The introduction of synthetic mesh and biological grafts in vaginal prolapse surgery was a direct consequence of the poor surgical outcomes highlighted in numerous studies over the past two decades. Evidence from the 2016 Cochrane systematic review on the safety and effectiveness of surgery for anterior and posterior compartment prolapse suggested that, while permanent mesh provides minimal advantage compared with native tissue repair with regards to awareness of prolapse and staging of prolapse on examination, it is associated with higher rates of reoperation for prolapse, stress urinary incontinence or mesh exposure and increased risk of bladder injury at surgery. It also highlighted the lack of evidence regarding the potential advantages of biological grafts over native tissue repair.
The PROSPECT trial aimed to provide the lacking evidence on the effectiveness and safety of synthetic mesh and biological grafts versus standard repair in women undergoing primary surgery for prolapse in the anterior and posterior compartment. It comprised two pragmatic, parallel-group randomised controlled trials in women undergoing primary transvaginal anterior or posterior compartment prolapse surgery in 35 centres in the UK, allowing for concomitant uterine and vault suspension, as well as continence surgery. 1352 eligible women were randomised to treatment at a 1:1:1 ratio for standard repair, use of non-absorbable type 1 monofilament macroporous polypropylene mesh or insertion of biological graft materials, such as porcine acellular collagen matrix, porcine small intestinal submucosa, or bovine dermal grafts. Primary outcome was women’s reported symptoms of prolapse at 6 months, 1 year and 2 years and clinical evaluation with POPQ at 1 year. Secondary outcomes included condition-specific quality of life measures and adverse effects and complications, assessed by use of the IUGA/ICS complications classification system.
The study results showed no difference in POP symptoms score for each comparison at 1 and 2 years, i.e between standard repair and synthetic mesh groups or standard repair and biological grafts groups [standard 5·4 (SD 5·5) vs mesh 5·5 (SD 5·1), mean difference 0·00, 95% CI –0·70 to 0·71; p=0·99; standard 5·5 (SD 5·6) vs graft 5·6 (SD 5·6), mean difference –0·15, –0·93 to 0·63; p=0·71]. No difference was detected either between groups when prolapse-related quality-of-life scores and symptoms of urinary incontinence, faecal incontinence and dyspareunia were considered. With regard to objective outcomes, there was a trend towards higher objective failure (leading edge of prolapse >0cm beyond the hymen) of the procedure in the permanent mesh and biological grafts groups, however this did not reach statistical significance.
As far as safety was concerned, less than 10 % of all women recruited in this study suffered serious adverse effects during and after prolapse surgery in the first year, with no detectable difference between groups, except for mesh exposure and subsequent treatment for mesh complications. Most complications relating to mesh insertion were small or asymptomatic and required partial removal as day cases. The overall complication rate for women who received mesh according to the allocated treatment or in a different compartment was 12%.
The PROSPECT trial concluded that, in contrast with the 2016 Cochrane review, in the first 2 years after surgery, there is no benefit from the use of transvaginal synthetic mesh or biological graft to reinforce a standard anterior or posterior repair, either in reported prolapse symptoms or anatomical cure. Moreover, >30% of women will have a residual feeling of something coming down and >80% will report at least one prolapse symptom postoperatively, irrespective of the surgical technique employed.
Glazener CM, Breeman S, Elders A, Hemming C, Cooper KG, Freeman RM, Smith AR, Reid F, Hagen S, Montgomery I, Kilonzo M, Boyers D, McDonald A, McPherson G, MacLennan G, Norrie J; PROSPECT study group). Mesh, graft, or standard repair for women having primary transvaginal anterior or posterior compartment prolapse surgery: two parallel-group, multicentre, randomised, controlled trials (PROSPECT). Lancet. 2016 Dec 20. pii: S0140-6736(16)31596-3. doi: 10.1016/S0140-6736(16)31596-3.
Article by Alexandros Derpapas on behalf of the Publication and Communications Committee.