CO2 Surgical Laser for Treatment of Stress Urinary Incontinence in Women: A Randomized Controlled Trial
Authors: Alexander James W. , Karjalainen Paivi , Ow Lin Li , Kulkarni Mugdha , Lee Joseph K. , Karjalainen Teemu , Leitch Alison , Ryan Germana , Rosamilia Anna 
Published: March 2023

The common condition of stress urinary incontinence (SUI) has a reported prevalence of 10% to 39% in adult women in most studies. Although treatment of SUI via surgical means is an option, factors such as adverse effects of surgery and mesh-related risks lead many to seek alternative options. In overweight and obese patients, lifestyle changes for improving SUI symptoms entail mainly weight loss. Although pelvic floor muscle training (PFMT) can lead to improvements, further treatment is often necessary. Because of this, interest is high for developing effective nonsurgical treatments for SUI. One such possible treatment is vaginal laser therapy, which has been used as treatment for various vaginal conditions. The authors therefore carried out a randomized controlled trial (RCT) comparing CO2 laser with sham treatment for SUI.

This multicenter, participant-blinded, sham-controlled, parallel-group, superiority RCT involved participants from 2 hospitals in Southeast Melbourne in the outpatient setting. Patients aged 18 to 80 years experiencing symptomatic and objective SUI and seeking conservative management participated. Women with prior surgery for SUI were excluded. A positive cough stress test with a comfortably full bladder and uroflow was used to determine objective SUI. Participants lacking positive cough stress test were still eligible for study inclusion with a positive pad weight test in the absence of urgency incontinence symptoms.

Intervention took place using FemTouch delivery system in conjunction with the AcuScan 120 Microscanner and the AcuPulse CO2 laser system for fractional treatment. Laser energy was delivered via a standard foot pedal in a fractional manner. The sham treatment used identical methods and settings but used an inactive pedal, which only made mechanical clicks and no electronic beeps. A total of 3 treatments were administered to participants, 4 weeks apart, with incrementally greater density settings. The primary outcome of the study was subjective SUI (defined as positive answers to the inquiries: “Do you leak when you cough or sneeze?” or “Do you leak when physically active/exercising?”). Secondary outcomes were assessed via the Patient Global Impression of Improvement, and International Consultation on Incontinence Questionnaire–urinary incontinence change, International Consultation on Incontinence Questionnaire-overactive bladder, the Pelvic Organ Prolapse/Urinary Incontinence Sexual Function Questionnaire, the Incontinence Impact Questionnaire–Short Form, and EQ-5D scores. In addition, adverse events (such as pain during the procedure as measured on a visual analog scale) and objective SUI were recorded.

A sample size of 101 was chosen to provide 80% power to detect differences between groups for the primary outcome (even assuming a 10% rate of attrition). A total of 97 participants ultimately were treated. Randomization of participants occurred with equal probability to sham treatment or the CO2 laser using a computer-generated random sequence, which allocated participants to blocks of 4, 6, and 8. Unblinding of participants to their allocation occurred following the 3-month review.

Participants had a mean age of 53 years and a mean body mass index of 26.1 kg/m2, and 90% were vaginally parous. Most participants had attempted PFMT either independently or under supervision. No detectable difference was found between the sham and active treatment arm in the primary outcome of leak with laughter or cough. Furthermore, there were no significant differences between groups with regard to any of the secondary, patient-reported outcomes of questionnaires. The authors tested the reliability of their masking by assessing whether patients could identify their allocation group. Between the 2 groups, 17 (54%) of the sham group and 15 (63%) of the active treatment group believed they received sham treatment. Adverse events were rare in both groups, with similar visual analog pain scores during treatment and only rare vaginal bleeding and urgency incontinence in both groups.

Strengths of this study are several and include its blinded design and randomization methods. The primary outcome was focused on patient-reported outcomes. Responsive and validated questionnaires were utilized for assessment of secondary outcomes. Study limitations include a lack of blinding for investigators, which could have introduced an element of detection bias for SUI.

In conclusion, no benefit was shown for 3 treatment sessions of the CO2 vaginal laser when compared with sham therapy. Additional trials with various laser modalities are necessary to determine whether this may produce varying results. Women considering CO2 vaginal laser therapy for SUI should be made aware of the lack of consistent high-quality evidence in support of this treatment.