KISSIMMEE, FLA. – Indocyanine green-augmented diode laser treatment appears promising for the treatment of both port wine stains and telangiectatic leg veins, preliminary data have shown.
This novel treatment involves an off-label use of the water-soluble indocyanine green fluorescent dye commonly used in medical diagnostics and approved by the Food and Drug Administration for determining cardiac output, hepatic function, and liver blood flow, and for ophthalmic angiography. Indocyanine green has a peak spectral absorption of 800 nm.
Port Wine Stains
A randomized, controlled pilot study compared indocyanine green-augmented diode laser (ICG+DL) treatment with standard flashlamp-pumped pulsed dye laser (FPDL) treatment in split-face fashion in 31 patients with port wine stains. After one treatment, two blinded investigators rated ICG+DL treatment as slightly, though not significantly, better than FPDL with respect to clearance rates and cosmetic appearance at 12 weeks’ follow-up (Br. J. Dermatol. 2012[doi:10.1111/j.1365-2133.2012.10950.x]). The patients rated the ICG+DL treatment as significantly superior to FPDL on these measures, Dr. Philipp Babilas reported at the annual meeting of the American Society for Laser Medicine and Surgery.
ICG+DL was applied at 810 nm with a fluence of 20-50 J/cm2, a spot size of 7 mm, a pulse duration of 10-25 milliseconds, and an ICG concentration of 2 mg/kg of body weight; FPDL was applied at 585 nm with a fluence of 6 J/cm2 and a pulse duration of 0.45 milliseconds, he said noting that the treatments were well tolerated.
Complete clearance of port wine stains is rarely achieved, largely because of the resistance of small blood vessels to laser irradiation. Prior studies suggested that the use of ICG with diode laser treatment could overcome this resistance, but in this study, histology revealed that the approach provided photocoagulation only of blood vessels larger than 20 mcm in diameter with collateral damage of surrounding dermal tissue, said Dr. Babilas of University Hospital Regensburg (Germany).
The results were nonetheless intriguing, he said, noting that histology also showed that there was no epidermal damage at 1 week and that complete remodeling of dermal tissue had occurred by 3 months.
Many smaller blood vessels replaced the larger blood vessels, which could be one reason the treatment was not as effective as expected, he said.
The findings, including the patient assessments of outcomes, suggest ICG+DL represents a promising treatment modality for port wine stains – a treatment that may prove even more effective as laser parameters and ICG concentrations undergo further study and optimization. Such studies, including one that is evaluating an increased concentration of indocyanine green, are underway in an effort to enhance results, he added.
The search for improved treatments for port wine stains is important given that available treatments typically provide only partial clearing, that about 20% of cases are resistant to FPDL treatment, and that port wine stains can be associated with significant adverse psychological effects, he said.
Leg Veins
In a separate proof-of-concept study, Dr. Babilas and his colleagues also evaluated ICG+DL for telangiectatic leg veins, which, like port wine stains, are rarely completely cleared.
The treatment was evaluated in 15 women with skin types II or III and telangiectatic leg veins of 0.25-3 mm in diameter. After intravenous administration of ICG, diode laser pulses were applied as a single treatment. The treatment was safe, with no persistent side effects, Dr. Annette Klein, also of University Hospital of Regensburg, reported.
ICG+DL in this study was applied at 808 nm, with a fluence of 50-110 J/cm2 and an ICG concentration of 2 mg/kg of body weight (Lasers Surg. Med. 2012[doi:10.1002/lsm.22022]).
Vessel clearance was dose-dependent, with "good" (40%-50%) vessel clearance in those receiving a radiant exposure of 100-110 J/cm2 and "excellent" (greater than 50%) clearance when double pulses of the diode laser were used, Dr. Klein said, noting that vessel clearance was rated only as "poor" or "moderate" (only up to 25%) with pulsed dye laser, which was used in this study as a reference treatment.
"We conclude that ICG-augmented diode laser therapy is a safe and effective new therapy option for the treatment of spider leg veins, and double pulses improved our results," she said, noting that follow-up studies to identify the optimal ICG concentration and laser parameters are underway.
Neither Dr. Babilas nor Dr. Klein reported any relevant financial disclosures.