Comparison of the mini sling or retropubic sling in the treatment of women with severe (Intrinsic Sphincter Deficiency -ISD) stress urinary incontinence (SUI)

Stress incontinence (SUI) is defined as urinary leakage with activities that increase intra-abdominal pressure (e.g. cough, sneeze, laugh and exercise). SUI is a prevalent condition with high burden of suffering. Midurethral slings (MUS) have become the operation of choice for treatment of female stress urinary incontinence. MUS are synthetic tapes that are implanted transvaginally to support the urethra. The urethra is a tube that connects the bladder to the outside of the body and removes urine from the body. Midurethral slings can be deployed in a retropubic or transobturator fashion. A retropubic approach involves tunneling the sling from the suburethral region, in close contact to the bladder in the retropubic space (behind the pubic bone), to the lower abdominal wall. In contrast, the transobturator approach involves the passage of a sling through the obturator membrane which is further away from the bladder. This approach has been shown to have a reduced rate of intra-operative bladder perforation. Recent systematic reviews of retropubic or transobturator midurethral tapes suggest equivalent efficacy, at least in the medium term. Both midurethral systems continue to have clinically significant complications such as bladder injuries, vagina mesh exposures, voiding difficulty, denovo (new onset) urgency and groin/thigh pain reported. Retropubic slings have more hematoma, bladder perforations, whereas transobturator slings have less over active bladder symptoms and less voiding difficulties. The minisling is a single incision sling system with small integrated self-fixating tips that anchor into the obturator internus muscle. This potentially avoids complications associated with trocar passage through retropubic or transobturator route. Comparative trials of retropubic against transobturator slings have shown retropubic slings to be superior in the cure rates of women with intrinsic sphincter deficiency (a severe form of stress urinary incontinence – ISD) . Randomised trials of minislings against transobturator slings have shown similar results, with the added advantage of less overactive bladder symptoms and voiding difficulties. The self-fixating tips of the minislings allow them to be placed under more tension, whilst retaining the advantages of the transobturator sling. The retropubic sling comes with superior efficacy, but has higher risks of pelvic hematoma, bladder perforations, denovo urgency and voiding dysfunction. Minislings, placed under more tension, may provide equivalent or better results than retropubic slings in patients with ISD, whilst retaining the advantages of transobturator slings. We seek to examine if the minisling is as efficacious as the retropubic sling for women with urodynamic stress incontinence (USI) and intrinsic sphincter deficiency (ISD) and compare their clinical outcomes.