The FAST- Study: The Follow-up After Shorter Tapes Study Effectiveness and Safety of Shorter Trans-obturator Tapes: A Prospective Observational Study From the Norwegian Female Incontinence Registry

Background:

Stress Urinary incontinence (SUI) is a frequent consequence of childbirth and affects 1/3 of the general female population. It gravely diminishes the quality of life of numerous women by limiting their ability to be physically active, and impairing their sexual function. Mid-urethral sling (MUS) procedures have been the dominant surgical treatment for SUI over the last two decades. The traditional MUS procedures places a polypropylene mesh for support under the urethra, either in front of the bladder passing through the pelvis to the lower abdomen (tension free vaginal tape (TVT)), or to the side of the pelvis in the groin area (tension-free vaginal tape obturator inside-out (TVT-O)). These traditional techniques have well documented long lasting results and have improved the quality of life in most women with SUI. However, a few women experience serious complications such as severe chronic pain, dyspareunia, erosion/expulsion of the mesh, and voiding dysfunctions. Even though these devastating complications are rare, the consequence for affected women is lifelong reduced quality of life, even if the synthetic material is removed in its entirety. This has led to massive negative publicity, lawsuits against manufacturers and a movement in social media to ban these procedures. Several countries have therefore reverted to older, less effective surgical methods to avoid the use of synthetic materials.

Single incision mini-slings (SIMS), with much less synthetic mesh than traditional slings were introduced worldwide in 2006. In 2010, the TVT-O Abbrevo (TVT-A), an intermediate sling, was introduced hoping to refine the clinical performance of shorter slings. SIMS and intermediate slings have shown promising short-term results, but regarding long-term efficacy and complication rates, there are only a few published studies with small sample sizes. Given that shorter slings could represent a middle ground between the risk of severe complications and a loss of life quality due to untreated urinary incontinence, data on long-term effect and safety of the newer shorter slings is urgently needed. Retrieving such knowledge would make it possible to update surgical guidelines and provide patients considering surgical options with evidence-based recommendations.

Since 1998, Norway has had a compulsory registry of all incontinence surgeries performed in the country, the Norwegian Female Incontinence Registry (NFIR). Akershus University hospitals (AHUS) started already in 2009 using the SIMS Ajust and later intermediate slings as their preferred incontinence procedure. We therefore have a unique possibility to study the long-term results and complication rates by inviting women back to a long-term follow-up having undergone SIMS and intermediate sling surgery at AHUS. This follow-up also provides the possibility of investigating sling position using 2D dynamic and 3D trans-perineal ultrasound (TPUS). AHUS has the expertise in advanced ultrasound within the research group. How positioning of intermediate slings under the urethra may affect long-term success rates and adverse events is largely unknown. This lack of knowledge makes it difficult for gynecologists evaluating patients in need of repeat surgery, due to either treatment failure or long-term complications. Understanding the biomechanical effects visualized by ultrasound of the increasingly popular shorter slings would enable researchers and doctors to develop the treatment techniques for female incontinence further.

Research questions and methodology: