To examine the double sling position by pelvic floor ultrasound and cure rate in patients who have received a retropubic suburethral sling (TVT) after a transoburator tape (TOT) failure.

Observational study involving patients with recurrent stress urinary incontinence (SUI) treated in a tertiary University European hospital between January 2006 and December 2009. All women included received a TVT procedure secondarily after a TOT failure. Medical and surgical background of each patient were collected, besides data related to the surgery. Based on the perineal ultrasound, the position of the sling was described relative to the bladder neck and the lower margin of the pubic symphysis at rest and on Valsalva1,2, and the angle formed by the arms of the sling tape as describes Rodrigues et al3. This study was registered and received institutional review board approval by the Institutional Review Board.

Fourteen patients, out of the twenty-three that had received a double sling, were studied by pelvic floor ultrasound to evaluate the double sling position. 85,7% were postmenopausal, 78,6% multiparous. In 57,1% the TVT was placed due to SUI and in 42,9% because of MUI. 14,3% needed a TOT excision previous to the second antiincontinence surgery. 
The median follow-up has been 106 months, and 35,7% is currently cured, 35,7% much better and 28,6% not cured (mainly because of UUI and MUI). Only one patient during the surgery had to have the TVT removed due to a complication immediately after the surgery. No other complications have been shown during their follow-up. 
Ultrasound results show a post void residual volume of 31cc and a detrusor wall of 3mm. The mean urethral length was 29,5mm, and the bladder neck descent (BND) was 7,8mm. The hiatal area if relaxed, valsalva or contraction was 16,9cm2, 19,1 cm2 and 14,5cm2 respectively. 14,3% had a levator muscle avulsion and 100% external and internal anal sphincter integrity. Comparative data scan between meshes are shown in Table 1. Sling distance to the urethral lumen is statistically different between TOT and TVT (p<0.001) both in relax and valsalva, as well as the angle between 2 mesh-arms. Failed cases do not show any ultrasound differences compared to the cured ones (Figure 1).

To our knowledge this is the first time to report ultrasound results correlated to clinical outcomes in patients who have received double antiincontinence mesh. According to our data, we accept that TVT is effective to treat recurrent SUI after TOT failure, while the pelvic floor ultrasound shows some differences in some parameters between the two slings position.

In conclusion, the use of pelvic floor ultrasound might help the surgeon to understand the reason of a failed sling in complex UI cases.

Shek KL, Dietz HP. Imaging of slings and meshes. Australas J Ultrasound Med. 2014 May;17(2):61-71.
Tamma A, Bjelic-Radisic V, Hölbfer S, et al. Sonographic sling position and cure rate 10-years after TVT- O procedure [published correction appears in PLoS One. 2019 Feb 14;14(2):e0212597]. PLoS One. 2019;14(1):e0209668. Published 2019 Jan 7. doi:10.1371/journal.pone.0209668
Rodrigues CA1, Bianchi-Ferraro AMHM1, Zucchi EVM1, Sartori MGF1, Girão MJBC1, Jarmy-Di Bella ZIK1. Pelvic Floor 3D Ultrasound of Women with a TVT, TVT-O, or TVT-S for Stress Urinary Incontinence at the Three-year Follow-up. Rev Bras Ginecol Obstet. 2017 Sep;39(9):471-479.