[Comparison of transobturator tape (TOT) and tension-free vaginal tape (TVT) using perineal ultrasound]

Abstract

Objective: Using perineal ultrasound in two groups of patients having either TVT or TOT procedure to know if TOT is sufficiently oblique and if the large dissection in TOT procedure might be responsible for migration of the tape.

Patients and methods: Thirty-two patients, 16 TVT and 16 TOT, had a sonography. The tape is visualised in the sagittal and frontal planes at rest, maximum holding and valsalva straining. The angle between the two limbs of the tape is measured as well as the distance tape-bladder neck and the width of the tape.

Results: The aspect of the tape at rest is like a V, in both groups. During straining, the urethra is flattened on the tape which becomes round. During maximum retaining, the V closes by traction on the limbs. The mean angle under the urethra at rest is 109.9 degrees. In the TVT group it is 101.6 degrees versus 118.1 degrees in the TOT group. This difference is statistically significant (P=0.001). The width of the tape is 6.7 mm (2.4-10.3). The distance tape-bladder neck is 14.8 mm (8.2-25.7), 14.6 mm for the TVT group and 15.6 mm for the TOT group, the mean urethral length being 33.1 mm.

Discussion and conclusion: The angle of TOT is more open. It remains sufficiently oblique and allows the tape to be put with light tension if needed in low-pressure urethra. In spite of larger urethrovaginal dissection in TOT, the tape does not migrate close to the bladder neck and remains at mid-urethra.