Analysis of the Completely Dry Rate Over Time After Mid-urethral Sling in a Real-world Clinical Setting

Objective: To improve patient counseling regarding mid-urethral slings (MUS), we performed an analysis of MUS patients dry at initial follow-up to evaluate probability of remaining dry over time, and analyzed clinical factors potentially influencing the probability of remaining dry. Methods: A retrospective review of our prospectively-collected institutional database identified patients who underwent retropubic MUS (RMUS) or transobturator MUS (TMUS) between January 2001 and March 2016 and were completely dry, defined as an answer of “not at all” to UDI-6 question 3, at first follow-up within 1.5 years of surgery. Proportion remaining dry over time was estimated by Kaplan-Meier. Associated factors were evaluated using Cox proportional hazards modeling. Proportion with urge urinary incontinence at time of sling failure was assessed. Results: Of 1102 patients undergoing MUS, 38.4% returned questionnaires and 47.5% of these were completely dry at initial follow-up (139 RMUS, 62 TMUS). Probability (95% CI, n = total patients) of remaining dry after RMUS at 3, 5, and 10 years was 72% (64%-81%, n = 70), 60% (51%-70%, n = 51), and 26% (18%-43%, n = 17). Probability estimates for TMUS at 3 and 5 years were 74% (62%-88%, n = 27) and 50% (35%-70%, n = 14). Obesity (Hazard ratio 2.22, P =.003) and age (Hazard ratio 1.043, P <.001) were associated with lower probability of remaining dry after RMUS. Of patients no longer completely dry at last follow-up, 72% RMUS and 75% TMUS had urge urinary incontinence. Conclusion: In our real-world cohort, patients who are dry within the first 1.5 years following MUS have ≥50% chance of remaining dry for 4 more years.