Pelvic prolapse surgery using mesh or graft not more effective than standard technique, study finds

Two controversial methods of surgical repair of prolapse in women have been found to be no more effective than the existing standard repair technique, up to two years after surgery.

Widespread concerns about the use of mesh and graft in prolapse surgery have been raised in public, with some patients reporting serious complications. Consequently, the use of mesh was banned in Scotland (with the exception of clinical trials) in June 2014 until further evidence was found regarding its suitability.

Researchers at the University of Aberdeen led a national collaborative research project comparing the outcome of pelvic organ prolapse repairs reinforced by either non-absorbable synthetic mesh or biological grafts against standard native tissue repairs in 1348 women.

They found the mesh, inserted through the vagina, resulted in a number of complications but did not offer any clear benefits, concluding that its use for these procedures could be considered an “unnecessary risk”, until further research was conducted.

The study was the largest randomised trial of the use of mesh or graft in transvaginal prolapse surgery and the results have been published today in the world’s leading medical journal The Lancet.

Pelvic organ prolapse occurs when one or more of the pelvic organs bulges into the vagina, which can affect around 40% of women. It is associated with childbirth and increasing age. Symptoms can include vaginal discomfort and urinary, bowel and sexual problems.

Up to one in 20 women with prolapse symptoms will need surgery to correct it and of those women, around three in ten will eventually need more prolapse surgery. On average, this happens about 12 years after the first operation.

Previous studies suggested non-absorbable mesh was more successful than standard native tissue to repair prolapse but there was not enough reliable evidence about other symptoms or quality of life. Studies comparing biological grafts with standard repair were inconclusive. There was not enough information about adverse effects to enable women and their doctors to judge which operation was safest.

The PROSPECT study was funded by an NHS research grant from the National Institute for Health Research (NIHR) Health Technology Assessment programme in 2007 to find that necessary reliable evidence. It consisted of two parallel randomised controlled trials, involving 1348 women having surgery for pelvic organ prolapse. The study was carried out in women attending 35 different hospitals across the UK, in conjunction with over 100 doctors and researchers between January 2010 and August 2013.

Participating women used a self-assessment questionnaire (Pelvic Organ Prolapse Symptom Score or POP-SS) to record their prolapse symptoms. Other symptoms and side-effects were also measured.

The Lancet paper published today reports the results for women having their first vaginal prolapse operation.

The results revealed that there was no significant clinical or statistical difference between those who had the mesh or graft surgery, compared to the standard native tissue repair, at one or two years after the surgery.

The study also revealed that more than one in ten women who had synthetic (non-absorbable) mesh had a mesh complication – though most were asymptomatic. However, there were no similar risks with biological grafts.

Researchers stressed that this study has only recorded the outcomes during the first two years after the operation. Because half the prolapse surgeries that fail, do so within 12 years, they are following up the same women at regular intervals up to at least 12 years. This is vital to determine whether mesh or graft repairs might prove more durable in the longer term.

The researchers concluded that using mesh, inserted through the vagina, could pose an unnecessary risk because some women who had been treated with mesh required extra surgical procedures in theatre for mesh complications. They suggested that in the future, synthetic mesh should only be used in clinical trials aimed at identifying better materials, improving insertion techniques or for use in a defined category of high risk women.

Professor Cathryn Glazener, who led the study said:

This study showed in the first two years after surgery, there was no benefit to women having their first prolapse repair from the use of transvaginal synthetic mesh or biological graft to reinforce a standard anterior or posterior repair, either in terms of prolapse symptoms or in short term anatomical cure.

This contrasts with the conclusions of the most recent Cochrane review which reported that fewer women were aware of prolapse symptoms with synthetic mesh and fewer had anatomical recurrence, compared with women who did not have mesh.

Our findings provide robust evidence on which to base counselling for surgical decision making. However, these findings are confined to the first two years after surgery and only to women having their first repair. Longer-term follow up is required to truly assess any potential benefits or adverse effects of transvaginal mesh or graft.

Because mesh did result in a number of complications, with no clear benefits, we conclude its use for these procedures could be considered an unnecessary risk. Therefore we consider that mesh should only be used in the future in high quality clinical trials aimed at improving the results of vaginal prolapse surgery.

The study was carried out in collaboration with Glasgow Caledonian University, NHS Grampian, Plymouth Hospitals NHS Trust, Central Manchester University Hospitals and NHS Foundation Trust.