Unilateral renal agenesis: a systematic review on associated anomalies and renal injury

A case of a blind-ending right ureter first identified intraoperatively during total laparoscopic hysterectomy for uterine adenomyosis and fibroids in a woman with severe ipsilateral kidney hypoplasia

Detecting ureteral injury-a serious intraoperative and postoperative complication of hysterectomy-is a high level of difficulty if ureteral malformations are not identified preoperatively. A 39-year-old Japanese woman underwent total laparoscopic hysterectomy for uterine adenomyosis. During surgery, ureteral peristalsis was absent on the right side, whereas the left ureter was visible under the peritoneum. Transabdominal ultrasonography failed to locate the right kidney, with cystoscopy showing no flow from the right ureteral orifice. The ureteral tunnel was identified by tracing the vascular path of the internal iliac and uterine arteries, confirming that the corded tissue was the right ureter. Postoperative contrast-enhanced CT revealed severe right kidney atrophy with no contrast effect or connected ureter. Based on intraoperative laparoscopy and postoperative examination, a diagnosis of a unilateral ureteral scar with a proximal blind end and ipsilateral renal dysgenesis was established, marking the first reported instance of endoscopic visualization of this anomaly. In addition to normal pelvic anatomy, surgeons must consider embryological abnormalities to prevent intraoperative complications.

Genetic analysis of congenital unilateral renal agenesis in children based on next-generation sequencing

BACKGROUND

Congenital unilateral renal agenesis (URA) is a kind of rare birth defect during fetal development with varies clinical phenotypes. The pathogenesis and the relationship between gene and phenotype are still unclear.

METHODS

Ten URA fetuses were followed up after birth using postnatal renal ultrasound examination to confirm the diagnosis with nine children were URA and one was Renal Ectopy (RE). Trio- WES, CNV- seq were performed with the 10 children and their close relatives.

RESULTS

There were 3 heterozygous variants of CHD7, PROKR2 and NRIP1 genes were identified in 3 children, respectively. CHD7 (c.2663T>C, p.M888T) is classified as likely pathogenic (LP), PROKR2 (c.685G>C, p.G229R) and NRIP1 (c.2705T>G, p.F902C) are classified as variants of uncertain significance (VUS). CHD7 (c.2663T>C, p.M888T) and PROKR2 (c.685G>C, p.G229R) as URA-related genes may be associated with idiopathic hypogonadotropic hypogonadism (IHH) or CHARGE syndrome (CS), and 3D-protein structure prediction revealed that the two variants may affect the stability in the CHD7 protein or PROKR2 protein, separately. The RE-related gene NRIP1 (c.2705T>G, p.F902C) may be causative of congenital anomalies of the kidneys and urinary tract (CAKUT).

CONCLUSIONS

Identification of these variants can in exploring the etiology of URA or RE and improve the level of genetic counseling.

IMPACTS

We performed trio-whole-exome sequencing (trio- WES) and copy number variation sequencing (CNV- seq) in 10 children, including 9 children with Unilateral Renal Agenesis and 1 with Renal Ectopy after birth. The possible pathogenic genes of URA can be screened using prenatal and postnatal diagnosis of URA fetuses and gene detection after birth. Future studies evaluating this association may lead to a better understanding of URA and elucidate exploring the etiology of URA or RE and improve the level of genetic counseling.

A case report on rare co-occurrence of invasive ovarian mucinous adenocarcinoma, unilateral renal agenesis, and bicornuate uterus: is it a new triad?

BACKGROUND

Concomitant invasive ovarian mucinous adenocarcinoma, unilateral renal agenesis and bicornuate uterus is a rare combination. Unilateral renal agenesis has been associated with genital anomalies, such as unicornuate and bicornuate uterus. Furthermore, a wealth of studies has reported the association between unicornuate uterus and ovarian anomalies, such as the absence of an ovary or ectopic ovaries, but rarely has there been a combination of the three to the best of our knowledge. The present case report is the first case presentation with a combination of the three syndromes: ovarian mucinous tumor, unilateral renal agenesis, and bicornuate uterus.

CASE PRESENTATION

We report the case of a 17-year-old who presented with abdominal distension. On examination, a CT scan revealed a large multicystic abdominal mass on the right side, with an absence of the right kidney while the left kidney was normal in size, appearance, and position. Intraoperatively, massive blood-stained ascitic fluid was evacuated. Additionally, a large whitish polycystic intra-abdominal mass with mucus-like materials and solid areas was attached to the midpoint of the colon and the right ovary, with visible metastasis to the omentum. The uterus was bicornuate. The mass and omentum were taken for histopathology and a diagnosis of invasive ovarian mucinous cystadenocarcinoma with metastasis to the colon and omentum was made after a pathological report.

CONCLUSIONS

The presence of these conditions in the same individual could potentially complicate medical management and fertility considerations. Thus, a need for a multidisciplinary medical team, including gynecologists, urologists, and oncologists, to address their unique needs and provide appropriate treatment and guidance. Further research and case studies are needed to better understand the possible association and implications of these rare co-occurring conditions.

Early diagnosis of solitary functioning kidney: comparing the prognosis of kidney agenesis and multicystic dysplastic kidney

BACKGROUND

Individuals with congenital solitary functioning kidney (SFK) are at an increased risk of kidney damage. According to some studies, the risk is higher in unilateral kidney agenesis (UKA) than in unilateral multicystic dysplastic kidney (UMCDK). We hypothesized that with early detection of children with UKA and UMCDK, there would be no difference in the presence of hypertension, proteinuria, and reduced glomerular filtration rate (GFR) between UKA and UMCDK.

METHODS

Based on a long-term follow-up protocol, we evaluated a cohort of 160 children followed from birth for SFK (84 with UKA and 76 with UMCDK) detected by prenatal or routine neonatal ultrasound screening. Hypertension, proteinuria, and reduced GFR were monitored as markers of kidney damage. We compared the characteristics and outcomes of the subgroups of children with UKA and UMCDK.

RESULTS

GFR was reduced in 42 (26.2%) children, of whom 41 showed only mild reduction. Hypertension and proteinuria were found in 22 (13.8%) and 14 (8.8%) children, respectively. Combined kidney damage was present in 57 (35.6%) children. The UMCDK and UKA subgroups differed in GFR at final examination, with UMCDK patients being significantly more likely to have normal GFR compared to UKA patients (82% vs. 67%; p = 0.039).

CONCLUSIONS

One third of the children showed signs of SFK damage, albeit mild. Patients with UKA had reduced GFR significantly more often than those with UMCDK, but did not differ in the rates of hyperfiltration injury or congenital anomalies of the kidneys and urinary tract (CAKUT) in SFK.

Long-term effects of surgically corrected menstrual outflow obstruction: A case-control study

OBJECTIVE

To enhance evidence-based knowledge on long-term sequalae in patients with surgically corrected obstructing Müllerian anomalies.

METHODS

This long-term case-control study included patients with menstrual outflow obstruction due to congenital anomalies of the uterus or vagina, who were at least 18 years old, and for whom 2 years had elapsed since the first surgery at the start of this study. The control group consisted of women without current gynecological problems. Patients underwent a surgical correction at the Radboud University Medical Center Nijmegen between 1980 and 2013. Of 78 patients approached, 38 (49%) were included in this study. The control group consisted of 54 females. The main outcome measures were pain and health state. The following questionnaires were used: Visual Analogue Scale pain scores, European Quality of Life-5 Dimensions questionnaire (EQ-5D-3L) and the adapted Endometriosis Health Profile questionnaire (EHP-30).

RESULTS

Patients had higher actual and maximum abdominal pain scores compared with controls (11 vs 0 [P = 0.007] and 48 vs 21 [P = 0.035], respectively). Based on the EQ-5D-3L scores, patients had more pain and discomfort (P = 0.005), more mood problems (P = 0.023), and a poorer subjective health state (P = 0.002) and self-rated health state (P = 0.031). Based on the EHP-30, patients had a significant poorer self-rated health state on four out of five subscales.

CONCLUSION

In this study, following surgically corrected menstrual obstruction, patients had statistically significant higher abdominal pain scores and a poorer self-rated health state compared with controls.

Congenital anomalies of the kidney and urinary tract: antenatal diagnosis, management and counselling of families

Congenital anomalies of the kidney and urinary tract are collectively one of the most commonly diagnosed antenatal conditions. Clinicians have several tools available to diagnose anomalies, including imaging, biomarkers, family history and genetic studies. In certain cases, antenatal interventions such as vesico-amniotic shunting may be considered to improve postnatal outcomes.Congenital kidney anomalies detected antenatally can vary in clinical significance from almost no impact postnatally to significant morbidity and perinatal mortality. Prognosis broadly depends on kidney size, structure and amount of amniotic fluid, alongside genetics and family history, and progression on subsequent scans. It is important to counsel parents appropriately using a parent-focused and personalised approach. The use of a multidisciplinary team should always be considered.

A renal aplasia case mimicking radiologically as unilateral renal agenesis in a child with spina bifida, atresia ani and unilateral undescended testis: a case report

BACKGROUND

As a result of the failure of embryogenic kidney formation, a condition can occur where not a single kidney appears and this phenomenon is known as unilateral renal agenesis (URA). Both aplastic and dysplastic kidney are different from renal agenesis, atrophy and renal hypoplasia. However, from this case report it can be seen that there are similarities, both radiologically and macroscopically, between cases of unilateral renal aplasia and renal agenesis.

CASE PRESENTATION

A 2 year old Javanese boy came to the health facility with complaints of recurrent fever and urinary tract symptoms such as dysuria and straining. Computerized Tomography (CT) scan of the abdomen and urography showed agenesis of the left kidney and a probable spina bifida. Cystourethrography examination was done and showed grade 5 voiding, then retrograde pyelography was performed with the diagnosis of unilateral renal agenesis was made because there was no visible left side collecting system even though there was a duplication in the left ureter. The next examination was carried out by histopathology and immunohistochemistry after resection of the left side of the ureter and the diagnosis increasingly pointed towards renal aplasia after primitive renal structures were found.

CONCLUSIONS

Renal agenesis and aplastic kidney are difficult to differentiate macroscopically and radiologically. Nevertheless, from this case report, we try to provide some interesting points to differentiate cases of unilateral renal agenesis from Renal Dysplasia which presents as unilateral renal aplasia.

A Case of Unilateral Renal Agenesis Detected by Abdominal Point-Of-Care Ultrasound

As the interest in point-of-care ultrasound (POCUS) for investigating pediatric abdominal emergencies has been growing, an increasing number of literatures about abdominal POCUS has been published. We describe a noteworthy instance of a systematic approach using abdominal POCUS for detecting unilateral renal agenesis (URA) in previously healthy children with suspected intussusception. A previously healthy three-year-old girl was brought to our emergency department (ED) due to abdominal pain and bloody diarrhea. POCUS was performed to investigate the presence of intussusception. POCUS was able to rule out intussusception and detect URA. The investigation led the patient to a proper nephrology follow-up. When performing abdominal POCUS to evaluate gastrointestinal pathologies, it is important to pay attention to concomitant congenital anomalies of the kidney and urinary tract (CAKUT).

Congenital anomalies of the kidney and urinary tract: defining risk factors of disease progression and determinants of outcomes

Congenital anomalies of the kidney and urinary tract (CAKUT) result from disruptions in normal kidney and urinary tract development during fetal life and collectively represent the most common cause of kidney failure in children worldwide. The antenatal determinants of CAKUT are diverse and include mutations in genes responsible for normal nephrogenesis, alterations in maternal and fetal environments, and obstruction within the normal developing urinary tract. The resultant clinical phenotypes are complex and depend on the timing of the insult, the penetrance of underlying gene mutations, and the severity and timing of obstruction related to the sequence of normal kidney development. Consequently, there is a broad spectrum of outcomes for children born with CAKUT. In this review, we explore the most common forms of CAKUT and those most likely to develop long-term complications of their associated kidney malformations. We discuss the relevant outcomes for the different forms of CAKUT and what is known about clinical characteristics across the CAKUT spectrum that are risk factors of long-term kidney injury and disease progression.

Incidental right renal agenesis in a 23-year-old patient: A case report

Renal agenesis refers to the congenital absence or complete failure of development of one or both kidneys. It occurs when the kidneys fail to form during embryonic development. This case report describes the presentation of a 23-year-old male patient who experienced sporadic episodes of abdominal pain on the right side and occasional episodes of hematuria. Diagnostic investigations, including ultrasonography and magnetic resonance imaging scans, confirmed the diagnosis of right renal agenesis. The management of the patient in this case report involved close monitoring of renal function and regular follow-up visits. Initially, the patient was followed for a period of 3 months and based on the patient's clinical status and any associated risk factors, it was determined that a follow-up schedule of visits every 6 months is appropriate. This interval allows for ongoing assessment of renal function and facilitates early detection of any potential complications or changes in kidney health. This case highlights the importance of early diagnosis, comprehensive management, and long-term monitoring in individuals with renal agenesis.

'Grumbling' Midgut Volvulus in an Older Paediatric Patient With Congenital Solitary Kidney: A Case Report

Midgut volvulus is a life-threatening condition, with the majority of cases presenting before the first year of life. Congenital gastrointestinal abnormalities can be associated with midgut volvulus; however, similar associations have not been described with congenital renal abnormalities. Congenital solitary kidney (CSK) means that a child is born with only one functional kidney. Here, we describe a case of a five-year-old child with CSK who atypically presents with midgut volvulus. The case highlights how midgut volvulus may present with chronic symptoms in those over the age of one and the importance of upper GI contrast studies for diagnosis of midgut volvulus in this population and suggests CSK along with other causes of solitary kidney as possible risk factors for volvulus.

Time to Change Our Viewpoints to Assess Renal Risks in Patients with Solitary Kidneys beyond Traditional Approaches?

Solitary functioning kidney (SFK) can be defined as the absence or hypofunction of a kidney due to acquired or congenital reasons. A congenital solitary functioning kidney (cSFK) is more common than is an acquired one (aSFK) and is characterized by the anatomical absence (agenesis) or hypofunction (hypoplasia; hypodysplasia) of one kidney from birth. Among the acquired causes, the most important is nephrectomy (Nx) (due to the donor, trauma or mass resection). Patients with SFK are at risk for the development of chronic kidney disease (CKD) in the long term. This risk potential is also significantly affected by hypertension. The relationship between hypertension and subclinical chronic inflammation is a connection that has not yet been fully clarified pathogenetically, but there are many studies highlighting this association. In recent years, studies examining different fibrosis and inflammation biomarkers in terms of the evaluation and prediction of renal risks have become increasingly popular in the literature. Oxidative stress is known to play an important role in homocysteine-induced endothelial dysfunction and has been associated with hypertension. In our study, we aimed to investigate the relationship between ambulatory blood pressure monitoring (ABPM) and urinary/serum fibrosis and inflammatory markers in patients with SFK. We prospectively investigated the relationship between ABPM results and soluble urokinase plasminogen activator receptor (suPAR), procollagen type III N-terminal peptide (PIIINP), homocysteine and other variables in 85 patients with SFK and compared them between cSFK and aSFK groups. In the etiology of SFK, a congenital or acquired origin may differ in terms of the significance of biomarkers. In particular, the serum homocysteine level may be associated with different clinical outcomes in patients with cSFK and aSFK.

Renal agenesis: A meta-analysis of its prevalence and clinical characteristics based on 15 641 184 patients

Our objective was to analyse the newest relevant data on worldwide prevalence and associated symptoms of renal agenesis (RA). This meta-analysis builds on previous systematic reviews to include bilateral RA, its symptoms and data on gender, unilateral RA and anomaly location prevalence. Review of available data included records in English and other languages from PubMed, Embase, ScienceDirect, Web of Science, SciELO, BIOSIS, Current Content Connect Korean Journal Database and Russian Citation Index and Google. A total of 15 641 184 patients were analysed in relation to the prevalence of RA. The pooled prevalence of RA was 0.03% (95% CI: 0.03%-0.04%). Based on 500 subjects, a pooled prevalence of 47.96% (95% CI: 31.55%-64.58%) for unilateral and 52.04% (95% CI: 35.42%-68.45%) for bilateral RA has been set. Our study presents the newest generalized findings on bilateral RA. There appears to be universal disease and symptom prevalence with minor differences between world regions, although quality of future observational research should include genomic data. This will provide even further insight into the prognosis of various renal anomalies and their etiologies.

GFR measurements and ultrasound findings in 154 children with a congenital solitary functioning kidney

BACKGROUND

Multicystic dysplastic kidney (MCDK) and unilateral renal agenesis (URA) are the most common reasons for a congenital solitary functioning kidney (SFK). We aimed to assess the presence of abnormalities in the congenital SFK and evaluate kidney function using chrome EDTA (CrEDTA) measurements.

METHODS

We retrospectively reviewed the medical records of 154 children with MCDK and URA in the period from 2005 to 2022 to analyze results from ultrasound scans and CrEDTA glomerular filtration rate (GFR) examinations.

RESULTS

Of 154 children with a solitary kidney due to MCDK (62%) or URA (38%), abnormalities on the congenital SFK were found in 13 children (8%). The abnormalities spontaneously resolved in 6 children (46%). The most common abnormality was hydronephrosis. Compensatory hypertrophy was found in 17% of the children within the first 6 months of life. 116 children (90%) had a standard GFR (sdGFR) above 75% of expected for the age. Out of those with a sdGFR below 75% of expected, 3 (23%) had abnormalities in the congenital SFK. There was no difference in sdGFR between children with MCDK and URA.

CONCLUSIONS

Our study is the first using CrEDTA for GFR measurements and suggests that most children with a congenital SFK due to MCDK or URA have a kidney function within expected for the age. Compensatory hypertrophy of the SFK is found in a minority of children within the first six months of life, suggesting that this process is developing over time. The prevalence of abnormalities in the SFK seems low, however those with abnormalities (e.g. hydronephrosis) are at higher risk of reduced sdGFR.

Principles of Zebrafish Nephron Segment Development

Nephrons are the functional units which comprise the kidney. Each nephron contains a number of physiologically unique populations of specialized epithelial cells that are organized into discrete domains known as segments. The principles of nephron segment development have been the subject of many studies in recent years. Understanding the mechanisms of nephrogenesis has enormous potential to expand our knowledge about the basis of congenital anomalies of the kidney and urinary tract (CAKUT), and to contribute to ongoing regenerative medicine efforts aimed at identifying renal repair mechanisms and generating replacement kidney tissue. The study of the zebrafish embryonic kidney, or pronephros, provides many opportunities to identify the genes and signaling pathways that control nephron segment development. Here, we describe recent advances of nephron segment patterning and differentiation in the zebrafish, with a focus on distal segment formation.

Modeling Podocyte Ontogeny and Podocytopathies with the Zebrafish

Podocytes are exquisitely fashioned kidney cells that serve an essential role in the process of blood filtration. Congenital malformation or damage to podocytes has dire consequences and initiates a cascade of pathological changes leading to renal disease states known as podocytopathies. In addition, animal models have been integral to discovering the molecular pathways that direct the development of podocytes. In this review, we explore how researchers have used the zebrafish to illuminate new insights about the processes of podocyte ontogeny, model podocytopathies, and create opportunities to discover future therapies.

Uncovering risk factors for kidney injury in children with a solitary functioning kidney

Children with a solitary functioning kidney (SFK) have an increased risk of kidney injury. The exact risk of and risk factors for kidney injury remain unknown, which impedes personalized care. Here, we recruited a nationwide multicenter cohort of 944 patients with SFK to get more insight into this by consenting patients born in 1993-2020 and diagnosed with congenital or acquired SFK before adulthood. The median follow-up was 12.8 years and four indications of kidney injury were studied: urine protein-creatinine ratios, blood pressure, estimated glomerular filtration rate and use of anti-hypertensive/proteinuric medication. For each indicator except medication use, separate cut-off values for any injury and severe injury were used. Survival analyses indicated that at 18 years of age, any or severe kidney injury were present in 75% and 39% of patients with congenital SFK, respectively. Risk factors for kidney injury included kidney agenesis as cause of the SFK, anomalies in the SFK, and high body mass index at last follow-up. Kidney agenesis and being overweight were specifically associated with proteinuria and high blood pressure, whereas anomalies in the SFK were associated with reduced estimated glomerular filtration rates. The high prevalence of kidney injury in patients with SFK emphasizes the need for long-term follow-up, in which lifestyle is an important topic to address. More research into the etiological role of risk factors will help to translate our findings into individualized care strategies. Thus, our study shows that a significant proportion of children with SFK will develop kidney injury over time.

Comparison of axial and coronal axis MRI kidney volume measurement in pediatric congenital solitary kidney

BACKGROUND

Accurate estimation of kidney size and volume in the solitary functioning kidney is crucial because of a higher risk of developing kidney injury. MRI is an accurate method and is suitable for kidney volume measurement. Usually, axial axis images and measurement methods are preferred for kidney volume measurements. However, the anteroposterior diameter of the kidney is smaller than the longitudinal diameter, meaning that imaging in the coronal axis could provide needed information in a shorter time, enabling imaging of younger patients without sedation. Therefore, the purpose of this study was to compare coronal and axial axis kidney volume measurement methods and evaluate intra-observer and inter-observer reliability.

METHODS

Axial axis T2W and coronal axis FIESTA images of kidneys were obtained with 10 mm slice thickness and no slice gap in pediatric patients with congenital solitary kidneys. Free-hand manual tracing was used to calculate volumes in both methods. Images were analyzed by two operators with different levels of experience. The expert operator computed solitary kidney volume twice in both methods for the intra-observer reliability, while the beginner operator's measurements were used for the inter-observer reliability.

RESULTS

High intra-observer (0.965 for axial and 0.972 for coronal) and inter-observer reliability were revealed (0.964 for axial and 0.963 for the coronal) for both measurement methods.

CONCLUSION

The coronal plane volume measurement method, which has a significantly shorter examination and post-processing time, is a highly reproducible and reliable method that can enable volume measurement with MRI in younger children, as the imaging time will be shortened. A higher resolution version of the Graphical abstract is available as Supplementary information.

Glomerular hyperfiltration: part 2-clinical significance in children

Glomerular hyperfiltration (GHF) is a phenomenon that can occur in various clinical conditions affecting the kidneys such as sickle cell disease, diabetes mellitus, autosomal dominant polycystic kidney disease, and solitary functioning kidney. Yet, the pathophysiological mechanisms vary from one disease to another and are not well understood. More so, it has been demonstrated that GHF may occur at the single-nephron in some clinical conditions while in others at the whole-kidney level. In this review, we explore the pathophysiological mechanisms of GHF in relation to various clinical conditions in the pediatric population. In addition, we discuss the role and mechanism of action of important factors such as gender, low birth weight, and race in the pathogenesis of GHF. Finally, in this current review, we further highlight the consequences of GHF in the progression of kidney disease.

Antenatally Diagnosed Kidney Anomalies

Congenital anomalies of the kidney and urinary tract encompass a broad spectrum of developmental conditions that together account for the majority of childhood chronic kidney diseases. Kidney abnormalities are the most commonly diagnosed congenital anomaly in children, and detection of this anomaly is increasing as a result of improved antenatal care and widespread access to more sensitive screening ultrasonography. Most paediatricians will encounter children with congenital kidney anomalies across a wide spectrum of disorders, and a broad understanding of the classification, investigation, and basis of management is important to appropriately direct their care.

Anatomy and embryology of congenital surgical anomalies: Congenital Anomalies of the Kidney and Urinary Tract

Congenital anomalies of the kidney and urinary tract or "CAKUT" describes a spectrum of developmental disorders with a range of associated clinical presentations and functional consequences. CAKUT underlies the majority of chronic kidney disease and kidney replacement therapy requirement in children, but functional deterioration can also emerge in adulthood. Understanding the normal embryological processes involved in kidney development allows us to appreciate the timing and sequence of critical events implicated when things go wrong. In this review, we will describe the normal developmental mechanisms and relate this to what we currently know about the pathological processes involved in various forms of CAKUT. We will also review the proposed etiological factors, in particular genetics, involved in CAKUT.

A novel combination of OHVIRA syndrome and likely causal variant in UMOD gene

OHVIRA syndrome (or Herlyn-Werner-Wunderlich syndrome) is a rare condition, consisting classically of obstructed hemi-vagina with ipsilateral renal agenesis. It may be associated with complex uterine malformations and more rarely with lower urinary tract anomalies. The contralateral kidney usually has normal function. A genetic etiology of this syndrome has not yet been confirmed. We report a patient who was diagnosed to have unilateral renal agenesis in early childhood, and then presented after menarche with features of OHVIRA syndrome. The contralateral kidney was relatively small and echogenic, and serum creatinine and uric acid were raised. A likely causal variant of the UMOD gene was detected on whole exome sequencing. Genetic studies in more patients with OHVIRA syndrome may elucidate further, whether the association with UMOD gene is causal in nature.

Unilateral renal agenesis, blind-ended ureter and ectopic ureterocele: An incidental finding on abdominal CT scan

Congenital renal anomalies are among the most common birth defects. They are often detected antenatally. If not, they can manifest in adulthood with variable clinical presentations. Herein, we present a case of a 72-year-old male patient who was incidentally found to have an extremely rare combination of urinary tract defects comprising: right-sided unilateral renal agenesis, blind ureter, and ectopic ureterocele.

Prostanoid receptors in hyperfiltration-mediated glomerular injury: Novel agonists and antagonists reveal opposing roles for EP2 and EP4 receptors

Increased fluid-flow shear stress (FFSS) contributes to hyperfiltration-induced podocyte and glomerular injury resulting in progression of chronic kidney disease (CKD). We reported that increased FFSS in vitro and in vivo upregulates PGE2 receptor EP2 (but not EP4 expression), COX2-PGE₂ -EP2 axis, and EP2-linked Akt-GSK3β-β-catenin signaling pathway in podocytes. To understand and use the disparities between PGE2 receptors, specific agonists, and antagonists of EP2 and EP4 were used to assess phosphorylation of Akt, GSK3β and β-catenin in podocytes using Western blotting, glomerular filtration barrier function using in vitro albumin permeability (P_alb ) assay, and mitigation of hyperfiltration-induced injury in unilaterally nephrectomized (UNX) mice at 1 and 6 months. Results show an increase in P_alb by PGE₂ , EP2 agonist (EP2^AGO ) and EP4 antagonist (EP4^ANT ), but not by EP2 antagonist (EP2^ANT ) or EP4 agonist (EP4^AGO ). Pretreatment with EP2^ANT blocked the effect of PGE₂ or EP2^AGO on P_alb . Modulation of EP2 and EP4 also induced opposite effects on phosphorylation of Akt and β-Catenin. Individual agonists or antagonists of EP2 or EP4 did not induce significant improvement in albuminuria in UNX mice. However, treatment with a combination EP2^ANT  + EP4^AGO for 1 or 6 months caused a robust decrease in albuminuria. EP2^ANT  + EP4^AGO combination did not impact adaptive hypertrophy or increased serum creatinine. Observed differences between expression of EP2 and EP4 on the glomerular barrier highlight these receptors as potential targets for intervention. Safe and effective mitigating effect of EP2^ANT  + EP4^AGO presents a novel opportunity to delay the progression of hyperfiltration-associated CKD as seen in transplant donors.

Solitary kidney functional damage due to caesarean ureteric injury monitored for 2 years after acute management: A case report

Caesarean section with associated ureteric injuries that damage kidney function is uncommon. Such injury in women with a solitary kidney has far-reaching effects if the diagnosis is delayed. The case report describes the successful acute management with stenting of ureteric damage after caesarean section in a woman with a solitary kidney.

A 29-year-old woman presented with anuria, hypertension (174/101 mmHg) and flank pain 3 days after caesarean section. Physical examination was significant for peri-orbital oedema, left flank tenderness, pallor and delirium. A diagnosis of acute kidney injury was confirmed by elevated blood urea and creatinine levels. An ultrasound scan revealed a solitary hydronephrotic left kidney. She had successful acute management at a resource-deprived facility, with normal renal function at a 2-year follow-up. Proteinuria lasted for about three months after surgery.

Recovery of solitary kidney function with acute kidney injury due to caesarean section ureteric injury may be associated with prolonged proteinuria without evidence of further functional deterioration.

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Caesarean ureteric obstruction is rare but consequential.

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Over 70% are diagnosed late with varied effects on the kidneys.

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Single kidney damage in a bilateral renal system may be compensated.

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Solitary kidney damage is a live threatening obstetric complication.

Evolution of congenital anomalies of urinary tract in children with and without solitary kidney

BACKGROUND

We hypothesized that children with congenital solitary functioning kidney (CSFK) present forms of congenital urinary tract anomalies (CUTA) with higher chance of spontaneous resolution compared with patients with two kidneys.

METHODS

We retrospectively selected 75 consecutive children with CUTA of the CSFK and 75 matched patients with unilateral CUTA but without CSFK (controls) with prenatal suspicion of unilateral CUTA and early evaluation. We compared the spontaneous CUTA resolution and the prevalence of kidney injury between groups at last follow-up. Patients and controls were clustered under the categories of "severe" and "non-severe" CUTA.

RESULTS

The mean age at first and last follow-up was 0.17 ± 0.07 and 8.5 ± 5.2 years. Compared with controls, patients with CSFK had lower prevalence of severe CUTA at first evaluation; lower prevalence of febrile urinary tract infections, need of surgical correction, and higher rate of spontaneous CUTA resolution during follow-up; and a similar prevalence of mild kidney injury at last follow-up. CSFK compared with controls presented higher cumulative proportion of spontaneous resolution from severe CUTA (100 vs 41.8%; p < 0.001) and from the single CUTA sub-categories (severe vesicoureteral reflux, non-obstructive hydronephrosis, and megaureter).

CONCLUSIONS

CSFK patients had lower prevalence of severe forms and better outcomes of their CUTA compared with controls.

IMPACT

One-third of patients with congenital solitary functioning kidney (CSFK) present congenital urinary tract anomalies (CUTA) and manifest poorer outcomes compared with CSFK without CUTA. CSFK patients had lower prevalence of severe forms and better outcomes of their CUTA in spite of similar prevalence of kidney injury compared with controls. This adds evidence about disturbed nephrogenesis in CSFK patients and emboldens conservative management of many of their non-obstructive CUTA.

Gestational Outcomes of Pregnant Women with Unilateral Congenital Renal Agenesis

ObjectiveWe evaluated if there were more adverse gestational outcomes of pregnant women with unilateral congenital renal agenesis (UCRA). Study design: This single center retrospective case-control study compared maternal complications and neonatal outcomes from 25 women with UCRA to the outcomes of 125 women with two kidneys. Results: UCRA women had lower gestational weeks at birth and higher rates of preterm delivery (p = 0.004 and <0.001; respectively). Mothers had higher rates of preeclampsia and newborns with congenital anomalies and neonatal intensive care unit (NICU) admission (p = 0.009, 0.042, and 0.039; respectively). Unadjusted odds ratios were significantly higher for preterm delivery and for any APGAR score of <7 at the first 10 min and preeclampsia [OR (95% CI):13.5 (4.66-39.05), 31 (3.44-279.32) and 5.76 (1.33-24.84), respectively]. Conclusion: Maternal UCRA is a risk factor for less optimal obstetric and neonatal outcomes.

Urologic Considerations in Pediatric Chronic Kidney Disease

Common causes of pediatric ESRD are distinct from those seen in the adult population. In the pediatric population, the most common are congenital anomalies of the kidney and urinary tract (CAKUT), affecting approximately 30% of children with CKD. These structural anomalies often require coordinated care with the pediatric urology team to address voiding issues, bladder involvement, and the potential need for surgical intervention. For pediatric nephrologists and urologists, common CAKUT that are encountered include antenatal hydronephrosis, obstructive uropathies (eg, posterior urethral valves), and vesicoureteral reflux. As more pediatric patients with CAKUT, CKD, and ESRD transition to adult care, it is important for receiving adult nephrologists to understand the clinical presentation, natural history, and prognosis for these diagnoses. This review outlines the diagnosis and potential interventions for these conditions, including strategies to address bladder dysfunction that is often seen in children with CAKUT. A discussion of these management decisions (including surgical intervention) for CAKUT, which are quite common to pediatric nephrology and urology practices, may provide unique learning opportunities for adult nephrologists who lack familiarity with these pediatric conditions.

Glomerular hyperfiltration

Circulating blood is filtered across the glomerular barrier to form an ultrafiltrate of plasma in the Bowman's space. The volume of glomerular filtration adjusted by time is defined as the glomerular filtration rate (GFR), and the total GFR is the sum of all single-nephron GFRs. Thus, when the single-nephron GFR is increased in the context of a normal number of functioning nephrons, single glomerular hyperfiltration results in 'absolute' hyperfiltration in the kidney. 'Absolute' hyperfiltration can occur in healthy people after high protein intake, during pregnancy and in patients with diabetes, obesity or autosomal-dominant polycystic kidney disease. When the number of functioning nephrons is reduced, single-nephron glomerular hyperfiltration can result in a GFR that is within or below the normal range. This 'relative' hyperfiltration can occur in patients with a congenitally reduced nephron number or with an acquired reduction in nephron mass consequent to surgery or kidney disease. Improved understanding of the mechanisms that underlie 'absolute' and 'relative' glomerular hyperfiltration in different clinical settings, and of whether and how the single-nephron haemodynamic and related biomechanical forces that underlie glomerular hyperfiltration promote glomerular injury, will pave the way toward the development of novel therapeutic interventions that attenuate glomerular hyperfiltration and potentially prevent or limit consequent progressive kidney injury and loss of function.

Imaging of congenital genitourinary anomalies

Congenital genitourinary anomalies are among the most frequent types of birth defects in neonates. Some anomalies can be a significant cause of morbidity in infancy, while others remain asymptomatic even until adulthood and can be at times the only manifestation of a complex systemic disease. The spectrum of these anomalies results from the developmental insults that can occur at various embryologic stages, and an understanding of the formation of the genitourinary system is helpful in the evaluation and treatment of a child with a congenital genitourinary anomaly. Imaging plays an essential role in the diagnosis of congenital genitourinary anomalies and treatment planning. In this article, we highlight the embryologic and characteristic imaging features of various congenital genitourinary anomalies, demonstrate the utility of different imaging modalities in management, and review specific imaging modalities and protocols for image optimization.

Multidisciplinary approaches for elucidating genetics and molecular pathogenesis of urinary tract malformations

Advances in clinical diagnostics and molecular tools have improved our understanding of the genetically heterogeneous causes underlying congenital anomalies of kidney and urinary tract (CAKUT). However, despite a sharp incline of CAKUT reports in the literature within the past 2 decades, there remains a plateau in the genetic diagnostic yield that is disproportionate to the accelerated ability to generate robust genome-wide data. Explanations for this observation include (i) diverse inheritance patterns with incomplete penetrance and variable expressivity, (ii) rarity of single-gene drivers such that large sample sizes are required to meet the burden of proof, and (iii) multigene interactions that might produce either intra- (e.g., copy number variants) or inter- (e.g., effects in trans) locus effects. These challenges present an opportunity for the community to implement innovative genetic and molecular avenues to explain the missing heritability and to better elucidate the mechanisms that underscore CAKUT. Here, we review recent multidisciplinary approaches at the intersection of genetics, genomics, in vivo modeling, and in vitro systems toward refining a blueprint for overcoming the diagnostic hurdles that are pervasive in urinary tract malformation cohorts. These approaches will not only benefit clinical management by reducing age at molecular diagnosis and prompting early evaluation for comorbid features but will also serve as a springboard for therapeutic development.

The term CAKUT has outlived its usefulness: the case for the defense

Congenital anomalies of the kidney and urinary tract form a spectrum of congenital structural disorders that are generally known under the term CAKUT. The term CAKUT was introduced 20 years ago and has been used extensively in literature since. Prof. Woolf has made a plea for abandoning this term in his "case for the prosecution." Here, I advocate for the continued use of CAKUT as an umbrella term for these related congenital kidney and urinary tract abnormalities. I explain why the term CAKUT accurately and usefully defines this group of related structural disorders with prenatal origin and why it makes sense to continue grouping these disorders given accumulating evidence for shared etiology of CAKUT phenotypes and the importance of grouping CAKUT phenotypes in genetic counseling.

Management of the congenital solitary kidney: consensus recommendations of the Italian Society of Pediatric Nephrology

In recent years, several studies have been published on the prognosis of children with congenital solitary kidney (CSK), with controversial results, and a worldwide consensus on management and follow-up is lacking. In this consensus statement, the Italian Society of Pediatric Nephrology summarizes the current knowledge on CSK and presents recommendations for its management, including diagnostic approach, nutritional and lifestyle habits, and follow-up. We recommend that any antenatal suspicion/diagnosis of CSK be confirmed by neonatal ultrasound (US), avoiding the routine use of further imaging if no other anomalies of kidney/urinary tract are detected. A CSK without additional abnormalities is expected to undergo compensatory enlargement, which should be assessed by US. We recommend that urinalysis, but not blood tests or genetic analysis, be routinely performed at diagnosis in infants and children showing compensatory enlargement of the CSK. Extrarenal malformations should be searched for, particularly genital tract malformations in females. An excessive protein and salt intake should be avoided, while sport participation should not be restricted. We recommend a lifelong follow-up, which should be tailored on risk stratification, as follows: low risk: CSK with compensatory enlargement, medium risk: CSK without compensatory enlargement and/or additional CAKUT, and high risk: decreased GFR and/or proteinuria, and/or hypertension. We recommend that in children at low-risk periodic US, urinalysis and BP measurement be performed; in those at medium risk, we recommend that serum creatinine also be measured; in high-risk children, the schedule has to be tailored according to kidney function and clinical data.

Outcomes of solitary functioning kidneys-renal agenesis is different than multicystic dysplastic kidney disease

BACKGROUND

Multicystic dysplastic kidney (MCDK) disease and unilateral renal agenesis (URA) are well-known causes of a solitary functioning kidney (SFK) and are associated with long-term kidney injury. The aims of this study were to characterize the natural history of SFK at our center, define the risk factors associated with chronic kidney injury, and identify distinguishing features between URA and MCDK that predict outcome.

METHODS

This was a retrospective cohort study of 230 SFK patients. We compared MCDK (n=160) and URA (n=70) according to clinical features at diagnosis and kidney outcomes over follow-up. Univariate and multivariate binary regression analysis was used to determine independent risk factors for chronic kidney injury, defined as the composite outcome of hypertension, proteinuria, or chronic kidney disease (eGFR <60 mL/min/1.73m²).

RESULTS

URA had a higher prevalence of comorbid genetic syndromes (15 vs. 6%, p=0.04), non-renal anomalies (39 vs. 11%, p<0.001), and congenital anomalies of the kidney and urinary tract (CAKUT) (51 vs. 26%, p<0.001) than MCDK. Over follow-up, URA experienced more hypertension (19 vs. 3%, p=0.002), proteinuria (12 vs. 3%, p=0.03), and the composite outcome (19 vs. 6%, p=0.003) than MCDK. Independent risk factors for chronic kidney injury included CAKUT (OR 5.01, p=0.002) and URA (OR 2.71, p=0.04).

CONCLUSIONS

In our population, URA was more likely to have associated syndromes or anomalies, and to have worse outcomes over time than MCDK. URA diagnosis was an independent risk factor for chronic kidney injury. Our results will be used to develop a standardized clinical pathway for SFK management. A higher resolution version of the Graphical abstract is available as Supplementary information.

Atypical granular cell tumor of the urinary bladder: A case report

BACKGROUND

Granular cell tumor (GCT) is a neurogenic tumor mainly occurring in the head and neck. GCT in the genitourinary system is extremely rare and only sporadic cases of urinary bladder GCT have been reported. Most urinary bladder GCT cases are benign and only two malignant cases have been reported. Due to its rarity, no consensus criteria for the treatment of urinary bladder GCT are available at present.

CASE SUMMARY

A 62-year-old Chinese woman was found to have a urinary bladder tumor without any clinical manifestations on physical examination. Cystoscopy revealed a semispherical shaped lesion measuring approximately 4.0 cm in diameter at the junction of the left wall and roof of the bladder, which was covered with normal bladder mucosa. Computed tomography scan demonstrated a high-density lesion on the left wall of the bladder, measuring approximately 2.9 cm × 2.4 cm with clear boundaries. Contrast-enhanced pelvic magnetic resonance imaging revealed a space-occupying lesion on the left wall of the bladder (non-mucosal origin/ external pressure), which was preliminarily suspected to be a desmoplastic fibroma or leiomyoma. In the context of the above findings, a pre-operative diagnosis of bladder leiomyoma was made. The patient consequently underwent a laparoscopic partial cystectomy. The resected bladder mass looked yellowish and well-demarcated, measuring 4.0 cm × 3.5 cm and infiltrated the muscular layer. The diagnosis of urinary bladder GCT was finally made by postoperative pathology, with positive immunohistochemical S-100 staining and negative pancytokeratin. The patient has been followed for 6 mo so far, with no tumor recurrence detected.

CONCLUSION

This case highlights the biological feature and differential diagnosis of urinary bladder GCT at the pathological and molecular levels. Transurethral resection of the bladder tumor and partial cystectomy are recommended in most urinary bladder GCT cases, while radical cystectomy is recommended in malignant cases.

Nephrotic Syndrome Associated with Hydronephrosis and Unilateral Renal Agenesis

We reported a case of nephrotic syndrome in a child presenting undiagnosed hydronephrosis and unilateral renal agenesis in a 3 years and 9 months old male patient presenting features of nephrotic syndrome, with left hydronephrosis and unilateral renal agenesis. The association of nephrotic syndrome with congenital anomalies is extremely rare. The importance of this unusual combination was discussed respecting the literature.

Is the prognosis of congenital single functioning kidney benign? A population-based study

BACKGROUND

We investigated the risk of kidney injury among adolescents with and without a congenital single functioning kidney (SFK).

METHODS

This retrospective study is based on a medical evaluation database of 17-year-old Israeli conscripts, born during 1989-1999. Those with congenital SFK diagnosis, verified by a pediatric nephrologist's review of the original military medical committee classifications, were compared to the rest of the cohort. Kidney injury (KI) was defined as proteinuria, high blood pressure (BP), or estimated glomerular filtration rate (eGFR) < 90 ml/min/1.73 m² prior to army recruitment. Risk factors for KI were examined using logistic regression.

RESULTS

Of 979,630 screened candidates, 353 were diagnosed with SFK. The yearly incidence of SFK gradually increased in the first years of the study, reaching a plateau in 1995 (5.5 ± 1.2/10,000 births/year). The male to female ratio was 2.7:1. Concomitant genital malformations were documented in 5.5% of those with SFK. KI was more prevalent in the SFK than the control group (42.2% vs. 23.5%, p < 0.001). All three components of KI were more common in the SFK than the control group: high BP (31.7% vs. 23.1%, p < 0.001), proteinuria (18.2% vs. 0.4%, p < 0.001), and eGFR <90 ml/min/1.73m² (12.0% vs 0.1%, p < 0.001). Multivariate analysis of the SFK group revealed associations of higher mean BMI, male sex, and smaller ultrasonographic kidney length with KI.

CONCLUSIONS

This large population-based study documents a significant risk for KI among adolescents with SFK. Obesity represents a major modifiable risk factor for KI, implicating the need for closer follow-up in this group during childhood.

Retrospective evaluation of children with unilateral renal agenesis

BACKGROUND

Children born with unilateral renal agenesis (URA) are thought to have a risk of developing hypertension, proteinuria, and progressive chronic kidney disease (CKD). The present study aimed to evaluate the long-term prognosis and clinical characteristics of children with URA.

METHODS

The study included 171 patients aged < 18 years diagnosed as URA who were followed-up for ≥ 1 year and 121 healthy controls matched for age, gender, and BMI.

RESULTS

Median age at diagnosis was 2 years (IQR: 1 month-16 years) and the incidence of URA in males (65.4%) was higher than in females. Among the patients, 21 (12.2%) had other urinary system anomalies. It was noted that 2.3% of the patients had proteinuria, 15.2% had hyperfiltration, and 2.9% had CKD. Hypertension based on ambulatory blood pressure monitoring (ABPM) was diagnosed in 18 (10.5%) of the patients, of whom 10 had masked hypertension. Diastolic blood pressure in the URA patients was significantly higher than in the healthy controls. The incidence of hypertension and CKD was significantly higher in the patients with other urinary system anomalies.

CONCLUSIONS

Patients with a single functional kidney should be periodically evaluated throughout their lifetime for urine protein, blood pressure, and kidney functions. The most remarkable finding of this study is the importance of the use of ABPM for evaluating blood pressure in pediatric URA patients, especially for the detection of masked hypertension and the non-dipper phenomenon, which cannot be achieved with office blood pressure measurement.

Renal function in children with a congenital solitary functioning kidney: A systematic review

INTRODUCTION

Abnormal renal development that results in lack of function or development of one of two kidneys is known as congenital solitary functioning kidney (CSFK). Two well characterized sub-categories of CFSK are unilateral renal agenesis (URA) and multicystic dysplastic kidney (MCDK). This systematic review sought to evaluate the change in renal function in children ≤18 years old with a CSFK as a result of URA or MCDK.

METHODS

A literature search in MEDLINE and Embase was conducted (1946 to July 13, 2020). All relevant articles were retrieved and evaluated based on pre-selected criteria by two independent researchers. Data was then extracted from variables of interest and conflicts were resolved by a third researcher. The primary outcome was renal function, and the secondary outcomes were proteinuria and hypertension.

RESULTS

Forty-five studies were included, of which 49% (n = 22) were retrospective and/or 58% (n = 26) were cohort studies. A combined total of 2148 and 885 patients were diagnosed with MCDK or URA, respectively. The proportion of children with worsened renal function at follow-up was found to be 8.4% (95% CI: 5.2%-13.4%). Among the studies reporting renal function as a group mean or median at follow-up, 84% (21/25) had a GFR/CrCl above 90 (mL/min/1.73  m²/ml/min). In terms of secondary outcomes, the proportion of children with proteinuria and hypertension was found to be 10.1% (95% CI: 6.9%-14.6%) and 7.4% (95% CI: 5.0%-10.9%), respectively.

CONCLUSION

The risk of developing proteinuria (10.1%), hypertension (7.4%), and/or worsened renal function (8.4%) for children with CFSK as a result of MCDK or URA is low. However, the level of evidence in the literature is weak. Further research is needed to identify the predisposing factors that may differentiate the small subset of children with CSFK at a higher risk of developing adverse renal outcomes.

Nephron-deficient HSRA rats exhibit renal injury with age but have limited renal damage from streptozotocin-induced hyperglycemia

Hypertension and diabetes are the greatest factors influencing the progression of chronic kidney disease (CKD). Investigation into the role of nephron number in CKD alone or with hypertension has revealed a strong inverse relationship between the two; however, not much is known about the connection between nephron number and diabetic kidney disease. The heterogeneous stock-derived model of unilateral renal agenesis (HSRA) rat, a novel model of nephron deficiency, provides a unique opportunity to study the association between nephron number and hypertension and diabetes on CKD. HSRA rats exhibit failure of one kidney to develop in 50-75% of offspring, whereas the remaining offspring are born with two kidneys. Rats born with one kidney (HSRA-S) develop significant renal injury with age compared with two-kidney littermates (HSRA-C). The induction of hypertension as a secondary stressor leads to significantly more renal injury in HSRA-S compared with HSRA-C rats and nephrectomized HSRA-C (HSRA-UNX) rats. The present study sought to address the hypothesis that nephron deficiency in the HSRA rat would hasten renal injury in the presence of a secondary stressor of hyperglycemia. HSRA animals did not exhibit diabetes-related traits at any age; thus, streptozotocin (STZ) was used to induce hyperglycemia in HSRA-S, HSRA-C, and HSRA-UNX rats. STZ- and vehicle-treated animals were followed for 15 wk. STZ-treated animals developed robust hyperglycemia, but in contrast to the response to hypertension, neither HSRA-S nor HSRA-UNX animals developed proteinuria compared with vehicle treatment. In total, our data indicate that hyperglycemia from STZ alone does not have a significant impact on the onset or progression of injury in young one-kidney HSRA animals.NEW & NOTEWORTHY The HSRA rat, a novel model of nephron deficiency, provides a unique opportunity to study the association between nephron number and confounding cardiovascular complications that impact kidney health. Although hypertension was previously shown to exacerbate renal injury in young HSRA animals, diabetic hyperglycemia did not lead to worse renal injury, suggesting that nephron number has limited impact on kidney injury, at least in this model.

Transcription Factor β-Catenin Plays a Key Role in Fluid Flow Shear Stress-Mediated Glomerular Injury in Solitary Kidney

Increased fluid flow shear stress (FFSS) in solitary kidney alters podocyte function in vivo. FFSS-treated cultured podocytes show upregulated AKT-GSK3β-β-catenin signaling. The present study was undertaken to confirm (i) the activation of β-catenin signaling in podocytes in vivo using unilaterally nephrectomized (UNX) TOPGAL mice with the β-galactosidase reporter gene for β-catenin activation, (ii) β-catenin translocation in FFSS-treated mouse podocytes, and (iii) β-catenin signaling using publicly available data from UNX mice. The UNX of TOPGAL mice resulted in glomerular hypertrophy and increased the mesangial matrix consistent with hemodynamic adaptation. Uninephrectomized TOPGAL mice showed an increased β-galactosidase expression at 4 weeks but not at 12 weeks, as assessed using immunofluorescence microscopy (p < 0.001 at 4 weeks; p = 0.16 at 12 weeks) and X-gal staining (p = 0.008 at 4 weeks; p = 0.65 at 12 weeks). Immunofluorescence microscopy showed a significant increase in phospho-β-catenin (Ser552, p = 0.005) at 4 weeks but not at 12 weeks (p = 0.935) following UNX, and the levels of phospho-β-catenin (Ser675) did not change. In vitro FFSS caused a sustained increase in the nuclear translocation of phospho-β-catenin (Ser552) but not phospho-β-catenin (Ser675) in podocytes. The bioinformatic analysis of the GEO dataset, #GSE53996, also identified β-catenin as a key upstream regulator. We conclude that transcription factor β-catenin mediates FFSS-induced podocyte (glomerular) injury in solitary kidney.

A cross-sectional study of the genital duct and renal anomalies in Egyptian cases of congenital absence of the vas deferens

The aim of the study was to detect the incidence and types of genital and renal duct anomalies associated with congenital absent vas deferens (CAVD). In 200 males with CAVD, the demographic characteristics, physical examination findings were evaluated. Scrotal ultrasonography and transrectal ultrasonography (TRUS) were used as the diagnostic methods for evaluating unilateral or bilateral CAVD with associated abnormalities or agenesis of the testes, epididymes, seminal vesicles and prostate. Abdominal ultrasound was performed to detect any associated renal anomalies. There were a total of 111 CBAVD and 89 CUAVD males. Eight cases (8.98%) of CUAVD were associated with contralateral cryptorchidism. In most cases there were agenesis in the epididymal body and tail and seminal vesicles. Different types of renal anomalies (32.50%) especially renal agenesis were observed mainly in cases of left CUAVD and were predominately on the left hand side. An important implication of our study is the importance of requesting ultrasound of males with CAVD to discover any associated anomalies especially renal agenesis that may be ignored by many physicians.

Clinical Management of Children with a Congenital Solitary Functioning Kidney: Overview and Recommendations

CONTEXT

A congenital solitary functioning kidney (cSFK) is a common developmental defect that predisposes to hypertension and chronic kidney disease (CKD) as a consequence of hyperfiltration. Every urologist takes care of patients with a cSFK, since some will need lifelong urological care or will come with clinical problems or questions to an adult urologist later in life.

OBJECTIVE

We aim to provide clear recommendations for the initial clinical management and follow-up of children with a cSFK.

EVIDENCE ACQUISITION

PubMed and EMBASE were searched to identify relevant publications, which were combined with guidelines on related topics and expert opinion.

EVIDENCE SYNTHESIS

Initially, cSFK diagnosis should be confirmed and risk factors for kidney injury should be identified using ultrasound. Although more research into early predictors of kidney injury is needed, additional congenital anomalies of the kidney or urinary tract and absence of compensatory kidney hypertrophy have repeatedly been associated with a worse prognosis. The role of voiding cystourethrography and antibiotic prophylaxis remains controversial, and is complicated by the exclusion of children with a cSFK from studies. A yearly follow-up for signs of kidney injury is recommended for children with a cSFK. As masked hypertension is prevalent, annual ambulatory blood pressure measurement should be considered. During puberty, an increasing incidence of kidney injury is seen, indicating that long-term follow-up is necessary. If signs of kidney injury are present, angiotensin converting enzyme inhibitors are the first-line drugs of choice.

CONCLUSIONS

This overview points to the urological and medical clinical aspects and long-term care guidance for children with a cSFK, who are at risk of hypertension and CKD. Monitoring for signs of kidney injury is therefore recommended throughout life. Large, prospective studies with long-term follow-up of clearly defined cohorts are still needed to facilitate more risk-based and individualized clinical management.

PATIENT SUMMARY

Many children are born with only one functioning kidney, which could lead to kidney injury later in life. Therefore, a kidney ultrasound is made soon after birth, and other investigations may be needed as well. Urologists taking care of patients with a solitary functioning kidney should realize the long-term clinical aspects, which might need medical management.

Congenital Anomalies of the Upper Urinary Tract: A Comprehensive Review

The upper urinary tract is the most common human system affected by congenital anomalies. Congenital anomalies of the kidneys and ureters comprise a wide spectrum of disorders ranging from simple variants with no clinical significance to complex anomalies that may lead to severe complications and end-stage renal disease. They may be classified as anomalies of renal form, which are subclassified as structural anomalies (eg, persistent fetal lobulation, hypertrophied column of Bertin, and dromedary hump) and fusion anomalies (eg, horseshoe kidney and pancake kidney); anomalies of renal position (eg, renal malrotation, simple renal ectopia, and crossed renal ectopia) and renal number (eg, renal agenesis and supernumerary kidney); and abnormalities in development of the urinary collecting system (eg, pyelocaliceal diverticulum, megacalycosis, ureteropelvic junction obstruction, duplex collecting system, megaureter, ectopic ureter, and ureterocele). US is usually the first imaging modality used because of its low cost, wide availability, and absence of ionizing radiation. Intravenous urography and voiding cystourethrography are also useful, mainly for characterization of the collecting system and vesicoureteral reflux. However, intravenous urography has been replaced by CT urography and MR urography. These imaging methods not only allow direct visualization of the collecting system but also demonstrate the function of the kidneys, the vascular anatomy, adjacent structures, and complications. Comprehension of congenital anomalies of the upper urinary tract is crucial for an accurate diagnosis and correct management. The authors discuss the spectrum of these anomalies, with emphasis on embryologic development, imaging findings, clinical manifestations, and complications. Online supplemental material is available for this article. ^©RSNA, 2021.

Clinical Integration of Genome Diagnostics for Congenital Anomalies of the Kidney and Urinary Tract

Revolutions in genetics, epigenetics, and bioinformatics are currently changing the outline of diagnostics and clinical medicine. From a nephrologist's perspective, individuals with congenital anomalies of the kidney and urinary tract (CAKUT) are an important patient category: not only is CAKUT the predominant cause of kidney failure in children and young adults, but the strong phenotypic and genotypic heterogeneity of kidney and urinary tract malformations has hampered standardization of clinical decision making until now. However, patients with CAKUT may benefit from precision medicine, including an integrated diagnostics trajectory, genetic counseling, and personalized management to improve clinical outcomes of developmental kidney and urinary tract defects. In this review, we discuss the present understanding of the molecular etiology of CAKUT and the currently available genome diagnostic modalities in the clinical care of patients with CAKUT. Finally, we discuss how clinical integration of findings from large-scale genetic, epigenetic, and gene-environment interaction studies may improve the prognosis of all individuals with CAKUT.

Case Report: Uterine Anomalies in Girls With a Congenital Solitary Functioning Kidney

Unilateral renal agenesis and multicystic dysplastic kidney, resulting in a contralateral solitary functioning kidney (SFK), are part of the broad spectrum of congenital anomalies of the kidney and urinary tract (CAKUT). In girls with SFK, screening for asymptomatic Müllerian anomalies of uterus and vagina is not yet routinely performed, and therefore often overlooked until clinical complications in the menstrual cycle or fertility process occur. In this case series, we report on four teenagers with congenital SFK presenting with menstrual problems due to a Müllerian anomaly. Routine peri-menarchal screening for Müllerian anomalies in girls with SFK may provide timely counseling, surgical treatment and prevention of associated complications such as endometriosis, infertility and miscarriages.