Clinical characteristics and outcome of surgical treatment in children with tethered fatty filum or lipoma of filum at different ages

Abstract

Objective To evaluate the outcome of surgical treatment of tethered cord syndrome (TCS) in children with fatty filum or lipoma of filum at different ages and to explore the natural course and therapeutic strategy of this type of TCS. Methods and Results Total 77 TCS patients with fatty filum or lipoma of filum who underwent surgical division of the filum terminale between January 2017 and May 2022 in Children's Hospital of Fudan University were screened for eligibility. According to age, they were divided into young children group (< 3 years), preschool group (3-6 years) and school-age group (> 6 years). The reasons for admission (Fisher's exact probability: P = 0.001), sacrococcygeal skin abnormalities (χ² = 7.841, P = 0.021), the proportion of children with clinical symptoms (χ² = 13.618, P = 0.001), and the position of conus medullaris (Fisher's exact probability: P = 0.039) in the 3 groups were statistically significant. Compared with the young children group, the school -age group had a lower proportion of passive examination (Fisher's exact probability: P = 0.021), a higher proportion of patients seeking medical attention because of symptoms (adjusted χ² = 12.738, P = 0.000), a lower proportion of sacrococcygeal skin abnormalities (χ² = 6.481, P = 0.011), and a higher proportion of patients with clinical symptoms (χ² = 13.558, P = 0.000), and the proportion of conus medullaris located at or above L₂ was lower (Fisher's exact probability: P = 0.024). The proportion of patients with clinical symptoms in the school-age group was also higher than that in the preschool group (Fisher's exact probability: P = 0.034). The average diameter of the filum terminale after surgery was (2.17 ± 0.70) mm, which increased by (0.46 ± 0.28) mm compared with that before operation, and 26 cases (81.25%, 26/32) of the filum terminale continued to increase in diameter. Among the 9 cases with preoperative syringomyelia, 2 cases disappeared, 6 cases improved, and one case continued to worsen. Postoperative MRI showed 2 cases had spinal cord retethering. During 1.90 (1.11, 3.10) years of follow-up, no new clinical symptoms were found in asymptomatic patients and 35 symptomatic children had 13 cases in the young children group, 9 cases in the preschool group, and 13 cases in the school-age group. There was no significant difference in functional outcome among the 3 groups (Fisher's exact probability: P = 0.246). One patient was lost to follow-up. Conclusions The clinical features of TCSwith fatty filum or lipoma of filum are different. The older of the children, the higher of the proportion of clinical symptoms, more than half of the patients still have neurological abnormalities after surgical treatment. Division of the filum terminale is a low-risk procedure with few complications, and preventive surgery may reduce neurological damage.

DOI: 10.3969/j.issn.1672-6731.2023.05.004