One of the quirky consequences of the way our medical environment has developed is the fact that while pharmaceuticals are regulated to the nth degree, surgical procedures and the stuff surgeons stick into our bodies (e.g. stents and prostheses etc) are hardly regulated at all.
In 2007 the Health Products Act was passed, which to some extent rationalized the regulation of stents and prostheses (collectively called 'medical devices'), but regulation of these things remain, by comparison to pharmaceuticals, barely regulated. The regulations for these medical devices are to a large extent limited to registration, manufacture, supply and advertising. There is minimal expectation of any proof of safety and efficacy.
In otherwords, cardiologists and surgeons are pretty free to stick in any device into our bodies so long as these devices are registered at the HSA. The patient consumer really has no way to determine if any of the very many brands of devices being used have been proven for the disease, or have any reliability with respect to their longevity in the body, or their safety over long periods of time.
One would expect that hospital and clinics performing these procedures (and perhaps the MOH as well) should be collecting data on the outcomes of these procedures where devices are implanted into the body, but this is almost never done. So the patient consumer is really in a very vulnerable position.
To compound the problem, these medical devices are very often used in off-label indications.
5 years ago