Randomised prospective single-blinded study comparing 'inside-out' versus 'outside-in' transobturator tapes in the management of urodynamic stress incontinence: 1-year outcomes from the E-TOT study

Objective To compare the 'inside-out' versus 'outside-in' routes for transobturator tape insertion for urodynamic stress incontinence, and to identify independent risk factors for failure at 1 year. Design Prospective single-blinded randomised trial. Setting Tertiary urogynaecology centre. Population A cohort of 341 women undergoing transobturator tape procedures between April 2005 and April 2007. Methods Women were randomised to tension-free vaginal tape-obturator (TVT)-O (TM) for the 'inside-out' route (n = 170) and transobturator tape (TOT)-ARIS (R) for the 'outside-in' route (n = 171). Participants completed validated symptom-severity, quality-of-life and sexual-function questionnaires before and after surgery. In addition, they completed the patient global impression of improvement questionnaire (PGI-I) and standard 1-hour pad test postoperatively. Main outcome measures The primary outcome was the patient-reported success rate reported on the PGI-I scale. Secondary outcomes included objective cure rate and improvement in King's Health Questionnaire scores. Results A total of 341 women were recruited: 171 women to the 'outside-in' (TOT-ARIS (R)) group and 170 to the 'inside-out' (TVT-O (TM)) group; 299 completed the 1-year follow up. The patient-reported success rate was 80% with no statistically significant differences between the groups ('outside-in' 77.6% versus 'inside-out' 81.2%; OR 1.25; 95% CI 0.71, 2.20; P = 0.54). The objective cure rate was 91% with no statistically significant difference between the groups ('outside-in' 88% versus 'inside-out' 94%; OR 2.21; 95% CI 0.85, 5.75; P = 0.157). Previous incontinence surgery (OR 1.41; 95% CI 1.18, 1.91; P = 0.029) and preoperative urgency incontinence (OR 1.78; 95% CI 1.21, 3.91, P = 0.048) were significant risk factors for failure of transobturator tape at the 1-year follow up. Conclusions There are no significant differences in patient reported and objective cure rates between 'inside-out' and 'outside-in' transobturator tapes. Quality of life and sexual function significantly improved following surgery. Both previous incontinence surgery and preoperative urgency incontinence are associated with significantly lower patient-reported cure rates.