Objectives: To evaluate the anatomic changes in the polypropylene mesh sling after a tension-free vaginal tape (TVT) procedure using introital ultrasonography in a prospective study.
Methods: Eighty women with genuine stress incontinence but without pelvic relaxation syndrome underwent surgery. Introital ultrasound evaluation of the mid-urethra TVTs was performed after surgery.
Results: Of the 70 women available for evaluation at postoperative year 3, 62 (88.5%) were objectively cured and 6 had improvement; in 2 patients, the procedure had failed. The measurement of the tape position from the bladder neck at the first and third year compared with the tape position at 1 month revealed no statistically significant differences. The tapes were located at the mid-urethra in 60 patients (85.7%) and at the proximal urethra in 10. The measurement of the tape from the lower margin of the symphysis pubis using the rectangular coordinate system showed the tape had a downward descent of 1.7 mm at 3 years of follow-up. The rate of descent decreased during the study period. The mean thickness and width of the tape increased with time. A urethral knee angulation during maximal straining was found in 60 patients (92%), with the tape positioned at the mid-urethra for the follow-up period.
Conclusions: The observations of the tape position and characteristics suggest that shrinkage and compromise of the TVT sling does not occur. The TVT sling fixes to its original implanted site along the urethra and appears to slowly descend with the surrounding tissue with time. The urethra dynamic kinking contributes to the postoperative urinary continence when the TVT sling is placed at the mid-urethra.