concludes that transvaginal mesh products used to help treat incontinence and organ prolapse were approved on the basis of weak evidence and 鈥渕ay have exposed women to avoidable harms.鈥�
Researchers writing in the BMJ medical journal say regulatory 鈥渇ailings鈥� enabled the devices to be brought to market without good evidence to show the products were safe.
Vaginal mesh has been used for close to 20 years to treat urinary incontinence as well as pelvic organ prolapse (POP), a condition in which the muscles that hold pelvic organs become weak from childbirth or age.
While thousands of women have had no problems with the mesh, thousands of others have complained about serious complications, including painful and seemingly never-ending bacterial infections.
More than 100,000 lawsuits have been launched over the meshes. 麻豆影视 has spoken with many of the women behind the Canadian lawsuits, including Chrissy Brajcic, of Windsor, Ont., who suffered numerous infections even after having her mesh implant removed.
Brajcic died last week after being treated for sepsis. A coroner has yet to determine whether her mesh implant played a role in her death.
In the new BMJ paper, a research team from Oxford University's Centre for Evidence Based Medicine looked at how 61 mesh devices received approval from the Food and Drug Administration.
They found that in the U.S., the FDA initially considered transvaginal meshes as equivalent to mesh products already on the market for other uses. That allowed them to be approved and classified as 鈥淐lass II devices (lower risk).鈥�
The British researchers say they could not find evidence that manufacturers submitted data from clinical trials that tested the meshes specifically for use in POP or incontinence.
鈥淐linical trials evidence did not form part of the approval process, and when trials were conducted, they occurred a considerable time later (up to 14 years),鈥� the authors write.
The authors conclude that there was not enough evidence to approve the mesh products and 鈥渨hen evidence has been forthcoming, it has often emerged too late to inform clinical practice.鈥�
Dr. Vladimir Iakovlev at Toronto鈥檚 St. Michael鈥檚 Hospital, who has researched some of the complications of transvaginal mesh, notes that the regulatory approval process in Canada is typically based on FDA analysis.
鈥淲e use the same meshes (in Canada) and the complications with patients are exactly the same,鈥� he told 麻豆影视.
The researchers who traced the FDA approvals of the 61 mesh products found the approvals were often based on 鈥渆quivalence鈥� to two existing products approved in 1985 and 1996.
One of those products was called the Protegen sling, which was made from polyester. But newer transvaginal mesh is typically made from polypropylene 鈥� a significant difference 鈥渢hat should have negated the use of equivalence," the authors say.
Polypropylene has a tendency to shrink significantly after implantation, they write, which can lead to serious complications, such as tissue erosion and organ perforation.
Removing the mesh once problems arise is not simple, the authors note, since the meshes are designed to integrate into the nerves and blood supply of nearby tissues.
Iakovlev says there need to be a better regulatory approval system for new medical devices such as transvaginal mesh.
鈥淲e have to develop a better approach for how to assess their safety鈥� because these devices are implanted for life; they鈥檙e permanent,鈥� he said.
The report authors say they would like to see national registries of 鈥渋nvasive devices,鈥� that would detail the evidence behind the devices and keep track of any complications.
Iakovlev would like to see the same and says similar registries are needed for other devices such as hip replacements, implanted defibrillators.
鈥淭his study shows we need to monitor these devices. We need to slowly introduce them to the market. And that can only be achieved with nationwide registries.鈥�
With a report from CTV medical specialist Avis Favaro and producer Elizabeth St. Philip
