Six-Month Postoperative Urodynamic Score: A Potential Predictor of Long-Term Bladder Function after Detethering Surgery in Patients with Tethered Cord Syndrome

Abstract

We evaluated changes in urodynamic parameters of patients with tethered cord syndrome after detethering surgery and investigated factors predicting long-term urological outcome based on a previously described urodynamic scoring system. A total of 148 patients with tethered cord syndrome underwent detethering surgery at our hospital between January 2005 and March 2011. Of these patients 44 with preoperative and postoperative urodynamic data and a minimum followup of 2 years were included. Urodynamic score was composed of 4 parameters, with the sum ranging from 0 (favorable) to a maximum score of 17 (unfavorable). Mean ± SD age at surgery was 38.0 ± 77.2 months and followup was 57.2 ± 20.6 months. Preoperative symptoms were present in 24 patients. Total urodynamic score at 6 months postoperatively was higher than preoperatively (mean ± SD 5.61 ± 2.71 vs 4.43 ± 3.56, p = 0.033) and remained at a similar value during followup (5.88 ± 3.89). The 6-month postoperative total urodynamic score was significantly lower in the 23 patients with favorable urological outcomes than in those with unfavorable outcomes (3.87 ± 2.02 vs 7.52 ± 1.99, p <0.001), whereas the preoperative urodynamic scores did not differ between these groups. The difference in urodynamic scores between favorable and unfavorable outcome groups became more prominent with time. By regression analysis the total urodynamic score at 6-month followup was a predictor of urological symptoms at last followup (OR 2.763, 95% CI 1.514-5.043, p = 0.001). Six-month postoperative urodynamic scores accurately predicted the presence of urological symptoms on long-term followup and may be an important predictor of long-term urological outcomes after detethering surgery.