Integrated ultrasound with urodynamics illustrates effect of bladder volume on upper tract dilation: Should we trust surveillance ultrasounds?


Advocate Children's Medical Group, Advocate Health Care


OBJECTIVE: To evaluate if ultrasound during urodynamics (uUS) will show that traditional ultrasound (tUS) routinely underestimates the potential magnitude of upper tract dilation (UTD).

METHODS: Prospective pilot study of 10 consecutive patients ≥ 5 years of age undergoing same day uUS and tUS. Using randomized images, the study pediatric radiologist determined anterior-posterior renal pelvic diameter (APD), bladder volume, vesicoureteral reflux (VUR) and UTD grades. A single pediatric urologist determined urodynamic bladder capacity and assigned either hostile, intermediate, abnormal but safe, or normal national spina bifida patient registry classification (NSBPR).

RESULTS: Bladder volume on tUS was significantly smaller than final bladder volume on uUS (180 vs 363 ml: P

CONCLUSION: Despite instructions to the contrary, patients come for tUS with a relatively empty bladder as compared to either their urodynamic or patient-reported capacity. This translates to a significant underestimation of UTD with tUS, most notably in those with VUR. Alternatives to traditional protocols include insisting patients wait until their bladder is truly full for tUS, retrograde filling their bladder, or performing uUS. Accurate assessment of UTD severity may help guide long term management.

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