Piezo1-Regulated Mechanotransduction Controls Flow-Activated Lymphatic Expansion.

BACKGROUND: Mutations in PIEZO1 (Piezo type mechanosensitive ion channel component 1) cause human lymphatic malformations. We have previously uncovered an ORAI1 (ORAI calcium release-activated calcium modulator 1)-mediated mechanotransduction pathway that triggers lymphatic sprouting through Notch downregulation in response to fluid flow. However, the identity of its upstream mechanosensor remains unknown. This study aimed to identify and characterize the molecular sensor that translates the flow-mediated external signal to the Orai1-regulated lymphatic expansion. METHODS: Various mutant mouse models, cellular, biochemical, and molecular biology tools, and a mouse tail lymphedema model were employed to elucidate the role of Piezo1 in flow-induced lymphatic growth and regeneration. RESULTS: Piezo1 was found to be abundantly expressed in lymphatic endothelial cells. Piezo1 knockdown in cultured lymphatic endothelial cells inhibited the laminar flow-induced calcium influx and abrogated the flow-mediated regulation of the Orai1 downstream genes, such as KLF2 (Krüppel-like factor 2), DTX1 (Deltex E3 ubiquitin ligase 1), DTX3L (Deltex E3 ubiquitin ligase 3L,) and NOTCH1 (Notch receptor 1), which are involved in lymphatic sprouting. Conversely, stimulation of Piezo1 activated the Orai1-regulated mechanotransduction in the absence of fluid flow. Piezo1-mediated mechanotransduction was significantly blocked by Orai1 inhibition, establishing the epistatic relationship between Piezo1 and Orai1. Lymphatic-specific conditional Piezo1 knockout largely phenocopied sprouting defects shown in Orai1- or Klf2- knockout lymphatics during embryo development. Postnatal deletion of Piezo1 induced lymphatic regression in adults. Ectopic Dtx3L expression rescued the lymphatic defects caused by Piezo1 knockout, affirming that the Piezo1 promotes lymphatic sprouting through Notch downregulation. Consistently, transgenic Piezo1 expression or pharmacological Piezo1 activation enhanced lymphatic sprouting. Finally, we assessed a potential therapeutic value of Piezo1 activation in lymphatic regeneration and found that a Piezo1 agonist, Yoda1, effectively suppressed postsurgical lymphedema development. CONCLUSIONS: Piezo1 is an upstream mechanosensor for the lymphatic mechanotransduction pathway and regulates lymphatic growth in response to external physical stimuli. Piezo1 activation presents a novel therapeutic opportunity for preventing postsurgical lymphedema. The Piezo1-regulated lymphangiogenesis mechanism offers a molecular basis for Piezo1-associated lymphatic malformation in humans.

Fetal bladder morphology as a predictor of outcome in fetal lower urinary tract obstruction.

OBJECTIVE: We evaluate survival of fetuses with severe Lower Urinary Tract Obstruction (LUTO) based on bladder morphology. We hypothesize that fetuses with a "floppy" appearing bladder on initial prenatal ultrasound will have worse infant outcomes than fetuses with full/rounded bladders. METHOD: We retrospectively reviewed all cases of LUTO evaluated in our fetal center between January 2013 and December 2021. Ultrasonographic assessment, renal biochemistry, and bladder refilling contributed to a "favorable" or "unfavorable" evaluation. Bladder morphology on initial ultrasound was classified as "floppy" or "full/rounded." Vesicoamniotic shunting was offered for favorably evaluated fetuses. Baseline demographics, ultrasound parameters, prenatal evaluations of fetal renal function, and infant outcomes were collected. Fetuses diagnosed with severe LUTO were included in analysis using descriptive statistics. The primary outcome measured was survival at 6 months of life. RESULTS: 104 LUTO patients were evaluated; 24 were included in analysis. Infant survival rate at 6 months was 60% for rounded bladders and 0% for floppy bladders (p = 0.003). Bladder refill adequacy was lower in fetuses with floppy bladders compared with rounded bladders (p value < 0.00001). CONCLUSION: We propose that bladder morphology in fetuses with severe LUTO may be a prognostication factor for predicting infant outcomes and provides a valuable, noninvasive assessment tool.

The ChorioAnchor: Design and Testing of a Novel Chorioamniotic Anchoring Device to Enable Percutaneous Fetoscopic Surgery.

INTRODUCTION: Percutaneous fetoscopic surgery is hampered by an increased risk of preterm prelabor rupture of membranes (PPROM). Recent surgical techniques have shown that suturing the chorioamniotic membranes following laparotomy and uterine exteriorization is associated with a lower risk of PPROM compared to percutaneous in utero surgery. This study presents the ChorioAnchor, a novel resorbable device that percutaneously anchors the chorioamniotic membranes to the uterine wall. METHODS: Human factors testing and peel tests were used to simulate the worst-case in-use loading conditions, establishing the device strength requirements. Tensile testing was used to measure the time-zero strength of the device. Porcine cadaver testing was used to examine ultrasound visibility and acute handling characteristics. Short-term host response was examined through an acute 7-day implantation study in a rabbit model. RESULTS: With a time-zero tensile strength of 47 N, the ChorioAnchor exceeded the established 4 N strength requirement. Both the ChorioAnchor and delivery device were seen to be clearly visible under ultrasound imaging. Short-term host response to the device was well within the range expected for this type of device. CONCLUSION: The ChorioAnchor meets its engineering requirements in the early stages of implantation. Future studies will examine the kinetics of degradation of the device in vitro and in vivo.

Effect of Caudal vs. Penile Block on the Incidence of Hypospadias Complications Following Primary Repairs: A Retrospective Cohort Study.

PURPOSE: Primary repair of hypospadias is associated with risk of complications, specifically urethrocutaneous fistula and glanular dehiscence. Caudal block may potentially increase the risk of these complications. Therefore, we studied the incidence of hypospadias complications in children who underwent correction at our institution having received either penile or caudal block. MATERIALS AND METHODS: We analyzed all primary hypospadias repair cases from December 2011 through December 2018 at Texas Children's Hospital with a minimum of 1-year followup for the presence of complications: urethrocutaneous fistula and glanular dehiscence. Surgical (surgeon, operative time, block type, local anesthetic, meatal position) and patient (age at correction, prematurity) factors were additionally analyzed. RESULTS: For the primary aim, 983 patients underwent primary hypospadias correction with a minimum of 1 year of postoperative followup data. There were 897 patients (91.3%) in which no complications were identified and 86 (8.7%) with either urethrocutaneous fistula (81) or glanular dehiscence (5). Of the 86 identified complications, 45/812 (5.5%) were distal, 41/171 (24%) were proximal (p <0.001) with a complication. Rate of complications was not associated with caudal block (OR 0.67, 95% CI 0.41-1.09; p=0.11). On univariable analysis, age (OR 1.12, 95% CI 1.04-1.20; p=0.04), surgical duration (OR 1.02; 95% CI 1.01-1.02; p <0.001), prematurity <32 weeks (OR 4.38, 95% CI 1.54-4.11 p <0.001) and position of meatus as proximal (OR 5.38 95% CI 3.39-8.53; p <0.001) were associated with an increased rate of complications. However, on multivariable analysis, associations of age (OR 1.13, 95% CI 1.05-1.22; p=0.001), surgery duration (OR 1.01, 95% CI 1.01-1.02; p <0.001) and meatal position (OR 3.85, 95% CI 2.32-6.39; p <0.001) were associated with increased rate of complications. CONCLUSIONS: Our data suggest that meatal location, older age, extreme prematurity and surgical duration are associated with increased incidence of complications (urethrocutaneous fistula and glanular dehiscence) following hypospadias correction. Analgesic block was not associated with increased hypospadias complication risk.

Robot-assisted laparoscopic ureteral reimplantation in children: a valuable alternative to open surgery.

INTRODUCTION: Robot-assisted laparoscopic surgical systems have led to new minimally invasive options for complex reconstructive procedures in children including for vesicoureteral reflux (VUR). Robot-assisted laparoscopic ureteral reimplantation has been shown to be a viable minimally invasive surgical option for children with VUR. However, higher-than-expected complication rates and sub-optimal reflux resolution rates at some centers have also been reported. METHODS: This article provides a focused literature review as well as current perspectives on open reimplantation and robot-assisted laparoscopic ureteral reimplantation as non-endoscopic surgical options for pediatric VUR. RESULTS: The heterogeneity of surgical outcomes may, in part, be due to the learning curve inherent with all new technology and procedures. As a result, the current gold standard surgical option for VUR continues to be open ureteral reimplantation. While it remains to be seen if robot-assisted laparoscopic surgery will gradually replace open surgery as the most utilized surgical option for VUR in pediatric patients, robot-assisted laparoscopic ureteral reimplantation with the current robotic surgical systems may be just one step toward an eventual minimally invasive option that all experienced surgeons can offer with the requisite high success rates and low major complication rates. CONCLUSION: Robot-assisted laparoscopic ureteral reimplantation remains a viable minimally invasive surgical option for children with VUR, but with the expected learning curve associated with all new technologies.

Analysis of 1478 Cases of Hypospadias Repair: The Incidence of Requiring Repeated Anesthetic Exposure as Well as Exploration of the Involvement of Trainees on Case Duration.

BACKGROUND: Recently, there has been significant focus on the effects of anesthesia on the developing brain. Concern is heightened in children <3 years of age requiring lengthy and/or multiple anesthetics. Hypospadias correction is common in otherwise healthy children and may require both lengthy and repeated anesthetics. At academic centers, many of these cases are performed with the assistance of anesthesia and surgical trainees. We sought to identify both the incidence of these children undergoing additional anesthetics before age 3 as well as to understand the effect of trainees on duration of surgery and anesthesia and thus anesthetic exposure (AE), specifically focusing on those cases >3 hours. METHODS: We analyzed all cases of hypospadias repair from December 2011 through December 2018 at Texas Children's Hospital. In all, 1326 patients undergoing isolated hypospadias repair were analyzed for anesthesia time, surgical time, provider types involved, AE, caudal block, and additional AE related/unrelated to hypospadias. RESULTS: For the primary aim, a total of 1573 anesthetics were performed in children <3 years of age, including 1241 hypospadias repairs of which 1104 (89%) were completed with <3 hours of AE. For patients with <3 hours of AE, 86.1% had a single surgical intervention for hypospadias. Of patients <3 years of age, 17.3% required additional nonrelated surgeries. There was no difference in anesthesia time in cases performed solely by anesthesia attendings versus those performed with trainees/assistance (16.8 vs 16.8 minutes; P = .98). With regard to surgery, cases performed with surgical trainees were of longer duration than those performed solely by surgical attendings (83.5 vs 98.3 minutes; P < .001). Performance of surgery solely by attending surgeon resulted in a reduced total AE in minimal alveolar concentration (MAC) hours when compared to procedures done with trainees (1.92 vs 2.18; P < .001). Finally, comparison of patients undergoing initial correction of hypospadias with subsequent revisions revealed a longer time (117.7 vs 132.2 minutes; P < .001) and AE during the primary stage. CONCLUSIONS: The majority of children with hypospadias were repaired within a single AE. In general, most children did not require repeated AE before age 3. While presence of nonattending surgeons was associated with an increase in AE, this might at least partially be due to differences in case complexity. Moreover, the increase is likely not clinically significant. While it is critical to maintain a training environment, attempts to minimize AE are crucial. This information facilitates parental consent, particularly with regard to anesthesia duration and the need for additional anesthetics in hypospadias and nonhypospadias surgeries.

Neurodevelopmental Outcome in Infants with Lower Urinary Tract Obstruction Based on Different Degrees of Severity.

OBJECTIVE: To determine postnatal neurodevelopmental (ND) outcomes for children with congenital lower urinary tract obstruction (LUTO) based on disease severity. METHODS: Twenty male infants with LUTO were classified prenatally as Stage 1 (normal amniotic fluid and renal function; n = 5), Stage 2 (signs of obstruction with preserved renal function; n = 13), and Stage 3 (signs of severe renal damage; n = 2). ND status was assessed using the Developmental Profile-3 test in 5 developmental domains (physical, adaptive behavior, social-emotional, cognitive, and communication). Each domain was considered to be delayed if standard scores were 2 or more SD below the mean. ND outcomes were compared between cases with an expected normal renal function (LUTO Stage 1) and those with impaired renal function (LUTO Stages 2 and 3). Results from cases with Stage 2 were also compared to those from Stage 3. ORs were calculated to predict risk for adverse ND outcome for each domain considering prenatal and postnatal factors. RESULTS: Gestational age (GA) at the diagnosis of LUTO was similar between both groups (Stage 1: 24.85 ± 7.87 vs. Stages 2 and 3: 21.4 ± 4.31 weeks; p = 0.24). Twelve of 15 cases with Stage 2 or 3 underwent vesicoamniotic shunt placement compared to none of Stage 1 fetuses (p < 0.01). No differences in GA at delivery were detected between the groups (37.9 ± 1.6 vs. 35.1 ± 3.6 weeks; p = 0.1). One of the infants in the Stage 2 and 3 groups received a kidney transplant during follow-up. One case (20%) from Stage 1 group required dialysis during the first 6 months of life, and 1 case from Stage 2 to 3 group required it during the first 6 months (p = 1.0), whereas 3 additional cases needed dialysis from 6 to 24 months (p = 0.6). Mean age at Developmental Profile 3 (DP-3) testing was 20.3 ± 12.3 months (Stage 1: 11.2 ± 8.6 vs. Stages 2 and 3: 23.4 ± 13.4 months; p = 0.07). Fifteen of the 20 patients (75%) had no ND delays. Of the 5 patients with ND delays, 4 received dialysis. No differences in ND outcomes between infants with LUTO Stage 1 and those with Stages 2 and 3 were detected except for a trend toward better physical development in Stage 1 (102.6 ± 11.6 vs. 80.7 ± 34.9; p = 0.05). Infants diagnosed with LUTO Stage 3 showed significantly lower adaptive scores than those diagnosed with Stage 2 (Stage 2: 101.9 ± 22.3 vs. Stage 3: 41.5 ± 30.4; p = 0.04) and a nonsignificant trend for lower results in physical (85.8 ± 33.0 vs. 47.5 ± 38.9; p = 0.1) and socio-emotional (94.7 ±17.9 vs. 73.5 ± 13.4; p = 0.1) domains. Infants who received dialysis showed 15-fold increased risk (95% CI 0.89-251) for delayed socio-emotional development (p = 0.06). Diagnosis of fetal renal failure increased the risk for delays in the adaptive domain 30-fold (95% CI 1.29-93.1; p = 0.03). Infants with abnormal renal function had 19 times (95% CI 1.95-292) increased risk for delays in the physical domain (p = 0.03). CONCLUSIONS: While most patients with LUTO do not exhibiting ND delays, our results support the importance of ND monitoring, especially in severe forms of LUTO, as increased severity of this condition may be associated with poorer ND outcomes.

Baseline Urinary Tract Imaging in Infants Enrolled in the UMPIRE Protocol for Children with Spina Bifida.

PURPOSE: The lifetime risk of renal damage in children with spina bifida is high but only limited baseline imaging data are available for this population. We evaluated a large prospective cohort of infants with spina bifida to define their baseline imaging characteristics. MATERIALS AND METHODS: The UMPIRE Protocol for Young Children with Spina Bifida is an iterative quality improvement protocol that follows a cohort of newborns at 9 United States centers. Using descriptive statistics, we report the initial baseline imaging characteristics, specifically regarding renal bladder ultrasound, cystogram and dimercaptosuccinic acid nuclear medicine scan. RESULTS: Data on 193 infants from 2015 to 2018 were analyzed. Renal-bladder ultrasound was normal in 55.9% of infants, while 40.4% had Society for Fetal Urology grade 1 to 2 hydronephrosis in at least 1 kidney, 3.7% had grade 3 to 4 hydronephrosis in either kidney and 21.8% had grade 1 or higher bilateral hydronephrosis. There was no vesicoureteral reflux in 84.6% of infants. A third of enrolled infants underwent dimercaptosuccinic acid nuclear medicine renal scan, of whom 92.4% had no renal defects and 93.9% had a difference in differential function of less than 15%. CONCLUSIONS: The majority of infants born with spina bifida have normal baseline imaging characteristics and normal urinary tract anatomy at birth. This proactive protocol offers careful scheduled surveillance of the urinary tract with the goal of lifelong maintenance of normal renal function and healthy genitourinary development.

ORAI1 Activates Proliferation of Lymphatic Endothelial Cells in Response to Laminar Flow Through Krüppel-Like Factors 2 and 4.

RATIONALE: Lymphatic vessels function to drain interstitial fluid from a variety of tissues. Although shear stress generated by fluid flow is known to trigger lymphatic expansion and remodeling, the molecular basis underlying flow-induced lymphatic growth is unknown. OBJECTIVE: We aimed to gain a better understanding of the mechanism by which laminar shear stress activates lymphatic proliferation. METHODS AND RESULTS: Primary endothelial cells from dermal blood and lymphatic vessels (blood vascular endothelial cells and lymphatic endothelial cells [LECs]) were exposed to low-rate steady laminar flow. Shear stress-induced molecular and cellular responses were defined and verified using various mutant mouse models. Steady laminar flow induced the classic shear stress responses commonly in blood vascular endothelial cells and LECs. Surprisingly, however, only LECs showed enhanced cell proliferation by regulating the vascular endothelial growth factor (VEGF)-A, VEGF-C, FGFR3, and p57/CDKN1C genes. As an early signal mediator, ORAI1, a pore subunit of the calcium release-activated calcium channel, was identified to induce the shear stress phenotypes and cell proliferation in LECs responding to the fluid flow. Mechanistically, ORAI1 induced upregulation of Krüppel-like factor (KLF)-2 and KLF4 in the flow-activated LECs, and the 2 KLF proteins cooperate to regulate VEGF-A, VEGF-C, FGFR3, and p57 by binding to the regulatory regions of the genes. Consistently, freshly isolated LECs from Orai1 knockout embryos displayed reduced expression of KLF2, KLF4, VEGF-A, VEGF-C, and FGFR3 and elevated expression of p57. Accordingly, mouse embryos deficient in Orai1, Klf2, or Klf4 showed a significantly reduced lymphatic density and impaired lymphatic development. CONCLUSIONS: Our study identified a molecular mechanism for laminar flow-activated LEC proliferation.

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

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

Multi-Institutional Review of Outcomes and Complications of Robot-Assisted Laparoscopic Extravesical Ureteral Reimplantation for Treatment of Primary Vesicoureteral Reflux in Children.

PURPOSE: Robot-assisted laparoscopic extravesical ureteral reimplantation has been proposed as a minimally invasive alternative to open ureteral reimplantation for correcting primary vesicoureteral reflux in children. However, in the current literature there are conflicting data regarding the safety and efficacy of this approach. Amid ongoing debate we analyzed outcomes and complications from this procedure in a large multi-institutional cohort. MATERIALS AND METHODS: We reviewed the records of children who underwent robot-assisted laparoscopic extravesical ureteral reimplantation at 9 academic centers from 2005 to 2014. Radiographic failure was defined as persistent vesicoureteral reflux on postoperative voiding cystourethrogram or radionuclide cystogram. Complications were graded using the Clavien-Dindo scale. RESULTS: A total of 260 patients (363 ureters) underwent robot-assisted laparoscopic extravesical ureteral reimplantation for primary vesicoureteral reflux during the study period. The cohort included 90 patients with either duplex ureter (42), failed endoscopic treatment (40) or concomitant diverticulectomy (8). Of the 280 ureters with postoperative voiding cystourethrogram or radionuclide cystogram available radiographic resolution was seen in 246 (87.9%). There were 25 complications overall (9.6%), with 7 grade 3 complications (2.7%) and no grade 4 or 5 complications. Four patients (3.9%) had transient urinary retention following bilateral reimplantation. CONCLUSIONS: Robot-assisted laparoscopic extravesical ureteral reimplantation has a low complication rate consistent with published series of open ureteral reimplantation. Radiographic success rates are approaching those of the open procedure but continue to fall short of the gold standard approach. These findings necessitate critical thinking regarding potential technique improvements and further prospective investigation into the efficacy of this procedure.

Design and Methodological Considerations of the Centers for Disease Control and Prevention Urologic and Renal Protocol for the Newborn and Young Child with Spina Bifida.

PURPOSE: Care of children with spina bifida has significantly advanced in the last half century, resulting in gains in longevity and quality of life for affected children and caregivers. Bladder dysfunction is the norm in patients with spina bifida and may result in infection, renal scarring and chronic kidney disease. However, the optimal urological management for spina bifida related bladder dysfunction is unknown. MATERIALS AND METHODS: In 2012 the Centers for Disease Control and Prevention convened a working group composed of pediatric urologists, nephrologists, epidemiologists, methodologists, community advocates and Centers for Disease Control and Prevention personnel to develop a protocol to optimize urological care of children with spina bifida from the newborn period through age 5 years. RESULTS: An iterative quality improvement protocol was selected. In this model participating institutions agree to prospectively treat all newborns with spina bifida using a single consensus based protocol. During the 5-year study period outcomes will be routinely assessed and the protocol adjusted as needed to optimize patient and process outcomes. Primary study outcomes include urinary tract infections, renal scarring, renal function and bladder characteristics. The protocol specifies the timing and use of testing (eg ultrasonography, urodynamics) and interventions (eg intermittent catheterization, prophylactic antibiotics, antimuscarinic medications). Starting in 2014 the Centers for Disease Control and Prevention began funding 9 study sites to implement and evaluate the protocol. CONCLUSIONS: The Centers for Disease Control and Prevention Urologic and Renal Protocol for the Newborn and Young Child with Spina Bifida began accruing patients in 2015. Assessment in the first 5 years will focus on urinary tract infections, renal function, renal scarring and clinical process improvements.

Defining and predicting 'intrauterine fetal renal failure' in congenital lower urinary tract obstruction.

BACKGROUND: The aim of this study was to identify predictors of 'intrauterine fetal renal failure' in fetuses with severe congenital lower urinary tract obstruction (LUTO). METHODS: We undertook a retrospective study of 31 consecutive fetuses with a diagnosis of LUTO in a tertiary Fetal Center between April 2013 and April 2015. Predictors of 'intrauterine fetal renal failure' were evaluated in those infants with severe LUTO who had either a primary composite outcome measure of neonatal death in the first 24 h of life due to severe pulmonary hypoplasia or a need for renal replacement therapy within 7 days of life. The following variables were analyzed: fetal bladder re-expansion 48 h after vesicocentesis, fetal renal ultrasound characteristics, fetal urinary indices, and amniotic fluid volume. RESULTS: Of the 31 fetuses included in the study, eight met the criteria for 'intrauterine fetal renal failure'. All of the latter had composite poor postnatal outcomes based on death within 24 h of life (n = 6) or need for dialysis within 1 week of life (n = 2). The percentage of fetal bladder refilling after vesicocentesis at time of initial evaluation was the only predictor of 'intrauterine fetal renal failure' (cut-off <27 %, area under the time-concentration curve 0.86, 95 % confidence interval 0.68-0.99; p = 0.009). CONCLUSION: We propose the concept of 'intrauterine fetal renal failure' in fetuses with the most severe forms of LUTO. Fetal bladder refilling can be used to reliably predict 'intrauterine fetal renal failure', which is associated with severe pulmonary hypoplasia or the need for dialysis within a few days of life.

Factors associated with fetal shunt dislodgement in lower urinary tract obstruction.

OBJECTIVE: To identify factors associated with fetal shunt dislodgement in lower urinary tract obstruction (LUTO). METHODS: We conducted a retrospective study of 42 consecutive fetuses with a diagnosis of LUTO in a tertiary fetal center between April 2013 and November 2015. Possible factors associated with prenatal shunt dislodgment were evaluated in fetuses who underwent shunt placement, including gestational age at diagnosis, gestational age at procedure, presence of 'keyhole sign', initial fetal bladder volume and wall thickness, prenatal ultrasonographic renal characteristics, amniotic fluid volume, presence of ascites prior to shunting, and type of fetal shunt. RESULTS: Nineteen (46.3%) fetuses underwent shunt placement at a median gestational age of 19 (range: 16.3-31.1) weeks. Shunt dislodgement occurred in 10 (52.6%) patients. A total of 35 procedures were performed; among which 16 (45.7%) were repeat procedures. The only prenatal factor associated with shunt dislodgement was the type of the shunt; Kaplan-Meier analysis indicated that the Rocket was associated with increased likelihood of remaining orthotopic (p = 0.04). CONCLUSION: Fetal shunt dislodgement occurs in approximately half of the patients and appears to be associated with the type of the shunt. Future research is necessary to develop better shunt systems and to investigate different fetal therapeutic approaches. © 2016 John Wiley & Sons, Ltd.

Complications following Staged Hypospadias Repair Using Transposed Preputial Skin Flaps.

PURPOSE: Proximal hypospadias repair using a staged approach is a complex reconstructive operation with the potential for significant complications requiring repeat surgery. We report outcomes of staged hypospadias repair using transposed preputial skin flaps and factors predictive of postoperative complications. MATERIALS AND METHODS: We retrospectively analyzed patients who underwent staged proximal hypospadias repair using transposed preputial skin flaps between 2002 and 2013. Patient demographics, operative details, complications, reoperations and factors predictive of complications were reviewed. RESULTS: A total of 56 patients were identified with a mean age of 14.1 months (median 14.3) at first stage. Mean followup was 38.6 months (median 34.1). Complications requiring additional unplanned operation(s) were observed in 38 patients (68%), including fistulas in 32 (57%), diverticula in 8 (14%), meatal stenosis in 5 (9%), urethral stricture in 8 (14%) and glans dehiscence in 3 (5%). In addition, redo first stage repair was performed in 4 patients (7%). Since some patients had more than 1 complication, the total number of complications is greater than the number of patients undergoing a redo operation. On univariate analyses the use of small intestinal submucosa was significantly associated with an increased risk of fistula (91% vs 49%, p = 0.02) and urethral diverticulum (64% vs 24%, p = 0.04). Incision of the tunica albuginea of the corpora was associated with an increased likelihood of fistula (77% vs 44%, p = 0.03). Finally, patients with glans dehiscence were significantly younger at first stage (5.8 vs 14.8 months, p = 0.01). CONCLUSIONS: The reoperation rate for complications in children undergoing staged hypospadias repair using transposed preputial skin flaps is higher than previously reported.

Outcomes of endoscopic incision for the treatment of ureterocele in children at a single institution.

PURPOSE: We assessed outcomes in children with ureterocele after transurethral incision at our institution between 2001 and 2014, focusing on end points of vesicoureteral reflux, improvement of hydronephrosis and need for second surgery. MATERIALS AND METHODS: We performed chart reviews of 83 patients, collecting information including age at transurethral incision, gender, renal anatomy, ureterocele location, indication for transurethral incision, and preincision and postincision vesicoureteral reflux and hydronephrosis status. Patients were divided into those with single system and duplex system ureteroceles, and intravesical and extravesical location for analysis. Statistical evaluations were performed with the Wilcoxon rank test and Fisher exact test. RESULTS: Transurethral incision was performed at a mean age of 34.2 months in patients with single system ureterocele and 8.9 months in those with duplex system ureterocele (p <0.0001). Cure rates (improvement of hydronephrosis and absence of vesicoureteral reflux) were 55.6% in patients with single system ureterocele and 14.9% in those with duplex system ureterocele (p = 0.0031). Rates of de novo reflux into the ureterocele moiety were 27.8% for patients with single system ureterocele and 56.2% for those with duplex system ureterocele (p = 0.0773). Patients with single system ureterocele required significantly fewer second surgeries (3.8%) than those with duplex system ureterocele (73.7%, p <0.0001). CONCLUSIONS: Patients with single system ureterocele may benefit from endoscopic incision. Transurethral incision was definitive in all such patients except 1 in our study. Although most patients with duplex system ureterocele will need a second operation, transurethral incision remains of value in this population in instances of sepsis or bladder outlet obstruction, or to facilitate planned reconstruction when the child is older.

Opposing regulation of PROX1 by interleukin-3 receptor and NOTCH directs differential host cell fate reprogramming by Kaposi sarcoma herpes virus.

Lymphatic endothelial cells (LECs) are differentiated from blood vascular endothelial cells (BECs) during embryogenesis and this physiological cell fate specification is controlled by PROX1, the master regulator for lymphatic development. When Kaposi sarcoma herpes virus (KSHV) infects host cells, it activates the otherwise silenced embryonic endothelial differentiation program and reprograms their cell fates. Interestingly, previous studies demonstrated that KSHV drives BECs to acquire a partial lymphatic phenotype by upregulating PROX1 (forward reprogramming), but stimulates LECs to regain some BEC-signature genes by downregulating PROX1 (reverse reprogramming). Despite the significance of this KSHV-induced bidirectional cell fate reprogramming in KS pathogenesis, its underlying molecular mechanism remains undefined. Here, we report that IL3 receptor alpha (IL3Rα) and NOTCH play integral roles in the host cell type-specific regulation of PROX1 by KSHV. In BECs, KSHV upregulates IL3Rα and phosphorylates STAT5, which binds and activates the PROX1 promoter. In LECs, however, PROX1 was rather downregulated by KSHV-induced NOTCH signal via HEY1, which binds and represses the PROX1 promoter. Moreover, PROX1 was found to be required to maintain HEY1 expression in LECs, establishing a reciprocal regulation between PROX1 and HEY1. Upon co-activation of IL3Rα and NOTCH, PROX1 was upregulated in BECs, but downregulated in LECs. Together, our study provides the molecular mechanism underlying the cell type-specific endothelial fate reprogramming by KSHV.