Pre- and postoperative urodynamic risk stratification in infants and young children undergoing tethered cord release

Primary tethered cord syndrome (TCS) can lead to neurological and urologic dysfunction. While postoperative urodynamic studies (UDS) are standard for evaluating bladder function after spinal cord detethering (SCD), the role of preoperative UDS remains unclear, particularly in non-toilet trained (NTT) infants and children. This study assesses the utility of preoperative UDS by 1) comparing pre- and postoperative findings and risk stratification, and 2) examining correlations with long-term urologic outcomes.

We retrospectively reviewed records of children who underwent SCD between 2009 and 2022 and had UDS within one year before and after surgery. Patients were included if they were not toilet trained at time of preoperative UDS. Exclusion criteria included secondary SCD, incomplete UDS documentation, and prior urinary diversion. UDS tracings were independently reviewed by two pediatric urologists categorized as low-, intermediate-, and high-risk based on end-fill pressure (EFP) and detrusor overactivity (DO).

Forty-eight children met inclusion criteria. Median (IQR) age at preoperative UDS, SCD, and postoperative UDS was 7.7 (4.2-11.1), 8 (5-12), and 16.1 (12.7-20.5) months, respectively. Neurosurgeons had scheduled or definitively recommended surgery for 81.3% of patients prior to preoperative UDS. One child started CIC prior to SCD based on UDS findings of large capacity bladder and poor emptying; 97% of children had no preoperative change in urologic management. There was no significant difference in any individual urodynamic parameter pre- and postoperatively. Preoperatively, 34 (70.8%) children were low-risk, 14 (29.2%) intermediate-risk, and none high-risk. Change in risk categorization was observed in 16 (33.3%) children-11 (22.9%) improved and 5 (10.4%) worsened. At median follow-up of 5.4 years, children with intermediate- or high-risk postoperative UDS were 23.3 times more likely to require CIC at most recent follow-up than low-risk children (p = 0.010); no such association was found with preoperative risk status.

Among NTT infants and young children with TCS, preoperative UDS findings did not differ significantly from postoperative findings and were not associated with long-term bladder outcomes. These data suggest limited utility of routine baseline preoperative UDS and support reserving preoperative UDS for select cases where results are expected to provide clinically actionable information. Interdisciplinary collaboration is needed to refine testing protocols and promote high-value, patient-centered care.