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Necessity of performing voiding cystourethrography for children with unilateral multicystic dysplastic kidney
Kazuna Yamamoto1,2, Koichi Kamei3, Mai Sato1
1Division of Nephrology and Rheumatology, National Center for Child Health and Development, 2-10-1 Okura, Setagaya-ku, Tokyo, 157-8535, Japan.
Insights
Abnormal ultrasonography findings can identify children with unilateral multicystic dysplastic kidney (MCDK) who need voiding cystourethrography (VCUG). Repeated ultrasounds are crucial for detecting urinary tract anomalies.
Area of Science:
- Pediatric Urology
- Diagnostic Imaging
- Nephrology
Background:
- Unilateral multicystic dysplastic kidney (MCDK) is a common congenital anomaly.
- The necessity of voiding cystourethrography (VCUG) for all unilateral MCDK cases is debated.
- Identifying selective criteria for VCUG can optimize resource allocation and reduce patient exposure.
Purpose of the Study:
- To determine if abnormal ultrasonography findings can predict the need for voiding cystourethrography (VCUG) in children with unilateral multicystic dysplastic kidney (MCDK).
- To establish clinical guidelines for selective VCUG referral in pediatric MCDK patients.
Main Methods:
- Retrospective cross-sectional analysis of 75 children with unilateral MCDK.
- Multivariate logistic regression analysis to identify risk factors for abnormal VCUG.
- Exclusion of patients with other significant congenital abnormalities.
Main Results:
- 32% of patients had abnormal VCUG findings, including vesicoureteral reflux (VUR) and lower urinary tract disease.
- Abnormal ultrasonography findings were a significant independent predictor of abnormal VCUG (OR 6.57, P=0.002).
- Ultrasonography demonstrated high sensitivity (83%) and negative predictive value (88%) for detecting urologic anomalies.
Conclusions:
- Abnormal ultrasonography findings can effectively select children with unilateral MCDK who require VCUG.
- Repeated ultrasonography may be necessary to fully detect congenital urinary tract anomalies.
- This approach can help refine the diagnostic pathway for pediatric MCDK.
Background:
The purpose of this study was to resolve the clinical question as to whether all patients with unilateral multicystic dysplastic kidney (MCDK) should receive voiding cystourethrography (VCUG).
Methods:
This is a retrospective study using cross-sectional analysis. Seventy-five children with unilateral MCDK were enrolled, excluding patients with other genetic or chromosome abnormalities, spinal cord diseases, or anal atresia. We reviewed their records from medical charts and calculated risk factors for abnormal VCUG using multivariate logistic regression analysis.
Results:
Abnormal VCUG findings were present in 24 of 75 patients (32.0%), specifically, vesicoureteral reflux (VUR) in 8 (10.6%), including high-grade VUR in 2 (2.7%), and only lower urinary tract or bladder disease in 16 (21.3%). In multivariate analysis, only abnormal findings by ultrasonography was an independent risk factor for abnormal VCUG findings with statistical significance in multivariate analysis (OR 6.57; 95% CI 1.99-26.26; P = 0.002). When we excluded five patients who showed similar findings by ultrasonography and VCUG, abnormal findings by ultrasonography were again calculated as an independent risk factor (OR 4.44; 95% CI 1.26-28.42; P = 0.02). Sensitivity, specificity, positive predictive value, and negative predictive value of abnormal findings by ultrasonography to predict urologic anomalies by VCUG in these children were 83%, 59%, 49%, and 88%, respectively. Two children required a third ultrasonography to detect abnormal findings.
Conclusions:
We can select, using only abnormal findings by ultrasonography, children with unilateral MCDK who should undergo VCUG. We would also like to emphasize that ultrasonography should be performed repeatedly to detect congenital anomalies of the urinary tract.
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