The Evaluation of Hyaluronic Acid, With and Without Lidocaine, in the Filling of Nasolabial Folds as Measured by Ultrastructural Changes and Pain Management

March 2013 | Volume 12 | Issue 3 | Original Article | 46 | Copyright © March 2013

Josefina Royo de la Torre MD, Paloma Cornejo MD, Gema Pérez MD, Irene Cruz MD, Estefania Muñoz BSc, Maria J. Isarría MD, and J. Moreno-Moraga MD

Instituto Médico Láser, Servicio de Dermatología, Madrid, Spain

BACKGROUND: Pain management is an important objective in procedures involving dermal fillers composed of hyaluronic acid (HA).
OBJECTIVE: To compare the 1-year clinical results of filling the nasolabial fold with 2 types of filler: large-gel particle HA and large-gel particle HA plus 0.3% lidocaine (HA+L). We compared the level of pain during treatment and 10 minutes after treatment and assessed the safety and efficacy profile, satisfaction, and histological findings (using reflectance confocal microscopy [RCM]).
MATERIALS and METHODS: We performed a comparative, parallel-group, double-blind trial with an external observer (blinded to the type of treatment administered). The filler was applied to the nasolabial fold in 119 patients (HA in 62 patients and HA+L in 57). Patients were followed at months 3, 9, and 12. Pain was evaluated using a visual analog scale. Efficacy and satisfaction were evaluated using the Wrinkle Severity Rating Scale and the Global Aesthetic Improvement Scale. RCM images (n=32) were taken at baseline and at months 3 and 12.
RESULTS: Pain: The severity of pain was decreased in patients treated with HA+L on application (P<.001) and 10 minutes later (P=.008). Efficacy and satisfaction: No significant differences existed between the 2 groups at months 3, 9, and 12. RCM: Skin rejuvenation occurred with a 32% increase in the height of the dermoepidermal junction at month 12 (P<.001), which was similar in both groups. Adverse events: At month 3, the most common adverse events (AEs) were erythema (68%) and hematoma (11%). No AEs were recorded at months 9 or 12.
CONCLUSION: The use of HA+L provides pain relief without affecting efficacy, satisfaction, safety, or the duration of results. RCM showed that the changes in the dermoepidermal junction represented a histological improvement in the skin with similar results in both groups.

J Drugs Dermatol. 2013;12(3):e46-e52


Traditional techniques for structural facial rejuvenation of the lower and middle thirds of the face are based on manipulation of the loose, displaced tissue (surgical lifting) and on the replacement of tissue volume (eg, implants and fillers). On the middle third of the face, fat redistribution contributes to ptosis of the nasolabial fold.1-4 The most direct and simple treatment for correction of this condition involves fillers composed of various materials.4 The first and most commonly used material was bovine collagen, which attenuated facial defects; however, this approach had the drawback in that 75% of the correction had disappeared by month 6.5 Stabilized hyaluronic acid (HA) fillers were introduced in 1998, and have since proven very effective and more durable than previous methods. The first injectable nonanimal stabilized HA (NASHA) filler was approved by the US Food and Drug Administration (FDA) in 2003 in the form of a gel containing 100,000 particles/mL. Today, several products are marketed throughout the world. According to the American Society for Aesthetic Plastic Surgery, these fillers account for almost 80% of all fillers used. In the United States alone, they were used in 2 million infiltrations in 2006.6-19
One of the most common side effects of facial filling is pain; therefore, it is necessary to develop an effective analgesic that does not reduce the efficacy of treatment. Lidocaine is an amide-type local anesthetic that has fewer side effects than other members of its group.20 Its rapid onset, moderate duration, and local anesthetic activity make it the most versatile and widely used anesthetic. A new dermal filler combining lidocaine with HA in a single presentation has proven satisfactory in relieving pain.21
Our objectives were to study the pain relief achieved by incorporating 0.3% lidocaine in the preparation and to determine whether or not this combination affected efficacy, patient satisfaction, and durability of the correction. We used reflectance confocal microscopy (RCM) to analyze the histopathological changes in the superficial dermis and epidermis after infiltration using HA or HA combined with lidocaine.22-26


Study Design

We performed a comparative, parallel-group, double-blind trial with the participation of an external observer. The study sample comprised 119 patients older than 18 years (116 women and 3 men; mean age, 46.6 years) (Table 1). The predominant classification on the Wrinkle Severity Rating Scale (WSRS)5 was grade 2 to 3.