Comprehensive analysis of the clinical and urodynamic outcomes of primary tethered spinal cord before and after spinal cord untethering

SummaryIntroductionPrimary tethered spinal cord (TSC) refers to a group of abnormalities associated with a posterior bony spinal defect that develops beneath an intact dermis and epidermis. There is relative agreement that patients with symptomatic TSC will require surgical intervention. However, it is still debatable as to how to approach asymptomatic patients with primary TSC.ObjectiveTo study the clinical and urodynamic (UDS) outcomes of patients with primary TSC after spinal cord untethering (SCU).Study designCharts of patients with primary TSC between 1998 and 2010 were retrospectively reviewed. Patients that underwent before and after SCU clinical and UDS evaluation with minimum of 5-years follow-up were included. Continence status was assessed in children ≥5 years. Patients with dry intervals of ≥4 h were considered continent. Urologic and neuro-orthopedic manifestations, as well as UDS parameters, were compared before and after SCU.Categorical data were compared using Fisher-Exact test and continuous variables were compared using Wilcoxon-Signed-Rank test. A P-value <0.05 was considered significant.ResultsTwenty-two patients met the inclusion criteria. The median age at time of SCU was 11.5 months (range 3-211). The median age at time of follow-up UDS after SCU was 22 months (range 9-218). The median age at time of last follow-up was 153.5 months (range 65-228). The median follow-up time was 71 months (range 60-192). A total of 14/22 patients had clinical manifestation before SCU, while 8/22 were asymptomatic and diagnosed based on magnetic resonance imaging/UDS findings. Of the symptomatic patients, 86% had symptom improvement after SCU. The UDS parameters showed statistically significant improvement in the median percentage of change of actual bladder capacity (P = 0.01), median intravesical pressure for patients with pre-operative pressure ≥40 cm/H2O at total cystometric bladder capacity (P = 0.012), and median bladder compliance at 75% bladder capacity (P = 0.01) (Table).DiscussionTethered spinal cord syndrome (TSCS) is a clinical entity that presents with neurological, urological, and/or orthopedic symptoms caused by primary or secondary tethering of the spinal cord, which may result in ischemic damage of the neural tissue and symptom development.While some authors believe that surgical management should be reserved for symptomatic patients, others prefer prophylactic surgery to avoid possible irreversible neurological damage. The present study provides detailed discussion of the clinical and UDS outcomes for patients with primary TSC that underwent SCU.ConclusionFor patients with primary TSC, spinal cord untethering is beneficial in terms of clinical and UDS outcomes. A prospective long-term study with large numbers could further highlight outcomes for this particular group of patients.Table. Urodynamic outcomes.ParameterMedianRangeP-valuePercentage of change of EBC after SCU18.52.2-33.30.01Percentage of change of actual bladder capacity after SCU40.9−18 to 230Pressure at TCBC Before SCU (cmH2O)37.59-1000.1Pressure at TCBC After SCU (cmH2O)255-62Compliance at 75% capacity before SCU (ml/cmH2O)3.50.4-17.90.01Compliance at 75% capacity after SCU (ml/cmH2O)7.92.3-60.4EBC, expected bladder capacity; SCU, spinal cord untethering; TCBC, total cystometric bladder capacity.