Characterizing psychosocial services in a pediatric urology practice

INTRODUCTION

Psychosocial needs, which encompass behavioral health and social determinants of health (SDOH), are important mediators of the patient experience and health outcomes. However, many practices have limited experience with systematically assessing the non-billable psychosocial services provided to patients and families.

OBJECTIVE

To characterize the non-billable activities of three psychosocial providers in a pediatric urology practice at a freestanding children's hospital.

STUDY DESIGN

Following Institutional Review Board approval, an adapted version of the Care Coordination Measurement Tool (CCMT) was used to collect data prospectively on non-billable activities performed by a psychologist, social worker (SW), and certified child life specialist (CCLS) in a pediatric urology department. Variables included activity type, time spent per activity, and outcomes affected. Demographic data included age, sex, race, state, zip code, insurance type, and language.

RESULTS

From April to October 2022, 3096 activities were performed in support of psychosocial needs over 947 encounters for 527 patients. The median patient age was 9.2 years (IQR 4.8-12.4); 48.4 % were male. The psychosocial providers most commonly identified care coordination needs related to delivery of urologic care (73.4 %), mental/behavioral/developmental health (29.1 %), and referral and appointment management (19.9 %). The largest proportion of time was spent on providing direct psychosocial support (45.9 %), consisting of psychosocial assessments, education, and other behavioral health interventions. A large proportion of time was also spent on care coordination activities, namely logistics and navigation support (35.9 %). Relative time allocation across activities varied by provider type (p < 0.001); care coordination constituted 64.2 % of non-billable activities for the psychologist, 57.8 % for the SW, and 12.3 % for the CCLS. Activities were associated with treatment plan modification in 37.7 % (n = 357), outpatient coordination in 22.5 % (n = 213), and treatment plan adherence in 19.0 % (n = 180) of encounters.

DISCUSSION

This study enhances our understanding of psychosocial needs of patients in a pediatric urology practice by assessing non-billable psychosocial services not otherwise captured in the clinical workflow. In addition to direct psychosocial support, care coordination activities constitute a large proportion of such services. These data provide valuable insight into the range of activities necessary for the provision of specialty pediatric medical care.

CONCLUSION

Psychosocial providers in a pediatric urology practice perform many non-billable care coordination and psychosocial support activities. Characterizing these activities is important for beginning to understand patients' psychosocial needs and informing resource deployment.

Environmental Impact of a Pediatric and Young Adult Virtual Medicine Program: A Lesson from the COVID-19 Pandemic

OBJECTIVES

The Coronavirus Disease 2019 (COVID-19) pandemic led to the expansion of virtual medicine as a method to provide patient care. We aimed to determine the impact of pediatric and young adult virtual medicine use on fossil fuel consumption, greenhouse gas, and nongreenhouse traffic-related air pollutant emissions.

METHODS

We conducted a retrospective analysis of all virtual medicine patients at a single quaternary-care children's hospital with a geocoded address in the Commonwealth of Massachusetts prior to (March 16, 2019-March 15, 2020) and during the COVID-19 pandemic (March 16, 2020-March 15, 2021). Primary outcomes included patient travel distance, gasoline consumption, carbon dioxide and fine particulate matter emissions as well as savings in main hospital energy use.

RESULTS

There were 3,846 and 307,273 virtual visits performed with valid Massachusetts geocoded addresses prior to and during the COVID-19 pandemic, respectively. During 1 year of the pandemic, virtual medicine services resulted in a total reduction of 620,231 gallons of fossil fuel use and $1,620,002 avoided expenditure as well as 5,492.9 metric tons of carbon dioxide and 186.3 kg of fine particulate matter emitted. There were 3.1 million fewer kilowatt hours used by the hospital intrapandemic compared to the year prior. Accounting for equipment emissions, the combined intrapandemic emission reductions are equivalent to the electricity required by 1,234 homes for 1 year.

CONCLUSIONS

Widespread pediatric institutional use of virtual medicine provided environmental benefits. The true potential of virtual medicine for decreasing the environmental footprint of health care lies in scaling this mode of care to patient groups across the state and nation when medically feasible.

Robotic-assisted laparoscopic Malone appendicostomy: a 6-year perspective

PURPOSE

A robotic-assisted laparoscopic approach to appendicostomy offers the benefits of a minimally invasive approach to patients who would typically necessitate an open procedure, those with a larger body habitus, and those requiring combined complex colorectal and urologic reconstructive procedures. We present our experience performing robotic-assisted appendicostomies with a focus on patient selection, perioperative factors, and functional outcomes.

METHODS

A retrospective review of patients who underwent a robotic-assisted appendicostomy/neoappendicostomy at our institution was performed.

RESULTS

Twelve patients underwent robotic-assisted appendicostomy (n = 8) and neoappendicostomy (n = 4) at a range of 8.8-25.8 years. Five patients had a weight percentile > 50% for their age. Seven patients underwent combined procedures. Median operative time for appendicostomy/neoappendicostomy only was 185.0 min. Complications included surgical site infection (n = 3), stricture requiring minor operative revision (n = 2), conversion to an open procedure due to inadequate appendiceal length (prior to developing our technique for robotic neoappendicostomies; n = 1), and granuloma (n = 1). At a median follow-up of 10.8 months (range 1.7-74.3 months), 91.7% of patients were consistently clean with antegrade enemas.

DISCUSSION

Robotic-assisted laparoscopic appendicostomy and neoappendicostomy with cecal flap is a safe and effective operative approach. A robotic approach can potentially overcome the technical difficulties encountered in obese patients and can aid in patients requiring both a Malone and a Mitrofanoff in a single, combined minimally invasive procedure.

Patient Experience with Virtual Preoperative Consultations in Pediatric Surgical Specialties

BACKGROUND

A cross-sectional study was conducted to assess the comparative effectiveness of virtual visits for preoperative evaluation and surgical decision-making in three pediatric surgical subspecialties.

METHODS

Patients who underwent surgical procedures in the departments of Urology, Ophthalmology, and Plastic and Oral Surgery at a tertiary care pediatric hospital over a one-year period during the COVID-19 pandemic were included. Patients were assigned to one of three clinical pathways based on their preoperative visit(s): only in-person visit(s) (IP), a combination of in-person and virtual visit(s) (IP/VV), and only virtual visit(s) (VV). Demographics, procedure information, and patient experience survey results were collected. We then assessed variations in procedure types and patient experience scores in these three patient groups.

RESULTS

There were 431 patients who completed the modified patient experience survey. The most common procedures were circumcision (17%), excision of lesion (16%), and strabismus repair (11%). Survey results were positive, with 90% of participants rating that they would recommend the service to others. No significant differences were found among groups in their demographics, overall care rating, and duration between preoperative clinic visit and procedure. Post-hoc power analysis indicated 87% power to detect a 10% difference in survey ratings between IP and VV cases, confirming non-inferiority in patient satisfaction for virtual preoperative visits.

CONCLUSION

This study demonstrated the non-inferiority of preoperative virtual visits in three pediatric surgical subspecialties as measured by patient experience scores. Additional studies with more granular scope are necessary to further elucidate telemedicine's safety and efficacy for select diagnoses.

LEVEL OF EVIDENCE

III.

False-positive urine pregnancy screening tests are uncommon in the hospital setting among patients with bowel-containing urinary tract reconstruction

PURPOSE

False-positive urine pregnancy screening tests (UPST) have been reported among patients with bowel-containing urinary reconstruction (BCUR). However, the true frequency of such inaccurate results, which have been attributed to urinary mucous or other proteins interfering with or mimicking the binding of beta-HCG in the assay, is unknown in this population. We sought to determine the incidence of false-positive pregnancy screening tests among this patient population at our institution.

MATERIALS AND METHODS

Using existing databases of patients with spina bifida, bladder exstrophy, and genitourinary rhabdomyosarcoma, we identified female patients with BCUR who had UPST over a 10-year period as screening prior to procedures or imaging. Patient and test result information was recorded.

RESULTS

A total of 120 patients with a history of BCUR were identified: 33 with spina bifida, 73 within the exstrophy-epispadias complex (EEC), and 14 with genitourinary rhabdomyosarcoma. Of this group, 46 patients (38%) had at least one UPST during the study period; 15 had 1 UPST, 6 had 2 UPSTs, 4 had 3 UPSTs, and 21 had greater than 3 UPSTs, for a total of 244 UPST in this cohort. UPSTs used at our institution included Sure-Vue brand and Alere brand (HCG sensitivity 20 mIU/ml). Types of BCUR included ileal enterocystoplasty in 25 patients, colon enterocystoplasty in 6, stomach enterocystoplasty in 5, composite enterocystoplasty in 7, and continent catheterizable channel alone (e.g. Yang-Monti, appendicovesicostomy) in 3 patients. Of the 244 UPSTs in patients with BCUR, zero (0%) were positive.

CONCLUSIONS

Despite reports in the literature that false-positive UPST are common among patients with bowel-containing urinary diversions, we found no positive UPST among patients with BCUR in the healthcare setting. False-positive UPST in the home setting may be due to variability in sensitivity thresholds, binding agents, technical errors in test technique, kit quality control, or other factors.

Causes of death among people with myelomeningocele: A multi-institutional 47-year retrospective study

PURPOSE

This study aimed to analyze organ system-based causes and non-organ system-based mechanisms of death (COD, MOD) in people with myelomeningocele (MMC), comparing urological to other COD.

METHODS

A retrospective review was performed of 16 institutions in Canada/United States of non-random convenience sample of people with MMC (born > = 1972) using non-parametric statistics.

RESULTS

Of 293 deaths (89% shunted hydrocephalus), 12% occurred in infancy, 35% in childhood, and 53% in adulthood (documented COD: 74%). For 261 shunted individuals, leading COD were neurological (21%) and pulmonary (17%), and leading MOD were infections (34%, including shunt infections: 4%) and non-infectious shunt malfunctions (14%). For 32 unshunted individuals, leading COD were pulmonary (34%) and cardiovascular (13%), and leading MOD were infections (38%) and non-infectious pulmonary (16%). COD and MOD varied by shunt status and age (p < = 0.04), not ambulation or birthyear (p > = 0.16). Urology-related deaths (urosepsis, renal failure, hematuria, bladder perforation/cancer: 10%) were more likely in females (p = 0.01), independent of age, shunt, or ambulatory status (p > = 0.40). COD/MOD were independent of bladder augmentation (p = >0.11). Unexplained deaths while asleep (4%) were independent of age, shunt status, and epilepsy (p >= 0.47).

CONCLUSION

COD varied by shunt status. Leading MOD were infectious. Urology-related deaths (10%) were independent of shunt status; 26% of COD were unknown. Life-long multidisciplinary care and accurate mortality documentation are needed.

Hybrid Clinics: A New Model for Ambulatory Care to Reduce Infection Risk

Objectives: To assess the viability of a hybrid clinic model combining in-person examination with video-based consultation to minimize viral transmission risk. Methods: Data were collected prospectively in a pediatric urology clinic for in-person visits from January to April 2018 ("classic") and hybrid visits from October to December 2020 of the COVID-19 pandemic ("hybrid"). Variables included provider, diagnosis, patient type, time of day, prior surgery, postoperative status, and decision-making for surgery. The primary outcome was "room time" or time in-person. The secondary outcome was "total time" or visit duration. Proportion of visits involving close contact (room time ≥15 min) was assessed. Univariate analyses were performed using the Wilcoxon rank-sum test and Fisher's exact test. Mixed models were fitted for visit approach and other covariates as fixed effects and provider as random effect. Results: Data were collected for 346 visits (256 classic, 90 hybrid). Hybrid visits were associated with less room time (median 3 min vs. 10 min, p < 0.001) but greater total time (median 13.5 min vs. 10 min, p = 0.001) as compared with classic visits. On multivariate analysis, hybrid visits were associated with 3 min less room time (95% confidence intervals [CIs]: -5.3 to -1.7, p < 0.001) but 3.8 min more total time (95% CI: 1.5-6.1, p = 0.001). Close contact occurred in 6.7% of hybrid visits, as compared with 34.8% of classic visits (p < 0.001). Conclusions: Hybrid clinic visits reduce room time as compared with classic visits. This approach overcomes the examination limitations of telemedicine while minimizing viral transmission, and represents a viable model for ambulatory care whenever close contact carries infection risk.

Whole exome sequencing identifies potential candidate genes for spina bifida derived from mouse models

Spina bifida (SB) is the second most common nonlethal congenital malformation. The existence of monogenic SB mouse models and human monogenic syndromes with SB features indicate that human SB may be caused by monogenic genes. We hypothesized that whole exome sequencing (WES) allows identification of potential candidate genes by (i) generating a list of 136 candidate genes for SB, and (ii) by unbiased exome-wide analysis. We generated a list of 136 potential candidate genes from three categories and evaluated WES data of 50 unrelated SB cases for likely deleterious variants in 136 potential candidate genes, and for potential SB candidate genes exome-wide. We identified 6 likely deleterious variants in 6 of the 136 potential SB candidate genes in 6 of the 50 SB cases, whereof 4 genes were derived from mouse models, 1 gene was derived from human nonsyndromic SB, and 1 gene was derived from candidate genes known to cause human syndromic SB. In addition, by unbiased exome-wide analysis, we identified 12 genes as potential candidates for SB. Identification of these 18 potential candidate genes in larger SB cohorts will help decide which ones can be considered as novel monogenic causes of human SB.

The role of androgens in clitorophallus development and possible applications to transgender patients

BACKGROUND

The clitorophallus, or glans, is a critical structure in sexual development and plays an important role in how gender is conceptualized across the life span. This can be seen in both the evaluation and treatment of intersex individuals and the use of gender-affirming masculinizing therapies to help those born with a clitoris (small clitorophallus with separate urethra) enlarge or alter the function of that structure.

OBJECTIVES

To review the role of testosterone in clitorophallus development from embryo to adulthood, including how exogenous testosterone is used to stimulate clitorophallus enlargement in masculinizing gender-affirming therapy.

MATERIALS AND METHODS

Relevant English-language literature was identified and evaluated for data regarding clitorophallus development in endosex and intersex individuals and the utilization of hormonal and surgical masculinizing therapies on the clitorophallus. Studies included evaluated the spectrum of terms regarding the clitorophallus (genital tubercle, clitoris, micropenis, penis).

RESULTS

Endogenous testosterone, and its more active metabolite dihydrotestosterone, plays an important role in the development of the genital tubercle into the clitorophallus, primarily during the prenatal and early postnatal periods and then again during puberty. Androgens contribute to not only growth but also the inclusion of a urethra on the ventral aspect. Exogenous testosterone can be used to enlarge the small clitorophallus (clitoris or micropenis) as part of both intersex and gender-affirming care (in transmasculine patients, up to 2 cm of additional growth). Where testosterone is insufficient to provide the degree of masculinization desired, surgical options including phalloplasty and metoidioplasty are available.

DISCUSSION AND CONCLUSION

Endogenous testosterone plays an important role in clitorophallus development, and there are circumstances where exogenous testosterone may be useful for masculinization. Surgical options may also help some patients reach their personal goals. As masculinizing gender-affirming care advances, the options available for clitorophallus modifications will likely continue to expand and improve.

Anxiety, distress, and pain in pediatric urodynamics

AIMS

No one has assessed urodynamic studies (UDS) to determine those steps that elicit the greatest anxiety, distress, and pain in children. We sought to systematically evaluate a child's UDS experience to mollify these reactions.

METHODS

Prospective study involving children aged ≥5 undergoing UDS over a 6-month period (from 10 December 2018 to 22 May 2019). Upon arrival, patients completed a visual analog scale for anxiety (VAS-A, 0-10) about the upcoming procedure. A research assistant assessed the patient's behavior during each major step of UDS using a validated brief behavioral distress scale. Nursing staff also obtained patients' pain ratings (0-10) for these key elements. Immediately after UDS, each child completed a posttest VAS-A along with a survey about the UDS experience.

RESULTS

A total of 76 UDS were observed; almost half included sphincter needle electromyography (EMG). Mean patient VAS-A scores were 2.3 before UDS, compared to 0.8 afterward (P < .001). The highest proportion of distressful behaviors were observed during EMG needle (31%) and urethral catheter (29%) insertion, in agreement with the highest mean pain scores of 3.2 and 2.7, respectively. Fifty-four percent of children reported not being completely aware of what was going to happen before the procedure and 50% of those patients exhibited at least one interfering or potentially interfering behavior. Similarly, 60% of children with no prior history of UDS exhibited at least one interfering or potentially interfering behavior.

CONCLUSIONS

EMG needle and urethral catheter placement, initial urodynamic testing and not knowing what to expect were associated with greater pain and distress during pediatric UDS.

Augmentation Cystoplasty of Diseased Porcine Bladders with Bi-Layer Silk Fibroin Grafts

IMPACT STATEMENT

The search for an ideal "off-the-shelf" biomaterial for augmentation cystoplasty remains elusive and current scaffold configurations are hampered by mechanical and biocompatibility restrictions. In addition, preclinical evaluations of potential scaffold designs for bladder repair are limited by the lack of tractable large animal models of obstructive bladder disease that can mimic clinical pathology. The results of this study describe a novel, minimally invasive, porcine model of partial bladder outlet obstruction that simulates clinically relevant phenotypes. Utilizing this model, we demonstrate that acellular, bi-layer silk fibroin grafts can support the formation of vascularized, innervated bladder tissues with functional properties.

Advances in paediatric urology

Paediatric urological surgery is often required for managing congenital and acquired disorders of the genitourinary system. In this Series paper, we highlight advances in the surgical management of six paediatric urological disorders. The management of vesicoureteral reflux is evolving, with advocacy ranging from a less interventional assessment and antimicrobial prophylaxis to surgery including endoscopic injection of a bulking agent and minimally invasive ureteric reimplantation. Evidence supports early orchidopexy to improve fertility and reduce malignancy in boys with undescended testes. A variety of surgical techniques have been developed for hypospadias, with excellent outcomes for distal but not proximal hypospadias. Pelvi-ureteric junction obstruction is mostly detected prenatally; indications for surgery have been refined with evidence, and minimally invasive pyeloplasty is now standard. The outlook for patients with neurogenic bladder has been transformed by a combination of clean intermittent catheterisation, algorithms of diagnostic investigations, and innovative medical and surgical therapies. Posterior urethral valves are associated with considerable mortality; fetal diagnosis allows stratification of candidates for intervention, but ongoing bladder dysfunction in patients after valve ablation remains a cause of long-term morbidity.

Bilayer silk fibroin grafts support functional oesophageal repair in a rodent model of caustic injury

Surgical repair of caustic oesophageal injuries with autologous gastrointestinal segments is often associated with dysmotility, dysphagia and donor site morbidity, and therefore alternative graft options are needed. Bilayer silk fibroin (BLSF) scaffolds were assessed for their ability to support functional restoration of damaged oesophageal tissues in a rat model of onlay oesophagoplasty. Transient exposure of isolated oesophageal segments with 40% NaOH led to corrosive oesophagitis and a 91% reduction in the luminal cross-sectional area of damaged sites. Oesophageal repair with BLSF matrices was performed in injured rats (n = 27) as well as a nondiseased cohort (n = 12) for up to 2 months after implantation. Both implant groups exhibited >80% survival rates, displayed similar degrees of weight gain, and were capable of solid food consumption following a 3-day liquid diet. End-point μ-computed tomography of repaired sites demonstrated a 4.5-fold increase in luminal cross-sectional area over baseline injury levels. Reconstructed oesophageal conduits from damaged and nondiseased animals produced comparable contractile responses to KCl and electric field stimulation while isoproterenol generated similar tissue relaxation responses. Histological and immunohistochemical evaluations of neotissues from both implant groups showed formation of a stratified, squamous epithelium with robust cytokeratin expression as well as skeletal and smooth muscle layers positive for contractile protein expression. In addition, synaptophysin positive neuronal junctions and vessels lined with CD31 positive endothelial cells were also observed at graft sites in each setting. These results provide preclinical validation for the use of BLSF scaffolds in reconstructive strategies for oesophageal repair following caustic injury.

Bi-layer silk fibroin grafts support functional tissue regeneration in a porcine model of onlay esophagoplasty

Partial circumferential, full thickness defects of the esophagus can occur as a result of organ perforation or tumour resection, or during surgical reconstruction of strictured segments. Complications associated with autologous tissue flaps conventionally utilized for defect repair necessitate the development of new graft options. In this study, bi-layer silk fibroin (BLSF) scaffolds were investigated for their potential to support functional restoration of partial circumferential defects in a porcine model of esophageal repair. Onlay thoracic esophagoplasty with BLSF matrices (~3 x 1.5 cm) was performed in adult swine (N = 6) for 3 months of implantation. All animals receiving BLSF grafts survived with no complications and were capable of solid food consumption. Radiographic esophagrams revealed preservation of organ continuity with no evidence of contrast extravasation or strictures. Fluoroscopic analysis demonstrated peristaltic contractions. Ex vivo tissue bath studies displayed contractile responses to carbachol, electric field stimulation, and KCl while isoproterenol produced tissue relaxation. Histological and immunohistochemical evaluations of neotissues showed a stratified, squamous epithelium, a muscularis mucosa composed of smooth muscle bundles, and a muscularis externa organized into circular and longitudinal layers, with a mix of striated skeletal muscle fascicles interspersed with smooth muscle. De novo innervation and vascularization were observed throughout the graft sites and consisted of synaptophysin-positive neuronal boutons and vessels lined with CD31-positive endothelial cells. The results of this study demonstrate that BLSF scaffolds can facilitate constructive remodeling of partial circumferential, full thickness esophageal defects in a large animal model. Copyright © 2017 John Wiley & Sons, Ltd.

Robotic-assisted laparoscopic bladder augmentation in the pediatric patient

INTRODUCTION

Bladder augmentation is a common surgical intervention for neuropathic bladder dysfunction, and has conventionally been an open procedure. We present a robotic ileocystoplasty to demonstrate the feasibility of an entirely intracorporeal approach in a pediatric patient.

METHODS

The patient was a 6 year old (18.5 kg) boy with a neurogenic bladder secondary to lumbar myelomeningocele. Urodynamics revealed a small capacity and poorly compliant bladder and he was incontinent between frequent catheterizations. A robotic augmentation cystoplasty was performed.

RESULTS

At one-month postoperatively, a cystogram revealed no urine leak, and the suprapubic tube was removed. The patient resumed CIC every 3 h during the day and once overnight until postoperative urodynamic studies confirmed safe dynamics, after which the CIC interval was lengthened.

CONCLUSION

Robotic bladder augmentation is safe and feasible in a select pediatric population. The entire procedure including preparation of the bowel segment can be completed intracorporeally, even in smaller children.

Silk Fibroin Scaffolds for Urologic Tissue Engineering

Urologic tissue engineering efforts have been largely focused on bladder and urethral defect repair. The current surgical gold standard for treatment of poorly compliant pathological bladders and severe urethral stricture disease is enterocystoplasty and onlay urethroplasty with autologous tissue, respectively. The complications associated with autologous tissue use and harvesting have led to efforts to develop tissue-engineered alternatives. Natural and synthetic materials have been used with varying degrees of success, but none has proved consistently reliable for urologic tissue defect repair in humans. Silk fibroin (SF) scaffolds have been tested in bladder and urethral repair because of their favorable biomechanical properties including structural strength, elasticity, biodegradability, and biocompatibility. SF scaffolds have been used in multiple animal models and have demonstrated robust regeneration of smooth muscle and urothelium. The pre-clinical data involving SF scaffolds in urologic defect repair are encouraging and suggest that they hold potential for future clinical use.

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 effect of spinal cord level on sexual function in the spina bifida population

INTRODUCTION

Sexual dysfunction and infertility are prevalent in the spina bifida (SB) population; however, the mechanism of how they affect a person with spina bifida is poorly understood. Additionally, the management of children with spina bifida becomes more difficult as they exit from pediatric institutes.

OBJECTIVE

The present study sought to evaluate sexual health (using validated questionnaires) and fertility in adults with spina bifida and to correlate spinal cord level and ambulatory status with degree of sexual function.

STUDY DESIGN

After institutional board review approval, 199 adult patients with SB, aged 18 and older and who were followed in one pediatric institution, were identified. Patients who were non-English speaking, cognitively and/or developmentally delayed, or unable to be contacted were excluded. Surveys regarding demographics, sexual health and infertility were mailed to the patients and administered in the clinic with the option to opt-out of the survey. Survey questions regarding sexual health were constructed using validated questionnaires: Female Sexual Function Index (FSFI) for females, and International Index of Erectile Function (IIEF) and Sexual Health Inventory for Men (SHIM) for males. Sexual dysfunction scores were correlated to the patients' spinal level and ambulatory status.

RESULTS

Of the 121 eligible patients, 45 replied, with a response rate of 39%. For females, using a cut-off value of 26.5 for FSFI scoring, 25 out of 28 (89%) had sexual dysfunction. No association was seen between spinal level or ambulatory status and overall FSFI, satisfaction, or desire scores. For males, 10 out of 17 (59%) had severe erectile dysfunction (ED), and one out of 17 (6%) had no ED. No association was seen between ambulatory status and sexual function scores for the males. However, SHIM, satisfaction, and ED scores were higher in males with lower spinal lesions. People with spina bifida of both genders tended to have more severe dysfunction compared to those with sexual dysfunction of other etiologies, except with similar sexual desire scores. Regarding questions on fertility, no participant attempted to have children; thus, there was no infertility reported.

DISCUSSION

Few studies have been conducted on sexual health and fertility in adults with SB. Three studies have utilized validated questionnaires and found varying degrees of sexual dysfunction in this subset of patients; however, only one study found sexual activity to be more likely in patients with more caudal levels of neurologic impairment. The present study also showed that SHIM, satisfaction, and ED scores were higher in males with lower spinal lesions. Limitations to this study primarily included the small sample size and low survey response rate.

CONCLUSION

Limited information is known about adults with SB, and sexual function and fertility. While expressing sexual desire, adults with SB appear to experience high rates of sexual dysfunction. Fertility rates were inadequately assessed; this was possibly due to the high rate of sexual dysfunction. Sexual health in the SB population is an important component of the myriad of urologic care issues for these people. Due to the disparity in their care after reaching adulthood, it is prudent to follow these patients and understand their pathophysiology as they continue to mature through life.

Acellular bi-layer silk fibroin scaffolds support functional tissue regeneration in a rat model of onlay esophagoplasty

Surgical management of long-gap esophageal defects with autologous gastrointestinal tissues is frequently associated with adverse complications including organ dysmotility, dysphagia, and donor site morbidity. In order to develop alternative graft options, bi-layer silk fibroin (SF) scaffolds were investigated for their potential to support functional tissue regeneration in a rodent model of esophageal repair. Onlay esophagoplasty was performed with SF matrices (N = 40) in adult rats for up to 2 m of implantation. Parallel groups consisted of animals implanted with small intestinal submucosa (SIS) scaffolds (N = 22) or sham controls receiving esophagotomy alone (N = 20). Sham controls exhibited a 100% survival rate while rats implanted with SF and SIS scaffolds displayed respective survival rates of 93% and 91% prior to scheduled euthanasia. Animals in each experimental group were capable of solid food consumption following a 3 d post-op liquid diet and demonstrated similar degrees of weight gain throughout the study period. End-point μ-computed tomography at 2 m post-op revealed no evidence of contrast extravasation, fistulas, strictures, or diverticula in any of the implant groups. Ex vivo tissue bath studies demonstrated that reconstructed esophageal conduits supported by both SF and SIS scaffolds displayed contractile responses to carbachol, KCl and electrical field stimulation while isoproterenol produced tissue relaxation. Histological (Masson's trichrome and hematoxylin and eosin) and immunohistochemical (IHC) evaluations demonstrated both implant groups produced de novo formation of skeletal and smooth muscle bundles positive for contractile protein expression [fast myosin heavy chain (MY32) and α-smooth muscle actin (α-SMA)] within the graft site. However, SF matrices promoted a significant 4-fold increase in MY32+ skeletal muscle and a 2-fold gain in α-SMA+ smooth muscle in comparison to the SIS cohort as determined by histomorphometric analyses. A stratified squamous, keratinized epithelium expressing cytokeratin 5 and involucrin proteins was also present at 2 m post-op in all experimental groups. De novo innervation and vascularization were evident in all regenerated tissues indicated by the presence of synaptophysin (SYP38)+ boutons and vessels lined with CD31 expressing endothelial cells. In respect to SIS, the SF group supported a significant 4-fold increase in the density of SYP38+ boutons within the implant region. Evaluation of host tissue responses revealed that SIS matrices elicited chronic inflammatory reactions and severe fibrosis throughout the neotissues, in contrast to SF scaffolds. The results of this study demonstrate that bi-layer SF scaffolds represent promising biomaterials for onlay esophagoplasty, capable of producing superior regenerative outcomes in comparison to conventional SIS scaffolds.

In vitro evaluation of bi-layer silk fibroin scaffolds for gastrointestinal tissue engineering

Silk fibroin scaffolds were investigated for their ability to support attachment, proliferation, and differentiation of human gastrointestinal epithelial and smooth muscle cell lines in order to ascertain their potential for tissue engineering. A bi-layer silk fibroin matrix composed of a porous silk fibroin foam annealed to a homogeneous silk fibroin film was evaluated in parallel with small intestinal submucosa scaffolds. AlamarBlue analysis revealed that silk fibroin scaffolds supported significantly higher levels of small intestinal smooth muscle cell, colon smooth muscle cell, and esophageal smooth muscle cell attachment in comparison to small intestinal submucosa. Following 7 days of culture, relative numbers of each smooth muscle cell population maintained on both scaffold groups were significantly elevated over respective 1-day levels—indicative of cell proliferation. Real-time reverse transcription polymerase chain reaction and immunohistochemical analyses demonstrated that both silk fibroin and small intestinal submucosa scaffolds were permissive for contractile differentiation of small intestinal smooth muscle cell, colon smooth muscle cell, esophageal smooth muscle cell as determined by significant upregulation of α-smooth muscle actin and SM22α messenger RNA and protein expression levels following transforming growth factor-β1 stimulation. AlamarBlue analysis demonstrated that both matrix groups supported similar degrees of attachment and proliferation of gastrointestinal epithelial cell lines including colonic T84 cells and esophageal epithelial cells. Following 14 days of culture on both matrices, spontaneous differentiation of T84 cells toward an enterocyte lineage was confirmed by expression of brush border enzymes, lactase, and maltase, as determined by real-time reverse transcription polymerase chain reaction and immunohistochemical analyses. In contrast to small intestinal submucosa scaffolds, silk fibroin scaffolds supported spontaneous differentiation of esophageal epithelial cells toward a suprabasal cell lineage as indicated by significant upregulation of cytokeratin 4 and cytokeratin 13 messenger RNA transcript levels. In addition, esophageal epithelial cells maintained on silk fibroin scaffolds also produced significantly higher involucrin messenger RNA transcript levels in comparison to small intestinal submucosa counterparts, indicating an increased propensity for superficial, squamous cell specification. Collectively, these data provide evidence for the potential of silk fibroin scaffolds for gastrointestinal tissue engineering applications.

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.

Evaluation of a mobile voiding diary for pediatric patients with voiding dysfunction: a prospective comparative study

PURPOSE

One potential strategy for improving voiding diary completion rates and data quality is use of a mobile electronic format. We evaluated the acceptability and feasibility of mobile voiding diaries for patients with nonneurogenic lower urinary tract dysfunction, and compared mobile and paper voiding diaries.

MATERIALS AND METHODS

We prospectively enrolled children presenting with daytime symptoms of lower urinary tract dysfunction between July 2012 and April 2013. We enrolled an initial cohort of patients who were provided a paper voiding diary and a subsequent cohort who were provided a mobile voiding diary. We conducted in person interviews and assessed completion rates and quality, comparing paper and mobile voiding diary groups.

RESULTS

We enrolled 45 patients who received a paper voiding diary and 38 who received a mobile voiding diary. Completion rates were 78% for paper voiding diaries and 61% for mobile voiding diaries (p = 0.10). Data quality measures for patients completing paper vs mobile voiding diaries revealed a larger proportion (63% vs 52%) providing a full 5 days of data and a smaller proportion (20% vs 65%) with data gaps. However, the paper voiding diary also demonstrated a lower proportion (80% vs 100%) that was completely legible and a lower proportion (40% vs 65%) with completely prospective data entry.

CONCLUSIONS

The use of a mobile voiding diary was acceptable and feasible for our patients with lower urinary tract dysfunction, although completion rates were somewhat lower compared to paper voiding diaries. Data quality was not clearly better for either version. The mobile voiding diary format may offer data quality advantages for select groups but it did not display significant superiority when provided universally.

Multi-planar dynamic contrast-enhanced ultrasound assessment of blood flow in a rabbit model of testicular torsion

To assess correlation between multi-planar, dynamic contrast-enhanced ultrasound (US) blood flow measurements and radiolabeled microsphere blood flow measurements, five groups of six rabbits underwent unilateral testicular torsion of 0°, 180°, 360°, 540° or 720°. Five US measurements per testis (three transverse/two longitudinal) were obtained pre-operatively and immediately and 4 and 8 h post-operatively using linear transducers (7-4 MHz/center frequency 4.5 MHz/10 rabbits; 9-3 MHz/center frequency 5.5 MHz/20 rabbits). Björck's linear least-squares method fit the rise phase of mean pixel intensity over a 7-s period for each time curve. Slope of fit and intervention/control US pixel intensity ratios were calculated. Means of transverse, longitudinal and combined transverse/longitudinal US ratios as a function of torsion degree were compared with radiolabeled microsphere ratios using Pearson's correlation coefficient, ρ. There was high correlation between the two sets of ratios (ρ ≥ 0.88, p ≤ 0.05), except for the transverse US ratio in the immediate post-operative period (ρ = 0.79, p = 0.11). These results hold promise for future clinical applications.

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,β-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.

The performance of silk scaffolds in a rat model of augmentation cystoplasty

The diverse processing plasticity of silk-based biomaterials offers a versatile platform for understanding the impact of structural and mechanical matrix properties on bladder regenerative processes. Three distinct groups of 3-D matrices were fabricated from aqueous solutions of Bombyx mori silk fibroin either by a gel spinning technique (GS1 and GS2 groups) or a solvent-casting/salt-leaching method in combination with silk film casting (FF group). SEM analyses revealed that GS1 matrices consisted of smooth, compact multi-laminates of parallel-oriented silk fibers while GS2 scaffolds were composed of porous (pore size range, 5-50 μm) lamellar-like sheets buttressed by a dense outer layer. Bi-layer FF scaffolds were comprised of porous foams (pore size, ~400 μm) fused on their external face with a homogenous, nonporous silk film. Silk groups and small intestinal submucosa (SIS) matrices were evaluated in a rat model of augmentation cystoplasty for 10 weeks of implantation and compared to cystotomy controls. Gross tissue evaluations revealed the presence of intra-luminal stones in all experimental groups. The incidence and size of urinary calculi was the highest in animals implanted with gel spun silk matrices and SIS with frequencies ≥57% and stone diameters of 3-4 mm. In contrast, rats augmented with FF scaffolds displayed substantially lower rates (20%) and stone size (2 mm), similar to the levels observed in controls (13%, 2 mm). Histological (hematoxylin and eosin, Masson's trichrome) and immunohistochemical (IHC) analyses showed comparable extents of smooth muscle regeneration and contractile protein (α-smooth muscle actin and SM22α) expression within defect sites supported by all matrix groups similar to controls. Parallel evaluations demonstrated the formation of a transitional, multi-layered urothelium with prominent uroplakin and p63 protein expression in all experimental groups. De novo innervation and vascularization processes were evident in all regenerated tissues indicated by Fox3-positive neuronal cells and vessels lined with CD31 expressing endothelial cells. In comparison to other biomaterial groups, cystometric analyses at 10 weeks post-op revealed that animals implanted with the FF matrix configuration displayed superior urodynamic characteristics including compliance, functional capacity, as well as spontaneous non voiding contractions consistent with control levels. Our data demonstrate that variations in scaffold processing techniques can influence the in vivo functional performance of silk matrices in bladder reconstructive procedures.

Evaluation of silk biomaterials in combination with extracellular matrix coatings for bladder tissue engineering with primary and pluripotent cells

Silk-based biomaterials in combination with extracellular matrix (ECM) coatings were assessed as templates for cell-seeded bladder tissue engineering approaches. Two structurally diverse groups of silk scaffolds were produced by a gel spinning process and consisted of either smooth, compact multi-laminates (Group 1) or rough, porous lamellar-like sheets (Group 2). Scaffolds alone or coated with collagen types I or IV or fibronectin were assessed independently for their ability to support attachment, proliferation, and differentiation of primary cell lines including human bladder smooth muscle cells (SMC) and urothelial cells as well as pluripotent cell populations, such as murine embryonic stem cells (ESC) and induced pluripotent stem (iPS) cells. AlamarBlue evaluations revealed that fibronectin-coated Group 2 scaffolds promoted the highest degree of primary SMC and urothelial cell attachment in comparison to uncoated Group 2 controls and all Group 1 scaffold variants. Real time RT-PCR and immunohistochemical (IHC) analyses demonstrated that both fibronectin-coated silk groups were permissive for SMC contractile differentiation as determined by significant upregulation of α-actin and SM22α mRNA and protein expression levels following TGFβ1 stimulation. Prominent expression of epithelial differentiation markers, cytokeratins, was observed in urothelial cells cultured on both control and fibronectin-coated groups following IHC analysis. Evaluation of silk matrices for ESC and iPS cell attachment by alamarBlue showed that fibronectin-coated Group 2 scaffolds promoted the highest levels in comparison to all other scaffold formulations. In addition, real time RT-PCR and IHC analyses showed that fibronectin-coated Group 2 scaffolds facilitated ESC and iPS cell differentiation toward both urothelial and smooth muscle lineages in response to all trans retinoic acid as assessed by induction of uroplakin and contractile gene and protein expression. These results demonstrate that silk scaffolds support primary and pluripotent cell responses pertinent to bladder tissue engineering and that scaffold morphology and fibronectin coatings influence these processes.

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 capacity¹. 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 pressures². 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 fails³. 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 fibrosis⁸, graft contracture⁹, and calcification¹⁰, 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.

Contemporary use of nephron-sparing surgery for children with malignant renal tumors at freestanding children's hospitals

OBJECTIVE

It is widely accepted that, when feasible, nephron-sparing surgery (NSS) is preferable to radical nephrectomy (RN) for treatment of renal tumors in adults. However, RN is more frequently used in children. We sought to compare in-hospital outcomes after NSS and RN for malignant pediatric renal tumors.

MATERIAL AND METHODS

The pediatric health information system (PHIS) combines data from more than 40 North American pediatric hospitals. We queried PHIS to identify children with malignant renal tumors who underwent surgery from 2003 to 2009. We examined whether outcomes (complication rates, cost, and length of stay) differed by procedure type. Multivariate regression models were used to adjust for confounding, and generalized estimating equations were used to adjust for hospital clustering.

RESULTS

We identified 1235 children with renal tumors who underwent RN (91%) or NSS (9%). Patients undergoing RN and NSS had similar median comorbidity scores (P = .98), hospital lengths of stay (each 6.0 days, P = .54), in-hospital charges, ($25,700 vs $37,000, P = .11), and surgical complication rates (16.4 vs 20.5%, P = .24). These outcomes remained similar after adjusting for other patient and hospital factors.

CONCLUSIONS

Most children with malignant renal tumors treated at children's hospitals undergo RN. RN and NSS use were not significantly different in terms of their length of hospital stay, in-hospital charges, and complication rates. Although oncological outcomes are lacking, these data suggest that NSS may be performed in selected children with malignant renal tumors without significantly increasing their hospital charges, length of stay, or surgical complication rates.

The effect of manipulation of silk scaffold fabrication parameters on matrix performance in a murine model of bladder augmentation

Autologous gastrointestinal segments are utilized as the primary option for bladder reconstructive procedures despite their inherent morbidity and significant complication rate. Multi-laminate biomaterials derived from Bombyx mori silk fibroin and prepared from a gel spinning process may serve as a superior alternative for bladder tissue engineering due to their robust mechanical properties, biocompatibility, and processing plasticity. In the present study, we sought to determine the impact of variations in winding (axial slew rate: 2 and 40 mm/s) and post-winding (methanol and lyophilization) fabrication parameters on the in vivo performance of gel spun silk scaffolds in a murine model of bladder augmentation. Three silk matrix groups with distinct structural and mechanical properties were investigated following 10 weeks of implantation including our original prototype previously shown to support bladder regeneration, Group 1 (2 mm/s, methanol) as well as Group 2 (40 mm/s, methanol) and Group 3 (40 mm/s, lyophilization) configurations. Non surgical animals were assessed in parallel as controls. Quantification of residual scaffold area demonstrated that while Group 1 and 2 scaffolds were largely intact, processing parameters utilized for Group 3 led to significantly higher degrees of scaffold degradation in comparison to Group 1. Histological (hematoxylin and eosin, masson's trichrome) and immunohistochemical (IHC) analyses showed comparable extents of smooth muscle regeneration and contractile protein (α-smooth muscle actin and SM22α) expression within the original defect site throughout all matrix groups similar to controls. Parallel evaluations demonstrated transitional urothelial formation with prominent uroplakin and p63 protein expression supported by Group 1 and 3 scaffolds, while Group 2 variants supported a thin, immature epithelium composed primarily of uroplakin-negative, p63-positive basal cells. Voided stain on paper analysis revealed similar voiding patterns between all matrix groups; however Group 2 animals displayed substantially lower voided volumes with increased frequency in comparison to controls. In addition, cystometric assessments revealed all matrix groups supported comparable degrees of bladder compliance similar to control levels. The results of this study demonstrate that selective alterations in winding and post-winding fabrication parameters can enhance the degradation rate of gel spun silk scaffolds in vivo while preserving their ability to support bladder tissue regeneration and function.

Evaluation of gel spun silk-based biomaterials in a murine model of bladder augmentation

Currently, gastrointestinal segments are considered the gold standard for bladder reconstructive procedures. However, significant complications including chronic urinary tract infection, metabolic abnormalities, urinary stone formation, bowel dysfunction, and secondary malignancies are associated with this approach. Biomaterials derived from silk fibroin may represent a superior alternative due their robust mechanical properties, biodegradable features, and processing plasticity. In the present study, we evaluated the efficacy of a gel spun silk-based matrix for bladder augmentation in a murine model. Over the course of 70 d implantation period, H&E and Masson's trichrome (MTS) analysis revealed that silk matrices were capable of supporting both urothelial and smooth muscle regeneration at the defect site. Prominent uroplakin and contractile protein expression (α-actin, calponin, and SM22α) was evident by immunohistochemical analysis demonstrating maturation of the reconstituted bladder wall compartments. Gel spun silk matrices also elicited a minimal acute inflammatory reaction following 70 d of bladder integration, in contrast to parallel assessments of small intestinal submucosa (SIS) and poly-glycolic acid (PGA) matrices which routinely promoted evidence of fibrosis and chronic inflammatory responses. Voided stain on paper analysis revealed that silk augmented animals displayed similar voiding patterns in comparison to non surgical controls by 42 d of implantation. In addition, cystometric evaluations of augmented bladders at 70 d post-op demonstrated that silk scaffolds supported significant increases in bladder capacity and voided volume while maintaining similar degrees of compliance relative to the control group. These results provide evidence for the utility of gel spun silk-based matrices for functional bladder tissue engineering applications.

All-trans retinoic acid directs urothelial specification of murine embryonic stem cells via GATA4/6 signaling mechanisms

The urinary bladder and associated tract are lined by the urothelium, a transitional epithelium that acts as a specialized permeability barrier that protects the underlying tissue from urine via expression of a highly specific group of proteins known as the uroplakins (UP). To date, our understanding of the developmental processes responsible for urothelial differentiation has been hampered due to the lack of suitable models. In this study, we describe a novel in vitro cell culture system for derivation of urothelial cells from murine embryonic stem cells (ESCs) following cultivation on collagen matrices in the presence all trans retinoic acid (RA). Upon stimulation with micromolar concentrations of RA, ESCs significantly downregulated the pluripotency factor OCT-4 but markedly upregulated UP1A, UP1B, UP2, UP3A, and UP3B mRNA levels in comparison to naïve ESCs and spontaneously differentiating controls. Pan-UP protein expression was associated with both p63- and cytokeratin 20-positive cells in discrete aggregating populations of ESCs following 9 and 14 days of RA stimulation. Analysis of endodermal transcription factors such as GATA4 and GATA6 revealed significant upregulation and nuclear enrichment in RA-treated UP2-GFP+ populations. GATA4-/- and GATA6-/- transgenic ESC lines revealed substantial attenuation of RA-mediated UP expression in comparison to wild type controls. In addition, EMSA analysis revealed that RA treatment induced formation of transcriptional complexes containing GATA4/6 on both UP1B and UP2 promoter fragments containing putative GATA factor binding sites. Collectively, these data suggest that RA mediates ESC specification toward a urothelial lineage via GATA4/6-dependent processes.

Vesicoureteral reflux and urinary tract infection in children with a history of prenatal hydronephrosis--should voiding cystourethrography be performed in cases of postnatally persistent grade II hydronephrosis?

PURPOSE

The clinical relevance of prenatal hydronephrosis is not well-defined. We determined the risk of febrile urinary tract infection in the absence of screening for vesicoureteral reflux, and whether postnatal voiding cystourethrography should be performed in patients with a history of prenatal hydronephrosis and postnatally persistent Society for Fetal Urology grade II hydronephrosis.

MATERIALS AND METHODS

From a longitudinal database of patients with prenatal hydronephrosis maintained since 1998 we identified those with postnatally persistent grade II hydronephrosis. This cohort was divided into patients who were and were not screened with an initial voiding cystourethrogram. The rates of vesicoureteral reflux and development of febrile urinary tract infection were determined.

RESULTS

Of 2,076 patients with prenatal hydronephrosis 1,514 had grade II hydronephrosis. Of the patients 76% underwent an initial voiding cystourethrogram and vesicoureteral reflux was found in 28%. There was no relation between laterality of hydronephrosis and incidence of vesicoureteral reflux. There was no difference between nonscreened and screened patients with respect to gender and laterality of hydronephrosis. Urinary tract infection developed in 1.3% of the patients who were screened and did not have vesicoureteral reflux and, therefore, were not receiving antibiotics. Of the screened patients with vesicoureteral reflux who were receiving prophylactic antibiotics urinary tract infection developed in 1.6% at a mean age of 9.4 months. In 363 patients who did not undergo an initial voiding cystourethrogram we estimated (based on the screened population) that 101 would have vesicoureteral reflux and 5 would have a urinary tract infection. However, a febrile urinary tract infection developed in 16 patients (4.4% overall, p <0.0001) at a mean age of 9.3 months. Voiding cystourethrogram performed in these 16 patients revealed vesicoureteral reflux in 12. Of all the patients with a urinary tract infection who were ultimately observed to have vesicoureteral reflux (including those initially screened and those discovered to have reflux after a urinary tract infection) the laterality of hydronephrosis, grade of reflux and laterality of reflux were comparable.

CONCLUSIONS

In patients with a history of prenatal hydronephrosis who are observed to have postnatally persistent grade II hydronephrosis identification of vesicoureteral reflux and use of prophylactic antibiotics significantly reduce the risk of febrile urinary tract infection. Therefore, we recommend that patients with a history of prenatal hydronephrosis and postnatally persistent hydronephrosis be screened with voiding cystourethrography early in life, and be placed on prophylactic antibiotics until the screening results are known.