Lower urinary tract dysfunction due to spina bifida is a condition that needs the urological management from birth. However, it is often difficult to assess lower urinary tract function in infancy. The purpose of this retrospective study was to investigate the appropriate urological management of lower urinary tract function for the children with spina bifida who underwent neurosurgical intervention in infancy.

35 patients with spina bifida (16 boys and 19 girls), who underwent neurosurgical intervention under 1 year of age, and who referred to our department for the evaluation of lower urinary tract function between January 1, 2014, and December 31, 2023 were included.

The diagnosis was spinal meningomyelocele (MMC) in 11 patients and non-MMC (e.g., spinal lipoma) in 24 patients. Among 11 MMC patients, vesicoureteral reflux (VUR) was observed in 2 cases, bladder deformity in 9 cases in the first postoperative voiding cystourethrogram (VCUG). All patients had residual urine and 7 had findings suggestive of detrusor sphincter dyssynergia (DSD). On urodynamic study (UDS) in 10, the mean maximal detrusor pressure during filling phase was 11.3 cmH2O (0-30), and 4 had detrusor overactivity (DO). 10 patients (90%) required clean intermittent catheterization (CIC: median age of introduction: 6.5 months: 0-24). 6 patients required CIC under 1 year of age due to suggestive findings of lower urinary tract dysfunction such as urinary retention and/or large residual urine volume in 5, DO and DSD in UDS and VCUG in 1. Remaining 4 patients started CIC at more than 1 year due to apparent findings of lower urinary tract dysfunction such as progressive bladder deformity in all, febrile urinary tract infection in 2, and new-onset VUR in 1. The none of the patients showed the upper urinary tract dilation on ultrasonography. Of 21 patients with non-MMC. VUR was identified in 3, bladder deformity in 3, residual urine in 11, and suggestive findings of DSD in 5. In 9 patients with postoperative UDS, a mean the mean maximal detrusor pressure was 13.2 cmH2O (2-45) during filling phase, and 5 patients had DO. CIC was required in 2 patients (8%) (mean age of introduction 2.5 months: 2-3), due to urinary retention in 1 patient, DO and DSD in 1. In both cases, there was no upper urinary tract dilation on ultrasonography.

While abnormal findings on VCUG and UDS were present in cases with MMC or non-MMC, rate of the patients who required CIC was much higher in MMC (90% vs 8%). Apparent deterioration of urinary tract was observed in patients waiting for CIC until more than 1 year, especially with MMC. In both MMC and non-MMC patients, ultrasonographic screening of the upper urinary tract had limited power for detecting lower urinary tract dysfunction and predicting future deterioration of urinary tract.

Neural pathology of spina bifida (MMC or not) is one of the important factors in predicting prognosis of lower urinary tract function. Delayed introduction of CIC may cause progression of lower urinary tract deterioration (bladder deformity and VUR) especially with MMC. Accordingly, early evaluation by VCUG and UDS and introduction of CIC is recommended when suspected abnormal findings. Ultrasonographic examination as an initial evaluation may have limited power for screening of lower urinary tract function including the necessity for CIC or the presence of VUR.