The Impact of Postoperative Pain and Narcotic Use on Voiding Trial Success After Midurethral Sling Surgery

INTRODUCTION: Despite high efficacy and satisfaction with midurethral slings (MUS) for stress urinary incontinence (SUI), short-term postoperative urinary retention (POUR) complicates 25% of procedures. Prior studies have identified risk factors for POUR, including advancing age, higher BMI, baseline voiding dysfunction, and concomitant pelvic reconstructive procedures. However, narcotics may impair bladder detrusor contractility and exacerbate retention, and poorly controlled pain may inhibit levator ani relaxation and impact emptying. OBJECTIVE: Our primary objective was to evaluate whether post-anesthesia care unit (PACU) pain scores and opioid administration are associated with POUR after MUS. Secondary objectives included assessing the contribution of demographics, medical comorbidities, and surgical factors to POUR risk, to identify potentially modifiable predictors. METHODS: We conducted a retrospective cohort study of MUS from September 2021 to July 2025. Electronic health records were reviewed for sociodemographic variables, perioperative characteristics, and immediate postoperative variables. POUR was identified via a retrograde voiding trial instilling 300 mL with post-void residual >100 mL. Multivariable logistic regression identified factors associated with POUR, with covariates selected based on clinical relevance and significance. RESULTS: A total of 87 patients underwent MUS. Overall, 27.6% (n=24) developed POUR. Mean age was 54.8±14.0 years, BMI was 31.4±6.7 kg/m2, and the majority had SUI (78.4%) as opposed to mixed urinary incontinence. Those with POUR were more commonly White (81.8% vs 56.5%, p=0.04) and had longer operative times (median=75 min [IQR=49–125.5] vs 37 min [IQR=31–76], p=0.002). This was likely due to a higher rate of concomitant prolapse repairs with POUR (66.7% vs 34.9%, p=0.02). Other baseline and perioperative variables were similar between groups. On univariable analysis, different opioids used or dose did not impact POUR individually or in aggregate (p>0.05 for all comparisons), except when hydromorphone was used (POUR in 61.5% vs 21.6%, p=0.006). There was a trend towards higher maximal PACU pain (0–10 scale) with POUR (5.4±3.3 vs 3.9±3.2, p=0.07). In the multivariable model (Table 1), higher maximal PACU pain scores were not significantly associated with POUR (adjusted OR=1.14, 95% CI=0.95–1.36). In a second regression, opioid administration was not an independent predictor including hydromorphone use after adjusting for other factors. In contrast, concomitant prolapse surgery was strongly associated with POUR (aOR=3.98, 95% CI=1.25–12.64), consistent with prior literature suggesting increased pelvic dissection and periurethral edema may contribute. White race was a significant risk factor (aOR=4.54, 95% CI=1.22–16.88), raising questions about possible biological contributions, as well as unmeasured social and healthcare access factors. Interestingly, pre-existing mobility issues trended toward a protective effect (aOR=0.24, 95% CI 0.056–1.001). CONCLUSIONS: Contrary to our hypothesis, neither PACU pain nor opioid use in the OR/PACU were independent predictors of voiding trial failure after MUS. Instead, concomitant prolapse surgery and White race emerged as the strongest risk factors for POUR in this cohort, while mobility limitations trended protective. These findings suggest that demographic and surgical characteristics outweigh modifiable postoperative pain-related factors in predicting POUR. The identification of racial differences in POUR risk warrants further investigation into underlying biologic, structural, and systemic contributors, as these may represent novel targets for intervention.Table 1