Effect of bed rest duration after untethering surgery for thickened/fatty filum terminale: A systematic review and meta-analysis

Transection of the filum terminale is a common surgical procedure in paediatric patients and post-operative cerebrospinal fluid (CSF) leak/pseudomeningocoele is its most common surgical complication. Alongside intraoperative methods to achieve watertight dural closure, the recommendation of post-operative bed rest is common practice. The duration of bed rest varies considerably, with little evidence to support the efficacy of prolonged (> 24 h) durations. This work sought to evaluate existing literature to determine the effect of the duration of bed rest on the incidence of CSF complications after untethering. A systematic review of the literature was performed, with searches and data extraction conducted independently and in duplicate by two reviewers. Searches included Medline, Embase and Google Scholar libraries. Articles were included which reported outcomes of CSF complications (CSF leak and pseudomeningocoele) after surgery for untethering for simple fatty/thickened filum in paediatric patients. A meta-analysis of proportions was performed using a random effects model after logit transformation. For comparison of subgroups, a mixed-effects model was used. Nine retrospective studies were identified, reporting outcomes of a total of 1,438 patients. Four studies reported bed rest durations of ≤ 24 h, while seven reported > 24 h (two studies reported cohorts for both ≤ 24 h and > 24 h). For patients receiving ≤ 24 h bed rest (n = 542), estimated prevalence of CSF complications was 1.06% (95% CI 0.46, 2.43). For > 24 h bed rest (n = 896), estimated prevalence was 0.93% (95% CI 0.39, 1.79). Subgroup analysis demonstrated no significant difference between ≤ 24 h and > 24 h on the incidence of CSF complications (p = 0.6724). Whilst the findings of this study are significantly limited by the rarity of post-operative CSF leak, there is no current evidence to suggest that prolonged periods of bed rest > 24 h after untethering surgery for fatty/thickened filum has a large or statistically significant effect on incidence of post-operative CSF leak or pseudomeningocoele.