Lasers in ENT.pptx

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By : DR. ASHUTOSH KR. SINGH
LASERs in ENT

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Acronym - Light Amplification by
Stimulated Emission of Radiation
 Definition- Laser is a device that
produces and amplifies light by
stimulated emission of radiation.
 It can produce light in the UV,
visible and infrared region of the
electromagnetic spectrum.

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History
 In 1917, Albert Einstein described the-STIMULATED EMISSION.
 In 1960, Theodore Maiman demonstrated the First Laser-RUBY.
 In 1962, C Kumar N Patel introduced the CO2 gas laser.
Albert Einstein Theodore Maiman C Kumar N.Patel

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 1960 : Ruby(First laser)
 1961 : Neodymium-
doped(Nd):Glass laser
 1962 : CO2 Gas laser

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Difference between Ordinary light and Laser:
Ordinary light Laser
• Radiation from conventional light
source is emitted over a wide
range of wavelength or spectrum
• The light intensity decrease at the
distance due to divergent nature of
the conventional radiation
• Laser produces a beam with a very
narrow divergence
• Light leaves the source with a high
degree of collocation
• Directionality is maintained over a
long distance and high beam
intensity is also maintained
Ordinary light Laser
• Spontaneous emission
• Polychromatic(emitted over a wide
range of wavelength)
• Non-coherent
• Non-collimated(Divergent in
nature)
• The light intensity decrease at the
distance due to divergent nature
• Stimulated emission
• Monochromatic
• Coherent(wave travel in step)
• Collimated(Highly Directional),
• High beam intensity

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COMPONENTS OF LASER
 LASER consists of-
 lasing medium contained in an optical cavity
 pumping source provided by external energy.
 The highly reflective mirrors at each end ensure that the photons
bounce back parallel to the axis so that they turn collide with
excited atoms and stimulate further production of photons

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Principal of LASER light:
 Electrons in the atoms of the laser
medium are first pumped to excited
state by external energy source.
 Electrons are stimulated by external
photon to emit their stored energy in
form of photons-STIMULATED
EMISSION

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Cont…
 Photons now strike other excited
atoms to release even more photons.
 Photons move back and forth between
two parallel mirrors-Light amplification.

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Types of lasers acc. to materials used
 Solid : Nd: YAG(Neodymium doped: Yttrium Almunium Garnet)
laser
 Liquid : Organic dye laser(Rhoda in 6G,disodium fluorescein)

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.
 Gas: Helium Neon(HeNe)laser, CO2,Argon and Krypton Gas laser
 Semiconductors: Gallium Arsenide Diode laser
 Excited dimer(Eximer laser) : Argon fluoride and Krypton fluoride

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Depth penetraction of LASERs

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Comparison of different types of laser

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LASER reaction to tissues
 When laser radiation strikes a tissue, the
temperature begins to rise
 10 °-45°C:Conformation change of proteins
 50°C:Reduction of enzyme activity
 60°-99°C:Coagulation begins
 100°C and above:Vaporization starts
 400°-500°C:Char starts to burn

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Modes of LASER
 Continuous:Continuously pumped,emits light
Continuously (>0.1 sec)
 Pulse:Laser energy delivered with each peak over
an extremely short period of a few
nanoseconds(<0.1 sec)with rest period(allows time
for tissue to cool down)
 Q-switched:Allows a high buildup of energy within
the tube which is then released over a very short
duration of a few nanosecond (<0.1nsec)

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Delivery system of Laser Beam:
 Articulated arm
 Mirror lens system
 Hollow wave guides
 Micromanipulator
 Fiberoptic fiber
 Fiber tip
 Robotic scanner

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 Articulate arm:
System of hollow tubes & mirrors to direct laser beam to tissue
 Micromanipulator:
Focussing devise connected to microscope create an accurate &
reproducible spot on target tissue

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 Fiber optic cable:
 Inserted through biopsy channel of a fibro optic
endoscope
 End of laser fiber must protrude beyond the end of
endoscope

z Different types of Laser
1.CO2 LASER –
 Most commonly used Laser in ENT
 Highest power with continuous wave laser
used for- cutting or ablating tool using
water as target chromophore
 Focus to <500 mm area and seals blood
vessels less than 0.5 mm
 Used in Pulsed mode for thermal
relaxation time(post-op less pain and less
edema)

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Cont…
 Used in majority of procedures except
those requiring coagulation of laser
vessel
 Its use on the vocal cords has the
advantage of producing minimal
scarring therefore glottic competency
is rarely compromised

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.
 Uses of CO2 Laser:
 Laser stapedotomy
 Recurrent respiratory papillomatosis
 In pediatric pt.- Surgery for web,subglottic
stenosis,capillary hemangiomas
 Laser cordotomy

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Infantile vascular hemangioma

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Recurrent respiratory Papillomatosis

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2.Nd:YAG Laser(Neodymium-doped
Yttrium Aluminum Garnet)
 Solid state laser with fiberoptic carrier
 Deeper penetration(upto 4 mm)
 Ideal laser for ablation, coagulation and
hemostasis in vascular malformation
 Limitation –Greater scatter than CO2
Deep thermal injury
Risk for transmutation injury

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.
 Uses of Nd: YAG laser:
 Ablation palliation of obstructing
Tracheo-bronchial lesion, oesophageal
lesion.
 Removal of malignant tumors in oral
cavity

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Excision of oral malignant cancer

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3.KTP Laser(Potassium-Titanyl-Phosphate)
 Continuous wave(cw)mode for- cutting tissue
 Pulsed mode for- vascular lesion
 Q-switched mode for-red/orange tattoo pigment
 Delivery: Insulated fibers,
Fiber handpicked,
Scanner or microscope for CW/pulsed
mode

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.
 Uses of KTP Laser:
 Tonsillectomy
 Pigment dermal lesion
 Revision stapedotomy

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4.Helium-Neon Laser
 This laser emits at 633 nm in visible
spectrum
 Has also been used in-wound
healing and pain treatment

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5.Argon Laser:
 Mainly used in ophthalmological
procedures,Stapedotomy in
otosclerosis
 Limitation: Absorbed by epidermal and
dermal tissue due to melanin
 Higher prevalence of post operative
pigmentation alteration and fibrosis

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A)Laser selection in Lower airways
 Most common laser used:CO2,Nd:YAG
 INDICATIONS:
 Laser photo resection of obstructive
airways lesions- Subglottic and tracheal
stenosis,Granulation tissue,foreign
body,benign tumors,
 Photodynamic therapy: for CA in
situ,juvenile laryngotracheobronchial
papillomatosis

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Indications for LASER in Larynx
 Congenital disorder: Laryngomalacia,
laryngeal web,mucous cysts
 Functional dysphonia: Plica ventricularis
 Chronic inflammatory conditions: Reinke’s
edema, epidermis cysts
 Chronic trauma:Hematoma,ulceration
andscarring
 Neuromuscular disorder:Bilateral vocal
cord palsy,

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Cont..
 Recurrent respiratory papillomatosis
 Benign laryngeal
tumors:Cysts(Intracordal epidermis
mucous retention cysts),Laryngocoele
 Chronic hyperplastic
laryngitis:Leukoplakia,erythroplakia,spec
kled erythroplakia
 Excision for malignancy:Ca. In situ,micro-
invasive carcinoma,verrucous
carcinoma,supraglottic ca.

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B)Lasers for Nasal Surgery
 Create relatively bloodless field in endonasal
surgery
 CO2 laser is not commonly used in endonasal
laser surgery because of-
Poor coagulation
Poor haemostasis
Increased risk of synechiae
formation post operatively
 KTP laser is better in nasal surgery

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Benefits to the patient from laser technology in
Nose
 Minimally invasive surgery
 Minimal bleeding
 Minimal postoperative edema and
crusting
 Ambulatory surgery
 Cost effective

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Indications of laser surgery in nose :
 Reduction of turbines
 Nasal polyps removal
 Dacryocystorhinostomy(DCR)
 Laser assisted septoplasty
 FESS
 MISCELLANEOUS: Rhinophyma,
Recurrent Epistaxis,
Hereditary hemorrhagic telangiectasia,

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Turbinate Reduction
Laser Surgery

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Laser surgery for Nasal Polyp

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.
 Choanal atresia or stenosis,
 Nasopharyngeal stenosis,
 Adenoids hypertrophy,
 JNA,
 Nasopharyngeal carcinoma

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C)Laser selection in Otology:
 In vascular lesion of ear –Nd:YAG
Laser with its deep scatter
 For debulking of tissue- CO2 laser
 Temporal bone surgery-Visible KTP
laser

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Uses of Laser in otology
1.External auditory canal:
 Vascular lesion like haemangiomas,
telangiectasias,
 Aural polyp,
 Stenosis of EAC,
 Reshaping of cartilage
2.Tympanic membrane lesion:
Epidermoid cysts

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Laser surgery for Aural polyp

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Cont…
3.Middle ear cleft:
 Laser assisted myringoplasty,
 graft welding of tympanic membrane defects
 Laser assisted ossicular surgery
 Cholesteatoma surgery
 Vascular lesion of Middle ear
4.Inner ear:
 Cochleostomy,
 Labyrinthectomy

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D)Orofacial Surgery:Laser preference
 For vaporization and cutting in soft
tissue-CO2 laser is indicated
 For coagulation in Soft tissue- Nd:YAG
 For hard tissue such as bone,dentine
or enamel- Erbium:YAG used

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Use of Lasers in Orofacial surgery
 High intensity Laser treatment(HILT):
. Oral mucosa premalignant leucoplakia,
. Mucosa haemangiomatous lesion,
. Laser hemiglossectomy
 Low intensity Laser therapy(LILT):
. Post herpetic neuralgia,
. Idiopathic neuralgia

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Laser treatment for Trigeminal Neurolgia

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Cont…
 Surgery for snoring and obstructive
sleep apnea:Uvulopalatoplasty,
Midline glossectomy,
Linguloplasty
 Laser palatine tonsillectomy
 Laser lingual tonsillectomy
 Cryptologic for halitosis

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Uvulopalatoplasty for snoring and OSA patients

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Hazards of laser
 Damage to biological non-target tissue:Corneal or
retinal eye injury,skin and mucosa burn
 Damage to non-biological material:Anaesthetic tube
and draping material
 Side effect due to laser by product:Laser generated
smoke
 Laser malformation such as electric shock

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LASER Classification and Safety:

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Safety consideration:
Education:
 Appropriate credential certifying mechanism
required for physician, nurses to become
involved with each.
 Develop education policies for surgeon,
anaesthesiologist and nurses
 Periodic review of all laser related complications

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Eye & Skin protection :
 Laser absorbed by water (e.g., CO2) damage the
anterior portion of the eye ( cornea,lens).
 Protection :- Use wavelength specific Eye glass with
side protector
 Double layer of saline moistened eye pad
 Completely drape with saline saturated surgical towel

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Smoke Evacuation
 Separate suction set up for smoke and steam
evacuation from operative field
 Constant suctioning prevent inhalation by
patient surgeon or personnel

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Anaesthetic consideration and risk of
intraoperative fire :
 ET tube ignition & injury to laryngotracheal mucosa :
Tubes are made laser safe in two ways by using-
1. Non-combustile or fire-resistant materials such as a
metal spiral tube.
2. Compressed foam (Merocel Laser guard)-which is
made laser resistant by moistening

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 An ET tube should be kept out of the operating field if
at all possible
 If this cannot be done, a Laser –resistant tube should
be used

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 If a Laser-resistant tube cannot be used,the
surgeon should be able to identify the tube in
the operative field at any time
 In this case the part of the tube closest to the
surgical site can be protected by covering it
with wet neurosurgical cotton

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 50 ml bulb syringe and basin of saline should be
available
 Stop ventilation immediately
 Withdraw tube and flush saline
 Re-establish airway immediately

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 Bronchoscopy to assess degree of injury
 I/V steroids
 Remains intubated
 Repeate bronchoscopy
Surgical Fire in LASER Laryngeal surgery

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 Keep Laser in standby mode when not in operation
 Bystanders should remain at a safe distance
 Warning sign & locked doors
 Wear protective glasses in the laser enviroment

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 Never use the laser as a pointer(co-workers are not a target)
 Do not aim the beam at other instruments(reflections)
 Check your system(be informed)

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