Evolution in technique: use of hyalurostructure for lips rejuvenation as an alternative to needle injection without troncular anesthesia

Microanatomical Location of Hyaluronic Acid Gel Following Injection of the Upper Lip Vermillion Border: Comparison of Needle and Microcannula Injection Technique

PURPOSE

To compare needle and microcannula injection techniques in regards to the microanatomical location of hyaluronic acid (HA) gel injected in the upper lip vermillion border of cadaver specimens.

METHODS

The upper lip vermillion border was injected transcutaneously with HA gel in 8 fresh hemifaces of 4 female human cadavers. Each hemiface was injected by a single experienced injector, the right side using a 27-gauge microcannula and the left side using a 30-gauge needle. A 2-cm region of each lip was excised lateral to a point 1-cm lateral to the philtrum. Specimens were fixed in 95% alcohol, embedded in paraffin, and stained with hematoxylin-eosin for histologic examination.

RESULTS

Most HA injected with either a needle or a microcannula was located within the orbicularis oris muscle, and the remaining HA resided within the subcutaneous fat. In 3/4 right (microcannula) hemifaces, 100% of the HA was located within the muscle. Only 2/4 left (needle) hemifaces had at least 95% of the HA located within the muscle. Overall, in right (microcannula) hemifaces, 93% of the filler was located within the muscle, and in left (needle) hemifaces, 79% of the filler was located within the muscle (p =0.14).

CONCLUSIONS

Most HA filler injected into the vermillion border after either microcannula or needle injection resides within the orbicularis oris muscle rather than in a subcutaneous/submucosal location. Injection with a microcannula shows a trend for more uniform intramuscular location compared with needle injection.

Local Anesthetics: What's New in Minimal Pain Injection and Best Evidence in Pain Control

SUMMARY

Local anesthesia in plastic surgery is undergoing a revolution. In the last 10 years, significant improvements in technique have permitted surgeons to do more and more under pure local anesthesia to increase patient safety and convenience while maintaining total patient comfort during the injection of the local anesthesia and while the procedure is accomplished. Many procedures which used to require sedation are now being performed without it. This article explores some of the new advances in local anesthesia such as painless blunt-tipped cannula local anesthetic infiltration, decreased pain with sharp needle tip injection, and long-lasting local anesthetics with delayed release from liposomal encapsulation. This article also examines the best evidence of the last 10 years of advances of pain control with local anesthesia.