Aims of Study
TVT (tension-free vaginal tape) operation has been reported as a new surgical technique based on a series of experimental investigations of female urethral closure mechanism. We prospectively evaluated the safety and efficacy of the TVT procedure for surgical treatment of female stress incontinence.

Methods
TVT operation was performed in 195 incontinent women (stress incontinence in 153 and mixed incontinence in 11) with a mean age of 57.1 years ranging from 31 to 82 years. The patients were operated on under local anesthesia. A 60-minute pad test, uroflowmetry, measurement of postvoid residual urine, and urethrocystogram were performed pre- and postoperatively. Symptom and QOL (quality of life) were assessed by using short forms of Ueberssax et al. (Neurourol Urodyn. 14: 131, 1995). The safety of the procedure was evaluated in all patients and the efficacy was assessed in 164 patients followed more than 3 month.

Results
Pre-operative 60-minute pad test was 35.0g (0-498). 150 of 195 patients (83.3%) had the episode of incontinence more than once a day, 30 (16.7%) had experienced it a few times a week. 103 (55.7%) put on pads or diapers all day long and 39 (21.1%) put pads every time they go outside. The mean operating time was 45.8 minutes (20-145). 13 women (7.4%) simultaneously underwent hysterectomy and 33 (16.9%) repairs of pelvic floor prolapse. Bleeding was minimal and none necessitated blood transfusion. We found that this surgery that supports the mid-urethra requires little or no tension at all as the same way as the other sling operations do and that water spurt responding to strong coughings was a good indicator when the final adjustment of the tape tension is required. Although this water ejection was observed in the majority of the women (63.2%), those who failed to do so has to be completed based on surgeon's surgical experience. Difficulty in urination or retention occurred in 4 women, but none of them needed to be reoperated on to loose or remove the tape. At the postoperative evaluation carried out 3 months after the surgery, incontinence was cured in 120 of 146 patients (83.3%), minimal only on strong straining in 14 (9.7%), improved in 9 (6.3%) and unchanged in one (0.7%). Postoperatively, maximum flow rate declined from 27.2 to 18.6ml/sec and postvoid residual urine increased from 13.9 to 16.9ml which were not statistically significant. QOL asessed by a questionnaire comprising 13 items showed significant improvement postoperatively, the total score of the quetionnaire declining from 16.0 to 2.5 (mean) (p<0.05).

Conclusions
Since tension on the tape has to be minimal as with any other sling procedures, one should explain importance of a succession of coughings during surgery and makes a patient practice it prior to surgery. TVT surgery is minimally invasive and surgical outcomes are satisfactory for the correction of stress or mixed urinary incontinence.