Surgical treatment is the standard approach for women with SUI who have failed conservative management strategies such as lifestyle changes, physical therapies, scheduled voiding regimens, and behavioral therapies. Minimally invasive midurethral slings are now considered the first-line surgical treatment for female SUI. In just a few years, midurethral sling (MUS) surgery has revolutionized this urologic field [17] because of a very short learning curve for the procedure, combined with high clinical efficacy and safety [18–20]. This new concept of tension-free midurethral support was introduced in the 1990s by Ulmsten and Petros [17].

The use of tension-free vaginal tape (TVT) has been shown to produce significantly higher continence rates compared with Burch colposuspension [21]. Furthermore, the TVT procedure has been shown to outperform other retropubic slings (intravaginal sling, SPARCTM) (Table 26.2). As regards the long-term data, Nilsson et al. reported an objective cure rate for TVT of 84–90% with a follow-up ranging from 5 to 11 years [22].

In 2001, Delorme proposed a new device with a transobturator route of midurethral tape insertion (TOT) to reduce the risk of pelvic complications (particularly bladder injury) [23]. In controlled trials comparing MUS devices, patients randomized to retropubic or transobturator tapes yielded similar objective and subjective postoperative continence outcomes [21]. In the opinion of O’Connor, the retropubic sling is more effective among patients with intrinsic sphincter deficiency [24]. Rechberger et al. reported that the effectiveness of transobturator tape is significantly lower with Valsalva leak point pressure (VLPP) ≤ 60 cm H₂O, while the retropubic technique is effective with VLPP ≤ 60 cm H₂O [25]. Therefore, as reported in the literature, the TOT approach should be suggested in SUI patients with VLPP > 60 cm H₂O, while in patients with VLPP ≤ 60 cm H²O, the retrobubic approach should be considered [24].

Furthermore, regarding the two different TOT techniques, ‘inside-out’ and üoutside-in’, it has been reported in a prospective study that both have shown similar cure rates (86% versus 92%, respectively) [26]. Moreover, fewer postsurgical complications were seen after TOT than after the retropubic approach [27, 28].

In addition to the low risks of TOT, a much less invasive MUS (placed without use of any needles, and passed either retropubically or through the groin) has been developed. Gynecare TVT SECUR™, the first mini-sling manufactured by Ethicon, Inc., a Johnson and Johnson company, was released in the USA in 2006. More recently, the MiniArc® single-incision sling has been developed by AMS, Inc. In Tables 26.3 and 26.4, the outcomes of using mini-slings compared with TOT procedures are described [29, 30]. However, due to poor efficacy, TVT SECUR has been out of production since 2012.

There is conflicting evidence on the effectiveness of the MUS in MUI. While the cure rate for the urge component seems to be variable, there is good evidence that the MUS improves the stress component.

However, a few studies have reported positive results in UUI after the TVT procedure. Rezapour and Ulmsten reported that not only SUI, but also UUI, was cured in 85% of patients and significantly improved in 4% [31].

Paick et al. evaluated the outcome after TVT, SPARC, and TOT procedures in women with MUI. The cure rates in women with MUI were similar following the TVT, SPARC, and TOT approaches (for SUI: TVT 95.8%, SPARC 90.0%, TOT 94.0%; and for UUI: TVT 81.9%, SPARC 86.4%, and TOT 82.0%) [32].

However, a recent systematic review underlines the fact that specific randomized controlled trials of tapes with a long-term follow-up are needed in order to demonstrate the efficacy of retropubic and TOT techniques in women with urodynamically proven and symptomatic MUI [33].

Voiding dysfunction after sling procedures can be caused by urethral obstruction from hyperelevation of the bladder neck or an exaggerated kinking of urethra. Further voiding symptoms (e.g., hesitancy, slow stream, intermittency, incomplete bladder emptying) and obstruction can also lead to other urinary symptoms, such as pain or OAB syndrome. Voiding dysfunctions, transient or persistent, have been reported in about 3–38% of patients after MUS procedures [34]. Although there is neither an established cut-off point between normal and abnormal postvoid residual (PVR), nor evidence of a correlation between PVR and voiding symptoms, almost 90% of patients report a PVR of < 100 mL after MUS surgery [35, 36].