocompatibility often result in deleterious fibrosis(8), graft contracture(9), and calcification(10), thus increasing the risk of implant failure and need for secondary surgical procedures. In addition, restoration of normal voiding characteristics utilizing standard biomaterial constructs for augmentation cystoplasty has yet to be achieved, and therefore research and development of novel matrices which can fulfill this role is needed. In order to successfully develop and evaluate optimal biomaterials for clinical bladder augmentation, efficacy research must first be performed in standardized animal models using detailed surgical methods and functional outcome assessments. We have previously reported the use of a bladder augmentation model in mice to determine the potential of silk fibroin-based scaffolds to mediate tissue regeneration and functional voiding characteristics.(11,12) Cystometric analyses of this model have shown that variations in structural and mechanical implant properties can influence the resulting urodynamic features of the tissue engineered bladders(11,12). Positive correlations between the degree of matrix-mediated tissue regeneration determined histologically and functional compliance and capacity evaluated by cystometry were demonstrated in this model(11,12). These results therefore suggest that functional evaluations of biomaterial configurations in rodent bladder augmentation systems may be a useful format for assessing scaffold properties and establishing in vivo feasibility prior to large animal studies and clinical deployment. In the current study, we will present various surgical stages of bladder augmentation in both mice and rats using silk scaffolds and demonstrate techniques for awake and anesthetized cystometry.