O2216: Reassessing the Red: Challenges in Grading Pediatric Hemorrhagic Cystitis

Background: Pediatric hemorrhagic cystitis (HC) is an understudied condition. Currently pediatric HC is classified as grades I-IV, ranging from microscopic hematuria (Grade I) to severe hemorrhage requiring intervention (Grade IV) with notably inconsistent use of Grade IV. This study aims to refine the Grade IV classification through identifying predictive factors for earlier intervention.

Methods: This retrospective review examined inpatients at our institution between 2014-2024 diagnosed with HC grade II or higher. Collected data included chemotherapy/radiation exposure, laboratory and imaging findings, as well as HC grade, duration, and urologic consultation/intervention. Exclusion criteria included patients with concurrent urinary tract infections, upper tract bleeding, or incomplete data

Results: Our cohort included 65 patients, we identified exposure to ≥3 bladder-toxic chemotherapies or both busulfan and methotrexate predicted need for surgery (p=0.019, p=0.038) but did not lead to refining the HC grading system. Imaging findings proved to be more specific in predicting the need for intervention and this included patients with a median of 7 ultrasounds, with an average clot volume of 294mL, compared to a median of 0 ultrasounds (range 0-1) for those who did not undergo surgery. A single patient who did not require surgery had an organized clot on ultrasound measuring 75mL

Conclusion: Our study highlights the limitations of the current HC grading system in predicting progression to surgery. Previously identified risk factors do not significantly improve the grading system’s predictive value. However, imaging may be more specific for surgical need and may aid in refining the grading system.