Risk Factors for de Novo Postoperative Urinary Retention in Posterior Lumbar Spine Surgery.

Study DesignRetrospective cohort study.ObjectiveDe novo postoperative urinary retention (POUR) after lumbar posterior decompression surgery for lumbar spinal canal stenosis (LSCS) is a statistically known but uncommon complication for both patients and spine surgeons. The aim of this study is to review clinical data and imaging findings and identify preoperative predictors of de novo POUR.MethodsThe subjects were 738 surgically treated patients with LSCS, without preoperative bladder dysfunction or perioperative complications. Univariate and multivariate analyses using propensity score matching were performed to identify prognostic factors for POUR lasting for at least 1 week after postoperative urinary catheter removal.ResultsPOUR occurred in 23 patients (3.1%). The median recovery time was 41 days and only 12 patients (52.2%) showed improvement within 3 months. Patients with POUR were significantly older, and the lumbar Cobb angle, location of compressed dura mater (ventral or dorsal), and type of cauda equina redundancy (curve-type) were identified as independent prognostic factors. POUR had no association with sex, comorbidities, surgical procedures, number of decompressed segments, or degree of dura mater compression.ConclusionsThis study suggests that older age and curve-type stenosis with ventral or dorsal compression of the dura mater are risk factors for development of de novo POUR. Such preoperative imaging findings may indicate a higher risk of intraoperative thermal and nerve injuries, and possible uneven cauda equina flow improvement after decompression.