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

Abstract

Background The treatment of large vessels such as leg veins is successfully performed in clinical practice using pulsed Nd:YAG lasers. However, it is still unclear how laser parameters such as wavelength, fluence and pulse duration influence vessel destruction in leg veins. Objectives To elucidate the governing parameters in selective photothermolysis of large vessels. Methods A recently developed mathematical model for photothermolysis has been adapted for the treatment of leg veins. The model was used to analyse the effectiveness of the selective photothermolysis process in laser treatment of leg veins by Nd:YAG at 1064 nm. The efficiency of laser-induced vessel heating was defined as a ratio between the absorbed and delivered energy. Results The efficiency improved with increasing vessel diameter, in agreement with clinical findings in various studies. The pulse duration made a minor contribution for laser fluences of 100-400 J cm )2 , whereas the efficiency was better for a small spot. The use of moderate fluences of 100-200 J cm )2 reduced excess dermis heating and pain. Conclusions We provide reference parameters for optimal treatment of leg veins using Nd:YAG lasers at 1064 nm. Our model predicts a maximal efficiency of a range of fluences (100-200 J cm )2 ) and pulse durations (10-100 ms).

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

“…The smaller the vessel diameter, the faster is the cooling and the smaller is the thermal damage inside the vessel. This has been discussed when modeling the treatment of large vessels with Nd:YAG laser at 1,064 nm [16].…”

“…In order to achieve this, we modified our mathematical model of selective photothermolysis of portwine stains used in a previous study [14]. This model utilized finite element methods to solve the diffusion approximation of light tissue interaction and was successfully shown in animal model to be well correlated with clinical outcomes [14][15][16]. In the current study, we investigated the applicability of mathematical modeling for selective photothermolysis to multiple wavelengths in a simultaneous fashion.…”

Vasküler Lezyonlarda Lazer

“…1064 nm Nd:YAG lazerin deoksihemoglobin ve methemoglobin tarafından absorbsiyonu oldukça yüksektir ve 4-6 mm'ye kadar penetre olabilir 22 . Bu nedenle damarların daha derinde yerleştiği şarap lekeleri, hemanjiomlar ve bacak varislerinin tedavisinde ve daha az sıklıkla epilasyon amaçlı kullanılmaktadır [23][24][25][26] .…”

“…Ama yine de koyu tenlilerde soğutma sistemleri ile epidermis korunmalıdır. Uzun atım süresi sayesinde Nd:YAG lazer, damar duvarında rüptüre neden olmadan damarı yavaşça koagüle ederek purpura ve pigmentasyon gelişimini önler 22 . 1064 nm Nd:YAG lazerin yan etkileri iki hafta kadar sürebilen pigmentasyon değişiklikleridir.…”

Management of vascular lesions using advanced laser technology

“…Therefore, the investigators concluded that micropulse 1064 nm Nd:YAG laser is both safe and effective for the treatment of facial telangiectasia [57] . As far as the treatment of telangiectasias of the lower extremities using Nd:YAG laser is concerned, a model has been suggested, in accordance with the best treatment outcome achieved using a range of moderate fluences (100-200 J/cm 2 ) and pulse durations between 10 and 100 ms, in order to reduce excess dermis heating and pain [58] . Similar conclusions were reached in a recent study, according to which multiple treatment sessions, spaced 8 to 12 weeks apart, are necessary to reduce the colour and the size of the lesion, as well as to improve the contour of the skin with minimal side effects.…”