The mid-urethral slings (MUS) are the most common surgical treatment for women with stress urinary incontinence (SUI). The sonographic pattern of the MUS is well established in the literature and correlates with symptoms and complications. The dynamic interaction of the urethra with MUS during the Valsalva is a determinant factor of surgical success, requiring bladder neck mobility with MUS to perform the concordant movement (urethral kinking) which could be assessed by pelvic floor ultrasound (PF-US).
However, different alternatives exist for women with SUI and hypomobile urethra, such as readjustable slings (RAS). RAS is a closed system with a suburethral sling fixed to a device located in the suprapubic region, which allows sling tension regulation after placement and which achieves urethral closure extrinsically compressing it during Valsalva. Due to its special characteristics, making it capable of coapting the lumen of hypomobile urethras, RAS is usually reserved for patients with complex SUI and hypomobile urethra. There is a lack of information related to the RAS sonographic pattern in the literature.
We hypothesize that postoperative sonographic parameters of MUS and RAS differ due to different mechanisms of action. The aim of this study was to define the postsurgical sonographic parameters of the RAS compared with those previously described in the literature for transobturator and retropubic MUS approaches, as well as the correlation with symptoms.

We carried out an observational, prospective multicenter study of women undergoing SUI surgery with transobturator-MUS (TOT-MUS), retropubic-MUS (RT-MUS) and RAS between January 2012 and June 2020 in two university hospitals. 
The preoperative evaluation included a symptom evaluation with the Incontinence Questionnaire-Short Form (ICIQ-UI-SF), a 3-day bladder diary, a 24 hour-pad weight, a pelvic examination, a cough stress test and an ICS standard urodynamic test (ICS-SUT). 
At the postoperative follow up, one-year post-surgery, patients were assessed using ICIQ-UI-SF, 24 hour-pad weight test, an ICS-UCST and an optional ICS-SUT. A PF-US was performed to all patients at one-year follow-up visit and concordant movement was considered when the RAS achieved extrinsic compression of the urethra during Valsalva, compressing the posterior urethral wall, coapting the lumen, and displacing the urethra anteriorly. The movement was considered discordant if extrinsic compression was not observed. 
The primary outcome was comparison of the postsurgical sonographic parameters of RAS with those previously described in the literature for MUS. The secondary outcome were the associations between the sonographic parameters of RAS and patients’ symptoms and functional tests.

We included 165 patients (55 RAS, 55 TOT-MUS, 55 RT-MUS). The demographic data and presurgical symptoms of the three groups of patients included in the study are shown in Table 1.
We observed that RAS was more often located in the proximal urethra and farther from the lumen than MUS, and also have a different concordant movement on Valsalva in comparison with MUS (Table 2).
Postsurgical Incontinence Questionnaire-Short Form scores were significantly higher in patients with persisting bladder neck funneling [15.0 (3.9) vs. 10.6 (6.7); p=0.020] and in those with discordant movement of RAS on Valsalva [14.6 (5.7) vs. 10.3 (6.7); p=0.045].

Postsurgical pelvic floor ultrasound demonstrated that, in women with complex SUI and hypomobile urethra, RAS (Remeex®) has a different concordant movement on Valsalva compared with MUS. Discordant movement on Valsalva and bladder neck funneling after RAS surgery, correlates with higher postsurgical ICIQ-UI-SF scores, and may be sonographic markers of RAS failure.

Further studies using pelvic floor ultrasound in combination with functional tests are needed to understand the mechanisms of different SUI surgical techniques, especially after failure or complications.