Recent advancements in facial ultrasound imaging have provided unprecedented insights into the “live” anatomy during filler injection procedures. This newfound clarity has led to the identification of two remarkable phenomena that could significantly impact the way aesthetic surgeons approach filler treatments.
Retrograde Flow: A Surprising Discovery
One of the most intriguing discoveries is the phenomenon of “retrograde flow.” When injecting filler material, it’s expected to spread through regions of least resistance, forming a bolus at the desired location. However, ultrasound imaging has revealed that the filler can sometimes flow backwards along the shaft of the needle or cannula, creating a tunnel effect rather than a localized deposit. This is particularly evident with hyaluronic acid fillers.
While the exact frequency and factors influencing retrograde flow are still under investigation, it’s believed to be less common with needles compared to cannulas due to their smaller diameter. The choice between needles and cannulas may therefore play a role in mitigating or even harnessing this phenomenon. For instance, in areas where a sausage-shaped volume of filler is desired, a large-circumference cannula could be advantageous.
Accidental Placement Above the SMAS: A Potential Pitfall
Another important phenomenon observed is the unintentional placement of filler material above the superficial musculoaponeurotic system (SMAS). When using a cannula to inject filler into deeper layers, it’s essential to pierce through the SMAS to reach the desired target. However, if the SMAS is thick or the cannula is not inserted deep enough, the filler can become trapped between the fascial layers of the SMAS, leading to less-than-ideal results.
To address this issue, surgeons may need to employ techniques such as using a thicker needle to pierce both the skin and SMAS simultaneously or pushing the skin and subcutaneous tissue together before inserting the needle. Additionally, opting for needles instead of cannulas could help prevent accidental SMAS placement.
Key Takeaways
By understanding retrograde flow and accidental SMAS placement, aesthetic practitioners can make more informed decisions regarding needle or cannula selection, injection techniques, and patient expectations. Here’s a recap:
- Facial ultrasound imaging has provided valuable insights into filler injection phenomena.
- Retrograde flow occurs when filler material flows backwards along the needle or cannula.
- Accidental SMAS placement can result from insufficient cannula penetration.
- Understanding these phenomena can help aesthetic surgeons optimize treatment outcomes and minimize complications.
As research continues to shed light on these phenomena, aesthetic professionals can refine their techniques and provide even safer and more effective filler treatments for their patients. By staying informed about the latest advancements in the field, practitioners can ensure they are at the forefront of aesthetic medicine.
Additional Considerations
While these two phenomena are particularly noteworthy, there are other factors that can influence filler injection outcomes. The type of filler material used, the injection technique employed, and the patient’s anatomy can all play a role in determining the success and safety of a procedure.
For instance, certain types of fillers may be more prone to retrograde flow or accidental SMAS placement. Additionally, the angle and depth of injection can affect the distribution of filler material and the likelihood of complications. It’s essential for aesthetic surgeons to consider these factors in conjunction with the newly discovered phenomena to achieve optimal results.
By staying informed about the latest research and best practices in aesthetic surgery, practitioners can continue to improve their skills and provide exceptional care to their patients.
SOURCE: Aesthetic Surgery Journal
