Stress urinary incontinence (SUI) is the sudden, involuntary loss of urine occurring due to an increase in intraabdominal pressure (for example, coughing, laughing, sneezing, exercising). SUI affects up to 50% of women over 40 years of age [1] and can significantly impact quality of life and productivity. Several standard treatment options for SUI exist, ranging from conservative (weight loss, pelvic floor physiotherapy, continence pessaries) to surgical (sling procedures, with or without mesh).

Newer minimally invasive treatments for SUI have emerged recently, targeted thermal vaginal therapy, including the use of LASER vaginal treatment. The principle behind these new therapies is the controlled application of heat to vaginal tissues resulting in new collagen formation, a rapid contraction of collagen fibres, leading to the contraction and shrinking of the treated tissue reportedly providing greater support to the bladder and urethra and improved symptoms of SUI. Minimally invasive ambulatory LASER vaginal therapy is an attractive option for patients and has been used as a treatment for SUI however its efficacy is unclear [2, 3].

Given the limited information available, this trial was in conducted to determine if the Erbium-Yttrium Aluminum Garnet (Er-YAG) LASER therapy is an effective treatment for SUI in women. A randomized, sham-controlled double-blinded design was used with a primary outcome measured at 6 months after treatment.

This single site, randomized double-blinded sham-controlled interventional trial enrolled adult patients with a clinical diagnosis of SUI (primary symptoms of SUI, as confirmed by patient medical history and clinical symptoms, including positive cough test, 24-hour pad test >3 grams) and seeking treatment at a tertiary care hospital. Participants were randomized (randomization table with allocation concealment by opaque sequentially numbered sealed envelopes) into two groups: 1) vaginal Er-YAG LASER treatment group (two treatments, six weeks apart) or 2) placebo “sham” group (same procedure but no LASER energy applied to tissue). Participants, caregivers, and those assessing the outcomes were blinded to group assignment. Follow-up occurred at 6-weeks and 6-months (unblinding occurred at this time point) with objective and subjective measures. The primary outcome was the self-reported symptom of no urinary incontinence with the International Consultation on Incontinence Questionnaire--Urinary Incontinence (ICIQ-UI) Short Form (question 3) validated questionnaire at 6-months. Other secondary outcomes included the 24-hour pad test and standardized questionnaires: Urogenital Distress Inventory (UDI-6), Incontinence Impact Questionnaire Short Form (IIQ-7), King’s Health Questionnaire (KHQ), and Pelvic Organ Prolapse/Urinary Incontinence Sexual Function Questionnaire (PISQ-12). The original sample size of 182 was calculated based on a cure rate of 51% and 20% for the treatment and placebo groups respectively along with a drop out of 57% to provide a study power of 0.8 and an alpha of 0.05.

134 patients were enrolled, with 67/73 (91.78%) in the LASER treatment group and 58/61 (95%) in the sham treatment group reaching the primary outcome measure at 6 months post treatment. One of 67 and 1/58 from the LASER and sham treatment groups respectively reported “cure” (no urinary incontinence with the ICIQ-SF question 3). We experienced a lower drop out than expected and enrollment ended earlier.

At baseline both groups did not differ significantly in their 24-hour pad test weights, urodynamic testing and patient-reported outcome measures (validated questionnaires: ICIQ-SF, UDI-6, IIQ-7, PISQ, KHQ).

At 6 weeks, a significant improvement in UDI-6 symptom score from baseline was found in the LASER group (36.132+/-13.303 vs 27.753+/-13.087 p= 0.00051) and in the change in score from baseline (8.84+/-12.89 vs 3.08+/-15.23, p= 0.039) was found in the UDI-6 for the LASER group compared to the sham group.

At 6 months, a significant improvement in UDI-6 symptom score from baseline was also observed in the LASER group (36.132+/-13.303 vs 30.449+/-12.477 p=0.0126) though there was no difference in the change of UDI-6 symptoms between the LASER and sham group. Both the LASER and sham groups had significant improvements in their total ICIQ-SF scores compared to baseline (LASER 14.147+/-3.5123 vs 11.353+/-4.9104 p= .0002; sham: 14.421+/-2.7707 vs 12.121+/-4.6682 p= 0.002), though there was no significant difference in the changes in the LASER and sham groups.

No difference was found between the LASER and sham groups for the change in baseline to 6-weeks and the change from baseline to 6-months with other secondary measures that included: the 24-hour pad test weights (at 6 months: 15.06+/-25.9 vs 31.88+/-152.9 p= 0.46), ICIQ-SF scores (at 6 weeks: 3.048+/-1.01 vs 2.46+/-4.14 p= 0.40; at 6 months: 2.91+/-3.64 vs 2.05+/-3.88 p= 0.21), UDI-6 (at 6-months: 5.77+/-13.85 vs 6.07+/-15.73 p= 0.74), IIQ-7 (at 6 weeks: 11.66+/-19.02 vs 5.305+/- 24.28 p= 0.14; at 6 months: 10.26+/-22.79 vs 6.47+/-26.57 p= 0.40) and PISQ-12 scores (at 6 weeks: 1.81+/-6.32 vs 0.66+/-5.66 p= 0.36; at 6 months: 1.65+/-5.41 vs - 0.22+/-4.87 p= 0.069)

To our knowledge this study is the largest reported double-blind sham-controlled RCT evaluating the efficacy of Erbium-YAG LASER therapy as a treatment for female SUI.

Although there was improvement seen between baseline and 6 months within both the LASER and sham groups with the ICIQ-SF total score, there was no significant difference with the change in score between the LASER and the sham groups.

Based on this data, Erbium-YAG vaginal LASER treatment was no more effective than sham for curing or improving SUI at 6 months. We are presently following patients out to 24 months. At 6 weeks there was a significant difference in favor of the LASER group with the change in UDI-6 symptom score, which was not seen at the later time point.

Wu, J.M., Stress Incontinence in Women. N Engl J Med, 2021. 384(25): p. 2428-2436.
Mortensen, O.E., S.E. Christensen, and E. Lokkegaard, The evidence behind the use of LASER for genitourinary syndrome of menopause, vulvovaginal atrophy, urinary incontinence and lichen sclerosus: A state-of-the-art review. Acta Obstet Gynecol Scand, 2022. 101(6): p. 657-692
Seki, A.S., et al., CO(2) Laser and radiofrequency compared to a sham control group in treatment of stress urinary incontinence (LARF study arm 3). A randomized controlled trial. Int Urogynecol J, 2022. 33(12): p. 3535-3542

Continence 7S1 (2023) 100721
DOI: 10.1016/j.cont.2023.100721