Background: This study aims to evaluate the safety and efficacy of erbium:yttrium-aluminum-garnet (Er:YAG) laser treatment in female patients with mild-to-moderate stress urinary incontinence (SUI). Methods: From July 2018 to June 2020, 72 female patients with mild-to-moderate SUI were enrolled in this study. A baseline assessment was conducted, which included a 1-hour pad test, the validated International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form (ICIQ-UI-SF), postvoid residual (PVR) testing, pelvic organ prolapse quantification (POP-Q) testing, and a cough stress test. All patients underwent four sessions of Er:YAG laser treatment using a smooth mode. A reassessment was performed 6 months after treatment to evaluate the safety and efficacy of the Er:YAG laser. Results: All patients completed four clinic visits, with a 1-month interval, and were followed up for a minimum of 6 months. No severe adverse reactions were observed during the treatment process. The 1-hour pad test revealed a significant reduction in urinary leakage from baseline (6.30 ± 1.06 g) to the 6-month follow-up (2.70 ± 0.96 g, p < 0.001), with 34 of 72 (47.22%) patients achieving negative results. The ICIQ-UI-SF score significantly decreased from baseline to 6 months (10.82 ± 1.38 to 2.96 ± 0.52, p < 0.001). PVR experimental results showed a significant decrease in residual urine volume after treatment (103.72 ± 8.61 mL to 43.86 ± 4.92 mL, p < 0.001). At the 6-month follow-up, hematoxylin and eosin staining results demonstrated that Er:YAG laser treatment significantly facilitated an increase in the thickness of squamous epithelial cells. The efficacy of Er:YAG laser treatment for SUI was 77.78% (56/72). Conclusions: Several objective and subjective assessments confirmed the safety and efficacy of vaginal smooth mode Er:YAG laser treatment for mild-to-moderate SUI during the 6-month follow-up period. Nonablative Er:YAG laser in the smooth mode is a viable treatment option for SUI patients.
Keywords: Er:YAG laser therapy; ICIQ-UI-SF; pad test; smooth mode; stress urinary incontinence.