Hello, the response is very simple and factual.
Immediately under the skin lays a network of arteries, veins and nerves.
When the injector goes into that layer with a sharp needle, chances are that he/she ends up inside an artery or vein and accidentally injects the filler there, creating an embolism that has the potential to create a number of complications, from simple to extreme.
The very reason why micro-cannulas were designed was to protect the patient (and the injector too) from those kind of accidents.
Micro annuals have a dull, rounded tip that displaces arteries or veins instead of puncturing them.
Regards, DrC @
Avanti Derma.