Related Experiment Video
Updated: Jun 6, 2025
Author Spotlight: Developing a Bedside Protocol for Kidney and Genitourinary Ultrasonography
Published on: June 21, 2024
Spontaneous Resolution of Primary Obstructive Megaureter: Risk Stratification and Prediction Based on Early
Adree Khondker1,2, Jin Kyu Kim1,2, Ihtisham Ahmad3
1Division of Urology, Department of Surgery, University of Toronto, Toronto, Ontario, Canada.
Insights
Early ultrasound measurements can predict spontaneous resolution of primary obstructive megaureter (POM). High-risk features like large anteroposterior diameter (APD) on initial ultrasound suggest closer monitoring is needed for these pediatric patients.
Area of Science:
- Pediatric Urology
- Medical Imaging
- Predictive Analytics
Background:
- Primary obstructive megaureter (POM) is a condition requiring careful monitoring for spontaneous resolution.
- Predicting resolution aids in managing surgical interventions and patient follow-up.
Purpose of the Study:
- To identify early ultrasound predictors for spontaneous resolution of primary obstructive megaureter (POM).
- To develop a model for assessing the likelihood of resolution based on initial sonographic findings.
Main Methods:
- Retrospective review of 159 pediatric patients diagnosed with POM between 2007 and 2023.
- Utilized Kaplan-Meier curves and Cox proportional hazards regression to analyze resolution rates and identify predictors.
- Defined resolution by decreased hydronephrosis or Society for Fetal Urology grade.
Main Results:
- 89 out of 159 patients achieved spontaneous resolution.
- High-grade hydronephrosis, ureteral dilation > 10 mm, and ureter tortuosity were associated with lower resolution likelihood.
- A Cox regression model achieved an adjusted C-index of 0.68, with low anteroposterior diameter (APD) predicting higher resolution likelihood.
Conclusions:
- Early sonographic features, particularly APD, are significant predictors of spontaneous resolution in POM.
- Patients presenting with high-risk sonographic features require closer follow-up and monitoring.
Purpose:
We describe and develop predictors for spontaneous resolution of primary obstructive megaureter (POM) from early ultrasound (US) measures.
Materials And Methods:
Children referred to our institution between 2007 and 2023 for POM were reviewed. POM was defined as hydroureteronephrosis with ureteral dilation > 7 mm. We excluded patients with other etiologies for upper tract dilation. Resolution was defined as decrease in hydronephrosis to < 10 mm anteroposterior diameter (APD) or Society for Fetal Urology grade ≤ 2 or ≤ 7 mm in hydroureter. Patients were censored if they underwent surgical intervention or were lost to follow-up before documenting resolution. Kaplan-Meier curves were drawn to illustrate the cumulative resolution rate and determine univariate associations. Cox proportional hazards regression was performed to identify significant predictors for early resolution, and C index was calculated.
Results:
A total of 159 patients were included, with a median index age of 2 months and a median follow-up of 30 months. Of these, 89 patients reached spontaneous resolution during monitoring, and likelihood of surgical indication at 1 year from US was 30%. APD > 15 mm, high-grade hydronephrosis, ureteral dilation > 10 mm, and ureter tortuosity at presentation were associated with a lower likelihood of resolution for individual Kaplan-Meier curves. A Cox regression model trained on these predictors achieved an adjusted C index of 0.68, and low APD remained associated with a higher likelihood of resolution.
Conclusions:
Early sonographic features in POM, specifically APD, are associated with the likelihood of spontaneous resolution. Patients with high-risk features at first US warrant closer follow-up.
