Can urodynamic studies identify patients at risk for voiding difficulty after pubovaginal sling? The "voiding quality index".

OBJECTIVE

The value of urodynamics (UDS) as a predictor of voiding dysfunction after pubovaginal sling is controversial. We sought to determine whether individual urodynamic parameters or a "Voiding Quality Index" (VQI) can predict prolonged catheter time after sling.

METHODS

Individual voiding parameters for the 75 patients who had preoperative urodynamics included maximum detrusor pressure (Pdet), voiding time (VT), maximum uroflow (Qmax), post-void residual (PVR), and abdominal straining. Each parameter was scored 1 if normal and 0 if abnormal; these urodynamic scores were added to calculate the VQI (range 0-5). Each patient had a suprapubic catheter and maintained a voiding diary. Individual voiding parameters and the VQI were compared statistically between groups who required a catheter for more than 14 days and those who did not. Informed consent was obtained from all patients and the study was conducted with Ochsner Institutional Review Board approval.

RESULTS

Average catheter time for the 66 patients who completed the study was 11.1 days. Fifty patients voided within 14 days and were defined as being in the non-retention group (NR). Sixteen patients were catheter dependent at 14 days and were considered in the retention group (R). When each voiding parameter was individually analyzed between groups with respect to catheter time, the mean values in each group were not significantly different and offered no predictive value. When the VQI was analyzed between groups, the VQI was significantly lower for patients developing voiding difficulty (VQI-R = 3.81) than those who did not (VQI-NR = 2.31) p = .001.

CONCLUSION

No single urodynamic voiding parameter accurately predicts prolonged catheter time following sling. A combination of voiding parameters, the "Voiding Quality Index," may predict patients at risk for prolonged catheter time following sling.