Identification of facial vessels using Doppler ultrasound prior to cosmetic filler injection

In recent years, there has been a continual increase in the number of minimally invasive aesthetic procedures. Even among plastic surgeons, injections with botulinum toxin A and soft-tissue fillers for wrinkle treatment have replaced conventional surgical procedures at the top of the list of the most frequently performed interventions [1]. Given that – unlike botulinum toxin A – said fillers are no prescription drugs but rather medicinal products, they can be purchased relatively easily. Thus, filler treatments are not only performed by physicians but increasingly frequently also by non-medical personnel, such as alternative (non-medical) practitioners or cosmeticians, or even by patients themselves [2, 3]. However, filler injections are not entirely risk free and may be associated with severe adverse effects, especially when done without the proper anatomical knowledge and medical expertise [2, 4–6]. In addition to infections and granulomas, vascular complications are undoubtedly among the more dramatic complications, as they can lead to skin necrosis, scarring and even vision loss [6–9]. Vascular complications are caused either by embolic occlusion due to direct intra-arterial filler injection or by functional arterial obstruction due to the injection of large volumes (of fillers) into the perivascular tissue. Especially critical arteries are those that provide the only – or at least primary – blood supply to certain skin areas. In case of their occlusion, adequate perfusion by collateral vessels is no longer ensured (functional end arteries). Other critical arteries include those from which there are potential anastomoses with the retinal vascular plexus. As a consequence, “risk sites” for filler injection are the areas along the course of the facial/angular artery, the nasal artery and the supratrochlear artery as well as the various temporal artery branches and include the glabella, the under-eye hollows, the nasal bridge and the temples. The vast majority of vascular complications following filler injections have been reported to occur in the aforementioned areas [2, 6–8]. This may be due to the fact that – unlike the depiction in anatomy textbooks – the course of virtually every facial vessel shows great interindividual variability. Consequently, it is not always possible to reliably locate any given facial vessel even if one has appropriate anatomical knowledge. Measures recommended to avoid vascular complications include aspiration and (slow) injection of small Clinical Letter