Many studies and reports indicate that millions of women suffer from SUI , negatively contributing to their quality of life [1–3]. Often, many women with severe SUI have failed conservative measures, including pelvic floor physical therapy, lifestyle modifications, behavioral therapies, and timed voiding [3]. Patients who failed the aforementioned measures and who desire surgical intervention are often appropriate candidates for synthetic sling procedures, including the single-incision mini-sling.

There have been several different types of single-incision mini-slings available on the market (Table 18.1, Figs. 18.1, 18.2, 18.3, 18.4, 18.5, 18.6, and 18.7). Studies exploring the efficacy of the TVT-Secur™ (Ethicon Women’s Health and Urology, Somerville, New Jersey, USA) (Fig. 18.1), a third-generation mini-sling, had significantly lower cure rates as perceived by patients compared to retropubic approaches [3]. Of note, TVT-Secur™ is no longer on the market due to voluntary cessation of production by Ethicon. The MiniArc™ Precise Single Incision Sling System (Astora Women’s Health, L.L.C., Eden Prairie, Minnesota, USA) (Fig. 18.2) has been shown in a previous study to offer similar cure rates as the transobturator sling approach [4]. (Editor’s Note: MiniArc™ is no longer marketed as Astora Women’s Health has gone out of business.) Currently, we have 2 years of data on the MiniArc™ sling by Moore and colleagues and Kennelly and colleagues showing comparable outcomes to MUS, with similar subjective and objective improvement rates at 2 years. However, there are no long-term data studying the safety and efficacy of SIMS beyond that period [5, 6].

Despite the emerging studies on single-incision mini-slings , the ideal patient is yet to be determined [7]. SIMS have not been on the market as long as other traditional slings, thus it has been only studied in classic SUI patients. SIMS, however, may not be the best option for patients with severe cases of SUI . A study exploring the Ophira™ Mini Sling System (Promedon, Cordoba, Argentina) (Fig. 18.3), which anchors to the obturator internus muscles on the same plane as the tendinous arc, demonstrated the likely ideal candidate for the Ophira™ Mini Sling System are patients who have never had prior incontinence surgery [8]. Per this study, the best cure rates were witnessed in the cohort without prior surgery (89.6 %), as compared to the cohort with prior incontinence procedures (67.9 %) [8].

Women with conditions that may impair wound healing are not ideal candidates for MUS. This may also hold true for SIMS candidates. Women with a history of tobacco use, diabetes, pelvic radiation therapy or have any other risk factor that may affect surgical recovery are at increased risk for mesh erosions and exposure [9].

Similar to retropubic and transobturator midurethral slings, SIMS have very similar contraindications to placement. Current pregnancy is an absolute contraindication to sling procedures. Women who are of reproductive age should be counseled and certain that they have completed childbearing prior to undergoing incontinence procedures, as pregnancy and delivery disrupt the pelvic floor support [9]. Other contraindications to midurethral synthetic slings include previous or concurrent urethral surgery or injury (e.g., urethrovaginal fistula repair), hypersensitivity or allergy to mesh material, poor vaginal epithelium, any pelvic radiation, urethral diverticulum, and resting severe intrinsic sphincter deficiency (with or without urethral hypermobility) [10].

Urethral hypermobility is another facet that must be closely inspected. Slings are theorized to fulfill their purpose by acting as a 1 cm wide catching net that provides resistance beneath the urethra, leading to compression of the urethra between the sling and the pubic symphysis when intra-abdominal force is present. With this mechanism of action in mind, sling placement should theoretically be more effective in women with hypermobility of the urethra, compared to women with fixed urethras [8, 9, 11]. Typically, preoperative testing showing a maximum Q-tip mobility less than 30° indicates a fixed urethra, thus leading to a 1.9-fold increased risk of sling failure to treat SUI [9, 12].

Akin to MUS candidates, those women that are being considered for a single-incision mini-sling need to also be evaluated for mixed urinary incontinence. It is imperative to treat the urge component prior to SIMS placement. This may be done conservatively or with anticholinergic medications. In some cases, once the urge component is treated, the need for surgical treatment of SUI may be eliminated.

Some studies may suggest that age may also be a factor when deciding on SIMS. The study examining the Ophira™ Mini Sling System , as mentioned earlier, suggests that elderly patients may not benefit as much from this system compared to the younger patient. In this study, women over 60 years old were categorized as elderly. These women had a subjective cure rate of 80.6 %, which was acceptable to the authors [8]. However, many other studies concluded that patients greater than 70 years old resulted in decreased success rates, likely due to poorer tissue integrity [8, 9, 13].

Obesity is a well-studied risk factor for SUI [5]. Moore and colleagues suggests that the MiniArc™ has comparable cure rates in both obese (defined as body mass index greater than 30 kg/m²) and nonobese patients. This study introduces 2 years of data from a multicenter, prospective trial that demonstrates no difference in improvement rates or complication rates. Although no ideal patient has been defined for SIMS, this study suggests that obesity is likely not an exclusionary trait.

Single-incision mini-slings were developed with the aim of reducing intraoperative and postoperative complications that may be seen with retropubic and transobturator approaches. These include complications such as retropubic hematoma, groin pain, bladder perforation, infection, bowel perforation, and injury to nerves and vessels [14]. The aim of SIMS is to provide a minimally invasive sling that reduces risk, operative time, postoperative complications, and recovery.

Currently available SIMS are typically placed through a single 1.5 cm anterior vaginal incision at the midurethra in a transobturator direction. The obturator internus muscles or obturator membrane is the fixation point for the transobturator direction SIMS, without passing through the structures within the obturator foramen. Some other SIMS models may also be placed in a retropubic direction with the urogenital diaphragm serving as the fixation point [1, 7, 15].

Single-incision mini-slings may be placed in the operating room under general anesthesia, which comes with its own inherent risks. However, unlike the MUS, SIMS may also be implanted in the office under local anesthesia. Across various studies, operating time for mini-slings ranged anywhere from 7 to 16 min, demonstrating it to be a quick and easy procedure [16, 17]. Local anesthesia, typically lidocaine, is used with this approach. Care must be taken to ensure that the target fixation tissue is not over-infiltrated with local anesthesia, thus negatively affecting the pullout force. The Ophira Mini Sling™ study by Palma reports three patients with lidocaine hydrochloride toxicity, for which they were treated conservatively [8]. No additional studies were encountered that reproduced this adverse effect.

A key intraoperative point with several single-incision mini-slings that anchor in the obturator internus muscle is the inability to confirm tissue placement. During sharp tissue dissection, special care should be taken to avoid penetrating the urogenital diaphragm, obturator internus muscles, and the obturator membrane, as this may decrease the holding ability of the sling anchors. Fixation to tissue with good integrity cannot always be confirmed intraoperatively or tested for integrity. It is theorized that this may be contributory to early failures of single-incision mini-slings , which will be further discussed later in the chapter. Barber and colleagues discuss a high proportion of device malfunction or technical difficulties (8.8 %) with the TVT-Secur™ observed during implantation that ultimately resulted in using a second mini-sling device or alternate sling [2]. Additionally, the MiniArc™ and other SIMS have the reduced capabilities of correction after the self-fixating tips have been deployed in the tissue, leading to possibly ineffective slings.

The AJUST™ Adjustable Single-Incision Sling (C.R. Bard, Inc., Covington, Georgia, USA; Editor’s note: The AJUST™ sling no longer marketed) (Fig. 18.4) and ALTIS™ (Coloplast, Minneapolis, Minnesota, USA) (Fig. 18.5) were developed to address the concerns of incorrect anchor placement. With these systems, the anchors are placed through the obturator membrane, rather than surrounding obturator internus muscle or connective tissue [7]. Postinsertion adjustment of the mesh (tightening or loosening) can be performed to achieve optimal placement [7].

There have been documented reports of vaginal wall perforations with the placement of SIMS. Studies have demonstrated this occurrence to be as high as 2 % [11]. In order to avoid this, Taner and coworkers described using the surgeon’s index finger as a guide for the delivery trocar through the vaginal incision for the Ophira™ Mini Sling System . Once the surgeon feels the needle at the vaginal fornix, the needle was then directed toward the obturator internus muscle to set up the anchors for deployment [16].