Predictive factors of bladder outlet obstruction following the tension-free vaginal tape obturator (TVTO) procedure in females treated surgically for stress urinary incontinence
Objectives: To identify patients at risk for postoperative outlet obstruction after the tension-free vaginal tape obturator (TVTO) procedure in order to allow for better counseling and possible treatment alternatives.
Subjects and methods: This prospective study was carried out on 85 women who underwent the TVTO procedure for treatment of stress urinary incontinence (SUI). Preoperatively, a detailed medical history was taken from all patients, and all were subjected to physical examination, routine labs, abdominal and pelvic ultrasound and urodynamic studies (cystometry and assessment of the detrusor leak point pressure (DLPP), abdominal leak point pressure (ALPP), pressure flow and post-void residual (PVR) urine). The TVTO procedure was carried out by the same surgeon in all cases. Postoperative voiding dysfunction in this study was defined as the subjective feeling of difficult voiding, a weak stream and/or incomplete evacuation, and a PVR urine volume >100 ml, a urine flow rate <15 ml/s or urinary retention on examination. The following risk factors for postoperative bladder outlet obstruction were evaluated: age, history of previous incontinence surgery, parity, menopausal status, type of SUI, grade of SUI, residual urine, Qmax and PdetQmax. Statistical analysis was done using the SPSS package version 1.5.
Results: 75% of our patients were cured. Denovo urgency or urge incontinence developed in 5.8% of the patients. Voiding dysfunction according to our definition developed in 24.7% of the patients. On multivariate analysis, Qmax was the only risk factor that could predict postoperative bladder outlet obstruction (p = 0.002, odds ratio = 0.658, 95% C.I.).
Conclusion: Preoperative Qmax is the only independent risk factor for postoperative bladder outlet obstruction in women undergoing TVTO surgery. Brief summary: TVTO is an effective surgical option for genuine stress incontinence in females. Preoperative Qmax is the only independent risk factor for postoperative bladder outlet obstruction.