Predictors of postsurgical retethering in pediatric fatty or tight filum terminale: a systematic review and meta-analysis of 1167 patients.

Objective: The objective of this study was to characterize pediatric patients with tight filum terminale (TFT) or fatty filum terminale (FFT) who experienced retethering after transection of the filum, and to determine the risk factors for retethering.

Methods: A systematic review was conducted on May 31, 2023, using PubMed, Google Scholar, SCOPUS, and Web of Science databases according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to identify studies detailing retethering following transection for TFT or FFT. Studies were then screened using the Newcastle-Ottawa Scale for risk of bias assessment.

Results: Eleven articles met the inclusion criteria with an overall cohort of 1167 patients evaluated for retethering following transection for TFT or FFT. The combined retethering rate across all retrospective studies was 3.4% (95% CI 1.6%-5.2%). A random-effects model was used to estimate the prevalence of presenting symptoms, with the most common being lower-extremity weakness in the overall cohort (54.5%, 95% CI 32.6%-76.4%) and bowel or bladder dysfunction in the retethered cohort (57.9%, 95% CI 41.1%-74.8%). Patients who experienced retethering had a similar estimated prevalence of low-lying conus (71.1%, 95% CI 45.1%-97.1%) compared with the overall cohort (51.1%, 95% CI 39.3%-63.0%). The most common complication following surgery for the overall cohort was a wound complication (2.7%, 95% CI 0.8%-4.6%). Postoperative CSF leakage (OR 13.8, 95% CI 3.9-49.4) was a strong predictor of retethering. Sensory changes at initial presentation were also found to be a predictor of retethering (OR 2.9, 95% CI 1.3-6.5). Low-lying conus was not predictive of retethering.

Conclusions: Preoperative sensory changes and postsurgical CSF leakage were associated with an increased retethering rate following transection of the filum in cases of tethered cord syndrome secondary to fatty filum terminale.