Pre-operative opening detrusor pressure is predictive of detrusor overactivity following TVT in patients with pre-operative mixed urinary incontinence.

AIMS: To determine if specific pre-operative urodynamic parameters could predict detrusor overactivity following TVT in patients with urodynamic mixed incontinence.

METHODS: Notes of women with detrusor overactivity (DO) and urodynamic stress incontinence (USI) before undergoing tension-free vaginal tape (TVT) surgery were retrospectively reviewed. Patients underwent clinical evaluation pre-operatively including history, examination, and conventional urodynamic studies and were treated with pelvic floor exercises and anti-cholinergic medication. Those with persistent stress urinary incontinence (SUI) underwent TVT. Patients were re-assessed after at least 6 months post-operatively. Pre- and post-operative opening and closing detrusor pressure, and detrusor pressure at maximum flow were recorded retrospectively from pre-operative urodynamics traces by two clinicians independently and compared to the patients' post-operative symptoms and urodynamic diagnosis.

RESULTS: Fifty-one women were reviewed. Forty-six of the 51 attended follow-up and 35/51 agreed to conventional urodynamic studies. Seventeen of the 35 reported OAB symptoms, and 18/35 were asymptomatic. Nineteen of the 35 women had DO and 16/35 had normal urodynamic studies (NUDS). The median pre-operative opening detrusor pressure was higher in women with overactive bladder symptoms post-operatively. The median pre-operative opening detrusor pressure in women with DO post-operatively was 33.0 cmH(2)O and the median pre-operative opening detrusor pressure in those with NUDS post-operatively was 16 cmH(2)O (15.0-23.0 cmH(2)O) (P < 0.05 Mann-Whitney U-test).

CONCLUSIONS: Higher numbers of patients are required to demonstrate the value of opening detrusor pressure in predicting post-operative overactive bladder symptoms. Opening detrusor pressure is predictive of post-operative DO after TVT.