Knowledge of vesicoureteral reflux obtained by screening voiding cystourethrogram in children with multicystic dysplastic kidney does not change patient management or prevent febrile urinary tract infection

Utility of renal scintigraphy in diagnosis of multicystic dysplastic kidney

PURPOSE

To compare the prevalence of vesicoureteral reflux (VUR), febrile urinary tract infection (fUTI), and chronic kidney disease (CKD) among patients with multicystic dysplastic kidney (MCDK) diagnosed by renal scintigraphy (RS) versus follow-up renal ultrasound (RUS) alone.

METHODS

This was a retrospective review of patients seen at a tertiary care center from 2010 to 2020 with MCDK diagnosed by RS or follow-up RUS. Differences in the prevalence of VUR, fUTI, and CKD by cohort were assessed using logistic regression analysis, Pearson X² , and Fisher's Exact tests. Temporal trends in diagnostic methods used (RUS versus RUS + RS) were evaluated using the Cochran-Armitage trend test.

RESULTS

One-hundred seventy-two patients were included: 50% (n = 86) underwent RUS + RS and 50% (n = 86) underwent RUS alone to diagnose MCDK. Prevalence of VUR, fUTI, and CKD did not significantly vary between groups. Among patients who had a VCUG, 4.4% had contralateral VUR (1.7% RUS + RS group; 7.4% RUS group; p = 0.19) and 14.5% had at least one fUTI (16.3% RUS + RS group; 12.8% RUS group; p = 0.52). Females were significantly more likely to have at least one fUTI (p = 0.04). Four patients (2.3%) developed CKD, all in the RUS + RS cohort (p = 0.12). Diagnosis of MCDK by RUS versus RUS + RS did not significantly vary over time (p = 0.17).

CONCLUSION

Patients with unilateral MCDK confirmed by RS versus RUS alone do not significantly vary in the prevalence of VUR, fUTI, or CKD. Renal scintigraphy studies may not be necessary in unilateral MCDK diagnosis but continue to be used.

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.

Retrospective evaluation of the pediatric multicystic dysplastic kidney patients: experience of two centers from southeastern Turkey

Background/aim

The objective of this study is to determine the clinical features of unilateral multicystic dysplastic kidney (MCDK) patients.

Materials and methods

The demographic, clinical, laboratory, and radiologic features of MCDK patients at Diyarbakır Children’s Hospital and Diyarbakır Gazi Yaşargil Training and Research Hospital between January 2008-June 2019 were retrospectively evaluated.

Results

A total of 111 [59 (53.2%) male and 52(46.8%) female] patients with MCDK were followed for a mean period of 41.89 ± 32.03 months. MCDK was located on the left and right sides in 46 (41.4%) and 65 (58.6%) of the children, respectively (p > 0.05). A total of 87 (78.4%) patients had antenatal diagnosis. The mean age at diagnosis was 13.7 ± 34.2 months. Of the 49 voiding cystourethrogram (VCUG)-performed patients, vesicoureteral reflux was detected in 11 patients (22.4%). Other associated urological anomalies in the patients were detected in 12 (10.8%) patients. On Tc-99m dimercaptosuccinic acid (DMSA) scintigraphy which was performed in all patients showed scarring in four children. Eight patients had history of UTI (7.2%). Renal failure, hypertension, and proteinuria were diagnosed in three children (2.7%). Sixty-nine (62%) patients developed compensatory hypertrophy.

Conclusion

All cases should be followed up closely and VCUG should be reserved for patients with recurrent UTI and other urological problems indicated by ultrasonography and abnormal DMSA scan results.

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.

Voiding Cystourethrogram in Children With Unilateral Multicystic Dysplastic Kidney: Is It Still necessary?

OBJECTIVE

To evaluate the value of the voiding cystourethrogram (VCUG) in children with multicystic dysplastic kidney (MCDK) who have a normal versus abnormal contralateral kidney and bladder ultrasound (US), and assess the risk of having vesicoureteral reflux (VUR) or urinary tract infection (UTI) based on the US results.

METHODS

A retrospective chart review including children with unilateral MCDK with postnatal US and VCUG available at our institution between January 2008 and September 2017 was performed. Analysis was done to find association between abnormal contralateral US and contralateral VUR and UTI.

RESULTS

One hundred and fifty-six children were analyzed; 118(75.6%) patients had a normal contralateral kidney US, while 38(24.4%) had abnormal US. The rate of severe contralateral VUR (grade IV and V) was 2 (1.7%) and 5 (13.2%) in children with normal and abnormal contralateral US, respectively. The risk analysis demonstrated a significant association between severe VUR on the contralateral kidney and an abnormal contralateral US (odds ratio = 7.73; 95%CI: 1.43-41.81; P = 0.018) and no significant association with UTI (odds ratio = 1.58; 95%CI: 0.50-4.94; P = 0.435).

CONCLUSION

Our data suggests, the rate of severe contralateral VUR in children with unilateral MCDK and normal contralateral kidney is low. VCUG should be considered for infants with proven MCKD and alterations on the contralateral kidney on US. Following patients with MCDK and normal contralateral kidney without the use of VCUG is a reasonable approach, unless there is development of signs and symptoms of recurrent UTI or deterioration of the renal function. We found that abnormal contralateral kidney US was associated with severe VUR.