Use of three-dimensional ultrasound scan to assess the clinical importance of midurethral placement of the tension-free vaginal tape (TVT) for treatment of incontinence.

The aim of the study is to illustrate that the midurethral positioning of the tension-free vaginal tape (TVT) may not be necessary to achieve continence. Our secondary aim is to highlight that a fair number of successfully performed TVT procedures do not result in midurethral position of the tape. A review of 31 women who underwent TVT operations and consecutively returned for their follow-up visits from July 2003 to November 2003 was conducted. Their TVT procedures were performed between March 2000 and August 2003. Transperineal three-dimensional ultrasound was used to identify and obtain objective measurements of the position of the TVT tape relative to the urethra. Any patients with significant coexisting vault or uterovaginal prolapse were surgically corrected at the same time. Their stress urinary incontinence was objectively diagnosed by performing urodynamic studies (dual-channel subtraction cystometry, erect stress test) in the outpatient urogynaecology clinic. Postoperatively, patients were reviewed at 1 month and then at 6 months followed by annual reviews subsequently. All women were reassessed at the 6-month follow-up visit with a filling and voiding cystometry to detect recurrent genuine stress incontinence and detrusor instability. Any woman complaining of stress urinary incontinence after that was reassessed with urodynamic studies as mentioned above. The majority of women (67.7%, 21 women) had the TVT tape located in the middle one-third of the urethra; 9.7% (3 women) and 22.6% (7 women) of women had the TVT tape situated in the proximal and distal one-third of the urethra, respectively. Despite this, all 31 women remained continent at their postoperative follow-up visits. The midurethral position of the TVT tape may not be essential in restoring continence. The TVT tape once inserted may not always rest in the midurethral position as described.