Chapter 78: Lasers – Clinical applications

Introduction

It was thought best that before clinical examples of the use of lasers was narrated with photographs, the post-graduates in plastic surgery are acquainted with some basic terms and ideas concerning laser therapy. They are given below.

This chapter like the one preceding it was compiled almost entirely by Dr. Uddhav Patil of Kolhapur India who was ne of the first to introduce laser technology for surgical use in India.

• The laser beam of light is monochromatic bright unidirectional and coherent.
• Mono-chromaticity implies the waves that carry the light are of the same wavelength and energy and therefore in a narrow band and can be targeted without damage to the adjacent tissue
• Its brightness or brilliance is on account of its non-angulated centrality.
• The photons which constitute the light beam are unidirectional, occupy a very narrow zone and its divergence factor can be limited to less than one millimetre
• Coherence implies that the emitted photons are in the same phase both in space and time and therefore can be precisely focussed.
• A photon is a minute packet of electromagnetic radiation without mass.
• When the laser beam falls on the skin what is actually falling on it are continuous pulses of photons
• The energy within a photon can only be shed if there is present a chromophore in the matter on which it falls. In that event the energy in the photon is absorbed by the chromophore containing tissue.
• Chromophores are either endogenous or exogenous, for example some dyes
• The endogenous chromophores include melanin, all varieties of haemoglobins, proteins in the form of peptides and amino acids, water, nucleic acid, and bilirubin.
• The effects on the tissue by lasers therefore can occur only if a chromophore is present.
• If a chromophore is not present the laser beam (photons) will pass through.
• The laser beam can also be reflected from the surface.
• It can also scatter after it enters the tissue depending on the nature of the tissues
• If the lesion (with chromophores) is large, scattering is productive because all the photon pulses will be de- energised by the chromophores. In addition, the scatter remains within the zone and the bouncing of these photons will produce greater effects in the zone of action.
• If the lesion is small there are higher chances of scattering, and a better focussing is needed.
• The photons cause changes by heating the tissue, by its mechanical or physical effect and by its effect by way of a chemical reaction.
• Of the above the destruction by heat is most commonly employed, for example in removal of (unwanted) hair, in rejuvenation of the skin, vascular lesions (particularly capillary malformations).
• The mechanical effects are seen when employed as high energy protons in ultrashort pulses and this is effective in tattoos or pigmented lesions.
• The chemical changes are known to occur in nature, as in photosynthesis by leaves where the chromophore is chlorophyll, but can also lead to neoplastic changes as in basal cell carcinoma of the skin in the white races because of lack of the protection by melanin in the outer layers of the skin.                    

This is only a simple understandable summary. For details the student is referred to the chapter “Lasers and Energy devices in Plastic surgery” in the book “Textbook of Plastic Reconstructive and Aesthetic surgery (publishers Thieme) editor Karoon Agrawal, sectional editor Surajit Bhattacharya. The compiler of these notes acknowledges with gratitude the efforts Dr Uddhav Patil who wrote the chapter, together with Dr Laxyajeet Dhami in that book.

With acknowledgment to the editor, Textbook of Plastic, Reconstructive, and Aesthetic Surgery, Vol. 1, editor in chief Karoon Agarwal, Vol. editor Surajit Bhattacharya, authors Lakshyajit Dhami and Uddhav Patil, pages 401-428.

CLINICAL PHOTOGRAPHS OF LASER SURGERY CONTRIBUTED BY
DR. UDDHAV PATIL (KOLHAPUR)

I] LASER HAIR REMOVAL 

A] Bushy sideburns / (Excess hair growth) in adolescent girl, confirmed as not related to hormonal imbalance. B] Final Result. First four treatments with IPL 695 filter, 32-42 J/cm², triple pulse of 3.6 ms with a delay of 60 to 80 ms. Then fifth treatment with Diode 800 nm, 40 J/cm², 100 ms pulse width was followed by three touch-up sessions with Diode 800 nm, 40 J/cm², 30 and 20 ms pulse width for finer hair. Photograph 15 months after last touch-up session.

II] PIGMENTED LESIONS: 1) Epidermal Lesions (Café Au Lait Macule)

A] Café Au Lait Macule (CALM) B] Four months after a single treatment with 532 nm Q-Switch laser. 2 J/cm², 2 mm spot and 10Hz. These epidermal birthmarks are known to recur (are notorious for recurrence) and might not respond to laser treatment (as well as resistance to laser treatment) which warrants counselling for a guarded outcome.

II] PIGMENTED LESIONS: 1) Epidermal Lesions (Epidermal Nevus)

C] Epidermal nevus D] Complete clearance with 532 nm Q-Switch laser

II] PIGMENTED LESIONS: 1) Epidermal Lesions (Freckles or Ephelides)

A] Pigmented lesions (Freckles) on (sun bearing area of) the face actinic (exposure to the sun) B] After two treatments of 532 nm Q-Switch laser 2.1 & 2.6 J/cm², Spot: 2 mm, Hz: 10,

II] PIGMENTED LESIONS: 2) Dermal Lesions: Congenital Melanocytic Nevus (CMN)

A] Congenital Melanocytic Nevus (CMN) B] After Four IPL Treatments 645 Filter, 46-49 J/cm², Triple Pulse of 3.2 ms, 40 ms delay

A] Congenital Melanocytic Nevus (CMN) treated with Corneal Metal Shield protection B] After Five IPL Treatments, Filter 645, 32-46 J/cm², 3.2 ms Triple Pulse, 40 ms delay

II] PIGMENTED LESIONS: 2) Dermal Lesions: (Nevus of Ota)

A] Nevus of Ota: The deepest nevus of the skin can only be effectively treated with 1064 nm Q Switch laser. Initially, when pigment is in the deepest layers of the dermis, first 10 treatments were carried out with 6 mm spot for deeper penetration and 2.3 – 3.8 J/cm². B] For next 4 treatments, when the pigment is in the mid dermis, 3.5 mm spot and 6.6-7.1 J/cm² was used. C] Finally for superficial dermal pigment, 2.5 mm spot and 9-10.6 J/cm² was used. D] This tuning with the spot size has resulted in complete and permanent clearance after a total of 16 treatment sessions.

II] PIGMENTED LESIONS: 3) Mucosal Lesions: (Dark Lips)

A] Familial dark lips leading to aesthetic concern B] Permanent clearance after four treatments of 1064 nm Q-Switch laser, 4.4 J/cm^2,, spot 2.5 mm. With the same parameters, smoker’s lips and lip pigmentation due to lipsticks can also be treated.

III] TATTOO

A] Amateur (and re)tattooing on forearm B] After eight treatments with Q- Switch 1064 nm Nd:YAG laser, 3.4 to 7.8 J/cm², 2.5 mm spot and 5 Hz C] Professional Tattoos D] After Q Switch 1064 nm laser treatments.

IV] VASCULAR LESIONS: 1) Port Wine Stain (PWS) (Capillary)

A] Port Wine Stain (PWS) B] Treated with Intense Pulsed Light (IPL) with 590 nm filter, 50 J/cm², 3.5 ms Double Pulse 20 ms Delay – 10 treatments. For PWS, recommended laser is Pulsed Dye Laser (PDL) with 595 nm wavelength and ultra short pulse.

IV] VASCULAR LESIONS: 2) Rosacea (Fine Capillary)

A] Rosacea: Chromophore Oxy-Haemoglobin is in very fine capillaries <100μB] Treated with Pulse Dye Laser (PDL) 595 nm, 10 mm Spot, ultra short single pulse of 0.5 ms, 5 J/ cm², Three Sittings Photo Courtesey : Dr. Pramod Talwar, New Delhi

IV] VASCULAR LESIONS: 3) Hemangiomas (Cavernous)

A] Hemangioma in proliferative phase B] One Year after 5 treatments with 1064 nm Nd:YAG laser. 124 -133 J/cm², triple pulse of 4.5 ms each and 30 ms delay. C] Long term result after 14 years

A] Hemangioma in proliferative phase B] After 7 treatments with 1064 nm Nd:YAG laser. 130 J/Cm², 4.5 ms Triple pulse, 30 ms delay

A] A large exophytic hemangioma in proliferative phase B] & C] Complete resolution with 1064 nm Nd:YAG laser treatments administered without general anesthesia. Less number of shots but given repeatedly. Late result, at age 9 years, 5 year after last laser treatment.

IV] VASCULAR LESIONS: 3) Hemangiomas (Capillary-Cavernous Mixed)

A] Hemangioma occupying upper lip, extending into the nostrils and the central column B] Complete resolution after 9 treatments with 1064 nm Nd:YAG laser under short general anesthesia. 130-150 J/cm², triple and then double pulse of 4.5 ms with a delay of 30 ms. Last four treatments with 150 J/cm², single pulse of 5.7 ms Because, as the amount of chromophore reduces, we need to increase the joules C] One and a half year after last treatment. Please note absence of scarring.

IV] VASCULAR LESIONS: 4) Venous Malformations

A] Venous Malformation persistent till adolescence B] Considerable resolution in 5 treatments with 1064 nm Nd:YAG laser.

A] Venous Malformation persistent till age 23 years B] Dramatic resolution with just one treatment with 1064 nm Nd:YAG laser 110 J/cm², double pulse of 8 ms and 30 ms delay. Venous Malformations respond early to laser treatment as compared with those AVMs with arterial dominance

A] Venous Malformation since birth B] Complete resolution in 3 treatments with 1064 nm Nd:YAG laser. 150 J/cm², single pulse of 5.7 ms, 20-55 shots. Single, longer pulse of 5.7 ms was used as the entire lesion is acting as a large chromophore requiring slow heating. Note the absence of any scar left behind.

IV] VASCULAR LESIONS: 4) Complex Combined Malformation             

A] Capillary-Lymphatico-Venous Malformation (CLVM) B] After 3 laser treatments of the entire ear pinna with 1064 Nd:YAG laser C] Fourth treatment was given to ear lobe only                                       

V] RHINOPHYMA

A] Rhinophyma B] Eleven weeks post sculpting under local anaesthesia with Radio Frequency Unit ‘Ellman’ USA, using cutting + coagulation blend mode.

VI] SCARS: Post Burn

A] Hypertrophied post burn scars in a child B] Reduction in scar thickness after 3 treatments with Frac. CO₂ laser under short general anaesthesia.

A] Hypertropic Burn Scars B] After 12 treatments with Q Switch 1064 nm Laser and 16 treatments with Frac. CO₂ Laser administered simultaneously.

VI] SCARS: Chicken Pox

A] Chicken pox scars: Depressed and hyper pigmented B] After 6 spot treatments with Fractional CO₂ 30 watt, 100-200 micro sec, 4-10 X stacking, CVR 26-40 %

VI] SCARS: Traumatic or Post Surgical

A] Road accident and wind shield injury B] After primary Plastic Surgical repair C] After 3 IPL treatments for fresh scars 590 nm filter D] After 5 IPL treatments. This case was treated during 2001, when “no scar” Creams or Silicone Gel Sheets were not yet available.

VII] PHOTO REJUVENATION: Multilaser Approach

A] Freckles, moles, pigmentation and lack of glow B] After 2 full face Q Switch 1064 nm laser toning sessions 1.3 and 2.2 J/ cm², 6 mm spot, 10 Hz C] After Frac. CO2 treatment, 30 Watt, 400 Micro Sec, 6 Multiplication and 28% CVRD] Improvement continued over next 14 months E] Three months after Carbon Peel (Hollywood Laser Facial) This treatment is administered by applying a layer of nano carbon paste to the entire face which is then removed with two passes of Q-Switch 1064 nm laser using two different spots.