COMET (Composite Outcomes of Mesh vs suture Techniques for prolapse repair)- Protocol for a single blind randomized controlled multicenter trial testing surgical innovation in female pelvic surgery.

Background: Pelvic organ prolapse (POP) increases in incidence and severity with aging. At least 1 in 4 women seek pelvic floor care and many more suffer with concurrent symptoms of bowel, bladder and sexual dysfunction, which can have a large impact on quality of life. It is estimated that 1 in 5 women will undergo surgery for POP. POP is difficult to cure with existing surgeries and therefore treatment failure and reoperations are common. Surgical innovation in this area is urgently needed and we have developed a novel technique of bilateral sacrospinous vaginal vault fixation with synthetic mesh arms (BSSVF-M). Based on preliminary studies it may be more successful, durable and cost-effective than standard sacrospinous ligament suspension with sutures (SSLS). Preliminary development and exploration studies showed safety and efficacy of BSSVF-M. Following an established framework for research in surgical innovations, we now wish to conduct a randomized comparative effectiveness trial for assessment of this novel technique.

Methods: This is a multi-center randomized controlled trial in Canada comparing the surgical techniques of BSSVF-M vs. SSLS to address apical prolapse. In total, 358 women with symptomatic POP at five centers will be randomized with 80% power to detect a 15% difference in primary composite outcome and accounting for a 15% loss to follow-up over 2 years. The primary objective is to investigate BSSVF-M vs. SSLS using an established composite of 3 objective signs and 1 subjective symptom of POP measured 2 years postoperatively. Secondary objectives: 1) To determine changes in condition-specific pelvic symptoms, quality of life, pain and condition-specific body image post BSSVF-M vs. SSLS using validated questionnaires; 2) To determine changes in sexuality post BSSVF-M vs. SSLS; 3) To determine global impression of improvement, adverse events (validated classification scheme), reoperations and health utility post BSSVF-M vs. SSLS; 4) To determine the cost-effectiveness of BSSVF-M vs SSLS. Study Registration at clinicaltrials.gov (NCT02965313).

Discussion: There is a need for innovation to improve the surgical approach to vaginal apical suspension. Despite controversies with mesh, it has been shown to be safe when used appropriately and to have higher durability when compared with sutures. As well, the importance of restoring anatomy and tension-free surgical approach in pelvic reconstructive surgery has led to better long-term outcomes and fewer side effects. These principles have been applied when developing the novel BSSVF-M technique. Anticipated challenges of this trial include recruitment, compliance problems and loss to follow up However, the robust methodology will provide evidence on the best surgical approach to correct POP, a common condition among aging women.