The utility of the Whitaker test in the modern era of pediatric urology: A retrospective cohort study.

INTRODUCTION

Pediatric urologists are often tasked with recognizing upper urinary tract obstruction and managing these cases appropriately. The Whitaker test (WhT) is a diagnostic modality created to identify obstruction by measuring pressure differentials along the renal pelvis and bladder via antegrade contrast administration. Over time, the diuretic renogram has become preferred in the workup of pediatric obstruction due to concerns regarding need for percutaneous nephrostomy tube placement and variability in findings based on technique during WhT.

OBJECTIVE

This study evaluates the clinical utility of the WhT in a contemporary pediatric cohort - especially in patients with equivocal diuretic renograms or prior interventions for urinary tract obstruction.

STUDY

DESIGN

A retrospective chart review was conducted to identify patients less than 18 years old who underwent WhT between 2019 and 2025 at our tertiary referral center. Data collected included patient demographics such as prior upper tract reconstruction, renogram interpretations by radiologists, indications for and results of WhT, and concordance versus discordance between renogram and WhT. In cases of discordance, we examined whether ultimate decision-making reflected the findings of WhT or renogram.

RESULTS

38 patients underwent WhT between 2019 and 2025. Approximately 60 % of the cohort was male and 60 % of the cohort had prior upper tract urinary reconstruction. The most common indication for WhT was concern for recurrent unilateral ureteropelvic junction obstruction (UPJO) after pyeloplasty (30.8 %). Overall, almost 80 % of treatment decisions, regarding whether to intervene or observe, were aligned with WhT findings of whether obstruction was present.

DISCUSSION: This study confirms that there remains clinical value to WhT in the workup of pediatric urinary tract obstruction. Our findings align with prior literature that WhT is a useful supplemental tool to renogram, particularly in equivocal cases or for patients with prior reconstruction. The retrospective, single-center design of this study inherently limits its evidentiary strength and generalizability.

CONCLUSION

Our study found that select patients with inconclusive renal scans and complex urologic history may benefit from WhT for conclusive decisions regarding whether surgical intervention is needed to manage upper urinary tract obstruction.