Gotowa bibliografia na temat „Posterior urethral valves”

The most common cause of lower urinary tract obstruction in male infants is posterior urethral valves. Although the incidence has remained stable, the neonatal mortality for this disorder has improved due to early diagnosis and intensive neonatal care, thanks in part to the widespread use of prenatal ultrasound evaluations. In fact, the most common reason for the diagnosis of posterior urethral valves presently is the evaluation of infants for prenatal hydronephrosis. Since these children are often diagnosed early, the urethral obstruction can be alleviated rapidly through catheter insertion and eventual surgery, and their metabolic derangements can be normalized without delay, avoiding preventable infant mortality. Of the children that survive, however, early diagnosis has not had much effect on their long-term prognosis, as 30% still develop renal insufficiency before adolescence. A better understanding of the exact cause of the congenital obstruction of the male posterior urethra, prevention of postnatal bladder and renal injury, and the development of safe methods to treat urethral obstruction prenatally (and thereby avoiding the bladder and renal damage due to obstructive uropathy) are the goals for the care of children with posterior urethral valves[1].

Posterior urethral valves are the most common cause of mechanical infravesical obstruction in children. The disorder has a broad spectrum of severity and the patients could developcomplications on the long term, even after valves ablation. Objective: To record the various clinical presentations ofPUV and audit our experience in management of PUV and its various complications. Study design: Prospective studySetting: Department of Urology Allied Hospital Faisalabad. Period: From 01-01-2001 to 31-07-2004. Material &Methods: All male patients (children, infants & neonates) presented with various symptoms and signs of PUV wereincluded in the study. Detailed history & clinical examination was performed in each case. Diagnosis was confirmedby micturating Cystourethrogram. Posterior urethral valves were ablated in all patients by electric hook. The period offollow-up was 06 months. Results: Total number of patients were 32. Age of presentation was 40 days to 27 years.Majority 14(44%) of patients presented with urinary retention.13 (41%). Patients presented with dribbling of urine andpoor stream. 07(22%) had associated vesicouretral reflux. Vesicostomy was performed in one patient and one patienthad to be dialyzed. Complications occurred in 13 (14%) patients. Most common were urinary tract infections in 10 (31%)patients. One patient went into End stage renal disease. Conclusions: Valve ablation is the mainstay of treatmentof post urethral valves. Prenatal and postnatal factors like renal dysplasia and UTI have their role in final outcome.Drainage by feeding tube and Vesicostomy improves the outcome.

Thesis (MMed)--Stellenbosch University, 2014.
ENGLISH ABSTRACT: OBJECTIVES The aim of this study was to determine long-term renal function in boys presenting with posterior urethral valves at Tygerberg Children’s Hospital and to determine the prognostic value of certain clinical, biochemical and radiological variables DESIGN Retrospective, descriptive study of boys diagnosed and treated with posterior urethral valves at Tygerberg Children’s Hospital between 2001 and 2011. RESULTS Between 2001 and 2011, 47 cases of posterior urethral valves were diagnosed and treated at our institution. Thirteen patients were excluded from this study. Seven (20,6%) were diagnosed antenatally and 27 (79,4%) presented postnatally. Mean age at presentation was 13,9 months (median 2; range 0-74). The most common postnatal presentation was urinary tract infection (51,9%). Mean follow-up was 54,2 months (median 47,5; range 12-133). A total of 13 boys (38,2%) progressed to chronic renal failure or end-stage renal disease. Initial and nadir serum creatinine, poor corticomedullary differentiation and moderate-severe hydronephrosis were significant predictors of final renal function (p<0,050). Patient age at presentation, type of primary surgical intervention, increased renal echogenicity, bladder wall thickness, the presence of vesicoureteric reflux (no matter what the laterality or severity), severe bladder dysfunction and initial or breakthrough urinary tract infection had no significant impact on future renal function. Receiver operating characteristic curve analysis confirmed that boys with an initial serum creatinine ≥145μmol/L and a nadir serum creatinine ≥62μmol/L were at highest risk to develop chronic renal insufficiency (area under the curve 0,8 and 0,9, respectively). CONCLUSION More than a third of boys (38,2%) developed chronic renal failure or end-stage renal disease at the end of follow-up. Our data confirmed the high prognostic value of initial and nadir serum creatinine. Optimal threshold levels for initial and nadir serum creatinine to predict final renal function were 145μmol/L and 62μmol/L, respectively. Similarly, poor corticomedullary differentiation and moderate-severe hydronephrosis on initial kidney ultrasound were significant indicators of poor renal prognosis. Although all patients with posterior urethral valves should be counselled on potential renal morbidity, children with risk factors warrant closer monitoring.
AFRIKAANSE OPSOMMING: DOELWITTE Die doel van hierdie studie was om langtermyn nierfunksie te bepaal in seuns wat gediagnoseer is met posterior uretrale kleppe by Tygerberg-kinderhospitaal. Die prognostiese waarde van sekere kliniese, biochemiese en radiologiese veranderlikes is ook ondersoek. STUDIE ONTWERP Retrospektiewe, beskrywende studie van seuns wat tussen 2001 en 2011 by Tygerberg-kinderhospitaal gepresenteer het met posterior uretrale kleppe. RESULTATE Tussen 2001 en 2011 is 47 gevalle van posterior uretrale kleppe gediagnoseer en behandel by ons instelling. Dertien pasiënte is uitgesluit van hierdie studie. Sewe (20,6%) is met voorgeboorte sonar gediagnoseer en 27 (79,4%) het ná geboorte gepresenteer. Die gemiddelde ouderdom by diagnose was 13,9 maande (mediaan 2; reeks 0-74 ). Urienweginfeksie was die mees algemene metode waarmee postnatale pasiënte gepresenteer het (51,9%). Die gemiddelde opvolgperiode was 54,2 maande (mediaan 47,5; reeks 12-133). Dertien seuns (38,2%) het chroniese nierversaking of eind-stadium nierversaking ontwikkel. Aanvanklike en nadir serumkreatinien, swak kortiko-medullêre differensiasie en matig-erge hidronefrose was beduidende voorspellers van finale nierfunksie (p<0,050). Pasiënt ouderdom met diagnose, tipe chirurgiese ingryping, verhoogde niereggogenisiteit, blaaswanddikte, vesikoureteriese refluks, blaasdisfunksie en aanvanklike of deurbraak urienweginfeksies het geen beduidende impak op toekomstige nierfunksie gehad nie. Seuns met 'n aanvanklike serumkreatinien ≥145μmol/L en 'n nadir serumkreatinien ≥62μmol/L het die grootste risiko om chroniese nierversaking te ontwikkel, soos bevestig met ‘n ROC-ontleding (AUC 0,8 en 0,9, onderskeidelik). GEVOLGTREKKING Meer as 'n derde van die pasiënte (38,2%) het chroniese nierversaking of eindstadium nierversaking ontwikkel. Ons data bevestig die prognostiese waarde van aanvanklike en nadir serumkreatinienvlakke. Die optimale drempelwaardes vir die aanvanklike en nadir serumkreatinien om finale nierfunksie te voorspel was 145μmol/L en 62μmol/L, onderskeidelik. Swak kortiko-medullêre differensiasie en matig-erge hidronefrose op die aanvanklike niersonar was ook beduidende aanwysers van toekomstige nierfunksie. Alhoewel alle pasiënte met posterior uretrale kleppe berading moet ontvang oor potensiële niermorbiditeit, regverdig seuns met risikofaktore noukeurige monitering.

Posterior urethral valves cause bladder outflow obstruction and damage to the developing fetal kidney. Posterior urethral valves affect 1 in 8000 new-born males. A third of these children develop end stage renal failure by adolescence, despite valve ablation in the early post-natal period, implying that majority of the damage to the kidneys occurs in utero. How does this damage occur, and should we intervene in utero? The answers to these questions require further research, and are the basis to this thesis. This thesis focused on the effect bladder outflow obstruction has on morphology and apoptosis in the fetal kidney in a fetal lamb model. It also looked at the effect of bladder outflow obstruction on fetal stress hormone levels. Bladder outflow obstruction was created surgically in fetal lambs at day 70 of gestation, and fetal kidneys were analysed at day 2, 5, 10, 20 and 30 after creation of obstruction. Controls undergoing sham surgery were used for comparison. Four aspects were investigated: - effects of bladder outflow obstruction on renal histology effects of bladder outflow obstruction on expression of pro-apoptosis gene Bax and anti-apoptosis gene Bcl-X - effects of bladder outflow obstruction on renal regional apoptosis effects of bladder outflow obstruction on serum fetal ACTH and cortisol levels. Bladder outflow obstruction resulted in sequential morphological change in the fetal kidney over time. By 2 days post-obstruction, cystic change was noted. In addition, patchy attenuation of the nephrogenic blastema was evident by 5 days post-obstruction, with more confluent blastemal attenuation as well as generalized renal architectural disorganization by 10 days post-obstruction. By 20 and 30 days post-obstruction, cystic renal dysplasia had developed. Bladder outflow obstruction resulted in an increase in the ratio of renal expression of pro-apoptosis gene Bax to anti-apoptosis gene Bcl-X. Regional apoptosis counts showed increased tubular apoptosis compared to controls at 2 days post-obstruction, and increased blastemal apoptosis compared to controls at 5 days post-obstruction. By 10 days post-obstruction, blastemal apoptosis counts were reduced compared to controls. There were no significant differences in fetal serum ACTH and cortisol levels between fetal lambs with bladder outflow obstruction and controls. In conclusion, the results of this thesis outline the spectrum of morphological change in the fetal kidney over 30 days of bladder outflow obstruction. They show that detectable changes in morphology occur within two days of bladder outflow obstruction. Likewise, detectable changes in gene expression occur within 2 days of bladder outflow obstruction. The increased ratio of expression of Bax to Bcl-X suggests a swing towards increased apoptosis in response to bladder outflow obstruction. Further research is required to ascertain if these changes are reversible. However, the early onset of these changes as shown in this thesis suggests that any fetal intervention to protect the fetal kidney from the effects of bladder outflow obstruction may need to be instituted very early in gestation

Introdução: Dentre as anomalias congênitas obstrutivas do trato urinário a Válvula de Uretra Posterior (VUP) apresenta elevado risco para a sobrevida do recém-nascido e é a causa mais comum de doença renal crônica terminal na infância. Seu tratamento envolve múltiplas especialidades e necessita seguimento no longo prazo. Com esses aspectos torna-se imperativo a permanente reavaliação de condutas. Objetivo: Descrever os aspectos clínicos e evolutivos dos pacientes portadores de Válvula de Uretra Posterior buscando avaliar a necessidade de adequações ao protocolo de atendimento. Casuística e Métodos: Constituída por 68 pacientes portadores de VUP atendidos no HCFMRP-USP no período entre 1990 e 2015. Foram revistos os dados relativos ao nascimento, encaminhamento, exames complementares, cirurgias realizadas e evolução clínica. Resultados: houve predomínio da raça branca (76,5%) e procedentes da DRS XIII (82,4%). A maioria das crianças vieram encaminhadas de outros hospitais (80,9%), alguns já submetidos à derivação urinária. Quanto à idade ao encaminhamento, 52,7% chegaram após o primeiro ano de vida embora o diagnóstico tenha sido feito em 76,5% antes do primeiro ano. Avaliação ultrassonográfica pré-natal foi realizada em 40 gestantes (48,8%) e oligoâmnio observado em16/40 (40,0%). Dentre os exames complementares para diagnóstico e seguimento ambulatorial ressaltamos a urografia excretora (16,2%), cintilografia renal (70,6%) e renograma (29,4%). Uretrocistografia foi realizada em todos os pacientes. Quanto aos principais procedimentos, derivação vesico-amniótica intrauterina foi realizada em 3 pacientes, cateterismo vesical de demora em 20, derivação alta em 4 pacientes, vesicostomia em 33, ressecção parcial do colo vesical em 9 e cauterização da VUP em 67. Dez pacientes foram transplantados. Discussão e Conclusões: os resultados apresentados são comparáveis àqueles divulgados na literatura pelas melhores instituições quanto ao diagnóstico, procedimentos cirúrgicos e evolução. O que fica evidente são as condições sócioeconômicas e culturais do nosso País onde a obtenção de melhores resultados terapêuticos tropeça em questões sociais e educacionais, necessitando de ações conjuntas visando educação continuada e organização social. Exame pré-natal adequado, diagnóstico precoce e rápido encaminhamento a centros que possam absorver estes pacientes são cruciais para a melhor evolução clínica. O protocolo mínimo de assistência deve ser objeto de difusão aos profissionais de saúde de diferentes especialidades visando o reconhecimento do quadro clínico. É desejável a inclusão, no protocolo de atendimento, de exames laboratoriais com capacidade prognóstica relacionada à evolução para doença renal crônica.
Introduction: Among congenital anomalies of the urinary tract, the posterior urethral valve (PUV) has a high risk for newborn´s mortality and is the most frequent cause of terminal chronic kidney disease in children. Its treatment involves multidisciplinary approach and long-term follow-up is necessary. Therefore, it is mandatory to permanently re-evaluate conducts. Objective: To describe the clinical and evolutive aspects of patients with PUV, aiming to evaluate the need for care protocol adjustments. Patients and Methods: The records of 68 boys with PUV who were treated at HCFMRP-USP between 1990 and 2015 have been reviewed. The data analyzed consisted of information regarding birth, age at referral, complementary exams, surgeries and clinical evolution. Results: There was a predominance of Caucasian (76.4%) and patients have been referred from region DRS XIII (82.4%). Most of the children have already been referred from other hospitals (80.8%), and some of them were already submitted to urinary diversion. Regarding the age of referral, 52.7% arrived after the first year of life, although the children were diagnosed before the first year of life in 70,6% of the cases. Prenatal ultrasound evaluation has been performed in 40 pregnant women (48.8%) and oligohydramnios was found in 16/40 (40,0%). Concerning the complementary exams for diagnosis and outpatient follow-up we highlighted excretory urography (16.2%), renal scintigraphy (70,6%) and renogram (29,4%). Voiding cistourethrography was performed in all patients. Regarding the main procedures, intrauterine vesico-amniotic shunt was performed in 3 patients, temporary drainage of urinary tract with vesical catheterization in 20, higher diversion in 4 patients, vesicostomy in 33, partial resection of the bladder neck in 9 and ablation during cystoscopy of the VUP in 67 patients. Ten patients were submitted to transplantation. Discussion and Conclusions: the results presented are comparable to those published in the literature by the best institutions regarding diagnosis, surgical procedures and patient evolution. What has become evident are the socioeconomic and cultural conditions of our country, where obtaining better therapeutic results stumbles on social and educational issues, requiring joint actions aimed continuing education and social organization. Proper prenatal examination, early diagnosis and early referral to institutions that can absorb these patients are crucial for the best clinical outcome. The minimum protocol of assistance should be disseminated to health professionals of different specialties in order to recognize the clinical picture. It is desirable to include, in the attendance protocol, laboratory tests with prognostic capabilities regarding evolution to chronic kidney disease.

Includes abstract.
Includes bibliographical references (leaves 64-72).
Posterior urethral valve (PUV) is a congenital obstructing membrane of the male urethra. It is the commonest cause of bladder outlet obstruction in male children. PUV as a cause of obstructive uropathy is an important cause of end stage renal failure (ESRF) in children. Early detection and surgical intervention can slow down progression to ESRF.

Einleitung: Fehlbildungen der Nieren und ableitenden Harnwege gehören zu den häufigsten angeborenen Anomalien. Ihr Anteil an den pränatal diagnostizierten Fehlbildungen wird mit bis zu 50% angegeben. Die Behandlung urogenitaler Fehlbildungen hat sich nicht zuletzt unter dem Einfluss der Pränatalen Diagnostik erheblich gewandelt. Nach einer Phase der Übertherapie nach Einführung der pränatalen Diagnostik ergab sich nach modernen diagnostischen Kriterien und im Ergebnis von Langzeitstudien des natürlichen Ganges der Fehlbildungen eine wesentlich differenziertere Indikationsstellung für das aktive therapeutische Vorgehen Fragestellung: In der retro- und prospektiv angelegten Studie sollte untersucht werden, inwieweit die pränatale Diagnostik das postnatale Vorgehen beeinflusst. So sollte untersucht werden, aus welchen pränatalen Befunden welche pränatalen Verdachtsdiagnosen gestellt wurden und wie sich diese zu den definitiven postnatalen Diagnosen verhalten. Des weiteren sollte der Aussagewert einzelner pränataler Befunde herausgearbeitet werden. Besondere Beachtung sollte dabei die Frage finden, inwieweit aus den pränatalen Befunden eine Aussage über die postnatale Therapiebedürftigkeit und schließlich auch für die Prognose der Nierenfunktion möglich ist. Patienten und Methoden: Ausgangspunkt waren 21.616 in der Abteilung für pränatale Diagnostik und Therapie in der Zeit von 1984 bis 1996 untersuchte Schwangerschaften. Unter diesen fanden sich 1.574 Feten mit angeborenen Anomalien mit fraglich kinderchirurgischer Relevanz. 1077 Fälle konnten ausgewertet werden. Mit 990 Fällen dominierten die Fehlbildungen des Urogenitalsystems, von denen 693 in die komplette Analyse mit einbezogen werden konnten. Ergebnisse: Bei 7,28% aller untersuchten Feten fanden sich Organfehlbildungen außerhalb des Zentralnervensystems. Unter diesen dominierten Harntraktfehlbildungen mit 63%. Als häufigste Diagnose wurde pränatal eine "Hydronephrose" angegeben. Dieser Begriff umschreibt jedoch in dem hier verwandten Sinne eine Harntransportstörung jeglicher Ursache. Echte Diagnosen obstruktiver Uropathien wurden lediglich zu 30% in den einzelnen Gruppen gestellt. Die pränatalen Verdachtsdiagnosen bestätigen sich zu zwischen 80 und 90% wenn: - eine isolierte Hydronephrose mit einem Nierenbeckendurchmesser von über 10 mm als Ureterabgangsstenose befundet wurde - die typische Konfiguration einer Multizystischen Nierendysplasie gefunden wurde - aus der Kombination von Oligohydramnion, Megazystis und bilateraler Harntransportstörung des männlichen Feten auf Urethralklappen geschlossen wurde. Lediglich bei der unilateralen multizystischen Nierendysplasie und der subpelvinen Obstruktion wird im pränatalen Befund bezüglich der definitiven Diagnose eine akzeptable Sensitivität und Spezifität erreicht. Alle anderen Diagnosen werden zu 70% postnatal gestellt. Der Einfluss der pränatalen Diagnostik auf das postnatale Management bezieht sich in erster Linie auf die Aufdeckung vorerst symptomloser Fehlbildungen. Eine pränatale Aussage über die zu erwartende Nierenfunktion ist bei einseitigen Fehlbildungen derzeit nicht möglich. Zusammenfassung: Obstruktive Uropathien sind häufige, zumeist benigne Fehlbildungen. Sie sind der pränatalen Diagnostik gut zugänglich. Konkrete Diagnosen mit Aussagen zur postnatalen therapeutischen Relevanz können jedoch nur gestellt werden, wenn sonografisch pathognomonische Konstellationen dies ermöglichen. In allen anderen Fällen muss die pränatal beschriebene Auffälligkeit Anlass zu postnataler sorgfältiger Diagnostik sein, um im präsymptomatischen Intervall die Entscheidung zu konservativer oder operativer Therapie stellen zu können.
Introduction: Among congenital dysplasias the anomalies of kidney and urogenital tract are among the most frequent encountered. Their rate in prenatally made diagnoses is about 50 %. Modern prenatal diagnostic facilities have changed the therapeutic access to these anomalies in the last decade. After a phase of overtreatment in the beginning, nowadays new insights in the natural course of these dysplasias and the results of long-term follow-up studies resulted in a more differentiated apporach. Questions and methods: In this retro- and prospective study we looked for the the influence of prenatal diagnostics on the postnatal course and management. The question was to examine the relationship between the prenatal ultrasound results, the suggested prenatal diagnosis and then the defintive postnatal disease. Of interest was the prognostic impact of typical prenatal sonographic imaging on the postnatal course of the baby. Because of its frequency we focused on anomalies of the kidney and urogenital tract. Patients: Between 1984 and 1996 21.616 pregnancies were examined by ultrasound in our Department of Prenatal Medicine. Among these, 1.574 anomalies of surgical relevance were described. 1.077 cases were available for follow-up including 990 cases of urogenital anomalies. Among these, the records of 693 cases were complete and these patients form the collective of this study. Results: When the CNS was excluded we found organic anomalies in 7,28 % of these cases. Among them 63% were attributed to the urogenital system. The most common prenatal diagnosis was "hydronephrosis". But this term was used only in a descriptive manner because proof of a real obstructive uropathy postnatally was made only in 30% of these cases. Concerning all anomalies of the urogenital tract, the prenatal diagnosis proved correct in the overwhelming majority of cases ( 90%) if these sonographic signs have been described: - diameter fo the renal pelvis of more than 10 mm in isolated hydronephrosis predicted ureteropelvic junction obstruction - typical formation of a multicystic dysplastic kidney - combination of oligohydramnion, megacystis and bilateral kidney anomalies in a male fetus predicted posterior urethral valve disease Sensitivity and specifity in regard to the definitive diagnosis were acceptable in multicystic dysplasia of the kidney and ureteropelvic junction obstruction. In all other cases, the correct diagnosis was made postnatally in 70 %. Therefore, the main value of prenatal sonography was to reveal otherwise symptomless dysplasias. Until now, a prenatal prediction of kidney function in the unilateral case is not possible. Conclusion: Obstructive uropathies are common an in most cases benign anomalies. They are easily detected by prenatal ultrasound. Therapeutical consequences, however, only arise in selected cases if typical sonographic signs can be seen. In the majority of cases, therefore, the main purpose of prenatal diagnostic ultrasound points out the necessity for postnatal diagnostic workup in order to detect and treat severe diseases before symptoms occur.

M.Med. (Paediatrics), Faculty of Health Sciences, University of the Witwatersrand, 2008
Background: Posterior urethral valves (PUV) result in a spectrum of obstruction, and up to thirty percent of patients progress to renal failure. Objective: Descriptive study of patients with PUV, and to compare growth and renal function in the primary valve ablation versus vesicostomy group. Methods: Retrospective record review of patients with PUV at Chris Hani Baragwanath Hospital from January 1985 to December 2005. Results: A total of 128 boys were identified. The mean (range) age was 12.9 months (0 to 139.4). The mean duration of follow-up was 42 months, with 65% lost to follow- up. UTI and voiding problems were the most common modes of presentation. Young age at presentation and renal dysfunction after surgery were poor prognostic features. Hydronephrosis was present in 89.5%. Renal failure was present in 37% of patients at last visit. Primary valve ablation was performed in 44.2% and vesicostomy in 55.8%. No statistical difference in renal outcome or somatic growth was observed between the surgical groups. Conclusion: PUV is a common condition with significant morbidity. The renal outcome in black South African boys is similar to reports from developed countries. The type of initial surgical management did not impact on renal outcome or somatic growth.

Posterior urethral valves is the most common congenital cause of lower urinary tract obstruction in males, and a common cause (15–17%) for end-stage renal disease in childhood. Most commonly, posterior urethral valves is suspected on basis of a screening antenatal ultrasound. Ultrasound will not detect posterior urethral valves itself, but recognizes the consequences of lower urinary tract obstruction with a dilated thick-walled bladder and dilation of the prostatic portion of the urethra. After birth, urine drainage has to be secured by placement of a bladder catheter, and imaging is needed to confirm the presence of the urethral valves and estimate the degree of damage to the kidney. Consequences of posterior urethral valves depend on the degree of renal dysplasia and bladder dysfunction. Prevention or minimization of such consequences by intrauterine urine drainage has not definitively shown a benefit of early vesico-amniotic shunting.

Most disorders of the urethra in children are congenital in origin and affect boys more commonly than girls. They include; posterior urethral valves (PUV), anterior urethral valves, anterior urethral diverticulum, syringocele, urethral atresia, megalourethra, urethral web, urethral polyp, and urethral duplication. Urethral strictures may be congenital or acquired. Most cases of PUV are now diagnosed prenatally. Postnatal management comprises bladder drainage, correction of any metabolic disturbance, prevention of infection (UTI), and endoscopic valve ablation. Careful follow up is required with the aim of preventing urosepsis and preserving renal function. Persisting bladder dysfunction (‘valve’ bladder) can threaten renal function and should be managed aggressively. Chronic renal failure ultimately affects a third of boys with PUV, of whom 10–20% require renal transplantation during the course of childhood. PUV may also present clinically with recurrent UTI, urinary incontinence, or unexplained lower urinary tract symptoms.

This chapter provides background information on fetal and neonatal renal development, physiology, and function. Detailed information is given on management of common, antenatally diagnosed, renal anomalies (renal pelvis dilatation/hydronephrosis); post-natal diagnoses (hypospadius, hydrocele); posterior urethral valves; polycystic kidney disease; and rarer diagnoses. There is a guideline on the management of acute renal failure in the newborn, and information on dialysis.

Antenatal hydronephrosis is the most common abnormality detected during antenatal ultrasound screening (1 in 100–500 pregnancies). Depending on the degree of dilatation, postnatal evaluation with ultrasound and/or renography is indicated to detect urinary tract obstruction. Obstruction can be found at various levels of the urinary tract such as the pyeloureteric junction, vesicoureteric junction (resulting in a megaureter), and lower urinary tract (most commonly posterior urethral valves). The decision to surgically correct obstruction can be challenging to make, and additional markers (both radiological as urinary) are needed but are not yet available in daily practice.

The urinary bladder is an organ whose purpose is to store urine at low pressure and periodically expel it. This system normally operates at relatively low pressure to protect the kidneys from the deleterious effects of increased pressure. In certain pathologies, this organ can be subject to a decrease in compliance (“stiffening”) and an increase of the storage pressure which causes higher back pressure on the kidney and ultimately results in kidney damage if untreated. Clinically, these pathologies are exemplified in disorders such as myelomeningocele, posterior urethral valves, dysfunctional voiding, and disorders associated with spinal cord injuries. In these disorders, bladder structure is altered and the bladder becomes stiff and noncompliant.