Two-dimensional and three-dimensional ultrasound imaging of suburethral slings

Suburethral slings have become the most commonly performed anti-incontinence procedures in many developed countries. Three types of implant account for the majority of such surgery in Australia: tensionless vaginal tape (TVT), suprapubic arc procedure (SPARC) and intravaginal slingplasty (IVS). The aim of this study was to determine differences in position and mobility of these implants, and to determine whether such differences explain variations in clinical outcome.

In a prospective randomized controlled trial, 195 women were randomized to TVT (n = 67), IVS (n = 64) or SPARC (n = 64). Thirteen women were excluded from the study due to incomplete preoperative data. Of the remaining 182 women, 146 (50 TVT, 48 IVS, 48 SPARC) were seen between 2 and 23 months after their procedure (80%). After an interview, two-dimensional (2D) and three-dimensional (3D) pelvic floor ultrasound was performed. 3D-volume analysis was carried out on a computer with the help of proprietary software (GE Kretz 4D View). Assessors of ultrasound data were blinded against group allocation.

There were no significant differences in subjective cure/improvement of stress or urge incontinence or overall subjective cure/improvement. Symptoms, including those of voiding dysfunction, did not vary between groups. All tapes could be imaged by ultrasound. TVT and SPARC were highly echogenic, with the SPARC generally flatter and of wider weave. The IVS seemed narrower and less echogenic. Tape position and mobility were similar, with a trend towards greater distances between tape and symphysis pubis and greater horizontal tape mobility in the SPARC group.

The three types of suburethral sling, namely TVT, SPARC and IVS, investigated using 2D and 3D ultrasound, have comparable short-term clinical and anatomical outcomes.