The significance of 99mtechnetium dimercapto-succinic acid renal scan in children with spina bifida during long-term followup.

PURPOSE

(99m)Technetium dimercapto-succinic acid renal scans are ideal for demonstrating renal scarring in children with spina bifida. However, doubt persists about the need for routine application. We assessed the associations among abnormal (99m)technetium dimercapto-succinic acid renal scans, vesicoureteral reflux and urodynamic findings in patients with spina bifida during long-term followup.

MATERIALS AND METHODS

We retrospectively reviewed the records of 64 patients with spina bifida followed at our center. All patients were older than 10 years (mean 15.8, range 10 to 23). Dimercapto-succinic acid renal scans were considered abnormal with differential function of less than 40% or focal defects. Patient age, gender, previous febrile urinary tract infections, positive vesicoureteral reflux history, timing of clean intermittent catheterization initiation and the latest urodynamic findings were noted. Patients were grouped based on normal/abnormal scan results. Statistical analysis included univariate and multivariate regression analyses and chi-square tests.

RESULTS

A total of 16 patients (25%) had abnormal scans. Mean patient age, male-to-female ratio, leak point pressure, bladder compliance and timing of clean intermittent catheterization initiation did not differ between groups. Rates of previous febrile urinary tract infections differed significantly (11 of 16 in the abnormal group vs 9 of 48 in the normal group, p <0.01), as did positive reflux history (100% vs 31%, p <0.01). No patient with a negative reflux history had an abnormal dimercapto-succinic acid renal scan. Multivariate analysis identified previous febrile urinary tract infections as a significant risk factor for an abnormal scan.

CONCLUSIONS

A positive vesicoureteral reflux history and febrile urinary tract infections were associated with abnormal dimercapto-succinic acid renal scan in followup of patients older than 10 years with spina bifida. Thus, these factors are indicators of proactive evaluation of renal function using dimercapto-succinic acid renal scanning.