Can shear wave elastography predict urodynamic studies in pediatric population? - A prospective study in posterior urethral valve patients.

PURPOSE: The aim of this study was to evaluate bladder dysfunction non-invasively in patients operated for posterior urethral valve (PUV). For this purpose, findings obtained from shear wave elastography (SWE) were compared with simultaneous urodynamic findings.

MATERIAL AND

METHODS

Bladder functions of patients operated for PUV were examined with a urodynamic study (UDS) and compared with anterior and posterior bladder wall shear wave speed (SWS) measurements. Patients with vesicoureteral reflux were excluded from the study. Anticholinergic treatment that patients had previously used was discontinued for 2 weeks prior to the evaluation. The primary target parameters were detrusor pressure, bladder pressure, and the correlation between bladder compliance and SWS. Apart from that, upper urinary tract imaging, bladder capacity measurement, and postvoid residual urine amount were recorded.

RESULTS

Twenty-eight patients who underwent endoscopic posterior urethral valve ablation between 2006 and 2018 were included in this study. A statistically significant correlation was found between vesical pressure (Pves) and SWS at 25%, 50%, 75% and 100% occupancy, while detrusor pressure (Pdet) was correlated with SWS at 75%, 100% occupancy. A statistically significant difference was found between the low (<20 ml/cmH2O) and normal (≥20 ml/cmH2O) compliance groups in the SWS measurement values of the anterior wall of the empty bladder. SWS values were higher in the group with compliance lower than 20 ml/cmH2O. A linear regression model was created to estimate Pdet and Pves based on SWS values. 100% Pdet = (SWS x 1.104) - 12.798 50% Pves = (SWS x 0.775) + 4.027

CONCLUSIONS

Our findings demonstrate that key urodynamic parameters required for the follow-up of bladder dysfunction in PUV patients can be reliably predicted using shear wave elastography. In order to replace invasive urodynamics, studies with larger patient cohorts and patients with different pathologies are needed.