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Evaluation of Bladder Dysfunction Outcomes Among Standardized Bladder Shapes in Children With Spina Bifida
Zoe S Gan1, Joey Logan2, Ariana L Smith1
1Division of Urology, Department of Surgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA.
Insights
Standardized bladder shapes in pediatric spina bifida patients were established. Trabeculations and "Christmas tree" shapes correlate with higher bladder pressures, but not necessarily with other dysfunction indicators.
Area of Science:
- Pediatric Urology
- Neurourology
- Medical Imaging
Background:
- Spina bifida often leads to bladder dysfunction.
- Standardized terminology for bladder shapes in this population is lacking.
- Bladder shape may indicate underlying dysfunction.
Purpose of the Study:
- To propose standardized terminology for pediatric bladder shapes on fluoroscopic images.
- To assess the association between bladder shape and filling pressures.
- To determine if bladder shape correlates with other measures of bladder dysfunction.
Main Methods:
- Cross-sectional study of pediatric spina bifida patients undergoing video urodynamics.
- Unsupervised cluster analysis and expert clinician classification of bladder shapes (round, oblong, "Christmas tree", smooth, trabeculated).
- Comparison of bladder filling pressures and clinical dysfunction measures across shape categories.
Main Results:
- Four hundred seventeen pediatric patients were analyzed.
- Trabeculated and "Christmas tree" bladders showed significantly higher filling pressures compared to smooth bladders.
- Bladder shape differences were associated with vesicoureteral reflux, leakage, and detrusor-external sphincter dyssynergia, but not consistently with hydronephrosis or dysfunction severity.
Conclusions:
- A standardized bladder shape nomenclature for pediatric spina bifida was established.
- Bladder contour (trabeculated vs. smooth) and "Christmas tree" morphology are linked to higher filling pressures.
- Bladder shape alone is insufficient to consistently predict all types or severity of bladder dysfunction.
Objectives:
To (1) propose standardized terminology for bladder shapes on fluoroscopic images in a pediatric spina bifida population and (2) determine if bladder shape is associated with filling pressures and other measures of bladder dysfunction. We hypothesized that oblong, trabeculated, and "Christmas tree" bladders would have higher filling pressures and worse bladder function (higher filling pressures; higher presence of vesicoureteral reflux, leakage, detrusor-external sphincter dyssynergia, and hydronephrosis) than smooth and round-shaped bladders.
Methods:
We conducted a cross-sectional study of pediatric and adolescent patients with spina bifida who underwent video urodynamics (VUDS) at a tertiary center from July 2016 to June 2022. Representative fluoroscopic bladder images from the earliest available VUDS were categorized by unsupervised cluster analysis. Five urologists also determined standardized classifications for bladder shape (round, oblong, and "Christmas tree") and contour (smooth or trabeculated/diverticulated), which were applied to the bladder images. Bladder filling pressures and clinical measures of bladder function were compared among bladder shapes.
Results:
Four hundred seventeen patients with a median age of 2.6 years (IQR 0.4-8.0 years) were included. For the machine learning cluster analysis of bladder shape, clusters with more trabeculated-appearing bladders had higher filling pressures. For expert clinician classification, round trabeculated, oblong trabeculated, and "Christmas tree" bladders had higher filling pressures than round smooth and oblong smooth bladders, a difference that was statistically significant. Statistically significant differences were noted among bladder shapes for the presence of vesicoureteral reflux, leakage, detrusor-external sphincter dyssynergia, and hydronephrosis. Moderate and severe bladder dysfunction were present across all bladder shape clusters.
Conclusions:
We established a standardized bladder shape nomenclature in children and adolescents with spina bifida. Higher bladder filling pressures are associated with trabeculations and "Christmas tree" appearance versus smooth contour, but not oblong versus round shape. Bladder shape alone does not appear to consistently differentiate the presence of hydronephrosis, vesicoureteral reflux, leakage, detrusor-external sphincter dyssynergia, or bladder dysfunction severity.
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