Long-term urological outcomes of spinal lipoma after prophylactic untethering in infancy: real-world outcomes by lipoma anatomy.

STUDY DESIGN: Cohort study. OBJECTIVES: Long-term urological outcomes in patients with spinal lipoma after prophylactic tethered cord release (TCR) in infancy were investigated. SETTING: Children's hospital in Yokohama, Japan. METHODS: Children under one year of age with spinal lipoma who underwent TCR between 1990 and 2010 were investigated. According to Arai's classification, lipomas other than filar lipoma were classified into four types: caudal, dorsal, transitional, and lipomyelomeningocele. The level of the conus medullaris was divided into three categories: L3-5, L5/S1, and sacral. Urological outcomes, including the need for clean intermittent catheterization (CIC), urinary incontinence, presence of renal deterioration, and the need for bladder augmentation, were investigated by both lipoma type and level of the conus medullaris. RESULTS: Fifty-three patients met the inclusion criteria. The median follow-up period was 14.2 years (interquartile range 9.6-17.6 years). Of the 53 patients, ten (19%) were on CIC, and six (11%) were incontinent. Overall, two patients (4%) had renal deterioration detected by DMSA renal scan, and two (4%) needed augmentation cystoplasty. Of the lipoma types, transitional type showed the worst outcomes with respect to need for CIC (54%) and urinary incontinence (38%). There were no significant differences in renal deterioration and the rate of bladder augmentation by lipoma type. No urological outcomes were significantly associated with conus level. CONCLUSIONS: Even after prophylactic TCR in infancy in children with spinal lipoma, 19% of patients needed CIC in long-term follow-up. Of the lipoma types, transitional type showed the worst outcomes with respect to need for CIC and urinary incontinence.