Outcome in patients who underwent tethered cord release for occult spinal dysraphism.

Purpose: Tethered cord syndrome encompasses a group of clinical symptoms caused by abnormal spinal cord fixation. We evaluated a select cohort of patients with primary tethered cord syndrome in regard to urodynamic and clinical outcome after cord release.

Materials And Methods: We retrospectively reviewed the records of patients with the diagnosis of tethered cord from May 2001 to October 2004. Patients were assessed preoperatively by standard urodynamic studies, which was repeated a mean of 6.4 months after tethered cord release. Clinical and urodynamic outcomes were analyzed.

Results: Ten male and 14 female patients 1 month to 12 years old (median age 6 years) were evaluable. Preoperatively 14 of the 24 patients with a median age of 8.1 years were toilet trained and 7 (50%) had diurnal incontinence. Constipation was noted in 10 of 24 patients (42%) and urinary tract infections developed in 6 (25%). Postoperatively only 1 patient (7%) experienced diurnal incontinence (p = 0.04). Constipation was observed in 6 patients (25%) and urinary tract infections developed in 1 (4.2%) (p = 0.29 and 0.07, respectively). Ten of the 21 children (48%) with abnormal urodynamics had normalized studies postoperatively. Ten of the 17 patients with neurogenic detrusor overactivity achieved normalization and 7 remained unchanged. Two of 3 patients with normal preoperative urodynamics had neurogenic detrusor overactivity and 1 had poor bladder compliance. Four patients with low bladder capacity and/or low compliance preoperatively did not improve.

Conclusions: Our results suggest that tethered cord release is beneficial in terms of clinical and urodynamic outcomes. Patients with abnormal urodynamics had 48% improvement after tethered cord release. Neurogenic detrusor overactivity seems to respond better with 59% improvement in urodynamics. The level of the conus on magnetic resonance imaging did not seem to be predictive of urodynamic outcome. Patients with a normal bladder may show urodynamic deterioration postoperatively, which raises cause for concern.