Duration of the horizontal decubitus position for prevention of cerebrospinal fluid leakage following transection of a tight filum terminale

Object: The untethering of a tethered spinal cord in patients with a tight filum terminale is a relatively simple procedure that can prevent or improve neurological symptoms. Postoperatively, patients are usually kept in the horizontal decubitus position to prevent a CSF leak. However, the optimal period for keeping patients flat has not been determined yet. The authors compared 2 cohorts with different periods of horizontal decubitus; one with 72 hours and the other with 8 days. Methods: The authors retrospectively analyzed surgical results in 2 cohorts of pediatric patients who had tethered spinal cord with a tight filum terminale. One cohort was maintained flat for 8 days and the other cohort for 72 hours postoperatively. The patients' charts were reviewed for demographic data, clinical presentation, surgical therapy, and clinical course. Results: Three hundred fifty-four patients underwent sectioning of a tight filum terminale. Of those, 238 were kept lying flat for 8 days postoperatively, and 116 were maintained flat for 72 hours. Magnetic resonance imaging was performed 1 to 2 weeks after the surgery. None of the patients in either cohort developed a CSF leak. Pseudomeningocele, which was confirmed by MRI, developed in 1 patient who had been kept flat for 8 days. The occurrence rates of a CSF leak and pseudomeningocele were not significantly different in either cohort. Conclusions: Keeping patients flat for longer than 72 hours did not change the rate of postoperative CSF leakage or pseudomeningocele. Seventy-two hours or less would be an appropriate period for maintaining patients flat after transection of a tight filum terminale.