Evaluation of Device-Based Cutaneous Channels Using Optical Coherence Tomography: Impact for Topical Drug Delivery

Use of Optical Coherence Tomography to Assess Properties of Cutaneous Defects Following Radiofrequency Microneedling and Laser Treatment

OBJECTIVES

To characterize the properties of cutaneous defects created by energy-based devices using optical coherence tomography.

MATERIALS AND METHODS

Radiofrequency (RF) microneedling and non-ablative fractional laser (NAFL) treatment were performed in vivo with various parameters. Following treatment, optical coherence tomography (OCT) was used to image and measure cutaneous defects at multiple time points over a 24 h period.

RESULTS

Channel-like cutaneous defects were visible with OCT following bipolar RF microneedling and NAFL treatment. Using a double pulse technique with RF microneedling yielded a greater number of defects visible with OCT, as well as defects that were deeper and more durable over time. Following treatment with 1927 nm thulium fiber laser, the average diameter of the defects was greater when the energy level was 20 mJ as compared to 10 mJ (0.33 mm vs. 0.27 mm, p < 0.01).

CONCLUSIONS

Cutaneous defects were observed following both RF microneedling and NAFL treatment. Properties of the cutaneous defects varied based on device, treatment setting, and technique, which may be useful in guiding further study of device-assisted drug delivery.

Clinical and Optical Coherence Tomography Correlation of Vascular Conditions Treated With a Novel, Variable-Sequenced, Long-Pulsed, 532 and 1,064 nm Laser With Cryogen Spray Cooling

BACKGROUND

Patients frequently seek laser treatment for vascular conditions. More recently, a novel 532 and 1,064 nm laser was developed to offer greater flexibility.

OBJECTIVE

A prospective clinical trial evaluated the safety and efficacy of a novel, variable-sequenced, long-pulsed, 532 and 1,064 nm laser with cryogen spray cooling (DermaV, Lutronic, South Korea).

MATERIALS AND METHODS

Subjects with vascular conditions were enrolled for laser treatments. Clinical evaluations and optical coherence tomography (OCT) imaging were performed.

RESULTS

Thirteen subjects were enrolled. The mean age was 51.3 years, and 92.3% were women. Fitzpatrick skin types I-IV were included. Treatment indications included broken blood vessels, rosacea, port-wine birthmark, and spider angioma. For physician investigator grading, all subjects were graded as improved at both 30-day and 90-day follow-up. Blinded photographic review by 3 independent, blinded physicians had a mean of 89.7% of cases selected correctly with at least 2 of 3 in agreement for 100.0% of cases. Optical coherence tomography imaging showed significant reductions in vessel density ( p = .018) and diameter ( p = .003) of the superficial vascular plexus. No serious adverse events occurred.

CONCLUSION

A novel, variable-sequenced, long-pulsed, 532 and 1,064 nm laser with cryogen spray cooling can safely and effectively improve vascular conditions and lesions as determined by both clinical and OCT evaluation.

Laser-Assisted and Device-Assisted Filler Delivery: A Histologic Evaluation

BACKGROUND

Lasers and devices are used to enhance transcutaneous delivery of fillers. However, little has been published on the histologic findings of this form of laser/device-assisted delivery to determine the optimal devices and fillers.

OBJECTIVE

To objectively evaluate the histological effects of laser-assisted and device-assisted filler delivery.

METHODS

Ex vivo human abdominoplasty skin samples were treated with fractional CO 2 laser (ECO 2 , 120 μm tip, 120 mJ), fractional radiofrequency microneedling (FRMN, Genius, 1.5 mm, 20 mJ/pin), and microneedling (2.0 mm). Immediately after poly- l -lactic acid (PLLA), hyaluronic acid gel, calcium hydroxylapatite, and black tissue marking dye were topically applied. After treatment, biopsies were collected for histologic evaluation.

RESULTS

Histology revealed that PLLA and black dye were found in greatest abundance, hyaluronic acid was found to a lesser extent, and calcium hydroxylapatite was least found within channels created by fractional CO 2 laser. Microneedling was effective only at delivering black dye, whereas FRMN failed to show significant channel formation or delivery of the studied products.

CONCLUSION

Among the devices and fillers studied, fractional CO 2 laser and PLLA proved to be the most effective combination for laser/device-assisted filler delivery. Neither microneedling nor FRMN was effective as devices to enhance filler delivery.

Prospective Evaluation of the Safety and Efficacy of Thermomechanical Fractional Injury for Perioral Rhytides

BACKGROUND

Perioral rhytides can be treated with laser and energy-based devices. More recently, a novel fractional thermomechanical skin rejuvenation system was developed to cause controlled thermal injury through direct heat transfer.

OBJECTIVE

A prospective clinical trial evaluated the safety and efficacy of a thermomechanical fractional injury device (Tixel 2, Novoxel, Netanya, Israel) for perioral rhytides.

MATERIALS AND METHODS

Subjects with moderate-to-severe perioral rhytides were enrolled and underwent 4 monthly treatments.

RESULTS

Twenty-three subjects were enrolled and completed all study visits. Mean age was 62.5 years, and 100.0% were women. Fitzpatrick Skin Types I-IV were included. For Fitzpatrick Wrinkle Classification System (FWCS), mean baseline score was 6.9. Per investigator, there was a mean 1.9-grade improvement in FWCS at 3-month follow-up ( p < .0001). At 3-month follow-up, 8.7% (n = 2) of subjects had a 3-grade improvement, 69.6% (n = 16) had a 2-grade improvement, and 21.7% (n = 5) had a 1-grade improvement. For physician Global Aesthetics Improvement Scale at 3-month follow-up, 69.6% (n = 16) had 76% to 100% improvement, 13.0% (n = 3) had 51% to 75% improvement, and 17.4% (n = 4) had 26% to 50% improvement. There were no severe adverse events, and subjects experienced minimal pain.

CONCLUSION

A novel device using thermomechanical fractional injury was demonstrated to be safe and effective in the treatment of perioral rhytides.

Enhancing Skin Uptake of Topical Antioxidants With 1,440-nm Nonablative Fractional Diode Laser Pretreatment

BACKGROUND

Energy-based devices, such as nonablative lasers, are a promising method to enhance the delivery and absorption of topically applied molecules.

OBJECTIVE

To characterize ex vivo uptake of common antioxidant topicals after pretreatment with a nonablative laser wavelength.

MATERIALS AND METHODS

Using donor human skin tissue, uptake of 3 topical antioxidants was analyzed (C E Ferulic with 15% l-ascorbic acid [15% vitamin C serum], Phloretin CF with ferulic acid [10% vitamin C serum], and Phyto+ [botanical serum]; SkinCeuticals, Dallas, TX; 2010 formulations) after pretreatment with a 1,440-nm nonablative fractional diode laser.

RESULTS

Pretreatment with the 1,440-nm laser enhanced uptake of 15% and 10% vitamin C serums by approximately 10 and 21 times, respectively, compared to controls. Laser pretreatment also enhanced uptake of botanical serum by approximately 6 times relative to controls. Permeation of vitamin C and botanical serums was also enhanced through laser pretreatment.

CONCLUSION

Nonablative laser pretreatment increased uptake and permeation of topical antioxidants. Optimizing treatment requires consideration of the device and treatment parameters as well as the properties of the topical formulation.

Evidence-Based Clinical Practice Guidelines for Laser-Assisted Drug Delivery

Importance

Laser-assisted drug delivery (LADD) is used for various medical and cosmetic applications. However, there is insufficient evidence-based guidance to assist clinicians performing LADD.

Objective

To develop recommendations for the safe and effective use of LADD.

Evidence Review

A systematic literature review of Cochrane Central Register of Controlled Trials, Embase, and MEDLINE was conducted in December 2019 to identify publications reporting research on LADD. A multidisciplinary panel was convened to draft recommendations informed by the systematic review; they were refined through 2 rounds of Delphi survey, 2 consensus meetings, and iterative review by all panelists until unanimous consensus was achieved.

Findings

Of the 48 published studies of ablative fractional LADD that met inclusion criteria, 4 were cosmetic studies; 21, oncologic; and 23, medical (not cosmetic/oncologic), and 6 publications of nonablative fractional LADD were included at the request of the expert panel, producing a total of 54 studies. Thirty-four studies (63.0%) were deemed to have low risk of bias, 17 studies (31.5%) had moderate risk, and 3 (5.5%) had serious risk. The key findings that informed the guidelines developed by the expert panel were as follows: LADD is safe in adults and adolescents (≥12 years) with all Fitzpatrick skin types and in patients with immunosuppression; it is an effective treatment for actinic keratosis, cutaneous squamous cell carcinoma in situ, actinic cheilitis, hypertrophic scars, and keloids; it is useful for epidermal and dermal analgesia; drug delivery may be increased through the application of heat, pressure, or occlusion, or by using an aqueous drug solution; laser settings should be selected to ensure that channel diameter is greater than the delivered molecule; antibiotic prophylaxis is not recommended, except with impaired wound healing; antiviral prophylaxis is recommended when treating the face and genitalia; and antifungal prophylaxis is not recommended. The guideline's 15 recommendations address 5 areas of LADD use: (I) indications and contraindications; (II) parameters to report; (III) optimization of drug delivery; (IV) safety considerations; and (V) prophylaxis for bacterial, viral, and fungal infections.

Conclusions and Relevance

This systematic review and Delphi consensus approach culminated in an evidence-based clinical practice guideline for safe and effective use of LADD in a variety of applications. Future research will further improve our understanding of this novel treatment technique.