Posterior urethral valves: long-term outcome

Posterior urethral valve in thai boys

BACKGROUND

Posterior urethral valve (PUV) is the most common congenital bladder outlet obstruction in boys, causing renal damage beginning in utero. There are scarce data from Thailand regarding the long-term outcomes of PUV in boys, thus the aim of this study was to examine the presentation, clinical course, complications, outcomes and renal survival in PUV boys.

METHODS

We reviewed the medical records of PUV boys treated at the Pediatric Nephrology Clinic, Prince of Songkla University, Thailand, over a 30-year-period.

RESULTS

Seventy-seven PUV boys were identified, with a median age at diagnosis of 4.8 months. The most common presentations were urinary tract infection (UTI), poor urine stream and urinary dribbling in 26 (33.8%), 19 (24.7%) and 11 (14.3%) boys, respectively. Renal ultrasound results in 70 boys showed 8 (11.4%) unilateral and 56 (80%) bilateral hydronephroses. Of 72 voiding cystourethrograms, 18 (25.0%) showed unilateral and 22 (30.6%) bilateral vesicoureteral refluxes. 99mTc dimercaptosuccinic acid renal scans in 30 boys showed 12 (40%) unilateral and 8 (26.7%) bilateral renal damage. Fifty-nine (76.6%) boys had 149 UTIs; 42 (54.4%) had recurrent UTI. Forty-eight boys had valve ablation at the median age of 30.3 months. 22 boys (28.6%) developed chronic kidney disease (CKD) at a median age of 15.0 years.

CONCLUSION

Of 77 PUV Thai boys, UTI was the most common presentation. Recurrence of UTI and CKD was the most common consequence. Lifelong follow-up for renal and bladder functions is essential for all PUV patients.

Predicting childhood chronic kidney disease severity in infants with posterior urethral valve: a critical analysis of creatinine values in the first year of life

BACKGROUND

Posterior urethral valve (PUV) is a leading cause of chronic kidney failure in children. Studies have shown that a creatinine nadir above historical cutoff values of 0.8 or 1.0 mg/dL correlates with worse kidney outcomes. The ability to use nadir creatinine more discriminately as a test of kidney outcomes is otherwise limited.

METHODS

We performed a retrospective review of 102 infants treated with primary valve ablation prior to 1 year of age. Patient factors including creatinine at presentation (Cr-P), nadir within 6 weeks after ablation (Cr-6 W), and nadir within 1 year after ablation (Cr-1Y) were assessed as predictors of final chronic kidney disease (CKD) severity. An optimal threshold for four CKD levels was defined in incremental fashion using binary outcome with receiver operating characteristic (ROC). Multivariable logistic regression models compared Cr-P, Cr-6 W, and Cr-1Y while adjusting for patient factors.

RESULTS

Boys were ablated at mean age of 36.3 days and followed for 6.6 years (± 3.7). When compared to other demographics, only creatinine remained independently predictive of CKD outcomes on multivariable analysis. ROC analysis demonstrated excellent diagnostic accuracy for Cr-6 W and Cr-1Y (p < 0.001) and acceptable accuracy for Cr-P (p < 0.005). Using the Cr-6 W and Cr-1Y models, high sensitivity and specificity creatinine nadir cutoffs were determined to predict each CKD outcome.

CONCLUSIONS

The severity of childhood CKD can be predicted with high accuracy using the creatinine nadir within 6 weeks of ablation. The cutoff values described can be incorporated into a clinical setting for patient counseling and individual risk stratification.

Outcome of PUV Patients Following Ablation in a Tertiary Teaching Hospital in Addis Ababa, Ethiopia

Background

Posterior urethral valve  (PUV) is the most common cause of congenital lower urinary tract obstruction in boys. It is considered that early diagnosis and intervention have good outcomes in terms of renal function, though the varying extent of embryological insult requires these boys to remain in extended follow-up and care.

Objective

To assess the renal outcome of patients following PUV ablation.

Methods

This was a descriptive retrospective study. Data were collected from the operation logbooks of patients from 2015 to 2019 that had been admitted to the Tikur Anbessa Specialized Hospital pediatric surgery unit with a working diagnosis of PUV and had ablation done primarily or following diversion. Data were collected from January to April 2020 and analyzed using SPSS 25. P value≤0.05 was considered significant.

Results

Seventy patients were analyzed and followed for 3 years for the development of postoperative chronic kidney disease (CKD) after PUV ablation. Postoperative CKD was found in 52.9% of patients and end-stage renal disease in 2.9%. Risk factors associated with postoperative CKD were the presence of preoperative and postoperative proteinuria, postoperative hypertension, and elevated nadir serum creatinine. Results also showed that a delay between the development of vesicostomy and ablation had a significant correlation with renal outcome. Elevated nadir serum creatinine, postoperative proteinuria, and delay between the development of vesicostomy and ablation were found to be independent risk factors of development of CKD.

Conclusion

There was a high rate of CKD development in patients who had had ablation for PUV, which was comparable to other studies. Three variables were found to be independent risk factors for the progression of CKD, unlike other findings seen in low- and middle-income countries.

Renal, Bladder and Sexual Outcomes in Adult Men with History of Posterior Urethral Valves Treated in Childhood

OBJECTIVE

To determine the adulthood outcomes of bladder, kidney, and sexual functions of posterior urethral valve (PUV) patients.

MATERIALS AND METHODS

The records of patients who were treated for PUV between 1980, and 2001 and aged ≥18 years by the end of 2019 were retrospectively reviewed. Patients with complete adulthood data were included in the study. Renal, bladder, and sexual functions were assessed. Adulthood uroflowmetry results of 22 patients were also evaluated.

RESULTS

Thirty-nine patients with complete adulthood data out of 89 were included. The median follow-up time was 22.7 years (15-33 years). Median age at initial surgery for PUV was 36 months (1-168 months), and median age at last follow-up was 26 years (18-46 years). Lower urinary tract dysfunction was noted in 15 (38%) patients. In 22 patients (56%) with uroflowmetric analyses, median values of Q_max, voided volume, and post voiding residual urine volume were 20.5 mL/sec (7-43 mL/sec), 389 mL (154-1750 mL), and 18.5 mL (range 0-190 mL), respectively. Nineteen patients (48.7%) had normal glomerular filtration rate, 2 patients (5.1%) had chronic kidney disease, and the remaining 18 patients (46.1%) had end stage renal disease, 14 (35.9%) of whom underwent renal transplantation. Thirty-two patients (82%) had sexual function evaluation, none of which reported erectile dysfunction. However, 4 patients (12.5%) reported slow ejaculation. Five patients fathered a child whereas infertility was observed in 2 patients.

CONCLUSION

After 2 decades, glomerular filtration rate was normal almost in half of the PUV patients while lower urinary tract dysfunction was detected in 38%. Furthermore, erectile dysfunction was rare.

The posterior urethral valves revisited: embryological correlation, clinical classification, and risk stratification of the spectrum

Background

The diagnosis of posterior urethral valves (PUV) encompasses a vast spectrum of disease with variable severity and clinical features. It is vital to understand the extent of developmental insult and to define the different distinct entities grouped together under the diagnostic umbrella of PUV. This would help to determine the severity of the disease, enable better prognostication, and optimize therapy. The objective of this study is to analyze the variable features of PUV and correlate the different manifestations with the embryological development of the urinary system. The possible developmental basis of anomalies in PUV is analyzed, as recognition of the underlying defect would help to determine the severity of the disease. A clinical classification and a risk stratification approach encompassing the spectrum of PUV is proposed, to help define diagnosis and guide prognosis. A combined retrospective and prospective analysis of cases diagnosed as PUV at the tertiary teaching institute over a 5-year period from July 2014 to July 2019 was done. The outcome of selected cases was analyzed, based on the risk group stratification.

Results

The incidence of major complications during follow-up in each risk group was assessed individually and found to be highest in the high-risk group (92%), which was significantly higher than the other groups. The intermediate risk group was found to have a complication rate of 38%, while the low-risk group had only 12.5% complication rate. The three key concepts addressed in this study pertain to the embryological basis of PUV, the necessity of a clinical subdivision of patients, and the possibility of risk stratification based on clinical criteria. The limited review of institutional series is added to highlight the method of risk stratification and its probable utility.

Conclusions

The most critical factors to be accounted for in the diagnosis and management of PUV are the definition of disease severity, recognition of systemic complications, and identification of children at risk of progression to ESRD. The proposed developmental defect analysis, description of PUV sequence, clinical classification, and risk stratification approach are only the means to this end of segregating patient groups within the diagnostic spectrum.

Retroperitoneoscopic bilateral nephrectomy and extraperitoneal ureterocystoplasty in a child on peritoneal dialysis

A 4-year-old boy with posterior urethral valves and end stage kidney disease on peritoneal dialysis presented with high pressure non-compliant bladder with left ureterohydronephrosis. Inability to perform hemodialysis due to patient's weight exclusion, imposed the necessity to preserve peritoneal dialysis. A bilateral nephrectomy by retroperitoneoscopy with extraperitoneal augmentation ureterocystoplasty using left ureter and pelvis associated with continent diversion using right ureter as umbilical stoma was performed followed by kidney transplantation. An excellent outcome with voluntary voiding without CIC is reported eighteen months later. This treatment modality is the best option to manage End Stage Kidney Disease on peritoneal dialysis in those patients.

Acute kidney injury among critically ill neonates in a tertiary hospital in Tanzania; Prevalence, risk factors and outcome

Background

Neonatal acute kidney injury contributes to high mortality in developing countries. The burden of neonatal AKI is not known in Tanzania despite having high neonatal mortality. This study was conducted to determine the burden of AKI among critically ill neonates admitted at Muhimbili National Hospital.

Methods

This was a cross-sectional study conducted in the neonatal ward at the MNH. Eligible critically ill neonates were recruited consecutively between October 2017 and March 2018. Data was collected using a standardized structured questionnaire. Blood specimen was drawn to measure baseline creatinine at admission, 48^th hour, 72^nd hour and 14^th day. Data was analysed using SPSS version 20.0 Univariate analysis was done using chi-square to determine the association between categorical variables and multivariate logistic regression was performed to determine predictors of AKI.

Results

A total of 378 critically ill neonates were recruited, 31.5% had AKI and independent predictors of AKI were noted to be neonatal sepsis (aOR 2.237, 95%CI 1.3–3.6, P = 0.001), severe pneumonia (aOR3.0, 95%CI 1.0–9.3, P = 0.047) and use of gentamycin (aOR6.8, 95%CI 1.3–9.3, P = 0.02). Complete resolution of renal dysfunction at the fourteenth day was seen in 83.1% of the neonates while 16.9% had persistence of renal dysfunction. Ultrasound scan were performed among 105 participants with AKI revealed increased echogenicity, mild hydronephrosis and ectopic kidneys in 25 (23.8%), 4 (3.8%) and 2 (1.9%) respectively. In-hospital mortality was significantly higher among neonates with AKI (70.6%) as compared to those without (29.4%) p< 0.001.

Conclusions

AKI was noted in a third of critically ill neonates, with neonatal sepsis, severe pneumonia and use of gentamycin as independent predictors of AKI. Neonates who suffered AKI had twice as much mortality as compared to those without.

Gross Hematuria as a Presenting Feature of Posterior Urethral Valves in a Neonate with Normal Antenatal Sonograms

Background: Posterior urethral valves (PUVs) are usually suspected during antenatal sonograms or by postnatal evidence of bilateral hydronephrosis with enlarged bladder. Gross hematuria as an initial manifestation of PUV with a history of normal antenatal sonogram is very rare. Methods: This is a retrospective chart study. Results: We describe a nine-day-old male neonate who presented with gross hematuria and was later found to have a urinary tract infection (UTI) and severe acute kidney injury (AKI). The mother apparently had normal antenatal sonograms with no evidence of fetal hydronephrosis. The child did not have postnatal renal bladder sonogram done until gross hematuria occurred at Day 9 of life. Sonogram showed bilateral severe hydronephrosis and hydroureter with enlarged bladder. The patient underwent ablation of the PUVs after initial bladder decompression with indwelling urethral catheterization. His AKI resolved after prompt treatment of UTI and PUV ablation. Conclusions: This report emphasizes the importance of a high index of suspicion for obstructive uropathy in a newborn with gross hematuria irrespective of prenatal sonogram findings.

Survival and Kidney Outcomes of Children with an Early Diagnosis of Posterior Urethral Valves

BACKGROUND AND OBJECTIVES

Posterior urethral valve is the most common cause of bladder outlet obstruction in infants. We aimed to describe the rate and timing of kidney-related and survival outcomes for children diagnosed with posterior urethral valves in United States children's hospitals using the Pediatric Health Information System database.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This retrospective cohort study included children hospitalized between January 1, 1992 and December 31, 2006, who were in their first year of life, had a diagnosis of congenital urethral stenosis, and underwent endoscopic valve ablation or urinary drainage intervention, or died. Records were searched up to December 31, 2018 for kidney-related mortality, placement of a dialysis catheter, and kidney transplantation. Cox regression analysis was used to identify risk factors, and Kaplan-Meier survival analysis used to determine time-to-event probability. Subgroup survival analysis was performed with outcomes stratified by the strongest identified risk factor.

RESULTS

Included were 685 children hospitalized at a median age of 7 (interquartile range, 1-37) days. Thirty four children (5%) died, over half during their initial hospitalization. Pulmonary hypoplasia was the strongest risk factor for death (hazard ratio, 7.5; 95% confidence interval [95% CI], 3.3 to 17.0). Ten-year survival probability was 94%. Fifty-nine children (9%) underwent one or more dialysis catheter placements. Children with kidney dysplasia had over four-fold risk of dialysis catheter placement (hazard ratio, 4.6; 95% CI, 2.6 to 8.1). Thirty-six (7%) children underwent kidney transplant at a median age of 3 (interquartile range, 2-8) years. Kidney dysplasia had a nine-fold higher risk of kidney transplant (hazard ratio, 9.5; 95% CI, 4.1 to 22.2).

CONCLUSIONS

Patients in this multicenter cohort with posterior urethral valves had a 5% risk of death, and were most likely to die during their initial hospitalization. Risk of death was higher with a diagnosis of pulmonary hypoplasia. Kidney dysplasia was associated with a higher risk of need for dialysis/transplant.

PODCAST

This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2019_10_03_CJN04350419.mp3.

Fetal Cystoscopy and Vesicoamniotic Shunting in Lower Urinary Tract Obstruction: Long-Term Outcome and Current Technical Limitations

BACKGROUND

In utero therapeutic approaches for lower urinary tract obstruction (LUTO) have been developed to salvage the fetal kidney function.

OBJECTIVE

The aim of this work was to report the long-term survival, nephrological, and urological outcome of children treated prenatally for LUTO using operative fetal cystoscopy (FC) and vesicoamniotic shunting (VAS) or both.

METHODS

A retrospective study of 48 procedures (23 FC, 25 VAS) was performed on 33 patients (between 2008 and 2018). Reviewed data included prenatal management and clinical follow-up by a pediatric nephrologist and a pediatric urologist. Both intention-to-treat and per-protocol analyses were conducted.

RESULTS

The median follow-up was 3.6 years (0.5-7) for FC and 2.5 years (1.1-5.1) for VAS. There was no difference between FC and VAS in terms of survival (92 vs. 83%, p = 1), complication rate (74 vs. 92%, p = 0.88), or chronic kidney disease (58 vs. 50%, p = 1). The number of procedures was higher in the VAS group: 1.7 (1-3) versus 1.1 (1-2), p = 0.01. With a 30% rate of technical failure, FC added diagnostic value in 3 out of 21 cases.

CONCLUSIONS

No difference was found between FC and VAS regarding survival, long-term kidney function, or urological outcome. Despite overly optimistic reports on FC, it lacks reproducibility due to posterior-urethra inadequate visualization and inappropriate instrumentation.

The protective arm of the renin-angiotensin system may counteract the intense inflammatory process in fetuses with posterior urethral valves

OBJECTIVE

Posterior urethral valve is the most common lower urinary tract obstruction in male children. A high percentage of patients with posterior urethral valve evolve to end-stage renal disease. Previous studies showed that cytokines, chemokines, and components of the renin-angiotensin system contribute to the renal damage in obstructive uropathies. The authors recently found that urine samples from fetuses with posterior urethral valve have increased levels of inflammatory molecules. The aim of this study was to measure renin-angiotensin system molecules and to investigate their correlation with previously detected inflammatory markers in the same urine samples of fetuses with posterior urethral valve.

METHODS

Urine samples from 24 fetuses with posterior urethral valve were collected and compared to those from 22 healthy male newborns at the same gestational age (controls). Renin-angiotensin system components levels were measured by enzyme-linked immunosorbent assay.

RESULTS

Fetuses with posterior urethral valve presented increased urinary levels of angiotensin (Ang) I, Ang-(1-7) and angiotensin-converting enzyme 2 in comparison with controls. ACE levels were significantly reduced and Ang II levels were similar in fetuses with posterior urethral valve in comparison with controls.

CONCLUSIONS

Increased urinary levels of angiotensin-converting enzyme 2 and of Ang-(1-7) in fetuses with posterior urethral valve could represent a regulatory response to the intense inflammatory process triggered by posterior urethral valve.

A clinical predictive model of chronic kidney disease in children with posterior urethral valves

BACKGROUND

Posterior urethral valves (PUVs) are associated with severe consequences to the urinary tract and are a common cause of chronic kidney disease (CKD). The aim of this study was to develop clinical predictive model of CKD in a cohort of patients with PUVs.

METHODS

In this retrospective cohort study, 173 patients with PUVs were systematically followed up at a single tertiary unit. The primary endpoint was CKD ≥ stage 3. Survival analyses were performed by Cox regression proportional hazard models with time-fixed and time-dependent covariables.

RESULTS

Mean follow-up time was 83 months (SD, 70 months). Sixty-five children (37.6%) developed CKD stage ≥ 3. After adjustment by the time-dependent Cox model, baseline creatinine, nadir creatinine, hypertension, and proteinuria remained as predictors of the endpoint. After adjustment by time-fixed model, three variables were predictors of CKD ≥ stage 3: baseline creatinine, nadir creatinine, and proteinuria. The prognostic risk score was divided into three categories: low-risk (69 children, 39.9%), medium-risk (45, 26%), and high-risk (59, 34.1%). The probability of CKD ≥ stage 3 at 10 years age was estimated as 6%, 40%, and 70% for patients assigned to the low-risk, medium-risk, and high-risk groups, respectively (P < 0.001). The main limitation was the preclusion of some relevant variables, especially bladder dysfunction, that might contribute to a more accurate prediction of renal outcome.

CONCLUSION

The model accurately predicts the risk of CKD in PUVs patients. This model could be clinically useful in applying timely intervention and in preventing the impairment of renal function.

Consensus on the Management of Posterior Urethral Valves from Antenatal Period to Puberty

The need for successful management of posterior urethral valves always captivates the minds of pediatric surgeons. Its success, however, depends on several factors ranging from prenatal preservation of upper tracts to postoperative pharmacological compliance. Regardless of measures available, some cases do not respond and progress to end stage. The management depends on several issues ranging from age and severity at presentation to long-term follow-up and prevention of secondary renal damage and managing valve bladder syndrome. This article is based on a consensus to the set of questionnaires, prepared by research section of Indian Association of Paediatric Surgeons and discussed by experienced pediatric surgeons based in different institutions in the country. Standard operating procedures for conducting a voiding cystourethrogram and cystoscopy were formulated. Age-wise contrast dosage was calculated for ready reference. Current evidence from literature was also reviewed and included to complete the topic.

Urine biochemistry to predict long-term outcomes in fetuses with posterior urethral valves

OBJECTIVE

Because the literature on the predictive value of fetal urinalysis is controversial in fetuses with lower urinary tract obstruction, we determined the best model of fetal urine biochemical markers correlated with long-term postnatal renal function based on glomerular filtration rate (GFR).

METHOD

This retrospective study concerned 89 fetuses with lower urinary tract obstruction and their renal function after 10 years of age. We correlated fetal urine biochemical markers (total protein, β2-microglobulin, sodium, chloride, glucose, calcium, and phosphorus) with GFR at 10 to 30 years of age in 89 patients with posterior urethral valves. We defined five stages of chronic kidney disease (CKD).

RESULTS

Of the 89 patients, 18 (20%) are 20 years old or over. Postnatal renal function was good in 67.4% (GFR > 60 mL/min/1.73 m² ) and poor in 17% (GFR < 30 mL/min/1.73 m² ). All fetal urine markers differed between CKD stage 1 + 2 and CKD stage 4 + 5 (P < 0.001). β2-microblobulin showed an 87% sensitivity for a 72% specificity. A combination of β2-microglobulin and chloride gave the best results (93% sensitivity and 71% specificity) versus amniotic fluid volume (80% sensitivity and 73% specificity).

CONCLUSION

Fetal urine biochemistry predicts long-term (10-30 years) postnatal renal function.

Caring for infants with posterior urethral valves: A qualitative study of parents' experiences

This study aimed to explore the perspectives and experiences of parents caring for an infant with posterior urethral valves (PUVs). Eight parents participated in a semi-structured, individual telephone interview, with qualitative data collected and analysed thematically using NVivo11 software. Two main themes emerged as interconnecting aspects of parents' experiences: (1) trying to face the challenges and (2) learning to cope. Parents felt challenged by the need to attend to their child's medical care, while developing a bond with their baby, trying to maintain positivity for their child's future and managing the impact of the condition on their family. Nevertheless, parents developed strategies to cope with these challenges, such as seeking support, normalizing the experience and focusing on the positives. This preliminary understanding of parents' experiences provides direction for improving care pathways for infants with PUV and their parents as well as guides further research in this previously unexplored area.

Holding Water: Congenital Anomalies of the Kidney and Urinary Tract, CKD, and the Ongoing Role of Excellence in Plumbing

Congenital anomalies of the kidneys and urinary tracts can result in diminished natal kidney function, possibly through common embryologic pathway disruption or as a result of development taking place in the face of disordered 'post-renal' drainage. Impaired conduit and reservoir function present potential for an ongoing assault leading to further deterioration and progression of chronic kidney disease, a risk that extends to adults with these conditions, even after "correction". The drainage and storage aspects of the urinary system that can impact kidney function are reviewed with attention to correctable or manageable problems including: Bladder dysfunction wherein the low pressure storage of urine is compromised requiring the kidney to work against a pressure gradient, the classic post renal failure problem. The kidney in the aftermath of obstruction which may have lost concentrating capacity leading to a tendency to dehydration ('pre-renal' failure) and through polyuria which exacerbates bladder pressure problems. Further there is an added challenge in evaluation for ongoing or reemergent obstruction in a significantly dilated system where the capacious system leads to slow turnover of urine often requiring a ureteral stent or nephrostomy to clearly establish clinical significance of delayed drainage. Stasis where slow urine flow leads to buildup of debris (stone) or potentiates infection. Vessicoureteral reflux which allows for introduction of lower urinary tract bacteria to the kidney and can lead to pyelonephritis. Conditions which combine problems such as posterior urethral valves where the bladder outlet obstruction compromises kidney function potentially impairing concentrating ability, creates bladder compromise often reducing emptying efficiency or elevating bladder storage pressures, as well as dilating the system potentially promoting stasis. Cognizance of the potential for plumbing problems to further kidney deterioration as patients with congenital urinary tract anomalies, even after they have been repaired is incumbent on those caring for these patients as they age. Thoughtful evaluation of those patients in whom kidney compromise maybe aggravated by drainage and storage disorder will optimize native renal function.

Preventative effects of a HIF inhibitor, 17-DMAG, on partial bladder outlet obstruction-induced bladder dysfunction

Posterior urethral valves are the most common cause of partial bladder outlet obstruction (PBOO) in the pediatric population. Pathological changes in the bladder developed during PBOO are responsible for long-lasting voiding dysfunction in this population despite early surgical interventions. Increasing evidence showed PBOO induces an upregulation of hypoxia-inducible factors (HIFs) and their transcriptional target genes, and they play a role in pathophysiological changes in the obstructed bladders. We hypothesized that blocking HIF pathways can prevent PBOO-induced bladder dysfunction. PBOO was surgically created by ligation of the bladder neck in male C57BL/6J mice for 2 wk. PBOO mice received intraperitoneal injection of either saline or 17-DMAG (alvespimycin, 3 mg/kg) every 48 h starting from day 1 postsurgery. Sham-operated animals received injection of saline on the same schedule as PBOO mice and served as controls. The bladders were harvested after 2 wk, and basal activity and evoked contractility of the detrusor smooth muscle (DSM) were evaluated in vitro. Bladder function was assessed in vivo by void spot assay and cystometry in conscious, unrestrained mice. Results indicated the 17-DMAG treatment preserved DSM contractility and partially prevented the development of detrusor over activity in obstructed bladders. In addition, PBOO caused a significant increase in the frequency of micturition, which was significantly reduced by 17-DMAG treatment. The 17-DMAG treatment improved urodynamic parameters, including increases in the bladder pressure at micturition and nonvoid contractions observed in PBOO mice. These results demonstrate that treatment with 17-DMAG, a HIF inhibitor, significantly alleviated PBOO-induced bladder pathology in vivo.

Factors Predicting Renal Function Outcome after Augmentation Cystoplasty

We determined the cause of renal deterioration after augmentation cystoplasty (AC). Twenty-nine adult patients with refractory bladder dysfunction and who underwent ileocystoplasty from 2004 to 2015 were studied. Patients with a decline in glomerular filtration rate (GFR) after augmentation were reviewed. The primary outcome was to determine the factors that might lead to deterioration of estimated GFR. Median follow-up was 7.0 ± 2.6 years. Significant bladder capacity, end filling pressure, and bladder compliance were achieved from median 114 ± 53.6 to 342.1 ± 68.3 ml (p = .0001), 68.5 ± 19.9 to 28.2 ± 6.9 cm H₂O (p = .0001), and 3.0 ± 2.1 to 12.8 ± 3.9 (p = .0001), respectively. Renal function remained stable and improved in 22 (76%) patients from median eGFR 135 ± 81.98 to 142.82 ± 94.4 ml/min/1.73 m² (p = .160). Significant deterioration was found in 7 (24%) patients from median eGFR 68.25 ± 42 to 36.57 ± 35.33 (p = .001). The causes of renal deterioration were noncompliance to self-catheterization (2 patients), posterior urethral valve/dysplastic kidneys (2 patients), and reflux/infection (2 patients). On multivariate analysis, recurrent pyelonephritis (OR 3.87, p = 0.0155) and noncompliance (OR 30.78, p = 0.0156) were significant. We concluded that AC is not the cause of progression to end-stage renal disease in patients with renal insufficiency.

The Long-term Effect of Superficial Bladder Neck Incision on Ejaculation and Incontinence in Boys with Primary and Secondary Bladder Neck Obstruction

OBJECTIVE

Superficial bladder neck incision (SBNI) is controversial at young age, with retrograde ejaculation after puberty as main concern. The aim of the study is to investigate the long-term effect of SBNI on ejaculation and incontinence in boys with primary and secondary bladder neck obstruction (BNO).

MATERIALS AND METHODS

In boys with infravesical obstruction, SBNI was performed in case of a persistent BNO after earlier desobstruction or in case of primary severely obstructive bladder neck. SBNI was performed with a diathermy hook, always superficially (2-3 mm) and unilaterally at 7 O'clock. Males that had SBNI during childhood after posterior urethral valve incision or relief of other obstruction between 1986 and 2003 were included. Evaluation was done by International Continence Society male sex questionnaire, International Prostate Symptom Score, developmental International Consultation Modular Questionnaire on Urinary Incontinence, frequency volume chart, and uroflowmetry.

RESULTS

Of 79 traceable patients, 40 (50.6%) participated. Of these, 37 (92.5%) completed all questionnaires and 28 (70%) performed uroflowmetry. Median age at SBNI was 4.7 years [interquartile range (IQR) 0.6-8.5] and was 19.6 years (IQR 17.3-20.9) at follow-up. All men had antegrade ejaculation, 4/37 (10.8%) reported possibly reduced ejaculatory volume. Eight (22%) had moderate lower urinary tract symptoms and two (5.4%) had moderate incontinence. Median maximum flow rate was 30.1 mL/s (IQR 24.4-42.6).

CONCLUSION

SBNI in boys with severe infravesical obstruction can be done safely with preservation of antegrade ejaculation and no additional lower urinary tract dysfunction.

Organ bioengineering for the newborn

Regenerative medicine has recently been established as an emerging interdisciplinary field focused on the repair; replacement or regeneration of cells, tissues and organs. It involves various disciplines, which are focused on different aspects of the regeneration process such as cell biology, gene therapy, bioengineering, material science and pharmacology. In this article, we will outline progress on tissue engineering of specific tissues and organs relevant to paediatric surgery.

Role of vesicostomy in the management of posterior urethral valve in Sub-Saharan Africa

OBJECTIVE

To review the role of vesicostomy in the management of posterior urethral valve (PUV), in neonates and infants, given the limitations for endoscopic treatment in this setting.

METHODS

A review of 35 patients who presented with posterior urethral valve over a 10-year period. Demographic and clinical information were prospectively recorded on a structured pro forma, and the data extracted analysed using SPSS 11.0.

RESULTS

The 35 boys were aged 3 days to 10 years (median 3 weeks). Twenty-three (65.7%) had a vesicostomy (age range 3 days-3 years, median 3 weeks). The mode of presentation was poor urinary stream 15 (65.2%), urinary retention 4 (17.4%), and renal failure 6 (26.1%). Main findings were palpable bladder 23 (100%), hydronephrosis 4 (17.4%). Abdominal ultrasound confirmed hydronephrosis and thickened bladder wall, and voiding/expressive cystourethrogram confirmed dilated posterior urethra and vesicoureteric reflux in all 23 patients. Complications following vesicostomy were stoma stenosis 1 (4.3%), bladder mucosal prolapse 1 (4.3%), perivesicostomy abscess 1 (4.3%); there was no mortality. Following vesicostomy, 10 (43.5%) patients had excision of the valves and vesicostomy closure at age 2-8 years (median 4 years). They are well, with normal renal ultrasonographic findings, bladder capacity range 115-280 ml, and normal urea, serum electrolytes, creatinine, at 3 years of follow up. Thirteen (56.5%) are still awaiting valvotomy but have remained well and with normal ultrasonographic renal findings.

CONCLUSION

Vesicostomy is a useful temporising mode of urinary diversion in neonates and infants with posterior urethral valve (in the absence of unobstructed upper tracts) when facilities for endoscopic valve ablation are not readily available.

Which patients are at higher risk for residual valves after posterior urethral valve ablation?

Purpose

To find patients at high risk of obstructive remnant leaflets after valve ablation among boys with posterior urethral valve (PUV), we evaluated any possible relationship between preoperative findings in our patients and residual obstructive leaflets after valve ablation.

Materials and Methods

We retrospectively reviewed the medical records of 55 patients with PUV that was treated by the same surgeon between 2008 and 2012. Of these, 37 patients (67.3%) had no obstructive remnant leaflets (group A) and 18 patients (32.7%) had obstructive remnant leaflets (group B) in follow-up cystoscopy. Preoperative clinical and radiological findings were evaluated and compared between the groups.

Results

Among all the preoperative data we examined, the analysis revealed that age at the time of surgery (median age: group A, 15 months; group B, 7 months; p=0.017), echogenicity of kidneys (p<0.05), presence of vesicoureteral reflux (p<0.05), and grade of reflux (p<0.05) were significantly different between the groups. Method of valve ablation, anterior-posterior diameters of the renal pelvis, renal cortical thickness, bladder wall thickening, and scarring on the dimercaptosuccinic acid scan showed no significant differences between the two groups.

Conclusions

In our patients, younger age at surgery time, hyperechogenicity of renal parenchyma, presence of vesicoureteral reflux, and grade 4 or 5 reflux before surgery had a significant relationship with residual valves. More studies may result in enhanced management of patients at high risk of residual valves after PUV ablation, because the sooner the obstruction is resolved entirely, the better the outcome.

Renal impairment in children with posterior urethral valves

BACKGROUND

Posterior urethral valves (PUV) are a common cause of end-stage renal failure in childhood. Our aim was to describe a cohort of patients with PUV and to investigate the predictors of renal impairment.

METHODS

We performed a retrospective chart review of children with PUV who were followed at King Abdulaziz University hospital between 2002 and 2011.

RESULTS

The cohort comprised 68 boys. There was a significant difference in the duration of follow-up (p = 0.024), nadir serum creatinine (p < 0.001), and last known serum creatinine level (p = 0.001) between the patients with and without renal impairment. The duration of follow-up appeared to be a significant predictor for serum creatinine doubling (p = 0.003; odds ratio, 1.8). There was no difference in the age of presentation, age at the time of the study, and first or last serum creatinine between children who initially had vesicostomy and children who had ablation.

CONCLUSIONS

Ablation of PUV or vesicostomy did not influence kidney function in our study cohort. Children with a normal nadir serum creatinine who presented early had a better outcome.

Rapamycin attenuates bladder hypertrophy during long-term outlet obstruction in vivo: tissue, matrix and mechanistic insights

PURPOSE

Previous molecular studies showed that the mTOR inhibitor rapamycin prevents bladder smooth muscle hypertrophy in vitro. We investigated the effect of rapamycin treatment in vivo on bladder smooth muscle hypertrophy in a rat model of partial bladder outlet obstruction.

MATERIALS AND METHODS

A total of 48 female Sprague-Dawley® rats underwent partial bladder outlet obstruction and received daily subcutaneous injections of rapamycin (1 mg/kg) or vehicle commencing 2 weeks postoperatively. A total of 36 rats underwent sham surgery and received rapamycin or vehicle. Rats were sacrificed 3, 6 and 12 weeks after surgery. Before sacrifice, voiding was observed in a metabolic cage for 24 hours. Bladder-to-body weight in gm bladder weight per kg body weight and post-void residual urine were assessed. We evaluated Col1a1, Col3a1, Eln and Mmp7 mRNA expression and histology. Two-factor ANOVA and the post hoc t test were applied.

RESULTS

Bladder outlet obstruction caused a significant increase in bladder weight in all obstructed groups. Three weeks postoperatively (1 week of treatment) there was no difference in the bladder-to-body weight ratio in the obstructed group. However, at 6 and 12 weeks (4 and 10 weeks of treatment, respectively) the bladder-to-body weight ratio of rats with obstruction plus rapamycin was significantly lower than that of rats with obstruction plus vehicle. Post-void residual urine volume after 6 and 12 weeks of obstruction was lower in obstructed rats with rapamycin compared to that in obstructed rats with vehicle. Rapamycin decreased the obstruction induced expression of Col1a1, Col3a1, Eln and Mmp7.

CONCLUSIONS

Rapamycin prevents mechanically induced hypertrophy in cardiovascular smooth muscle. In vivo mTOR inhibition may attenuate obstruction induced detrusor hypertrophy and help preserve bladder function.

Posterior urethral valves and adult sexual function

OBJECTIVES

To evaluate sexual function and fertility in adult patients treated for posterior urethral valves (PUV) in childhood and to compare these patients with the normal population. To examine if patient characteristics such as chronic renal failure (CRF), history of cryptorchidism and bladder neck incision in childhood have an impact on sexual function.

PATIENTS AND METHODS

Information on sexual function was assessed using questions from the International Index of Erectile Function (IIEF). In addition, the patients were asked if they had had children or been treated for CRF. Out of 108 adult patients with PUV, 67 (62%) returned the questionnaires. Sexual function in these patients was compared with 201 controls and paternity rates were compared with a national database.

RESULTS

The mean (sd) age of the patients and controls was 38 (9) and 38 (7) years, respectively. Six percent of the patients and 9% of the controls reported problems in achieving erection during sexual stimulation and 9% of the patients and 10% of the controls reported problems with the hardness of erection (P = nonsignificant). Ejaculation was absent in 1/61 sexually active patients (2%). The only significant risk factor in patients for erectile dysfunction (ED) was increasing age. Thirty-three (49%) of all 67 patients and four (57%) of the seven patients with kidney transplantation had had children. The paternity rates were similar to those in corresponding age groups of the general Finnish population. Eight patients (12%) had attempted to have children without success.

CONCLUSIONS

Men treated for PUV have a similar prevalence of ED and similar paternity rates to men without PUV. Erectile function and paternity rates can be satisfactory in spite of CRF.