Time Factor and Disc Herniation Size: Are They Really Predictive for Outcome of Urinary Dysfunction in Patients With Cauda Equina Syndrome?

BACKGROUND Timing of surgery and the importance of the size of disc prolapse in cauda equina syndrome (CES) remain controversial. OBJECTIVE To investigate whether there is a relationship between postoperative urinary function, preoperative duration of neurogenic lower urinary tract dysfunction (NLUTD), and the level of canal compromise. METHODS Seventy-one patients operated for CES were prospectively identified between 2010 and 2013. Fifty-two cases with preoperative NLUTD were included. The "Prolapse: Canal ratio" (PCR) was calculated as a proportion of cross-sectional area of disc prolapse on total cross-sectional area of spinal canal. RESULTS Median of preoperative duration of NLUTD was 72 h (48; 132) and period from first assessment to surgery 10.5 h (7; 18.5). Urinary incontinence was seen in 46.2% of patients, 38.4% had painless retention and 15.4% had painful retention. In 38.5% of cases, urinary symptoms persisted for more than 20 mo postoperatively. There was no correlation between duration of preoperative NLUTD and urinary dysfunction persistence (P = .921). The outcome was not significantly influenced by having surgery more than the 48 h after presentation (P = .135). Preoperative incontinence persisted in 58% and painless retention in 30% of cases. The mean PCR was 0.6 ± 0.18. There was no correlation between PCR and outcome (P = .537) even after adjusting for duration of preoperative NLUTD (P = .7264). CONCLUSION No significant correlation was demonstrated between the preoperative duration of urinary dysfunction, the size of disc herniation relative to size of spinal canal, and postoperative urinary function in a large consecutive series of patients with CES.