Predictors of the efficacy of CO2 laser therapy for female stress urinary incontinence

Background: Predictors of the efficacy of a single session of CO2 laser therapy for female stress urinary incontinence are important for pretreatment consultation. Therefore, this study aimed to evaluate these predictors. Methods: All consecutive women who underwent vaginal CO2 laser therapy for stress urinary incontinence were prospectively enrolled in the obstetrics and gynecology department of a medical center from October 2018 to December 2021. Women with a global response assessment (GRA) <= 0 during follow-up were considered to have subjective failure. A multivariable backward stepwise Cox proportional hazard model was used to identify factors influencing subjective failure. Results: A total of 75 women who underwent single-session vaginal CO2 laser therapy were evaluated. The median duration of subjective improvement (defined as >= 1 on the GRA) was 18.3 (95% CI, 12.1-18.3 months) months. Multivariable analysis revealed that low voided volume (dL, hazard ratio [HR] = 0.707; area under the curve [AUC] = 0.66, cutoff value of voided volume <= 4.0 dL), high postvoid residual volume (dL, HR = 2.714; AUC = 0.60, cutoff value of postvoid residual volume >= 1.0 dL), and low functional profile length (HR = 0.956; AUC = 0.58, cutoff value of functional profile length <= 2.8 cm) were predictors of subjective failure. Logit(p) was found to predict failure (HR = 1.775; AUC = 0.71, cutoff value of logit(p) >= 0.0). Pad weights decreased at 3- and 6-month follow-up visits (e.g., pad weights: 46.9 +/- 62.8 g at baseline, 13.1 +/- 29.5 g at 3 months, and 21.0 +/- 38.2 g at 6 months, p = 0.006). At 6 months, 8 (21%) women were cured (<1 g pad weight), and 16 (42%) women showed improvement (>50% decrease in pad weight). Overactive bladder symptom improved at 3 and 6 months (ie, Overactive Bladder Symptom Score: 3.2 +/- 2.7 at baseline, 2.1 +/- 2.2 at 3 months, and 2.0 +/- 1.2 at 6 months, p < 0.001). However, no significant change in female sexual function was observed from baseline. Conclusion: Low voided volume and high postvoid residual volume are significant predictors of subjective failure following a single session of transvaginal CO2 laser therapy. However, the subjective therapeutic effects appear to diminish over a median duration of 18 months.