Laser leg vein treatment: a brief overview

Effects of long-pulsed 1064-nm Nd:YAG laser on telangiectasias and reticular veins: a human in-vivo histological study

BACKGROUND

Telangiectasias and reticular veins are associated with aesthetic disorders. Sclerotherapy is the gold standard treatment, but long-pulsed 1064-nm Nd:YAG laser (LP1064 laser) is also used. No data on the human histological effects of these lasers are reported. The objective was to test different LP1064 laser parameters and their histological effects on the dermis, collagen, telangiectasias, and reticular veins.

METHODS

This was a single-center, prospective, single-arm, case-control, human study. During surgery (dermolipectomy), the abdominal section of 10 female patients was irradiated with 6 different transdermal LP1064 laser parameters after anesthesia. Ten pieces with areas of varying irradiation were evaluated according to the characteristics of the vessels identified by area. In each piece, two irradiation areas were performed per group, totaling 12 irradiation areas per piece, with 120 regions later analyzed at the end of the ten samples. After removing the surgical product, histological sections were extracted, and the dermis, telangiectasias, and reticular veins were analyzed.

RESULTS

Histological analysis showed that exposition to six different parameters from LP1064 laser led to significant dermal layer separation and collagen alterations. The effects were inconsistent on the loss of endothelial cells, intravascular thrombus formation, and fusion of vascular walls for both telangiectasias and reticular veins. In reticular veins, effects on intravascular thrombus formation and vascular wall fusion were not observed.

CONCLUSIONS

The LP1064 laser in monotherapy with fixed settings did not lead to a consistent vascular lesion to promote immediate occlusion in telangiectasias and reticular veins. This strategy may not work as monotherapy for small vein treatment, but the possible late response to the LP1064 laser cannot be ruled out and require further investigation.

Long-pulsed 1064-nm and 755-nm lasers for C1 leg veins on skin type IV patients: a side-by-side comparison

Long-pulsed 1064-nm (LP1064) and 755-nm (LP755) lasers have been demonstrated as effective treatments for leg veins. However, few studies of these treatments on Asian skin type as well as direct comparison between two methods were reported. The aim of this study was to compare the clinical efficacy and safety of LP1064 with LP755 in the treatment of C1 leg veins on skin type IV patients. Patients with symmetric matched areas C1 leg veins were treated with single session of LP1064 for the right and LP755 for the left. Treated areas of every patient were divided into matrices of 2 × 2 cm squares. Vessels in the highest density squares were subjected to evaluation. Spot sizes were 5 mm fixed. Pulse durations and fluences were according to vessel diameters and endpoints, respectively. The clearances were evaluated at 1 and 3 months post treatment. Side effects were recorded immediately, 10 min, 24 h, and 1 and 3 months after treatment. Twenty-two patients were enrolled with total 96 vessels from 22 selected squares in the right and 106 vessels from 22 selected squares in the left. At 1-month follow-up, the clearances of LP1064 and LP755 were not significantly different (71.87% and 71.69%, respectively; p = 0.99). At 3-month follow-up, the efficacies were constant and no recurrence occurred. Pain levels of both methods were moderate and significantly lower in LP755. These findings suggest that LP1064 and LP755 laser treatments were comparatively effective and safe for C1 leg veins of skin type IV patients.

Short laser pulse-induced irreversible photothermal effects in red blood cells

BACKGROUND AND OBJECTIVES

Photothermal (PT) responses of individual red blood cells (RBC) to short laser pulses may depend upon PT interactions at microscale.

STUDY DESIGN/MATERIALS AND METHODS

A sequence of identical short laser pulses (0.5 and 10 nanoseconds, 532 nm) was applied to individual RBCs, and their PT properties were analyzed at microscale in real time after each single pulse.

RESULTS

PT interactions in RBC were found to be localized to sub-micrometer zones associated with Hb that may be responsible for overheating and evaporation at higher optical energies. At sub-ablative energies, a single short laser pulse induced irreversible changes in the optical properties of RBC that stimulated the transition from a heating-cooling response to ablative evaporation in individual erythrocytes during their exposure to subsequent, but identical pulses.

CONCLUSION

The PT response of RBCs to short laser pulses of specific energy includes localized irreversible modifications of cell structure, resulting in three different effects: thermal non-ablative response, ablative evaporation, and residual thermal response.

Laser therapy for leg veins

Visible veins on the leg are a common cosmetic concern affecting approximately 80% of women in the United States (Engel A, Johnson MI, Haynes SG. Health effects of sunlight exposure in the United States: results from the first national health and nutrition examination survey, 1971-1974. Arch Dermatol 1988;124:72-9). Without a quick and noninvasive treatment available, leg veins present a therapeutic challenge. This challenge has been tackled by the design of lasers with longer pulse durations, and the use of lasers with longer wavelengths and cooling devices. Recent studies show the efficacy of laser treatment beginning to approach that of sclerotherapy, the gold standard. This review outlines the principles guiding laser treatment, the current available options, and a clinically oriented approach to treating leg veins.

The 800-nm diode laser in the treatment of leg veins: assessment at 6 months

BACKGROUND

The efficacy of the 800-nm diode laser system in clearing leg veins was analyzed subjectively and objectively in a variety of leg veins.

METHODS

A total of 10 women (age 25-55 years, skin types II-IV) with a variety of leg vein types were treated with an 800-nm diode laser. A sequence of pulses (5-8 stacked pulses, pulse duration 50 milliseconds, delay 50 milliseconds) was applied on a 3-mm spot (210-336 J/cm2 fluence, depending on vessel size). Treatment on the same vein was performed at intervals of 2 months until complete clearance was achieved (maximum: 3 treatments). The results were assessed at 6 months from the last treatment. Patients evaluated their subjective improvement by means of a questionnaire to elicit the satisfaction index. In an independent objective assessment, the clearance index was based on the pretreatment and posttreatment clinical photography, also analyzed by a computer program.

RESULTS

All patients completed the trial with mild but transient side effects. The patient 6-month assessments for very good, good, fair, poor, and worse were 1, 5, 3, 1, and 0, respectively. For the clinician-assessed clearance index, the numbers for the same grades were 2, 6, 2, 0, and 0, and for the computer assessment they were 1, 6, 2, 1, and 0. No patient scored worse in any assessment. The overall satisfaction index and clinician and computer clearance indexes were 60%, 80%, and 70%, respectively.

LIMITATIONS

No control group could be obtained in this study.

CONCLUSIONS

The 800-nm diode laser as used in the study may well offer an effective treatment method for leg veins that is comparatively pain and side-effect free. Best results were obtained in vessels of 3 to 4 mm in diameter located on the thigh, and in patients with phototype III skin. No correlation was seen between results and patient age.

Mechanistic comparison of blood undergoing laser photocoagulation at 532 and 1,064 nm

BACKGROUND AND OBJECTIVES

We seek to compare and contrast the mechanisms of blood photocoagulation under 532 and 1,064 nm laser irradiation in vitro in order to better understand the in vivo observations. We also seek to validate a finite element model (FEM) developed to study the thermodynamics of coagulation.

STUDY DESIGN/MATERIALS AND METHODS

We study the photocoagulation of whole blood in vitro at 532 and 1,064 nm using time-domain spectroscopic and optical coherence tomography (OCT)-based imaging techniques. We model the coagulation using an FEM program that includes the latent heat of vaporization (LHV) of water, consideration of the pulse shape of the laser, and the bathochromic shift in the hemoglobin absorption spectrum.

RESULTS

We find significant similarities in the spectroscopic, chemical, and structural changes occurring in hemoglobin and in the blood matrix during photocoagulation despite the very large difference in the absorption coefficients. The more uniform temperature profile developed by the deeper-penetrating 1,064 nm laser allows us to resolve the structural phase transition in the red blood cells (going from biconcave disc to spherocyte) and the chemical transition creating met-hemoglobin. We find that the RBC morphology transition happens first, and that the met-Hb transition happens at a much higher temperature ( > 90 degrees C) than is found in slow bath heating. The FEM analysis with the LHV constraint and bathochromic shift predicts accurately the imaging results in both cases, and can be used to show that at 1,064 nm there is the potential for a runaway increase in absorption during the laser pulse.

CONCLUSIONS

Photothermally mediated processes dominate the in vitro coagulation dynamics in both regimes despite the difference in absorption coefficients. There is a significant risk under 1,064 nm irradiation of vascular lesions in vivo that the dynamic optical properties of blood will cause runaway absorption and heating. This may in turn explain some recent results at this wavelength where full-thickness burns resulted from laser treatment.