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

Abstract

Objective: Secondary tethering of the spinal cord (TSC) occurs in 3-30% of patients with history of spinal cord dysraphism repair. As many patients with spinal cord dysraphism already have symptoms, it might be difficult to diagnose secondary TSC. Regular clinical/urodynamic (UDS) evaluation is therefore advised to pick-up changes early before they progress. This study aimed at presenting clinical/UDS outcomes for patients with secondary TSC who underwent spinal cord untethering (SCU).

Study design: Charts of patients with secondary TSC between 1998 and 2010 were reviewed retrospectively. Patients who underwent pre/post SCU clinical/UDS evaluation were included. All patients were followed-up for a minimum of 5 years for proper clinical outcomes assessment. Urologic, neuro-orthopedic, and UDS outcomes were collected and studied. Continence status was assessed in children aged ≥5 years. Patients were considered continent if they were dry for ≥4 h or socially continent if they stayed dry most of the day using maximum 1-2 pads/day. Categorical data were compared using the Fisher-Exact test and continuous variables were compared using the Wilcoxon Signed Rank test. A p-value < 0.05 was considered significant.

Results: Twenty-three patients met our inclusion criteria. The median age at time of SCU was 8.8 (range 2.3-16.2) years. The median age at time of UDS follow-up after SCU was 8.8 (range 2.9-17) years. The median follow-up time was 5 (range 5-13.4) years. Urological symptoms were reported in 56.5% of patients before SCU and improved in 61.5% post SCU. Neuro-orthopedic symptoms were reported in 87% of patients before SCU and improved in 65% post SCU. Continence was achieved in 73.9% of the entire cohort on long-term follow-up, while 26.1% had socially acceptable continence. UDS outcomes are summarized in the Table.

Conclusions: Patients with secondary TSC are expected to have progression of their symptoms over time if not untethered. From here comes the importance of closely performing clinical/UDS evaluation to pick-up changes early before they progress. Surprisingly, clinical outcomes after SCU with detailed description of the auxiliary management are sparse in the literature. Most studies focus on UDS outcomes. We provided in the current study a detailed discussion of the clinical outcomes, auxiliary-managements used to achieve continence, and the UDS outcomes. Careful periodic clinical/UDS evaluation is recommended for early pick-up of changes suggestive of TSC. SCU could improve existing symptoms, and prevent worsening or development of new symptoms. UDS parameters that showed most improvement were intravesical pressure at TCBC and bladder compliance.

Keywords: Neural tube defect; Spinal dysraphism; Tethered spinal cord syndrome; Urinary bladder; Urodynamics.