Much has been written about selection of filling agents and anatomic considerations for soft-tissue augmentation. An increased understanding of the volumetric changes that occur with aging and their effect on our perception of beauty has changed the way we use fillers over the last decade. Rather than filling individual wrinkles, modern soft-tissue augmentation focuses on replenishing lost fat pads, providing increased structural support and volume, and constructing facial contours. Injections may be done by bolus to lift or by fanning along vectors. In recent years, the availability of new tools has introduced still more possibilities for variation in the injection procedure. Although manufacturers may claim improved cosmetic results and fewer complications, is it the product being injected, the tool used to inject, the injection technique, the injector or a combination that is responsible? Herein, we describe injection techniques with and without the use of blunt-tipped microcannulas for facial contouring, and we outline when and where their use can provide a less traumatic, reliable, and versatile technical option for the treatment of facial aging.
Blunt-tipped microcannulas are sterile, disposable (single use) surgical steel injection tips available in a range of gauges and lengths (Fig. 37-1). They may be used in places or situations in which there is a significant risk of the cutting bevels of the hypodermic needle causing tissue trauma and vessel injury with resultant complications. Most short-term adverse effects, such as pain, erythema, edema, and ecchymosis, are considered to be expected injection-related complications and are more from the injection technique rather than the filler itself.1,2 Although there are reports of serious complications such as skin necrosis, blindness, or stroke, complications of soft-tissue filling generally can be avoided with proper technique and patient and material selection.3–5
Microcannula examples. There are many types of microcannulas, but all have blunt ends and distal port sites in common (see insets). This company (DermaSculpt, CosmoFrance, Inc.) makes hubs of various colors to correlate with the microcannula gauge. Various lengths are available, but the most commonly used in dermatology range from 1 to 2.75 in.
Blunt-tipped cannulas have a long-standing history of use in the injection of autologous fat (fat transfer) for volume restoration and have only become popular for dermal fillers over the past few years following their introduction in Europe.6,7 The large size and flexibility of these cannulas makes them suitable for use with dermal fillers in the subcutaneous and supraperiosteal planes, although smaller sizes (larger gauges) are available and may be useful for intradermal injections, which require greater precision in their placement.8,9 The proposed benefits, as compared to sharp needle injection, include the reduction in postinjection bleeding and ecchymosis (atraumatic injection), a decrease in the number of injection entry points, decreased risk of inadvertent intravascular injection, and less patient discomfort ...