Optimal parameters for the treatment of leg veins using Nd:YAG lasers at 1064 nm

Long-pulsed 1064nm Nd:YAG laser in the treatment of leg veins: Systematic review

OBJECTIVE

Long-pulsed 1064 nm Nd:YAG laser can damage vessels with higher diameters and penetrate to a deeper level than other laser therapies. We aim to analyze outcomes of the treatment of leg veins with long-pulsed 1064 nm Nd:YAG laser regarding intervention protocol, technical success, clinical success, and side effects.

METHODS

A research of the published literature was conducted, using PubMed and Embase databases, in April 2022. The key words used were telangiectasia, reticular veins, neodymium YAG laser, clearance, satisfaction, and treatment. PRISMA guidelines were followed.

RESULTS

We included twenty-six articles, twenty-three prospective and three retrospective studies, with a total of 1991 patients. The articles were organized in different sections according to the control group. The four outcomes were analyzed in each section. These studies showed that the long-pulsed 1064 nm Nd:YAG laser is a safe and very good option for the treatment of leg veins measuring up to 3 mm in diameter. Studies comparing long-pulsed 1064 nm Nd:YAG laser therapy and sclerotherapy showed similar clearance rates with no significant differences. However, sclerotherapy seemed to be less painful and to have faster clinical improvements. In two articles, Nd:YAG laser had better outcomes in the treatment of smaller vessels with less than 1 mm in diameter, than sclerotherapy alone. Treatment with polidocanol microfoam and Nd:YAG laser had better clearance rates than Nd:YAG laser alone in three studies. In the comparison of 1064 nm Nd:YAG laser therapy with other lasers and light sources, the studies had contradictory results.

CONCLUSION

Long-pulsed 1064 nm Nd:YAG laser is a valid therapeutic option for leg telangiectasia and reticular veins with great aesthetic outcomes and minor side effects. Nd:YAG laser therapy could be combined with sclerotherapy or other laser therapies or IPL in order to achieve better results. Serious side effects are rare, but the procedure is almost always accompanied by moderate tolerable pain.

Optimized selection of neodymium laser parameters for successful enlarged veins treatment

Full clearance and no side effects method of treating enlarged veins was successfully accomplished by one laser session. This is the ambition and dream of both dermatologists and patients. Most vascularity treatment protocols had shown some unpleasant adverse effects. The purpose of the present work is to work out, in advance, the accurate dose of laser pulse duration and fluence in order to treat varicose veins in the face, arms and legs with no adverse effects. This mission required the calculation of the exact rise in temperature of the enlarged vein; prior to laser treatment. These pre-calculated temperature rise values were tested on 20 subjects in order to have the best clinical outcomes; using fundamental frequency (1064 nm) pulsed Nd: YAG laser. This work necessitated the use of pulse length (15-30 ms), spot size (3, 5 mm), fluence (110-190 J/cm2) and skin cooling temperature (3-18 °C). Cooling of the skin before and after the treatment was needed to guarantee ultimate impactful results without side effects.

Skin vascular lesions: A new therapeutic option with sequential laser-assisted technique

Treatment of skin unaesthetic vascular lesions is still suboptimal. In this article, we present a multicenter study evaluating the efficacy and safety of the sequential 755 nm Alexandrite and 1064 nm ND:YAG lasers for the treatment of acquired and congenital vascular lesions of the skin. A total of 171 patients were included in the study (141 female and 30 male), median age 38, skin type from I to IV. Numbers of patients categorized for treated disease: 22 spider angiomas, 67 facial telangiectasia/spider veins, 58 leg telangiectasia/reticular leg veins, 24 port wine stains (PWS). Of those lesions 30.7% was on legs, 63.7% on face (6.7% on forehead, 10.1% on temples, 21.7% on cheeks, 25.2% on nose, 1.7% on chin) and 5.6% on chest. Spider angiomas required from 1 to 3 treatments. Facial telangiectasias had been treated from 1 to 4 times. Leg telangiectasias needed from 2 to 6 treatment sessions. Regarding PWS, it takes from 6 to 9 laser treatment to reach the clearance of the lesion. All the vascular disorders treated showed marked improvement while side effects were limited to low pain sensation and transitory fenomena. This sequential treatment is an effective, safe, and new approach for unaesthetic skin vascular lesions.

Low cost blood vein detection system based on near-infrared LEDs and image-processing techniques

Drawing blood and injecting drugs are common medical procedures, for which accurate identification of veins is needed to avoid causing unnecessary pain. In this paper, we propose a low-cost system for the detection of veins. The system emits near-infrared radiation from four light-emitting diodes (LEDs), with a charge-coupled device (CCD) camera located in the middle of the LEDs. The camera captures an image of the palm of the hand. A series of digital image-processing techniques, ranging from image enhancement and increased contrast to isolation using a threshold limit based on statistical properties, are applied to effectively isolate the veins from the rest of the image.

Evaluation of a new diode laser for the treatment of lower extremity leg veins

INTRODUCTION

Visible leg veins are a common cosmetic concern treated mostly by 1064 nm Nd:YAG laser that has become the chosen laser therapy for treating all leg veins up to 3 mm in size. The objective of the current prospective study was to evaluate the safety and efficacy of a new 1064 nm diode laser for leg veins and spider veins on the lower extremities.

METHODS

A total of 15 female subjects seeking leg veins and spider veins treatment were recruited to this study. The treatment protocol included two treatment sessions 6 weeks apart and two follow-up visits at three and 6 months after the last diode laser treatment. Results were evaluated by photographs and an investigator classification of the treated vascular lesions appearance on five scores scale from 0 (normal) to 4 (severe).

RESULTS

Treatment area photos demonstrated improvement in vascular lesions appearance. Average vascular lesions classification was reduced by approximately one score from baseline score of 2.9 (score 3 is moderate) to an average score 2 (mild) at the 3-month follow-up visit. This improved classification sustained also at 6-month follow-up visit, indicating the long-term effect of the treatment impact. No significant or unexpected adverse events were detected in any of the patients as a result of the treatments.

CONCLUSIONS

This study has demonstrated that the new 1064 nm diode laser is safe and effective for the treatment of leg vascular lesions on the lower extremities.

Effects of 1064-nm Nd:YAG long-pulse laser on polidocanol microfoam injected for varicose vein treatment: a controlled observational study of 404 legs, after 5-year-long treatment

Sclerotherapy continues to be the treatment of choice for varicose veins in the legs. However, isolated treatment using microfoam or lasers requires a high number of sessions to eliminate them. In 2013, we published results about the efficacy and safety 3 years after the combined treatment with microfoam injections and subsequent application of Nd:YAG laser. The aim of this paper is to clinically evaluate the treatment of varices in a control visit after 5 years, when polidocanol microfoam is used and is immediately irradiated in the tissue with 1064-nm Nd:YAG laser beam. The outcome persistence after 5 years was studied in the legs that had received combined treatment and had been studied 3 years after treatment. Patients were contacted by phone, interviewed, and examined with echo-Doppler. Out of the 259 patients who were contacted, 221 agreed to make the appointment, although in the end, only 202 came, which meant analysing 404 legs. At 5 years, the clearance rates were very high: patients were included in class CEAP C1 showing vessels of from 0.5 to 3 mm diameter. The patients showed a high level of satisfaction. Regarding adverse effects, only 4 cases of hypopigmentation described in the previous publication persisted. Although the action mechanisms between the microfoam and the Nd:YAG laser must still be elucidated, it is notable that combining microfoam with laser exposure obtained a complete, effective treatment of legs in only 2 sessions, with high clearance rates and high level of satisfaction among patients.

An Overview of Laser in Dermatology: The Past, the Present and … the Future (?)

The authors discuss a brief history of lasers and their use in dermatology. Although the excellent results achieved by the use of laser in dermatology, this special treatment modality is in continuous evolution. At present, new devices have been under development for the therapy of different kind of diseases, while lasers, already in use, has been changing, in order to be more secure, effective and be useful in many others disorders.

Guidelines of care for vascular lasers and intense pulse light sources from the European Society for Laser Dermatology

AIM

Lasers and non-coherent intense pulse light sources (IPLS) are based on the principle of selective photothermolysis and can be used for the treatment of many vascular skin lesions. A variety of lasers has been developed for the treatment of congenital and acquired vascular lesions which incorporate these concepts into their design. Although laser and light sources are very popular due to their non-invasive nature, caution should be considered by practitioners and patients to avoid permanent side-effects. The aim of these guidelines is to give evidence-based recommendations for the use of lasers and IPLS in the treatment of vascular lesions.

METHODS

These guidelines were produced by a Consensus Panel made up of experts in the field of vascular laser surgery under the auspices of the European Society of Laser Dermatology. Recommendations on the use of vascular lasers and IPLS were made based on the quality of evidence for efficacy, safety, tolerability, cosmetic outcome, patient satisfaction/preference and, where appropriate, on the experts' opinion. The recommendations of these guidelines are graded according to the American College of Chest Physicians Task Force recommendations on Grading Strength of Recommendations and Quality of Evidence in Clinical Guidelines.

RESULTS

Lasers and IPLS are very useful and sometimes the only available method to treat various vascular lesions. It is of a paramount importance that the type of laser or IPLS and their specific parameters are adapted to the indication but also that the treating physician is familiar with the device to be used. The crucial issue in treating vascular lesions is to recognize the immediate end-point after laser treatment. This is the single most important factor to ensure both the efficacy of the treatment and avoidance of serious side-effects.

A new finite element approach for near real-time simulation of light propagation in locally advanced head and neck tumors

Background and Objectives

Several clinical studies suggest that interstitial photodynamic therapy (I‐PDT) may benefit patients with locally advanced head and neck cancer (LAHNC). For I‐PDT, the therapeutic light is delivered through optical fibers inserted into the target tumor. The complex anatomy of the head and neck requires careful planning of fiber insertions. Often the fibers' location and tumor optical properties may vary from the original plan therefore pretreatment planning needs near real‐time updating to account for any changes. The purpose of this work was to develop a finite element analysis (FEA) approach for near real‐time simulation of light propagation in LAHNC.

Methods

Our previously developed FEA for modeling light propagation in skin tissue was modified to simulate light propagation from interstitial optical fibers. The modified model was validated by comparing the calculations with measurements in a phantom mimicking tumor optical properties. We investigated the impact of mesh element size and growth rate on the computation time, and defined optimal settings for the FEA. We demonstrated how the optimized FEA can be used for simulating light propagation in two cases of LAHNC amenable to I‐PDT, as proof‐of‐concept.

Results

The modified FEA was in agreement with the measurements (P = 0.0271). The optimal maximum mesh size and growth rate were 0.005–0.02 m and 2–2.5 m/m, respectively. Using these settings the computation time for simulating light propagation in LAHNC was reduced from 25.9 to 3.7 minutes in one case, and 10.1 to 4 minutes in another case. There were minor differences (1.62%, 1.13%) between the radiant exposures calculated with either mesh in both cases.

Conclusions

Our FEA approach can be used to model light propagation from diffused optical fibers in complex heterogeneous geometries representing LAHNC. There is a range of maximum element size (MES) and maximum element growth rate (MEGR) that can be used to minimize the computation time of the FEA to 4 minutes. Lasers Surg. Med. 47:60–67, 2015. © 2015 The Authors. Lasers in Surgery and Medicine Published by Wiley Periodicals, Inc.

Discomfort during Periorbital and Lateral Temporal Laser Vein Treatment: A Double-blind Randomized Controlled Trial

BACKGROUND

Treatments for cosmetically unpleasing periocular and lateral temporal veins are limited. The purpose of this study was to test the hypothesis that the application of topical lidocaine before the cosmetic treatment of periorbital and lateral temporal veins with a neodymium-doped yttrium aluminum garnet (ND:YAG) laser will result in a significant reduction in subjective pain compared with placebo as assessed using a visual analogue scale.

METHODS

Twenty patients who required bilateral treatment of facial veins were randomly assigned to receive either placebo or 30% lidocaine gel applied topically over the veins, a split-body design. Both the investigator and the patient were blinded to the treatment. An ND:YAG laser was used to treat the veins. Patients completed a visual analogue scale to assess the pain on each side of the face. Data were analyzed using nonparametric data testing.

RESULTS

There was a 64.0% reduction in pain on the treatment side compared with the placebo side (P < 0.001). There was no significant difference in patient-assessed subjective efficacy between sides (P = 0.2). Complications were minimal and mild.

CONCLUSIONS

Patients undergoing periorbital and temporal vein ablation using ND:YAG laser should be offered topical lidocaine as the pain levels are moderate. The use of topical 30% lidocaine results in a significant reduction in pain levels.

Treatment of superficial cutaneous vascular lesions: experience with the long-pulsed 1064 nm Nd:YAG laser

Recent published studies evaluating the long-pulsed 1064 nm Nd:YAG laser for superficial cutaneous vascular lesions have limited subjects and optimal treatment parameters have not been established. To determine the efficacy and safety of the long-pulsed 1064 nm Nd:YAG laser on superficial cutaneus vascular lesions and analyse retrospectively our experience of a 3-year period are the aims of this study. Over the 3-year period, 255 patients were treated [189 female and 66 male; median age 35 (range 7-65) years; Fitzpatrick skin types II-V]. Twenty-six patients with spider angioma, 130 with facial telangiectasia, and 99 with leg telangiectasia were treated. A long-pulsed 1064 nm Nd:YAG laser was used. A test dose was performed at the initial consultation and thereafter patients were reviewed and treated at 4-week intervals for 5 months. Of those patients who completed treatment and followup, 26/26 (100%) of spider angiomas, 125/130 (97%) of facial telangiectasia, and 80/99 (80,8%) of leg telangiectasia markedly improved or cleared. We suggest that the long pulsed Nd:YAG laser is a safe and effective treatment for common superficial cutaneous vascular lesions. However, it is not the first choise to use to treat superficial vessels on the face where depth is not the concern.

Laser treatment of superficial leg veins: a review

BACKGROUND

Superficial leg veins affect millions of people worldwide, and treatment of these vessels is a common dermatologic request. The advance of lasers in recent years has led to numerous laser and light devices intended to treat these superficial vessels.

OBJECTIVE AND METHOD

A review of the literature on the laser and light devices available for the treatment of superficial leg vessels with historical and recent trends is presented.

RESULTS AND CONCLUSIONS

The appropriate choice of light system to treat telangiectases, venulectases, and reticular veins varies depending on anatomical, physiological, and biological differences in the vessels. Safe and efficacious treatment of superficial leg vessels can be achieved with multiple lasers by taking advantage of the oxyhemoglobin absorption peaks. The authors have indicated no significant interest with commercial supporters.

Single cell viability and impact of heating by laser absorption

Optical traps such as tweezers and stretchers are widely used to probe the mechanical properties of cells. Beyond their large range of applications, the use of infrared laser light in optical traps causes significant heating effects in the cell. This study investigated the effect of laser-induced heating on cell viability. Common viability assays are not very sensitive to damages caused in short periods of time or are not practicable for single cell analysis. We used cell spreading, a vital ability of cells, as a new sensitive viability marker. The optical stretcher, a two beam laser trap, was used to simulate heat shocks that cells typically experience during measurements in optical traps. The results show that about 60% of the cells survived heat shocks without vital damage at temperatures of up to 58 ± 2°C for 0.5 s. By varying the duration of the heat shocks, it was shown that 60% of the cells stayed viable when exposed to 48 ± 2°C for 5 s.

Shedding light: laser physics and mechanism of action

Lasers have affected health care in many ways. Clinical applications have been found in a number of medical and surgical specialities. In particular, applications of laser technology in phlebology has made it essential for vein physicians to obtain a fundamental knowledge of laser physics, laser operation and also to be well versed in laser safety procedures.

This article reviews recommended text books and current literature to detail the basics of laser physics and its application to venous disease. Laser safety and laser side effects are also discussed.

Conductive interstitial thermal therapy device for surgical margin ablation:In vivoverification of a theoretical model

PURPOSE

To demonstrate the efficacy and predictability of a new conductive interstitial thermal therapy (CITT) device to ablate surgical margins.

METHOD

The temperature distributions during thermal ablation of CITT were calculated with finite element modelling in a geometrical representation of perfused tissue. The depth of ablation was derived using the Arrhenius and the Sapareto and Dewey (S&D) models for the temperature range of 90 to 150 degrees C. The female pig animal model was used to test the validity of the mathematical model. Breast tissues were ablated to temperatures in the range of 79-170 degrees C, in vivo. Triphenyltetrazolium chloride viability stain was used to delineate viable tissue from ablated regions and the ablation depths were measured using digital imaging.

RESULTS

The calculations suggest that the CITT can be used to ablate perfused tissues to a 10-15 mm width within 20 minutes. The measured and calculated depths of ablation were statistically equivalent (99% confidence intervals) within +/- 1mm at 170 degrees C. At lower temperatures the equivalence between the model and the observations was within +/- 2 mm.

CONCLUSION

The CITT device can reliably and uniformly ablate a 10-15 mm wide region of soft tissue. Thus, it can be used to secure negative margins following the resection of a primary tumor, which could impede local recurrences in the treatment of local diseases such as early staged, non-metastatic, breast cancer.

Update on hemangiomas and vascular malformations of the head and neck

Although the current classification systems of vascular malformations and hemangiomas are increasingly accepted, there are nonetheless several aspects that show us how special and at the same time difficult it is to diagnose, evaluate, and treat some of those diseases. Close interdisciplinary cooperation of all involved disciplines is essential; the discussion of the adequate individual procedure must be performed in angioma boards, as it is already well established in the context of tumor boards. The interface of angioma therapy and tumor therapy seems to be very close, which is certainly true for the aspect of angiogenesis and of course for the inhibited proliferation as promising therapeutic approach of complex vascular malformations. This leads to another obvious necessity of intensifying experimental scientific research on vascular malformations and hemangiomas, which is a precondition for optimizing or elimination of different current problems and deficits in the mentioned field.

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.

Conductive interstitial thermal therapy (CITT) device evaluation in VX2 rabbit model

We have developed a conductive interstitial thermal therapy (CITT) device to precisely and reliably deliver controlled thermal doses to the surgical margins at the cavity site following tumor resection, intraoperatively. The temperature field created by CITT ablation of a perfused tissue was modeled with a finite element package Femlab. The modeling suggested that a maximum probe temperature of 120 degrees C and an ablation time of 20 minutes were required to ablate highly perfused tissue such as the VX2 carcinoma. Deployable pins enable faster and more reliable thermal ablation. The model predictions were tested by thermal ablation of VX2 carcinoma tumors implanted in adult New Zealand rabbits. The size of the ablated region was confirmed with a viability stain, triphenyltetrazolium chloride (TTC). Histopathological examination revealed 3 regions in the ablated area: a carbonized region (1-3 mm); a region that contained thermally fixed cells; and an area of coagulated necrosis cells. Cells in the thermally fixed region stained for PCNA (proliferating cell nuclear antigen) and were bounded by the carbonized layer at the cavity wall, and by necrotic cells that exhibit nuclear fragmentation and cell dissociation, 5 to 10 mm away from the CITT probe. Adjacent tissue outside the target region was spared with a clear demarcation between ablated and normal viable tissue. It is suggested that the CITT device can be used, clinically, to inhibit local recurrence by creating negative surgical margins following the resection of a primary tumor in non-metastatic early staged tumors.

Photothermolysis of blood vessels using indocyanine green and pulsed diode laser irradiation in the dorsal skinfold chamber model

BACKGROUND AND OBJECTIVE

For the treatment of vascular lesions, the use of laser light absorbed by the endogenous chromophore hemoglobin may still be improved.

MATERIALS AND METHODS

Laser treatment (lambda(em) = 805 nm; fluence rate: 106 kW/cm2; fluence: 3.2 J/cm2 (3 milliseconds)), of blood vessels directly after i.v. application of indocyanine green (ICG) (ICG-concentration: 0, 2, or 4 mg/kg body weight (b.w.)) (n = 14,117) was investigated in the skinfold chamber model. Vessel diameters (1-351 microm) were measured using intravital fluorescence microscopy up to 24 hours following irradiation. Histology was taken 1 or 24 hours after irradiation. Results were compared to a mathematical model based on the finite element method.

RESULTS

The reduction of blood vessel perfusion was proportional to ICG-concentration and pulse duration; only a 30 milliseconds pulse duration (2 or 4 mg/kg b.w. ICG-concentration) induced a loss of perfusion even of blood vessels with a diameter <30 microm. Histology revealed photocoagulation of blood vessels up to 24 hours. Results were in agreement with mathematical calculations.

CONCLUSION

ICG-mediated laser irradiation induces irreversible photocoagulation of blood vessels of all diameters in this model.

The effects of intense pulsed light (IPL) on blood vessels investigated by mathematical modeling

BACKGROUND AND OBJECTIVES

Intense pulsed light (IPL) sources have been successfully used for coagulation of blood vessels in clinical practice. However, the broadband emission of IPL hampers the clinical evaluation of optimal light parameters. We describe a mathematical model in order to visualize the thermal effects of IPL on skin vessels, which was not available, so far.

STUDY DESIGN/MATERIALS AND METHODS

One IPL spectrum was shifted towards the near infrared range (near IR shifted spectrum: NIRSS) and the other was heavily shifted toward the visible range (visible shifted spectrum: VSS). The broadband emission was separated in distinct wavelengths with the respective relative light intensity. For each wavelength, the light and heat diffusion equations were simultaneously solved with the finite element method. The thermal effects of all wavelengths at the given radiant exposure (15 or 30 J/cm2) were added and the temperature in the vessels of varying diameters (60, 150, 300, 500 microm) was calculated for the entire pulse duration of 30 milliseconds.

RESULTS

VSS and NIRSS both provided homogeneous heating in the entire vessel. With the exception of the small vessels (60 microm), which showed only a moderate temperature increase, all vessels exhibited a temperature raise within the vessel sufficient for coagulation with each IPL parameter. The time interval for effective temperature raise in larger vessels (diameter >60 microm) was clearly shorter than the pulse duration. In most instances, the vessel temperature was higher for VSS when compared to NIRSS.

CONCLUSIONS

We presented a mathematical model capable of calculating the photon distribution and the thermal effects of the broadband IPL emission within cutaneous blood vessels.

Mathematical modeling of selective photothermolysis to aid the treatment of vascular malformations and hemangioma with pulsed dye laser

Pulsed dye lasers (PDL) are the standard of care in the treatment of cutaneous vascular disorders such as the port-wine strains or hemangiomas of infancy. Nonetheless, there is still uncertainty regarding the specific laser parameters that are likely to yield optimal clinical outcomes. Using mathematical modeling, we explain and associate clinical outcomes with laser wavelength, radiant exposure, and pulse time and shape. The model's prediction that a continuous PDL pulse of 0.45 ms with a radiant exposure of 6 J/cm(2) is equivalent to delivering a 1.5-ms pulse consisting of three pulses with a radiant exposure of 12 J/cm(2) is in agreement with clinical studies. The model also suggests that for vascular malformations involving vessel diameters in the range of 150-500 microm, one should use a PDL at a wavelength of 595 nm with a radiant exposure of at least 12 J/cm(2) and pulse time of 1.5 ms, delivered in three pulses. Whereas it is calculated that malformations with vessels smaller than 50 microm will not respond to PDL in any clinical setting, an excellent response to PDL treatment at either a 585- or 595-nm wavelength can be expected for malformations with vessel diameters of 50-150 microm. Epidermal cooling is highly recommended for all settings to minimize pain and the risk of side effects. Finally, the model is used to generate a reference table that suggests specific PDL parameters for the treatment of various malformations and hemangiomas. The table cannot replace a clinician's experience with respect to which and how parameters should be changed, but provides a defined window of parameters that should be tried to improve clinical response.

Laser therapy of vascular lesions

Since the first construction of a laser by Maiman in 1960 and the first clinical application of a laser in the therapy of skin lesions by Leon Goldman, laser therapy has become an important therapeutic modality in dermatology. Various lasers can be used for the treatment of different vascular and non-vascular lesions. According to our results, vascular lesions constitute the most important indication for laser therapy in dermatology.