Description of the condition

Urinary incontinence has been shown to affect up to 50% of women (Melville 2005). Studies in the United States have shown that up to 80% of these women will have an element of stress urinary incontinence (Hampel 1997).  The surgical approach to stress urinary incontinence has progressed rapidly over the past one and a half decades. In the mid‐1990s, a prospective randomized study confirmed the superiority of the colposuspension over the Kelly plication and the modified Pereyra needle suspension techniques, with five year cure rates in excess of 80% (Bergman 1995). This established the colposuspension as the standard approach to stress incontinence surgery.  A colposuspension, however, entails major surgery with a substantial operating time and lengthy hospital stay, and a significant potential for morbidity (Lapitan 2009). The pubovaginal sling, which employs a fascial strip for support, is an effective alternative to the colposuspension with similar efficacy (Bezerra 2005). The incidence of severe adverse events following these procedures is high, for example 10% after colposuspension (Lapitan 2009) and 13% after pubovaginal slings (Bezerra 2005). 

Description of the intervention

In 1993 Ulmsten and Petros proposed the Integral Theory, a new concept in the maintenance of female urinary continence (Ulmsten 1998). This is considered to be one of the drivers for the development of the “Tension‐free vaginal Tape” (TVT), which was the first effective minimally invasive procedure for stress incontinence in women (Ulmsten 1998).  The five year efficacy of the TVT has recently been shown to be comparable to the Burch colposuspension, with the benefits of a shorter operating time and decreased hospital stay (Ward 2008).

The major disadvantage of the TVT procedure is that it involves the “blind” passage of a retropubic needle, which poses a significant risk for bladder, bowel and major vessel damage. The incidence of bladder injury is approximately 6% (Ogah 2009). This led to the development of the next generation of suburethral sling procedures with the launch of the Transoburator Tape (Delorme 2001). The transobturator passage resulted in fewer injuries to the bladder and other organs. A recent Cochrane Review (Ogah 2009) describes lower complication rates with the transobturator tape, including less bladder perforation and shorter operating time. Objective efficacy appears to be poorer with the transobturator than the retropubic route (Ogah 2009), but subjective efficacy is comparable for the two approaches.  The transobturator approach is not without complications and it has been shown to be associated with a significant risk of groin and hip pain following surgery. A recent meta‐analysis (Latthe 2007) reported an incidence of 12% for groin and hip pain following an obturator type sling compared to only 1% for the retropubic approach.

The significant risk of visceral injury associated with the retropubic tape and the high incidence of groin pain following the transobturator route has led to the development of a new generation of stress incontinence devices. Popularly known as the “single‐incision slings” (Moore 2009), these third generation devices differ from previous sling procedures in that a single incision is made within the vagina with no tape exit incisions. They have also been called the single incision slings (Molden 2008).  The tape used in these devices is significantly shorter (eight to 14 cm) in length than the first and second generation slings. The insertion pass stops short of the obturator membrane or pelvic floor. This less invasive approach is thought to reduce complications including bladder, bowel and vascular injury, groin/thigh pain, with a shorter hospital stay and less postoperative pain. Interest is gradually increasing regarding the efficacy and safety of the mini‐slings but there is at present a paucity of clinical data on these procedures.

How the intervention might work

There are currently five minimally invasive sling devices available including TVT Secur, Mini‐arc, Ajust, Needless and Solyx. There are a number of differences between the various devices:

• The TVT‐Secur is inserted using a metal introducer that anchors the device in the Obturator membrane. It is placed snugly  against the urethra.

• The Mini‐arc has a curved introducer that clips into two plastic anchoring hooks on the ends of the sling and this is used to insert the sling and secure it into the Obturator membrane.

• The Ajust also has a curved introducer with plastic anchoring hooks but it differs from the other devices in that it has a pulley‐like system that allows adjustment following insertion.

• The Needless device is 60% longer than the other Mini‐slings. It has a pocket‐like fold on each end and an artery forceps is placed onto the end of the sling in this pouch and the sling is pushed laterally and through the Obturator membrane at insertion.

• The Solyx also has a curved metal insertion trocar which slots into two plastic anchoring tips on the ends of the sling. It also has a deployment system that enables adjustment.

Why it is important to do this review

A number of observational trials have reported cure rates of 77% (Debodinance 2008) and 81% (Meschia 2009) for the TVT‐Secur and 77% for the Mini‐arc (Gauruder‐Burmester 2009).  Preliminary data also suggests lower rates of bladder injury and groin or hip pain following the insertion of these devices.

With the introduction of new devices, clinicians have to decide if they are going to adopt the new technique. A systematic unbiased review of the mini‐sling devices is therefore urgently needed at this time.