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BACKGROUND Baseline and interval dimercaptosuccinic acid (DMSA) scans and urodynamic (UD) studies are often obtained in infants and young children with spinal dysraphism (SD). OBJECTIVE To identify practical UD parameters which accurately stratify urologic risk young children with SD. STUDY DESIGN 130 expectantly managed infants/young children with SD and initial DMSA and UD before age 2 were reviewed. End fill pressure (EFP), bladder trabeculations, vesicoureteral reflux (VUR), initial volume (IV) drained at UD catheter placement, and detrusor pressure at initial volume (DPIV) were evaluated for association with subsequent febrile urinary tract infection (UTI), DMSA abnormalities, and early clean intermittent catheterization (CIC). A combination of factors to accurately stratify risk was sought. Groups were compared by log-rank test. The association of CIC and febrile UTI incidence was evaluated. RESULTS 31/130 patients developed DMSA abnormalities, 52/130 started early CIC, and 61/130 developed a febrile UTI with median follow-up of 3.8 years. Trabeculations, VUR, EFP ≥40 cm H2O, IV ≥50% estimated bladder capacity (EBC), and DPIV >10 cm H2O were associated with subsequent abnormal DMSA scan (p < 0.001). The best predictor was combination of trabeculation and/or VUR (p < 0.001) (Figure). Among patients who maintained a non-trabeculated bladder without VUR during follow-up, 0/51 developed DMSA abnormalities compared with 31/79 who developed one or both (p < 0.001). Patients with trabeculations and/or VUR were more likely to start early CIC (8/51 vs. 44/79; p < 0.001) and have febrile UTI (11/51 vs. 50/79; p < 0.001). In those with trabeculations, CIC was associated with decreased incidence of febrile UTI (incidence rate ratio (IRR) 0.5, 95% CI 0.3-0.9); in those without trabeculations, CIC was associated with increased incidence of febrile UTI (IRR 1.8, 95% CI 1.1-3.1). CONCLUSIONS VUR, bladder trabeculations, EFP ≥40 cm H20, IV ≥50% of EBC, and DPIV >10 cm H2O were associated with subsequent DMSA abnormalities in young children with SD managed expectantly. Many of these parameters were associated with febrile UTI and early CIC. The combination of trabeculations and/or VUR outperformed other UD parameters in identifying those high and low-risk for adverse urologic outcomes. Routine DMSA scan may have limited utility in patients with a non-trabeculated bladder without VUR, as none developed an abnormal DMSA. Most (71%) abnormal DMSAs were in patients with trabeculations and/or VUR following a febrile UTI. Given these findings and that incidence of febrile UTI may be lower in those with trabeculations while on CIC, patients with trabeculations and/or VUR should be managed aggressively to protect kidneys.