Combining Oxygenated Cold Perfusion With Normothermic Ex Vivo Perfusion Improves the Outcome of Donation After Circulatory Death Porcine Kidney Transplantation.

BACKGROUND: Ex vivo machine perfusion is a novel preservation technique for storing and assessing marginal kidney grafts. All ex vivo perfusion techniques have advantages and shortcomings. The current study analyzed whether a combination of oxygenated hypothermic machine perfusion (oxHMP) followed by a short period of normothermic ex vivo kidney perfusion (NEVKP) could combine the advantages of both techniques. METHODS: Porcine kidneys were exposed to 30 min of warm ischemia followed by perfusion. Kidneys underwent either 16-h NEVKP or 16-h oxHMP. The third group was exposed to 16-h oxHMP followed by 3-h NEVKP (oxHMP + NEVKP group). After contralateral nephrectomy, grafts were autotransplanted and animals were followed up for 8 d. RESULTS: All animals survived the follow-up period. Grafts preserved by continuous NEVKP showed improved function with lower peak serum creatinine and more rapid recovery compared with the other 2 groups. Urine neutrophil gelatinase-associated lipocalin, a marker of kidney injury, was found to be significantly lowered on postoperative day 3 in the oxHMP + NEVKP group compared with the other 2 groups. CONCLUSIONS: A short period of NEVKP after oxHMP provides comparable short-term outcomes to prolonged NEVKP and is superior to oxHMP alone. A combination of oxHMP with end-ischemic NEVKP could be an attractive, practical strategy to combine the advantages of both preservation techniques.

Translational and linguistic validation of the Arabic version of dysfunctional voiding symptom score questionnaire.

INTRODUCTION: Dysfunctional voiding is a multifactorial condition that encompasses a wide variety of symptoms rendering its diagnosis a challenging process. In this setting, several tools have been proposed to aid the diagnosis of this disease among which is the Dysfunctional Voiding Symptom Score (DVSS). The DVSS has been translated and validated to different languages including Japanese, Thai, Chinese, Serbian, and Portuguese. The aim of the current study is to translate and cross-culturally validate the DVSS into the Arabic language. MATERIAL AND METHODS: The DVSS was translated and culturally adapted to the Arabic language following the standards of the ISPOR for the translation and cultural adaptation process for patient-reported outcomes measures. Subsequently, the translated version underwent a pre-test on 15 patients with dysfunctional voiding. Afterwards, the translated version was filled by 82 pediatric patients and/or their parents with dysfunctional voiding and then the same questionnaire was refilled by the patients and their families one week later at home. Finally, a group of healthy children and/or their parents were recruited to fill the questionnaire as a control group. Cronbach's alpha, Pearson's correlation, and Interclass correlation were used to assess for internal consistency and reliability between test-retest of the Arabic version. RESULTS: The mean total score of DVSS for the case and control groups was 16.66 ± 6.07 and 6.11 ± 3.36, respectively (P < 0.001). The Arabic-DVSS showed excellent internal consistency (Cronbach's α > 0.9) for all the questions except Q1, Q3, Q6, and Q7 that showed good internal consistency. DISCUSSION: Translational and linguistic validation of the DVSS questionnaire into Arabic language is an important step toward its introduction in the clinical practice in Arabic countries; however, this step has also to consider the cultural variations between countries and not just linguistic translation. Generally, the Arabic-DVSS showed a satisfactory test-retest internal consistency and reliability with an excellent Cronbach's α (0.982) and ICC (0.962) for the total score of the Arabic-DVSS. Yet, the main limitation of this study was that it was only advocated for the translation and validation of the Arabic-DVSS and did not assess its value in patients' follow-up. CONCLUSION: The Arabic version of the DVSS is reliable and valid to help in the evaluation of DV in children of Arabic countries.

A systematic review of paediatric neurogenic lower urinary tract dysfunction guidelines using the Appraisal of Guidelines and Research Evaluation (AGREE) II instrument.

OBJECTIVE: To examine and critique current international clinical practice guidelines (CPGs) on management of paediatric neurogenic lower urinary tract dysfunction (NLUTD) and assess the applicability of these guidelines to clinical practice. MATERIALS AND METHODS: We conducted a systematic review of all CPGs on NLUTD published in English from the year 2010 to 2022. Six reviewers independently used the Appraisal of Guidelines and Research Evaluation (AGREE) II instrument to appraise all eligible CPGs. This instrument is comprised of 23 items organised into six quality domains. The scores for each item and domain were tabulated for each reviewer and interrater reliability was assessed for each domain using the intraclass correlation coefficient (ICC). RESULTS: Six CPGs were appraised and these included: National Institute for Health and Care Excellence (NICE), European Society for Paediatric Urology, International Children's Continence Society, Irish, Spina Bifida Association (SBA), and International Brazilian Journal of Urology guidelines. They had high mean standardised scores in the domain on 'scope and purpose' and 'clarity of presentation' but had low scores in the domain of 'applicability'. The top three CPGs based on overall score were the NICE, Irish and SBA guidelines and the reviewers had high degree of interrater reliability (ICC 0.912, P < 0.001). The mean scores in various domains for the top three guidelines were 95.8 (scope and purpose), 87.5 (stakeholder involvement), 69.1 (rigour of development), 94.0 (clarity of presentation), 68.4 (applicability), and 59.7 (editorial independence). The diagnostic and treatment recommendations of the top three guidelines were presented. CONCLUSION: The existing CPGs on paediatric NLUTD provide high-quality evidence based recommendations. The NICE, Irish and SBA guidelines were the top three CPGs identified. They scored high on most domains except applicability and editorial independence. These domains need to be considered for future updates to improve the utility.

Scoping review of neurogenic bladder patient-reported readiness and experience following care in a transitional urology clinic.

OBJECTIVE: To generate a scoping review that summarizes thematically on all reported patient perceptions on readiness and experiences during transitional urologic care for patients with neurogenic bladder and or congenital genitourinary conditions that require continuity of care into adulthood. METHODS: A systematic literature search was performed in October 2021. Records were screened and identified for studies relevant to reported readiness and experience in urologic transitional care among patients needing life-long urologic care. The methodological quality of the cross-sectional studies was assessed using AXIS. The included studies were clustered according to patient readiness in transition and patient experience-satisfaction in the urologic transition process. This scoping review was part of a systematic review registered on PROSPERO CRD42022306229 and was conducted in compliance with the PRISMA extension for scoping reviews. RESULTS: A total of 12 articles were included that assessed patients with neurogenic bladder that reported either readiness or patient experience following the transitional care process. The patient readiness was assessed in six studies, determined using the TRAQ score with a range of 3-4/5. Older age, high health literacy, and parental or families' transition process awareness were associated with readiness. Generally, patients experience better satisfaction with pediatric care than with adult care facilities. Most patients felt that sexuality and fertility were not adequately tackled during the transition. The reported barriers to successful transition were patient, provider, and system factors, including lack of insurance coverage/financial management, patient preference, long-term bond with the pediatric providers, and communication by the adult provider. Based on AXIS, all of the studies identified for this scoping review did not determine the sample size, and most of the studies did not categorize the responders, which could introduce bias to the interpretation of their results. CONCLUSION: This scoping review summarizes the readiness and experience of neurogenic bladder patients who underwent the urologic transitional process. Overall, understanding the patient, provider, and system factors associated with better readiness and enhancing the patient experience will ensure a better transition process.

The utilization of hyperbaric oxygenation therapy in hypospadias repair: a systematic review and meta-analysis.

INTRODUCTION: This study aimed to evaluate the efficacy and safety of Hyperbaric Oxygen Therapy (HBOT) use in hypospadias repair through systematic review and meta-analysis of comparative studies. METHODS: A systematic literature search was performed in May 2021. Comparative studies assessing the surgical outcome of hypospadias repair between control versus HBOT utilization were identified and evaluated according to Cochrane collaboration recommendations. The assessed outcome includes hypospadias repair failures and graft failure for staged repair using a buccal graft. Relative risk with corresponding 95% confidence intervals (CI) were extrapolated. A random-effect model was used to generate pooled effect estimates. Heterogeneity and inter-study variability were assessed using Chi-square and I-square. Subgroup analysis was performed according to primary repair versus redo-hypospadias with buccal graft. PROSPERO registration (CRD42021251423). RESULTS: Five comparative studies with 576 cases (301 HBOT versus 275 controls) were included. Overall pooled effect estimates showed that the HBOT group has significantly lesser hypospadias repair failure (RR 0.52, 95%CI 0.37, 0.72). Subgroup analysis on the use of HBOT for graft take showed lesser graft failure compared to the control group (RR 0.20, 95% CI 0.05, 0.75), while the use of HBOT for primary and redo single staged hypospadias repair showed lesser complication rate (RR 0.56, 95%CI 0.40, 0.78). Based on ROBINS-I assessment, all included comparative studies are determined to be of serious risk of bias mainly due to presence of confounding. CONCLUSION: The currently available low-quality of evidence suggests that compared to control groups, HBOT as an adjunctive intervention to complicated hypospadias repair was able to reduce surgical outcome failure and graft failure rates.

Perinatal testicular torsion: The clear cut, the controversial, and the "quiet" scenarios.

BACKGROUND: Perinatal testicular torsion (PTT) is a catastrophic event that occurs in utero or up to 30 days postnatally, with testicular loss being the most common outcome. OBJECTIVE: To assess clinical evaluation, surgical management and clinical outcomes in patients with PTT in a quaternary referral pediatric center, to determine testicular salvageability and propose future management options. METHODS: We retrospectively reviewed a cohort of males born outside the quaternary center with a diagnosis of PTT, from May 2000 to July 2020. Data collection included mode of delivery, gestational age, birth weight, testicular examination at birth, clinical presentation, ultrasound results at diagnosis, surgical management and findings, perioperative complications, and follow-up. RESULTS: 62 patients, including 2 patients with bilateral asynchronous PTT, were identified. Median (IQR) gestational age and birth weight were 39 (38-39.4) weeks and 3.4 (3.1-3.72) kg, respectively. Abnormal testicular examination at birth was found in 69% (Table 1). Doppler ultrasound was performed in all but 1 patient. 59 patients underwent surgery, 21 within 4 h, with bilateral exploration in 44 cases. Affected and non-affected testicles were explored in 76% and 98% of cases, respectively. 3 "nubbins" were found, of which 2 were excised. 3 nonsurgical complications were identified. During a median (IQR) follow-up of 3 (3-3) months, 63 testicles were removed or found to be non-functional, with compensatory hypertrophy in 38% of patients. CONCLUSION: Given that 3% of our patients presented with asynchronous bilateral PTT, as well as the safety of general anesthesia in a referral pediatric hospital, early bilateral scrotal exploration of PTT is recommended. LEVEL OF EVIDENCE: IV.

Cost Effectiveness and Impact in Quality of Care of a Pediatric Multidisciplinary Stone Clinic.

Herein, we assess the cost-effectiveness of a multidisciplinary clinic for children with urinary stones. The clinic's primary goals were to decrease unnecessary visits, imaging, and costs while optimizing the quality of care. METHODS: Between October 2012 and January 2016, children with complex stone disease, previously treated in urology and/or nephrology clinics, were seen at a triannual pediatric combined stone clinic. We compared the number and cost of ultrasounds, emergency room (ER) visits, and stone surgeries performed before and after each patient's initial evaluation. All patients received satisfaction surveys. RESULTS: Among the 79 patients, 27 were seen at least twice in the combined clinic and followed multiple times in either urology or nephrology clinics. The mean number of ER visits per patient per year significantly decreased from 0.29 ± 0.36 to 0.10 ± 0.15 (P = 0.002). The mean cost of ER visits went from CAD$ 23.44 ± 28.80 to CAD$ 4.14 ± 12.18 (P = 0.002). Likewise, the mean annual number and cost of stone-related surgeries significantly decreased [(0.38 ± 0.63 versus 0.20 ± 0.32 after the MSC started (P = 0.026) and mean annual cost of surgeries went from CAD$ 182.97 ± 301.49 to CAD$ 41.59 ± 110.97 (P = 0.022)]. Among the survey responses returned, 75% of families believed the clinic was time-saving. CONCLUSIONS: Despite a small sample size, the number of ER visits and stone-related operations significantly decreased after the initial combined clinic intervention. Longer-term data will hopefully confirm if the positive findings continue.

Prolonged Normothermic Ex Vivo Kidney Perfusion Is Superior to Cold Nonoxygenated and Oxygenated Machine Perfusion for the Preservation of DCD Porcine Kidney Grafts.

The increased usage of marginal grafts has triggered interest in perfused kidney preservation to minimize graft injury. We used a donation after circulatory death (DCD) porcine kidney autotransplantation model to compare 3 of the most frequently used ex vivo kidney perfusion techniques: nonoxygenated hypothermic machine perfusion (non-oxHMP), oxygenated hypothermic machine perfusion (oxHMP), and normothermic ex vivo kidney perfusion (NEVKP). METHODS: Following 30 min of warm ischemia, grafts were retrieved and preserved with either 16 h of non-oxHMP, oxHMP, or NEVKP (n = 5 per group). After contralateral nephrectomy, grafts were autotransplanted and animals were followed for 8 d. Kidney function and injury markers were compared between groups. RESULTS: NEVKP demonstrated a significant reduction in preservation injury compared with either cold preservation method. Grafts preserved by NEVKP showed superior function with lower peak serum creatinine (NEVKP versus non-oxHMP versus oxHMP: 3.66 ± 1.33 mg/dL, 8.82 ± 3.17 mg/dL, and 9.02 ± 5.5 mg/dL) and more rapid recovery. The NEVKP group demonstrated significantly increased creatinine clearance on postoperative day 3 compared with the cold perfused groups. Tubular injury scores on postoperative day 8 were similar in all groups. CONCLUSIONS: Addition of oxygen during HMP did not reduce preservation injury of DCD kidney grafts. Grafts preserved with prolonged NEVKP demonstrated superior initial graft function compared with grafts preserved with non-oxHMP or oxHMP in a model of pig DCD kidney transplantation.

Do post-operative phone calls enhance family satisfaction and outcomes after outpatient pediatric urological surgeries? A prospective study.

INTRODUCTION: This study assesses whether post-operative check-in phone calls (POPC) performed within 48 h of outpatient pediatric urological surgeries by a non-medical professional (NMP) would increase patient/family satisfaction and minimize extraneous resource use by increasing email/telephone communication, while reducing emergency department (ED) visits within 30 days of that procedure. METHODS: Families of patients undergoing ambulatory pediatric urology surgeries were enrolled over 8 weeks. Group 1 did not receive POPC. Group 2 received a POPC within 48 h of their operation by a NMP. Both groups received a phone-call survey 2 weeks after surgery to assess families' perioperative satisfaction. RESULTS: In total, 74 families were enrolled (Group 1 = 44, Group 2 = 31). The response rates to phone surveys for Groups 1 and 2 were 59.1% and 77.4%, respectively. POPC did not improve perioperative satisfaction, nor did it significantly promote the use of nursing email/telephone communication (19.2% vs. 4.2%, p = 0.128) or reduce ED visits (15.4% vs. 0.0%, p = 0.111). However, all families in Group 2 thought POPC was timed appropriately and 79.1% perceived it to be helpful in reducing post-operative anxiety. CONCLUSION: POPC by a NMP within 48 h of surgery may not affect perioperative satisfaction of families of patients undergoing same-day pediatric urology surgery but may have an impact in reducing post-operative anxiety.

Turning a new "page": ways to decrease the number of pages after hours without compromising patient care

Background: Pages to house staff after hours, especially overnight, lead to interrupted sleep and fatigue the next day. Although some pages are urgent, others may not need an immediate response. In this study we aimed to identify unwarranted pages and to establish ways to reduce them. Methods: Over 2 months, all pages to the Department of Pediatric Urology at the Hospital for Sick Children in Toronto, Canada, during call hours were documented, including the assessment of the responding physicians of their medical necessity. After analyzing the reasons for inappropriate pages, we took several steps to try to reduce them without impairing patient care. One year later, pages were tracked again to evaluate the efficacy of our interventions. Results: In the initial measurement period, no calls from parents and approximately 50% of the in-hospital pages (15 of 36 pages from the wards, 27 of 49 pages from the emergency department, 17 of 31 pages requesting consultations, and 8 of 8 pages from the inhouse pharmacy and outside pharmacies) were considered medically urgent. The reasons for unwarranted pages were inconsistent parent teaching, lack of adequate triaging and prioritizing on the ward and lack of awareness of the structure of the on-call provisions among different services in the hospital. Several steps were taken to streamline the teaching of parents and nurses, standardize information, provide alternative means of communication within the hospital and restrict parents' access by phone to the urologist on call. One year later, the number of pages had decreased by 70%. Conclusion: Although physician coverage throughout the day and night is necessary for high-quality and safe patient care, communication with on-call physicians should be only for appropriate reasons. The provision of consistent teaching and alternative communication channels can improve patient care as well as decrease the number of after-hour pages.

Contexte: Les appels au personnel interne par téléavertisseur, surtout la nuit, perturbent le sommeil et entraînent de la fatigue le lendemain. Même si certains de ces appels sont urgents, d'autres ne nécessitent pas de réponse immédiate. Avec cette étude nous avons voulu identifier les appels par téléavertisseur qui sont injustifiés et trouver des façons d'en réduire le nombre. Méthodes: Sur une période 2 mois, nous avons documenté tous les appels par téléavertisseur adressés durant les heures de garde au service d'urologie pédiatrique de l'Hôpital SickKids de Toronto, au Canada, et demandé aux médecins y ayant répondu d'en évaluer le bien-fondé au plan médical. Après avoir analysé les raisons des appels jugés injustifiés, nous avons adopté plusieurs mesures pour en réduire le nombre sans compromettre les soins. Un an plus tard, nous avons de nouveau comptabilisé les appels par téléavertisseur pour mesurer l'efficacité de nos interventions. Résultats: Durant la période de mesure initiale, aucun appel des parents n'a été considéré médicalement urgent, tout comme environ 50 % des appels provenant de l'hôpital même (15 appels sur 36 des unités de soins, 27 appels sur 49 du service des urgences, 17 appels sur 31 pour des demandes de consultation et 8 appels sur 8 de la pharmacie de l'hôpital ou de pharmacies de l'extérieur). Les raisons des appels injustifiés étaient entre autres incohérence dans l'enseignement aux parents, triage et priorisation inadéquats à l'unité de soin et méconnaissance des différents services de l'hôpital quant à la structure et au fonctionnement du système de garde. Plusieurs mesures ont été prises pour simplifier l'enseignement aux parents et au personnel infirmier, standardiser l'information, fournir d'autres moyens de communication dans l'hôpital même et restreindre l'accès des parents à l'urologue de garde par téléphone. Un an plus tard, le nombre d'appels avait diminué de 70 %. Conclusion: Même si les médecins doivent être joignables jour et nuit pour assurer la qualité des soins et la sécurité des patients, les raisons de communiquer avec eux doivent être appropriées. Le rappel des consignes et le recours à d'autres canaux de communication peuvent améliorer les soins aux patients et réduire le nombre d'appels le soir et la nuit.

Persistent myopathy despite release of partial obstruction: in vivo reversal of dysfunction and transcriptional responses using rapamycin.

Current and potential medical therapy for obstruction-induced myopathic bladder dysfunction (from benign prostatic hyperplasia or posterior urethral valves) focuses on symptoms. The persistent tissue pathology and dysfunction after release of obstruction is often deemed irreversible without any systematic therapeutic approaches. As rapamycin can attenuate bladder smooth muscle hypertrophy and dysfunction during the genesis of partial obstruction in vivo, we tested whether rapamycin could improve persistent function after release of obstruction (de-obstruction or REL). Female Sprague-Dawley rat bladders were partially obstructed (PBO) by suturing around both the urethra and a para-urethral steel rod, then removing the rod. One day prior to release of obstruction (preREL), voiding parameters and residual urine volume of preREL+future rapa, preREL+future veh groups were recorded. Release of obstruction (REL) was performed by suture removal following 6 weeks of PBO. For 4 more weeks after the de-obstruction, REL animals were randomized to rapamycin (REL+rapa) or vehicle (REL+veh). PBO for 6 weeks were used as positive controls. In shams, the urethra was exposed, but no suture tied. Voiding parameters and residual urine volume were measured prior to sacrifice of sham and REL+veh or REL+rapa, and PBO. Rapamycin efficacy was tested by pair-wise comparison of changes in individual voiding data from preREL+future veh or preREL+future rapa versus REL+veh or REL+rapa, respectively, as well as by comparisons of REL+veh to REL+rapa groups. Bladders were weighed and processed for a high-throughput QPCR array, and histopathology. Bladder/body mass ratios with PBO increased significantly and remained higher in the release phase in REL+veh animals. REL+rapa versus REL+veh improved residual volumes and micturition fractions toward sham levels. Three genes encoding extracellular proteins, BMP2, SOD3, and IGFBP7, correlated with functional improvement by Pearson's correlations. The promoters of these genes showed enrichment for several motifs including circadian E-boxes. While obstruction and REL augmented CLOCK and NPAS2 expression above sham levels, rapamycin treatment during release significantly blocked their expression. This experimental design of pharmaco-intervention during the de-obstruction phase revealed a novel pathway dysregulated during the clinically relevant treatment phase of obstructive bladder myopathy.

Normothermic Ex Vivo Kidney Perfusion Improves Early DCD Graft Function Compared With Hypothermic Machine Perfusion and Static Cold Storage.

BACKGROUND: Better preservation strategies for the storage of donation after circulatory death grafts are essential to improve graft function and to increase the kidney donor pool. We compared continuous normothermic ex vivo kidney perfusion (NEVKP) with hypothermic anoxic machine perfusion (HAMP) and static cold storage (SCS) in a porcine kidney autotransplantation model. METHODS: Porcine kidneys were exposed to 30 minutes of warm ischemia and then reimplanted following either 16 hours of either SCS, HAMP (LifePort 1.0), or NEVKP before autotransplantation (n = 5 per group). The contralateral kidney was removed. Animals were followed for 8 days. RESULTS: Grafts preserved by NEVKP demonstrated improved function with more rapid recovery compared with HAMP and SCS (mean peak serum creatinine: 3.66 ± 1.33 mg/dL [postoperative d 1 [(POD1)], 8.82 ± 3.17 mg/dL [POD2], and 12.90 ± 2.19 mg/dL [POD3], respectively). The NEVKP group demonstrated significantly increased creatinine clearance calculated on POD3 (63.6 ± 19.0 mL/min) compared with HAMP (13.5 ± 10.3 mL/min, P = 0.001) and SCS (4.0 ± 2.6 mL/min, P = 0.001). Histopathologic injury scores on POD8 were lower in both perfused groups (NEVKP and HAMP, score: 1-1.5) compared with SCS (score: 1-3, P = 0.3), without reaching statistical significance. CONCLUSIONS: NEVKP storage significantly improved early kidney function compared with both cold preservation strategies, although HAMP also demonstrates improvement over SCS. NEVKP may represent a novel, superior preservation option for donation after circulatory death renal grafts compared with conventional hypothermic methods.

Artificial Intelligence. How Artificial is Urology Practice Becoming? / Inteligencia artificial. ¿Qué tan artificial se está volviendo la práctica urológica?

The evolution of medical practice has changed from the most basic tool of patient interrogation to current technologies of artificial intelligence and machine-learning driven practice.[1] Traditionally at the forefront of technology, once again urology has an opportunity to embrace and lead in these rapid changes in medical practice.

Over-reliance on P Values in Urology: Fragility of Findings in the Hydronephrosis Literature Calls for Systematic Reporting of Robustness Indicators.

OBJECTIVE: To review the robustness of hydronephrosis literature with the application of fragility index (FI) and fragility quotient (FQ) calculations. METHODS: A literature review was conducted using Pubmed, Medline, and Ovid for "hydronephrosis" and associated terms and we included all studies with at least 2 groups being compared. FI was calculated by populating study results into a 2-by-2 contingency table and generating a P value using Fisher's exact test. Next, events were manually added to the group with the fewest events, while removing a nonevent from the same group and Fisher's exact test repeated until the P value was >.05. FQ was calculated by dividing FI by the total sample size. RESULTS: The 130 included articles were published between 1986 and 2018 in 32 journals. Median citation count was 14 (0-252), 30% were RCTs and most papers originated in the United States (28%), Turkey(10%), and Canada(9%). Median FI was 2 (1-112), FQ was 0.023 (0.0010-0.55), and 60 papers (46%) had a FI of 1, indicating extremely fragile results. There was a significant difference in the FI between observational studies and RCTs (10 ± 17 vs 4 ± 5; P = .02); however, there was no difference in FQ (0.032 ± 0.030 vs 0.053 ± 0.080; P = .09) between them. CONCLUSION: Nearly half of studies in hydronephrosis literature reporting significant results are extremely fragile, requiring addition of only a couple of events in 1 treatment arm to significantly modify the results. As such, objective reporting of robustness of results should include FI and FQ which may help diminish over-reliance on P values as the main indicator of clinical significance in comparative studies.

DNA Methylation Reduces the Yes-Associated Protein 1/WW Domain Containing Transcription Regulator 1 Pathway and Prevents Pathologic Remodeling during Bladder Obstruction by Limiting Expression of BDNF.

Chronic bladder obstruction and bladder smooth muscle cell (SMC) stretch provide fibrotic and mechanical environments that can lead to epigenetic change. Therefore, we examined the role of DNA methylation in bladder pathology and transcriptional control. Sprague-Dawley female rats underwent partial bladder obstruction by ligation of a silk suture around the proximal urethra next to a 0.9-mm steel rod. Sham operation comprised passing the suture around the urethra. After 2 weeks, rats were randomized to normal saline or DNA methyltransferase inhibitor, 5-aza-2-deoxycytidine (DAC) at 1 mg/kg, three times/week intraperitoneally. After 6 weeks, bladders were weighed and divided for histology and RNA analysis by high-throughput real-time quantitative PCR arrays. DAC treatment during obstruction in vivo profoundly augmented brain-derived neurotrophic factor (BDNF) expression compared with the obstruction with vehicle group, which was statistically correlated with pathophysiologic parameters. BDNF, cysteine rich angiogenic inducer 61 (CYR61), and connective tissue growth factor (CTGF) expression clustered tightly together using Pearson's correlation analysis. Their promoters were associated with the TEA domain family member 1 (TEAD1) and Yes-associated protein 1/WW domain containing transcription regulator 1 pathways. Interestingly, DAC treatment increased BDNF expression in bladder SMCs (P < 0.0002). Stretch-induced BDNF was inhibited by the YAP/WWTR1 inhibitor verteporfin. Verteporfin improved the SMC phenotype (proliferative markers and SMC marker expression), in part by reducing BDNF. Expression of BDNF is limited by DNA methylation and associated with pathophysiologic changes during partial bladder outlet obstruction and SMC phenotypic change in vitro.