Trial Of Mid-Urethral Slings (TOMUS)

General Description

Urinary incontinence affects up to 50% of women, resulting in substantial medical, social, and economic burdens. Among U.S. women with urinary incontinence, 15 to 80% have a component of stress incontinence, which results in leakage of urine during physical exertion, sneezing, and coughing. Of these women, 4 to 10% undergo surgery.

TOMUS is a 2-arm, unmasked, multi-center randomized controlled trial that compared two types of mid-urethral slings used for treatment of stress incontinence: the retropubic mid-urethral mesh sling (RMUS) and the transobturator mid-urethral sling (TMUS). RMUS procedures are less invasive than the fascial sling procedures that were reference standards at the start of the study. Specifically, a synthetic tape is passed transvaginally at the midurethral level through the retropubic space. TMUS procedures were developed to minimize the potential for bladder and bowel injuries associated with the retropubic sling, since the sling is passed through the obturator canal, avoiding the pelvic organs in the retropubic space.

Eligible women 21 years of age or older who were planning to undergo surgery for the treatment of stress incontinence were invited to participate in TOMUS. Randomization was performed after anesthesia was administered. Women were randomly assigned with the use of a permuted-block randomization schedule, with stratification according to clinical site. After the surgery, information regarding the treatment assignment was not kept from the patient. Subjects were followed up at 12 and 24 months after the surgery.

ETOMUS: Women completing 2-year participation in a randomized equivalence trial who had not undergone surgical re-treatment for stress urinary incontinence were invited to participate in a 5-year observational cohort.

Objectives

The primary aim of this clinical trial was to compare treatment success for two mid-urethral sling procedures to treat stress urinary incontinence in women at 12 and 24 months after surgery. The secondary aims of the trial were to compare other outcomes for the two surgical procedures, including quality of life, sexual function, satisfaction with treatment outcomes, complications, and the need for other treatments(s) after surgery.

Outcome Measure

Primary:

1. Objective treatment success: negative stress test, negative 24-hour pad test, and no retreatment for stress urinary incontinence (SUI) including behavioral, pharmacologic or surgical procedures

2. Subjective treatment success: absence of self-reported symptoms of stress-type urinary incontinence, as assessed with the use of the Medical, Epidemiological and Social Aspects of Aging (MESA) questionnaire, no leakage recorded in a 3-day voiding diary and no retreatment for stress incontinence including behavioral, pharmacologic or surgical treatment.

Secondary:

1. Patient satisfaction at 12 months as assessed with the questions, "how satisfied or dissatisfied are you with the result of bladder surgery related to urine leakage?"

2. Change in Quality of Life from Baseline to 12 months as assessed by scores on the Incontinence Impact Questionnaire

3. Bother as measured by the Urogenital Distress Inventory (UDI) at 12 Months

ETOMUS: The primary outcome, treatment success, was defined as no re-treatment or self-reported stress incontinence symptoms. Secondary outcomes included urinary symptoms and quality of life, satisfaction, sexual function and adverse events.

Criteria

Female ≥ 21 years old

SUI as evidenced by all of the following:

1. Self-reported stress-type UI symptoms, of duration >3 months

2. MESA stress symptom score (percent of total possible stress score) greater than MESA urge symptom score (percent of total possible urge score)

3. Observation of leakage by provocative stress test at a bladder volume ≤ 300ml

4. Bladder capacity >200ml by stress test

5. Post-void residual (PVR) <100cc with pelvic organ prolapse (POP) Stage I or lower. If POP is Stage II-IV, PVR >100cc but ≤500cc is allowed

Eligible for both RMUS and TMUS procedures:

1. No medical contraindications, e.g., current UTI, history of pelvic irradiation, history of lower urinary tract cancer

2. ASA class I, II, or III

3. No current intermittent catheterization

Available for 24-months of follow-up and able to complete study assessments, per clinician judgment

Outcome

The unadjusted rates of treatment success with the retropubic and transobturator procedures according to objective criteria met the predefined criteria for equivalence. The unadjusted rates of treatment success according to subjective criteria did not differ significantly between the two procedures but did not meet the predefined criteria for equivalence.

The rates of patient satisfaction with the treatment were similar between the groups, and there were no significant differences between the groups in changes between baseline and postoperative “distress” and “bother” scores. (N Engl J Med. 2010 June 3; 362(22): 2066–2076.)

ETOMUS: Treatment success decreased during 5 years for retropubic and transobturator slings, and did not meet the prespecified criteria for equivalence with retropubic demonstrating a slight benefit. However, satisfaction remained high in both arms. Women undergoing a transobturator sling procedure reported more sustained improvement in urinary symptoms and sexual function. New mesh erosions occurred in both arms over time, although at a similarly low rate.