CORRESPONDENCE

Mini-slings - concern regarding marketing of these devices in South Africa

To the Editor: Aggressive marketing of medical devices impacts on the day-to-day practice of clinicians. The marketing of the mini-sling devices for stress urinary incontinence (SUI) in women is an area of major concern to us. SUI is the involuntary leakage of urine from the urethra with exertion, or on sneezing or coughing, and affects up to 35% of women.¹ It is a distressing condition and significantly impacts on quality of life.

Traditional interventions include pelvic floor exercises and open retropubic colposuspension. Ulmsten in 1995 introduced an effective minimally invasive option for surgically managing SUI, the 'tensionfree vaginal tape' (TVT) (Gynecare, Ethicon, Somerville, USA).² This was followed by development of the transoburator-type sling, which avoided the risks of bladder, bowel and major vascular injury.³ Both slings are made of synthetic mesh and are placed mid-urethrally, and their placement is the most commonly performed surgical procedure for SUI.

Long-term follow-up of Ulmsten's original series found an objective cure rate of 90% at 10 years. Level 1 evidence found efficacy to be equivalent to that of colposuspension. Meta-analysis has further shown equivalence in terms of cure between the trans-obturator and retropubic placement of mid-urethral slings.⁴

Mid-urethral slings therefore offer a highly efficacious minimally invasive surgical option with low postoperative morbidity. Device manufacturers have in the past 5 years introduced and strongly promoted eight further so-called 'mini-slings' that are claimed to be less invasive, and are placed via a small single vaginal incision.

There is little quality evidence to support the use of mini-slings. Nearly all the available studies show inferior efficacy. The most studied device, the TVT-Secure, was the subject of a 12-month outcome study that reported an objective cure rate of 76%, considerably lower than the 90% reported long-term cure rate for the standard TVT.⁵ The other widely marketed device, the Mini-Arc, also has inconsistent outcomes with some studies showing cure rates as low as 62%.⁶

Gynaecologists and urologists need to be aware of these poorer outcomes, for the TVT-Secur and the Mini-Arc in particular. While mini-slings hold future promise, present products are inferior to standard sling operations and their use should be discouraged.

John Lazarus

Division of Urology
Groote Schuur Hospital and University of Cape Town
j.lazarus@uct.ac.za

Stephen Jeffery

Department of Obstetrics and Gynaecology
Groote Schuur Hospital and University of Cape Town

Lisa Kaestner

Division of Urology
Groote Schuur Hospital and University of Cape Town

1. Luber KM. The definition, prevalence, and risk factors for stress urinary incontinence. Rev Urol 2004;6(suppl 3):S3-S9.        [ Links ]

2. Ulmsten U, Petros P. Intravaginal slingplasty (IVS): an ambulatory surgical procedure for treatment of female urinary incontinence. Scand J Urol Nephrol 1995;29:75-82.        [ Links ]

3. Delorme E. [Transobturator urethral suspension: mini-invasive procedure in the treatment of stress urinary incontinence in women]. Prog Urol 2001;11(6):1306-1313.        [ Links ]

4. Fong EDM, Nitti VW. Mid-urethral synthetic slings for female stress urinary incontinence. BJU Int 2010;106:596-608.        [ Links ]

5. Walsh CA. TVT-Secur mini-sling for stress urinary incontinence: a review of outcomes at 12 months. BJU Int 2011;108(5):652-627.        [ Links ]

6. Deole N, Kaufmann A, Arunkalaivanan A. Evaluation of safety and efficacy of single-incision midurethral short tape procedure (MiniArc^TM tape) for stress urinary incontinence under local anaesthesia. Int Urogynecol J 2011;22(3):335-339.        [ Links ]