Follow up of renal outcomes in children with solitary kidney.

BACKGROUND: Solitary kidney (SK) affects 1/1000 people worldwide, and there are controversies concerning renal outcomes in these patients. This study aimed to investigate clinical findings and renal outcomes in children with SK and to compare the results for congenital (CSK) and acquired SK (ASK) groups. METHODS: The study included patients that presented to our pediatric nephrology department with SK between January 2010 and January 2021. Demographic and clinical data were recorded retrospectively. RESULTS: Of the 101 patients with SK, 71 had CSK (55 had unilateral renal agenesis and 16 had a multicystic dysplastic kidney) and 30 had ASK (17 had previously undergone unilateral nephrectomy due to a renal tumor and 13 had urological structural anomalies). There were nine patients (9%) with renal injury. The serum uric acid level was significantly higher and the estimated glomerular filtration rate was significantly lower in the patients with ASK compared with those with CSK (p = 0.005 and p < 0.001, respectively). There was a positive correlation between renal injury and the uric acid level (p < 0.001, r = 0.45). CONCLUSION: In addition to the management of blood pressure and proteinuria, it is important to control uric acid levels in patients with SK, especially those with ASK, to prevent renal injury. The ASK group has a greater risk of renal injury than the CSK group. There is a need for new markers to predict early stage renal damage in SK.

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

BACKGROUND: 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.

Development of a multivariable prediction model for congenital unilateral absence of the vas deferens in male partners of infertile couples.

BACKGROUND: Congenital unilateral absence of vas deferens has been diagnosed in fertile and normozoospermic males and is associated with the risk of unilateral renal absence or cystic fibrosis transmembrane conductance regulator mutations; but no prediction model currently exists to diagnose this condition. OBJECTIVES: The study aims to identify clinical and biological variables that may have a predictive value for the diagnosis of congenital unilateral absence of vas deferens in male partners of infertile couples MATERIALS AND METHODS: We designed a retrospective, cross-sectional, case-control study on electronic health records of a single tertiary-care andrological centre collected between 1998 and 2018. We included all subjects diagnosed with congenital unilateral absence of vas deferens using combined scrotal and transrectal ultrasounds. Controls were confirmed free of congenital unilateral absence of vas deferens by the same way. Both groups received standardised exploration procedures. Multivariable logistic regression model was built in a backward stepwise manner. Model performance and calibration were assessed. The study is reported according to TRIPOD statement. RESULTS: We included 69 congenital unilateral absence of vas deferens cases and 78 controls. Cases had a lower semen volume than controls. The congenital unilateral absence of vas deferens risk was associated with history of cryptorchidism and both levels of semen fructose and α-glucosidase. These predictors were confirmed by a random forest algorithm. The area under the curve was 0.886 (95% interval: 0.81-0.92). Calibration was performed with the Hosmer-Lemeshow test (p = 0.88). DISCUSSION AND CONCLUSION: History of cryptorchidism, semen fructose and α-glucosidase were identified as relevant and independent predictors for the diagnosis of congenital unilateral absence of vas deferens. The model enables to identify male patients with a high risk of congenital unilateral absence of vas deferens to whom a transrectal ultrasounds would be proposed to confirm the diagnosis, whatever their semen parameters. It will also help to address the risks of unilateral renal absence and of cystic fibrosis transmembrane conductance regulator mutations carrying during the management of infertile couples.

Congenital Solitary Kidney from Birth to Adulthood.

PURPOSE: To evaluate the course of prenatally diagnosed and early-enrolled congenital solitary functioning kidney patients followed until adulthood and to identify risk factors for kidney injury. MATERIALS AND METHODS: Among all congenital solitary functioning kidney patients followed (1993-2018), we recalled 56 patients with prenatal diagnosis and congenital solitary functioning kidney confirmation at 1-3 months of life reaching at least 18 years of age. Serum uric acid, heavy smoking (≥25 cigarettes/day) and overweight/obesity were clustered as modifiable risk factors. Kidney injury was defined by estimated glomerular filtration rate <90 ml/minute/1.73 m2 and/or 24-hour ambulatory blood pressure monitoring confirmed hypertension and/or proteinuria. Modifiable risk factors and congenital anomalies of the kidney and urinary tract (CAKUT) of congenital solitary functioning kidney were evaluated as risk factors for kidney injury. RESULTS: The mean followup period was 21.1 years (range 18-33 years). Mild kidney injury was found in 15 out of 56 patients (26.8%). The mean age at proteinuria, reduced estimated glomerular filtration rate and hypertension onset was 19.7 years (1.2 SDS), 20.7 years (2.7 SDS), and 22 years (5.6 SDS), respectively. Patients with CAKUT of congenital solitary functioning kidney and with both CAKUT of congenital solitary functioning kidney and modifiable risk factors presented survival free from kidney injury of 0% at 22.2 and 24.2 years of age, respectively. Patients with modifiable risk factors presented 42.4% of survival at 30 years. Patients without CAKUT of congenital solitary functioning kidney nor modifiable risk factors presented 100% of survival at 30 years of age (p=0.002). The presence of CAKUT of congenital solitary functioning kidney was the only significant risk factor (HR 4.9; 95% CI 1.8-14.2; p=0.003). CONCLUSIONS: The outcomes of congenital solitary functioning kidney in early adulthood appear better than previously reported. Prompt diagnosis of congenital solitary functioning kidney, healthy lifestyle promotion and monitoring of serum uric acid may improve the prognosis of congenital solitary functioning kidney patients.

Herlyn-Werner-Wünderlich syndrome: An unusual case with presentation of menorrhagia.

OBJECTIVE: Herlyn-Werner-Wünderlich (HWW) syndrome is a rare condition in which patients present with a palpable pelvic mass and pain caused by an obstructed hemivagina. Here we present a case of HWW syndrome characterized by prolonged menstrual bleeding. CASE REPORT: A 19-year-old nonsexually active unmarried women experienced irregular menstrual cycles and menorrhagia. The duration of menstrual bleeding was 10-14 days. She also suffered from mild dysmenorrhea since menarche at the age of 13. Transabdominal sonography revealed a double uterus and a heterogeneous myoma-mimicking mass over the left cervical region. The left kidney was absent. Magnetic resonance imaging revealed a double uterus, a double vagina with an unperforated left hemivagina, and ipsilateral renal agenesis. The patient underwent cervicovaginal orifice reconstruction surgery. CONCLUSION: Left hematocolpos compression, a partially obstructed right vaginal channel, and an orifice with local venous drainage abnormalities resulted in prolonged menstrual bleeding. In HWW syndrome, the occurrence of a pelvic mass and pain is common; however, prolonged menstrual bleeding is rare.

Born with a solitary kidney: at risk of hypertension.

BACKGROUND: Subjects with a congenital solitary kidney (CSK) are believed to be at risk of hypertension due to their low number of nephrons. However, as CSK is a congenital abnormality of the kidney or urinary tract (CAKUT), subtle dysplastic changes contributing to hypertension cannot be excluded. METHODS: We retrospectively compared office blood pressure (OBP) and ambulatory blood pressure monitoring (ABPM) between two groups of children with CAKUT, aged 6-18 years: Group A with a CSK and Group B with two kidneys. All had normal renal parenchyma on scintigraphy and normal renal function. OBP and mean systolic and diastolic 24-h, daytime and nighttime ambulatory BP records were analyzed. The distribution of OBP and APBM as continuous values and the prevalence of hypertension (ambulatory/severe ambulatory or masked hypertension) in the two groups were compared. RESULTS: There were 81 patients in Group A and 45 in Group B. Median OBP standard deviation scores were normal in both groups, without significant differences. Median ABPM standard deviation scores, although normal, were significantly higher in Group A and the prevalence of hypertension was higher (ambulatory/severe ambulatory or masked) (33.3 vs. 13.3%, p = 0.019), mainly because of the greater occurrence of masked hypertension. CONCLUSIONS: Our data show that a CSK per se can be associated with an increased risk of hypertension from the pediatric age. Therefore, ABPM, which has proved valuable in the screening of hypertension, is warranted in children with a CSK, even if laboratory and imaging assessment is otherwise normal.

Is renal scintigraphy really a necessity in the routine diagnosis of congenital solitary kidney?

BACKGROUND: For a definitive diagnosis of congenital solitary kidney, renal scintigraphy is suggested as being the gold standard of ruling out ectopic functioning renal tissue, possibly missed by ultrasound. The aim of our study was to test ultrasonography precision in comparison with renal scintigraphy on a larger cohort of congenital solitary kidneys. METHODS: We performed a retrospective unicenter study of children with congenital solitary kidney with no contralateral tissue, who were treated in the period from 1980 to 2017. The findings in children who underwent both abdominopelvic ultrasound and nuclear renal scintigraphy were compared and the accuracy of ultrasound was assessed. RESULTS: 99 children met the inclusion criteria of congenital solitary kidney confirmed with abdominopelvic ultrasound and nuclear renal scintigraphy. The children were predominantly male (61.6%), and the congenital solitary kidney was largely right-sided (55.5%). In 97 cases (98%), ultrasound correctly predicted the absence of functional renal tissue on one side in the renal fossa or in an ectopic location (pelvis or ipsilateral side). The calculated accuracy of abdominopelvic ultrasound in diagnosing congenital solitary kidney was therefore 98%. CONCLUSIONS: Our findings confirm that abdominopelvic ultrasound alone is accurate enough to diagnose congenital solitary kidney. It gives enough information for consideration if further radiological evaluation is still needed.

A clinical predictive model of renal injury in children with congenital solitary functioning kidney.

BACKGROUND: Solitary functioning kidney (SFK) is an important condition in the spectrum of congenital anomalies of the kidney and urinary tract. The aim of this study was to describe the risk factors for renal injury in a cohort of patients with congenital SFK. METHODS: In this retrospective cohort study, 162 patients with SFK were systematically followed up (median, 8.5 years). The primary endpoint was time until the occurrence of a composite event of renal injury, which includes proteinuria, hypertension, and chronic kidney disease (CKD). A predictive model was developed using Cox proportional hazards model and evaluated by c statistics. RESULTS: Among 162 children with SFK included in the analysis, 132 (81.5%) presented multicystic dysplastic kidney, 20 (12.3%) renal hypodysplasia, and 10 (6.2%) unilateral renal agenesis. Of 162 patients included in the analysis, 10 (6.2%) presented persistent proteinuria, 11 (6.8%) had hypertension, 9 (5.6%) developed CKD stage ≥ 3, and 18 (11%) developed the composite outcome. After adjustment by the Cox model, three variables remained as independent predictors of the composite event: creatinine (HR, 3.93; P < 0.001), recurrent urinary tract infection (UTI) (HR, 5.05; P = 0.002), and contralateral renal length at admission (HR, 0.974; P = 0.002). The probability of the composite event at 10 years of age was estimated as 3%, 11%, and 56% for patients assigned to the low-risk, medium-risk, and high-risk groups, respectively (P < 0.001). CONCLUSION: Our findings have shown an overall low risk of renal injury for most of infants with congenital SFK. Nevertheless, our prediction model enabled the identification of a subgroup of patients with an increased risk of renal injury over time.

Correlation between hypertrophy and risk of hypertension in congenital solitary functioning kidney.

PURPOSE: Solitary functioning kidney (SFK) may be associated to hypertrophy, hypertension and chronic kidney disease. We evaluated blood pressure (BP) of children with congenital SFK comparing agenesis to multicystic dysplastic kidney (MCDK) and correlated BP profiles with renal dimensions of affected and contralateral kidney. METHODS: We compared 40 patients with MCDK, grouped for either treatment options (A: conservative vs B: nephrectomy) or involution time (A1: before 4 years-of-age vs A2: persistence-of-MCDK), to 10 unilateral agenesis (C). Patients were evaluated with ultrasound, scintigraphy, office-ambulatory BP monitoring. RESULTS: Compensatory hypertrophy was demonstrated in most of the subjects, without differences between subgroups, with an increase over time (p < 0.001). A1-C showed an overall percentage of hypertrophy significantly higher than A2-B (83%-88% vs 70%-73%, respectively; p = 0.03); moreover, cumulative risk to develop hypertension in A1-C is significantly higher compared to A2-B in office and ambulatory BP monitoring (p = 0.03). Insufficient dipping in systolic and/or diastolic BP was found in 82% children, without differences between subtypes. CONCLUSIONS: Patients with a small/absent dysplastic kidney have an increased risk to develop hypertrophy and hypertension compared to patients with a large residual, regardless of nephrectomy. ABPM revealed absent dipping in most patients with SFK, warning further investigations in apparently not symptomatic patients.

Congenital anal atresia with rectovestibular fistula, scoliosis, unilateral renal agenesis, and finger defect (VACTERL association) in a patient with partial bicornuate uterus and distal vaginal atresia: A case report.

RATIONALE: Vertebral defect, anal atresia, cardiac defect, tracheoesophageal fistula/esophageal atresia, renal defect, and limb defect (VACTERL) association and Müllerian duct anomalies are rare conditions. We present a rare condition with the co-occurrence of the VACTERL association and Müllerian duct hypoplasia to characterize patients' clinical presentations, outcomes, and treatment. PATIENT CONCERNS: An 11-year-old girl presented to our hospital with severe lower abdominal pain, lower vaginal atresia with enlargement of the upper vagina and a bicornuate uterus with a Y-shaped uterine cavity filled with hematometra on pelvic magnetic resonance imaging. Her medical history included congenital anal atresia with a rectovestibular fistula, congenital right renal deficiency, congenital right thumb malformation, and scoliosis. DIAGNOSES: 1. Congenital genital tract malformations, a partial bicornuate uterus, and distal vaginal atresia (U3aC0V4); 2. VACTERL association (congenital anal atresia with rectovestibular fistula, scoliosis with hemi vertebra and butterfly vertebra, unilateral renal agenesis, and finger defect). INTERVENTIONS: Colpotomy, laparoscopic exploration, pelvic adhesiolysis, and hysteroscopy were performed. OUTCOMES: Two months after surgery, a pelvic examination showed an unobstructed vagina which was 10 cm long and 2 fingers wide, without adhesion or constriction. LESSONS: Clinicians should have a high index of suspicion when evaluating patients with genital malformations associated with VACTERL. Early diagnosis of distal vaginal atresia with appropriate surgical intervention decreases long-term morbidity.

Case Report: First Reported Combined Heart-Liver Transplant in a Patient With a Congenital Solitary Kidney.

We report a case of successful combined heart liver transplant in a patient with a congenital solitary kidney. The patient had normal renal function before combined heart-liver transplantation and developed acute kidney injury requiring slow continuous dialysis and subsequent intermittent dialysis for almost 8 weeks post transplantation. Her renal function recovered and she remains off dialysis now 7 months post transplantation. She only currently has mild chronic renal insufficiency. We believe this is the first reported case of successful heart liver transplant in a patient with a congenital solitary kidney.

[SOLITARY KIDNEY - IS IT TOO LITTLE?]

INTRODUCTION: Solitary functioning kidney (SFK) occurs with unilateral renal agenesis (URA) in 1/2000 live births - or after uninephrectomy for tumor, trauma, uncontrolled infections or hypertension and post-kidney donation. URA-associated states include urological, cardiac, gastrointestinal and skeletal anomalies or it might be a component of a genetic syndrome. In 10% of cases of URA another family member is affected. In any case of SFK a compensatory process is triggered consisting of glomerular hypertension with hyperfiltration which achieves 75% of two kidneys' function. In the long-run this process might be detrimental causing further loss of functioning nephrons, inability to sustain functional compensation and progressive kidney function deterioration. The risk for this chain of events is determined in the first place by the number of nephrons in the SFK, which cannot be assessed in vivo. Hints for reduced nephron number in the single kidney include prematurity or SGA-small for date birth weight, urological anomalies with or without accompanying infections, lack of increased single kidney size - compensatory hypertrophy. Age of onset of the compensatory process and acquired factors including nephrotoxin exposure, overweight/obesity, excessive salt and/or protein intake contribute to the risk of progressive renal damage. Life-long follow-up of all subjects with SFK is recommended from early age for lifestyle education: recommended diet and tailored physical activity, nephrotoxin avoidance along with early detection of renal injury signs: albuminuria, hypertension or depressed kidney function - GFR (glomerular filtration rate) targeting timely intervention for preservation of functioning renal mass.

Outcomes of prenatally diagnosed solitary functioning kidney during early life.

OBJECTIVE: To evaluate outcomes of congenital solitary functioning kidney (SFK) in early childhood. STUDY DESIGN: A retrospective study of 32 children diagnosed in utero with SFK owing to unilateral renal agenesis or multicystic dysplastic kidney and followed for 1 to 11.5 years. RESULTS: SFK length was in the compensatory hypertrophy range in 45% of fetal sonographic evaluations from mid-pregnancy, and in 85% on postnatal follow-up. Glomerular filtration rate was below normal range in 44.4%, 12.5% and 0% at <1 year, age 1 to 3 years and thereafter, respectively. Hyperfiltration was detected in 18.5% and 82.6% at <1 year and >3 years, respectively. Hypertension was documented in 35% at age 1 to 3 years but in none at an older age. Proteinuria was absent in all children. CONCLUSION: Congenital SFK is apparently associated with little or no renal damage in infancy or childhood. Compensatory enlargement of the functioning kidney begins in utero and might serve as a prognostic indicator for normal renal function after birth.

Outcomes of a Cohort of Prenatally Diagnosed and Early Enrolled Patients with Congenital Solitary Functioning Kidney.

PURPOSE: We evaluated the clinical course of patients prenatally diagnosed and enrolled early with congenital solitary functioning kidney, and identified the risk factors for renal injury. MATERIALS AND METHODS: We retrospectively evaluated 322 patients with congenital solitary functioning kidney according to the inclusion criteria of 1) prenatal diagnosis of solitary kidney; 2) first evaluation at 1 to 3 months of life with confirmation of congenital solitary functioning kidney, and evaluation of possible associated congenital anomalies of the kidney and urinary tract by abdominal ultrasound, renal scintigraphy and cystography; and 3) absence of any condition potentially affecting renal function in the neonatal period as well as absence of renal injury at enrollment (1 to 3 months of life) confirmed by a normal estimated glomerular filtration rate, lack of proteinuria and hypertension. Followup of 306 patients was evaluated. RESULTS: Median followup was 7.2 years (range 1 to 23) and 1 or more signs of renal injury were found in 12 of 306 patients (3.9%). Considering the entire population the cumulative proportion of patients free from renal injury at 17 years old was 93.7%, vs 81.3% and 95.9% for subjects with and those without congenital anomalies of the kidney and urinary tract of congenital solitary functioning kidney (p <0.001), respectively. Of congenital anomalies of the kidney and urinary tract, congenital solitary functioning kidney resulted in significant risk factors for renal injury (HR 8.75, 95% CI 2.77-27.65). CONCLUSIONS: In an evaluation of a large cohort of patients enrolled early with congenital solitary functioning kidney with a prenatal diagnosis, excluding those with neonatal onset of renal damage, the prevalence of renal damage was 3.9%. Among congenital anomalies of the kidney and urinary tract, congenital solitary functioning kidney represented the major risk factor.

Evolution of blood pressure in children with congenital and acquired solitary functioning kidney.

BACKGROUND: It is not yet clear if blood pressure and renal function changes evolve differently in children with a congenital or acquired solitary functioning kidney. This study aims to assess if there are any differences between these two types of solitary kidney patients. METHODS: Current research is a retrospective study assessing the evolution of glomerular filtration rate, proteinuria, and blood pressure in clinical records of 55 children with a solitary functioning kidney (37 congenital and 18 acquired). We used the medical records of children who had been assisted, in our unit of pediatric nephrology, for a period of 14 years (168 months), from the time of diagnosis, between January/1997 and December/2015. RESULTS: During the study period, glomerular filtration rate (T0 128.89 ± 32.24 vs T14 118.51 ± 34.45 ml/min/1.73 m2, p NS) and proteinuria (T0 85.14 ± 83.13 vs T14 159.03 ± 234.66 mg/m2/die, p NS) demonstrated no significant change. However, after 14 years of follow-up 76.4% of patients had increased levels of arterial hypertension with values over the 90th percentile for gender, age, and height. Specifically, children with an acquired solitary functioning kidney mainly developed hypertension [T0 2/17 (12%) vs T14 9/17 (52.9%) p < 0.025], whereas children with a congenital solitary functioning kidney mainly developed pre-hypertension [T0 3/38 (7.9%) vs T14 17/38 (44.7%) p < 0.0005]. CONCLUSIONS: The renal function of children with solitary functioning kidneys remains stable during a follow-up of 14 years. However, these children should be carefully monitored for their tendency to develop arterial blood pressure greater than the 90th percentile for gender, age, and height.

Renal Nitric Oxide Deficiency and Chronic Kidney Disease in Young Sheep Born with a Solitary Functioning Kidney.

Previously, we demonstrated that renal hemodynamic responses to nitric oxide (NO) inhibition were attenuated in aged, hypertensive sheep born with a solitary functioning kidney (SFK). NO is an important regulator of renal function, particularly, in the postnatal period. We hypothesized that the onset of renal dysfunction and hypertension in individuals with a SFK is associated with NO deficiency early in life. In this study, renal and cardiovascular responses to L-NAME infusion (N(w)-nitro-L-arginine methyl ester) were examined in 6-month old lambs born with a SFK, induced by fetal unilateral nephrectomy (uni-x). Renal responses to L-NAME were attenuated in uni-x sheep with the fall in glomerular filtration rate (GFR) and urinary sodium excretion (UNaV) being less in the uni-x compared to sham lambs (%ΔGFR; -41 ± 3 vs -54 ± 4: P = 0.03, %ΔUNaV; -48 ± 5 vs -76 ± 3, P = 0.0008). 24 hour-basal urinary nitrate and nitrite (NOx) excretion was less in the uni-x animals compared to the sham (NOx excretion µM/min/kg; sham: 57 ± 7; uni-x: 38 ± 4, P = 0.02). L-NAME treatment reduced urinary NOx to undetectable levels in both groups. A reduction in NO bioavailability in early life may contribute to the initiation of glomerular and tubular dysfunction that promotes development and progression of hypertension in offspring with a congenital nephron deficit, including those with a SFK.