Visibility of the polypropylene tape after tension-free vaginal tape (TVT) procedure in women with stress urinary incontinence: comparison of introital ultrasound and magnetic resonance imaging in vitro and in vivo.

OBJECTIVE: To determine whether introital sonography and magnetic resonance imaging (MRI) after TVT (tension-free vaginal tape) insertion can depict the polypropylene tape, and thus be used for patient follow-up. METHODS: The study comprised an experimental part, which investigated in-vitro visualization of the polypropylene tape in a model (phantom), and a clinical part, in which 20 women (mean age, 53.4 years) with clinically and urodynamically proven stress urinary incontinence without prolapse were investigated by introital ultrasound and MRI before and 13 months after the TVT procedure. RESULTS: In the phantom, the polypropylene tape was depicted with a low signal intensity by MRI and as a highly echogenic structure by ultrasound. In the clinical study, introital ultrasound in a mediosagittal orientation depicted the vaginal tape in all patients: it was located under either the midurethra (n = 16) or the lower urethra (n = 4), and in either the muscular coat of the urethra (n = 8) or in the urethrovaginal space (n = 12), the tape was either flat (n = 6) or curled up (n = 14), and there was no retropubic visualization of the tape. Overall, depiction by MRI was limited, and was poorer in comparison with ultrasound, especially when the tape had a sub- or paraurethral location. Retropubically, however, MRI identified the tape near the periosteum of the pubic bone (55% of cases), in the retropubic space (37.5% of cases), or near the bladder wall (7.5% of cases). CONCLUSION: Sonography is recommended for evaluation of the suburethral and paraurethral tape portions, while MRI is suitable for retropubic evaluation after the TVT procedure.