Interpretation
The SIS used in our study was found comparable in the long term to an inside-out TOT sling concerning both subjective (83.3%) and objective cure rates (86.4%). Previously published RCTs determined that another SIS system (MiniArc) has comparable subjective and objective cure rates (86% and 89%, respectively), although after only three years follow-up17. Similar mid-term results were affirmed in a study evaluating the Contasure-needleless SIS system reported by Dogan et al.18. Conversely, another RCT specifically assessing Ophira SIS efficacy after three years indicated inferiority of this sling in comparison with TOT in both subjective and objective cure rates (68.3% vs. 85.4%). Possible explanation for this inconsistency might be inclusion of complex cases with prior anti-incontinence surgery and adoption of rigorous objective cure criteria including CST along with a pad weight test 20. Long term follow-up (over three years) data evaluating SIS are available only from one retrospective observational study, in which Lo et al reported MiniArc SIS efficacy with 84.7% objective and 80.0% subjective cure rates21.
It is worth acknowledging that not all SIS are equal. They differ in regards to exact insertion technique, sling material, and, especially, their anchoring system. The Ophira SIS is equipped with a sophisticated anchor system, which, in an obturator membrane, retains the power of 18-20 Newtons. Both anchors include special release stitches which allow a surgeon to select proper tape tension 12. Currently, some previously referenced SIS are no longer commercially available. Nevertheless, we feel that our results are generally applicable, at least for slings with a well-developed anchoring mechanism applied in urogynecology centers with sufficient expertise in SUI surgery.
The European Association of Urology 2018 guidelines note that, for one year, there is no difference in efficacy between available SIS and conventional MUS. However, not all SIS have been subjected to RCT evaluation, and it may be unsafe to assume that all collectively are technically similar devices 22. Likewise, the most recent Cochrane review of SIS placement in patients with SUI concludes that there is still insufficient evidence to reveal a difference in incontinence rates with a SIS compared with trans-obturator MUS. Significant differences were observed with postoperative and long-term pain rates and with duration of the operation 4. Our study’s encouraging results suggest that modern well anchored and adjustable SIS have promising treatment potential – even in the long term!