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Clearance While Upright on Initial Diuretic Renography Predicts the Need for Surgery in Children With Congenital
Bayan Shalash1, Michael Ernst2, Megan Stout3
1Department of Pediatric Urology, Nationwide Children's Hospital, Columbus, OH; The Ohio State University College of Medicine, Columbus, OH.
Insights
Clearance while upright (CUP) on diuretic renography can predict surgical intervention in children with congenital hydronephrosis. A CUP value below 22.4% suggests a high likelihood of needing surgery, aiding clinical decisions.
Area of Science:
- Pediatric Urology
- Diagnostic Imaging
- Nephrology
Background:
- Congenital hydronephrosis (CH) in infants often requires monitoring for ureteropelvic junction obstruction.
- Diuretic renography (DR) is used to assess kidney function and obstruction but predicting surgical need can be challenging.
Purpose of the Study:
- To enhance the predictive accuracy of diuretic renography (DR) for surgical intervention in pediatric patients with congenital hydronephrosis (CH).
- To identify optimal cut-off values for clearance while upright (CUP) and T ½ from DR to predict the need for surgery.
Main Methods:
- Retrospective analysis of 65 children with CH who underwent DR before six months of age.
- Evaluation of surgical intervention rates based on identified optimal cut-points for CUP and T ½.
Main Results:
- The optimal cut-point for CUP predicting surgery was 22.4%, with a sensitivity of 60.6% and specificity of 96.9%.
- A CUP value below 22.4% demonstrated high positive predictive value (95.2%) for surgical intervention.
Conclusions:
- Low clearance while upright (CUP) values (<22.4%) are predictive of surgical intervention in observed pediatric CH cases.
- Incorporating CUP into DR interpretation can aid management decisions for CH, though further research is needed for intermediate values.
Objective:
To improve the predictive ability of diuretic renography (DR) for surgical intervention in children with congenital hydronephrosis (CH) and concern for ureteropelvic junction obstruction.
Methods:
Children with CH born between 2007 and 2021 who underwent initial DR prior to 6months of life, had both clearance while upright (CUP) and T ½ reported, and did not have immediate surgical intervention after the first DR were retrospectively evaluated for surgical intervention during the period of clinical observation. Once the optimal cut-points were identified for CUP and T ½, they were used to calculate the sensitivity, specificity, positive predictive value, and negative predictive value.
Results:
In total 65 patients were included in the final analysis with 33 (50.8%) undergoing surgical intervention (pyeloplasty) and 32 (49.2%) still on observation at last follow-up. The optimal cut-points for predicting surgical intervention were 28.1 minutes for T ½ and 22.4% for CUP. Applying the CUP cut-point of 22.4% we achieved a sensitivity of 60.6% (95% CI: 43.9-77.3), specificity of 96.9% (95% CI: 90.1-100.0), positive predictive value of 95.2% (95% CI: 86.1-100.0), and negative predictive value of 70.5% (95% CI: 57.0-83.9).
Conclusion:
A low CUP accurately predicts surgical intervention in children with CH who are initially observed. Although there is no singular measure on DR that can with absolute certainty predict future clinical course, our data do suggest there is utility in incorporating CUP (if <22.4%) into the decision process. Further research is necessary to help guide the management of children with intermediate CUP values.
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