Ultrasound SWE useful in assessing bladder dysfunction in children
Ultrasound shear wave elastography (SWE) shows potential as a bedside tool for the evaluation of bladder dysfunction in children, with a recent study showing that SWE measurements correlate well with bladder pressures and differ between compliant and noncompliant bladders.
The study included 23 paediatric patients who underwent concurrent SWE and urodynamics. Ultrasound SWE was used to obtain the anterior and posterior wall when empty, at 25-, 50-, 75- and 100-percent expected bladder capacity, and end fill volume. A paediatric radiologist confirmed the regions of interest.
Patients were grouped into two according to their bladder capacity: compliant (capacity detrusor pressure <25 cm/H20) and noncompliant (capacity detrusor pressure ≥25 cm/H20). Analyses were performed using the Pearson correlation coefficients and mixed effects model to test the relationship between shear wave speed (SWS) and intravesical pressure, compliance and normalized compliance. An unpaired t-test was used for between-group analyses.
Mean SWS of both the anterior and posterior bladder walls was strongly associated with pressure throughout filling. When evaluating compliant against noncompliant bladders, mean SWS and detrusor SWS of the anterior wall markedly increased with filling of noncompliant bladders; SWS remained at baseline levels in compliant bladders. Mean SWS of the anterior wall showed a significant correlation with compliance and normalized compliance.
The findings underscore the utility of ultrasound SWE in evaluating bladder dysfunction in children, and provides an attractive alternative to urodynamics—an invasive test requiring catheterization.
Paediatric patients with bladder dysfunction leading to increased storage pressure are highly likely to have renal deterioration. Bladder dysfunction is characterized by an overactive bladder or involuntary and uninhibited bladder contractions, but the symptoms that patients present with tend to vary widely. Management of the condition poses a challenge to clinicians given the marginal success demonstrated by the currently available bladder-oriented treatments. [Curr Bladder Dysfunct Rep 2015;10:245; Curr Opin Urol 2011;21:334-8]