Rejuvenation of the dorsal hand by injectable poly-D, L-lactic acid: A pilot study

The dorsal hands are subject to photodamage and may present with increased wrinkling and soft tissue atrophy during the aging process. In recent years, dorsal hand rejuvenation has gained popularity in cosmetic dermatology. Several treatment modalities, including laser resurfacing, fat grafting, and dermal fillers, have been widely used.¹ Hyaluronic acid-based dermal fillers have been most commonly utilized for dorsal hand rejuvenation in the literature; however, some studies have used collagen stimulators, such as poly L-lactic acid (PLLA) and calcium hydroxylapatite (CaHA).¹ Injectable poly-D, L-lactic acid (PDLLA), another collagen-stimulating dermal filler, is commonly used for facial contouring and volumization.² However, its use in dorsal hand rejuvenation has not been reported. Thus, this pilot study aimed to evaluate the efficacy of injectable PDLLA in reducing the visibility of veins and tendons and diminishing wrinkling on the dorsal hand. Besides, the safety profile of PDLLA was also analysed.

The inclusion criteria for this study were healthy adult participants who wished to improve their dorsal hand appearance. Five participants were included in the study. Injectable PDLLA (AestheFill; REGEN) was used for dorsal hand rejuvenation. A total of 6 mL of sterile water was used for the reconstitution of a vial of injectable PDLLA, and 1 mL of 2% lidocaine was added to decrease the discomfort associated with injection. Each side of the dorsal hand was injected with 1 vial of PDLLA. During injection, the patient was placed supine on an operating table. A 23G cannula was used for PDLLA injection, and two injection entry points were chosen, including the interdigital space between the index and middle fingers and the space between the fourth and little fingers (Figure 1). PDLLA was injected just beneath the dermis layer and retrograde injection with distal-proximal fanning and cross-hatched techniques were used to ensure an even injection. After PDLLA injection, the area was gently massaged for 5–10 s. Ice packing after injection is suggested, for 10 min each time, several times a day within the first 3 days.

After injection, the veins and tendons on the dorsal hands became less evident, along with an improvement in wrinkling (Figure 2). The improvement in appearance was maintained up to 1-year post-injection, with a gradual decrease in efficacy afterward. Patient report outcomes, including attractiveness, a more youthful appearance, decreased visibility of veins and tendons, and satisfaction with the treatment results, were collected. The results showed that all participants had high level of satisfaction. Two participants experienced localized erythema, pain, and edema after the injection, which were mild and subsided gradually within 1 week. None of the patients experienced major complications, including infection, hematoma, allergy, or vascular occlusion.

Collagen stimulating agents, such as CaHA, PLLA, and PDLLA, are capable of generating subclinical inflammation, stimulating fibroblasts, inducing neocollagenesis, and thus producing a more durable cosmetic improvement compared to hyaluronic acid.³ Currently, CaHA (Radiesse, Merz Aesthetics) is the only FDA-approved collagen stimulator for dorsal hand augmentation.¹ PLLA has also achieved highly satisfactory cosmetic outcomes with mild post-injection discomfort in some reports, but required multiple sessions.^{1, 4, 5} In our pilot study, we found that a single subdermal PDLLA injection achieved excellent cosmetic outcomes and patient satisfaction lasting up to 1 year. The number of injection sessions needed for dorsal hand rejuvenation is still undetermined, but it may be reasonable to consider 2–3 sessions of PDLLA injection with 4–6 weeks apart, following the protocol for facial rejuvenation. Further studies with larger sample sizes, longer follow-up periods and different injection protocols are needed to determine the long-term safety, efficacy, and durability of PDLLA for dorsal hand rejuvenation.

This study was supported by the grants from the Ministry of Science and Technology, R.O.C. (MOST 110-2811-B-A49A-016), Taipei Veterans General Hospital, Taiwan (VN109-04), and the kind financial support by Dr. Morris Chang and Ms. Sophie Chang. The funding sources had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.

Dr. Lin J-Y and Dr. Lin C-Y are medical consultants of Jiangsu Wuzhong Aesthetic Biotech., and medical directors of REGEN Biotech.

This study was approved by the Institutional Review Board of Taipei Veterans General Hospital (2020–08-005B).

A written informed consent was obtained from the patient.