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Long Pulsed Nd YAG 1064nm Laser : Use in Onychomycosis and Verrucae Vulgaris

Authors: Dr. Avitus John Raakesh Prasad

Abstract

Neodynium Yittrium Aluminium Garnet ( Nd YAG ) 1064nm laser has been used for hair reduction but its use in other indications are less explored in Indian senario. This article helps in understanding this technology and its uses in two common indivations, onychomycosis and verrucae vulgaris. Device: Nd YAG 1064nm Laser from Belgium / Korea. Indications: This technology can be used for several indications such as Angiomas, Telangiectasias, Onychomycosis, Verrucae Vulgaris, Dermal remodelling and enlarged pores. Facility: Nd YAG 1064nm can be carried out in a clinic or hospital setting or a nursing home with a small operation theatre. Informed consent and counseling: The dermatologic consultation should include detailed assessment of the patient's skin condition and skin type. An informed consent is mandatory to protect the rights of the patient as well as the practitioner.

All patients must have carefully taken preoperative and postoperative pictures. Parameters: Depends on the indication, the size of the lesion, the site of the lesion, and the targeting chromophore. Anesthesia: There is acceptable pain and is tolerated well by patients but some may require perilesional anesthesia. Postoperative care: Postoperative care is minimal. Post-treatment pain, edema, blistering and redness settle in a few hours to few days. Postoperative analgesics and antibiotics depends on the indication being treated.

Keywords: Nd YAG laser, Onychomycosis, Verrucae Vulgaris,
Introduction:

The long-pulsed Nd:YAG laser which in Indian scenario was mainly used in hair reduction owing to its high safety profiles in the treatment of Fitzpatrick phototypes IV–VI as well as suntanned skin. Now it has gained increasing popularity over recent years for treatment of both vascular and pigmented lesions as well as skin rejuvenation. The advantages of the 1064 nm wavelength are its deeply penetrating wavelength coupled with its hemoglobin absorption and to a lesser extent, water, and melanin absorption. Recent studies shows the efficacy of use of Lp Nd YAG laser in treatment of onychomycosis and verrucae vulgaris.

The theory of selective photothermolysis developed by Anderson and Parrish 1 describes the necessary requirements for selective destruction of site-specific targets in tissue using electromagnetic radiation. Selective targeting of tissue targets requires (a) the use of a wavelength preferentially absorbed by the chromophore, (b) a pulse duration less than or equal than the thermal relaxation time (TRT), or cooling time, of the targeted structure, and (c) sufficient fluence to produce irreversible damage. In 2001, Drs. Altshules,Anderson, and colleagues proposed the extended theory of selective photothermolysis 2, which describes the pulse duration requirements for nonuniformly pigmented structures in tissue, such as blood vessels and hair follicles, should be significantly longer than the thermal relaxation time, and has been termed the thermal damage time (TDT).

Long pulse Nd YAG in Verrucae Vulgaris:

Mechanism of action:

Many studies have used 585-nm pulsed dye lasers for the treatment of warts, with the blood vessels as the target tissue 3-6. This is because hemoglobin in blood has strong absorption peaks at wavelengths ranging from 585 to 595 nm 7. Moreover, hemoglobin has a significant, albeit more modest, absorption peak between 800 and 1,100 nm. Therefore, it has been postulated that 1,064-nm Nd:YAG lasers could be used in the treatment of warts. ~ Targets the hemoglobin in the vessels proliferating under the warts. ~ Melanin granules in the epidermis of the wart and embedded within the wart 8,9.

Parameters:

1. Energy :

Energy is set to between 25 to 35J depending on spot size and the fluence needed to be generated. For warts on the normal skin lower joules or fluence, warts on thick skin like the palms and soles, periungual area higher joules / fluence is used. Fluence between 350 – 450 J/cm2

2. Spot size :

Spot size is set between 3- 4mm, Fluence is dependent on the spot size and energy. For example for an energy of 30j and spot size of 3mm Fluence generated will be 424.6 J/cm2

Calculation :

Fluence = Energy / Spot size = J / π r2 ( r = half of spot size) J =30, r2 = ( diameter 3mm = .3cm/2 =0.15) ( 0.15x0.15 = 0.0225) = 30 / 3.14x 0.0225 = 30 / 0.07065 = 424.62845=424.6 J/cm2When higher fluence is required , lower spot size should be used to achieve higher fluences. 3. Pulse Duration :


Pulse duration is kept between 10 – 15 ms.

4. Frequency / Repetition rate:

Frequency is set between 1- 3 Hz, or Auto.

Procedure:

Paring of the warts is used to remove the excess wart tissue, Depending on the size of the wart and the area involved the parameter are set accordingly. While firing the laser it should be cover the whole area of the wart to prevent reoccurrence. End point is the blanching of the wart, with perilesional whitening. The perilesional whitening denotes the destruction of the vasculature of the wart.

Figure 02A. Lp Nd YAG done after paring of the warts, Fluence 300- 320 J/cm2 , Pulse duration 10ms, Frequency 1Hz, Spot size 4mm Figure 02B. Note the perilesional whitening denoting the Endpoint. Figure 02C. 10 days post operative, showing, blistering, Haemorrhagic bullae, and necrosis.

Advantages :

  1. Faster treatment time and recovery time.
  2. Lesser pain compared to cryotherapy
  3. No reoccurrence was see in most cases, in some cases because of faulty technique of not firing the wart completely and incomplete perilesional whitening, reoccurrence was seen at the edges of the cleared wart.
  4. Minimum post operative care is needed unlike post electrocautery where daily dressing may be needed.
  5. Easy to approach and treat in case of genital warts, lower fluences should be used to attain the endpoint.
  6. Minimal scarring compared to other modalities.

Complications:

  1. Pain during procedure followed by numbness immediate post op.
  2. Necrosis, hemorrhagic blisters and ulceration which common.


Long pulse Nd YAG in Onychomycosis:

Onychomycosis is a persistent fungal infection of the nail bed and plate. Treatment of onychomycosis is often challenging. The available therapeutic options are either topical or systemic antifungal agents 10-12.Topical therapy is seldom effective as it is difficult to achieve local therapeutic concentrations. Systemic antifungal agents produce recovery rates of approximately 50%,13-15 however, they can damage the liver and the kidneys in some patients.

Mechanism of action:

~ Nd:YAG 1064-nm lasers can penetrate as deep as the lower nail plate, heating the nail plate.
~ Targets the hemoglobin in the superficial vessels on the nail bed.
~ Thermal and photoacoustic shock to the fungal elements 16.

1. Energy :

Energy is set to between 15 – 25J depending on spot size and the fluence needed to be generated. Fluence between 200 – 350 J/cm2

2. Spot size :

Spot size is set between 3- 4mm.

3. Pulse Duration :

Pulse duration is kept between 20 – 30 ms.

4. Frequency / Repetition rate:

Frequency is set between 1- 2 Hz, or Auto.

Procedure:

Clipping of the distal excess nail beyond the hyponychium is done. Depending on the thickness of the nail plate, the parameter are set accordingly. While firing the laser it should be in a spiral fashion starting from the edges of the nail plate and ending in the center if the whole nail is involved, or the areas involved can also be targeted individually. End point is when the patients says he feels a very hot sensation on the treated area and the blanching of the nail plate. In case the patients says he can’t feel the heat you can increase the fluence by 25 to 50 J/cm2 and try again to achieve the endpoint.

Advantages :

  1. Ideal when only one or two nails are involved and the use of oral antifungals can be avoided.
  2. Patients who are on other long term medications which will interact with the oral antifungals.
  3. Patients with liver disease.
  4. Better patient compliance, no post operative care is needed.
  5. Faster recovery and fewer treatment sessions.

Complications:

  1. Pain during procedure and few hours post operative.
  2. Hematoma formation.
Anaesthesia:

Perilesional anaesthesia may be given in case of verrucae. In case of Onychomycosis, the patients has to feel the heating of the nail plate for the endpoint. So its better to avoid local anaesthesia.

Contraindications:

  1. Patient who apprehensive about lasers.
  2. Pregnancy.
  3. Secondary infections which can be treated accordingly before attempting the laser.
Other Indications in which I use Lp Nd YAG commonly:
  • Cherry angiomas, Fluence 100 – 250 J/cm2 (lower for smaller vessels), spot size 4-6 mm according to size of the lesion, Pulse duration 15- 30ms ( shorter for smaller lesions).
  • Pyogenic granuloma.
  • Lymphangioma circumscriptum.
  • Telangiectasia


  • Conclusion:

    Long Pulse Nd YAG can be multifunctional laser, its indication in treating verrucae and onychomycosis has opened up the options for the dermatologists to effectively treat such condition effectively and at a short treatment duration. Among the available medical and destructive therapeutic options for cutaneous warts and onychomycosis, none is uniformly effective or cost effective. Invasive methods like Co2 laser,
    Electrocautery have downsides such as pain and long recovery periods. Topical management requires the application of drugs and oral medications for a long time and treatment success is, therefore, highly dependent on patient compliance. However, patients often request treatment because of social stigma or discomfort. Ideally, treatment should be simple with a low risk of adverse effects. Long Pulse Nd YAG has all these benefits over conventional treatment modalities and provides cure to the patient's physical and psychological discomfort, and to prevent the spread.

    References:

    1. Anderson RR, Parrish JA. Selective photothermolysis: precise microsurgery by selective absorption of pulsed radiation. Science 1983,220:524–7
    2. Altshuler GB, Anderson RR, Manstein D et al. Extended theory of selective photothermolysis. Laser Surg Med 2001; 29:416–432.
    3. 1. Robson KJ, Cunningham NM, Kruzan KL, Petal DS, Kreiter CD, O'Donnell MJ, Arpey CJ. Pulsed-dye laser versus conventional therapy in the treatment of warts: a prospective randomized trial. J Am Acad Dermatol. 2000;43:275–280. [PubMed]
    4. Kopera D. Verrucae vulgares: flashlamp-pumped pulsed dye laser treatment in 134 patients. Int J Dermatol. 2003;42:905–908. [PubMed]
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    8. Kimura, U., Takeuchi, K., Kinoshita, A et al. Long-pulsed 1064-nm neodymium:yttrium– aluminum–garnet laser treatment for refractory warts on hands and feet. J Dermatol. 2014 Mar;41(3):252-7.
    9. Egawa K1, Kasai S, Hattori N, et al A case of a human-papillomavirus-60-induced wart with clinical appearance of both pigmented and ridged warts.Dermatology. 1998;197(3):268-70.
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