Women have been exposed to unnecessary harm due to poor regulation for vaginal mesh products, medical experts have warned.



The team, from the University of Oxford, have called for clinical trials to be made mandatory for invasive medical devices and for a registry to be created in response to the vaginal mesh scandal.

Prof Carl Heneghan at Oxford’s Centre for Evidence-Based Medicine, who led the work, said: “Many women have been subjected to great harm because regulatory loopholes allowed mesh devices to be made available in large numbers with no evidence in humans. It is now clear that regulation is not fit for purpose for the riskiest of devices, those that are implanted in the body.

Q&A What is a vaginal mesh implant? Show The implants have been widely used as a simple, less invasive alternative to traditional surgical approaches for treating urinary incontinence and prolapse, conditions that can commonly occur after childbirth. For the majority of women the operation is successful.

However, concerns are mounting over the severe complications suffered by large numbers of patients, including chronic pain, mesh cutting through tissue into the vagina and being left unable to walk or have sex. Johnson & Johnson, whose subsidiary Ethicon produces one of the most widely used mesh products, is fighting a major class action in Australia. The Guardian revealed in August that thousands of women have undergone surgery to have vaginal mesh implants removed during the past decade, suggesting that about one in 15 women fitted with the most common type of mesh support later require surgery to have it extracted due to complications.

“We now know that women who received mesh implants have been part of a global experiment that in many cases has gone badly wrong.

“It is unacceptable for a health professional to make judgments on what they ‘feel is a good thing to do’. What matters is what does high-quality evidence from randomised trials show, and that is over the long-term – five years at least.”



The paper, published in the journal BMJ Open, examined marketing clearance of vaginal mesh devices through the US Food and Drug Administration.



In the US, transvaginal meshes were initially class II devices, allowing them to be marketed on the basis of equivalence to existing devices. The team found 61 devices that were approved on equivalence claims and said there was no clinical-trial evidence for these devices at the time of approval.

However, many of the devices were significantly different from the original device that had gained approval, with different materials, design and method of surgical implantation. Randomised clinical trials were found to be published an average of five years after device approval, the study found.

“Transvaginal mesh products for pelvic organ prolapse have been approved on the basis of weak evidence over the last 20 years,” the authors said.

“When evidence has been forthcoming, it has often emerged too late to inform clinical practice,” they added. “The current systems for ensuring patient safety are inadequate for medical devices.”



Concerns have been growing about the serious complications suffered by some women who have had mesh implants and about the introduction of dozens of different devices, most of which have never been assessed in a clinical trial.

In September, the Guardian reported that a vaginal mesh implant made by Johnson & Johnson had been launched without a clinical trial, and then marketed for five years after the company had learned that it had a higher failure rate than its two earlier devices.



The latest paper calls for clinical trials to be made mandatory in order for any implantable device to be marketed. It also calls for a publicly accessible registry of such devices with details of marketing status and linked evidence to the product.

Such a registry would also include details of which devices are given to which patient so if any “shortcomings” are identified then patients can be tracked down.

Later this month, England’s National Institute for Health and Care Excellence will publish guidance that is expected to recommend that vaginal mesh should no longer be used for prolapse, outside of a research context.



Stephen Evans, professor of pharmacoepidemiology at the London School of Hygiene & Tropical Medicine, said: “The absence of good trials for these vaginal meshes, which has been investigated carefully by these authors, shows the problem clearly. Changes in regulation are often driven by lessons learned from very bad situations, such as thalidomide, and the need for change in regard to devices is clear.”

Cathryn Glazener, emeritus professor at the University of Aberdeen, agreed that tighter regulation was needed to bring device regulation into line with the rigorous scrutiny in place for new drugs.

However, she said a distinction was needed between the use of mesh to treat incontinence, where she said evidence suggested mesh was as effective and safer in the short term than traditional non-mesh operations, and surgery for prolapse, which she said posed greater risks.