2. LASER – Light Amplification by Stimulated
Emission of Radiation
Laser system – compact tube in which
medium of laser can be filled. Foot control
to use for appropriate period
Principle
Vaporizes the tissue
Cuts (make incision)
Coagulates blood vessels
Break stones – lithotripsy, destroys cancer
cells
3. Types of lasers
Solid – Nd:Yag, KTP
Gas – CO2, argon, helium-neon
Depending on wavelength
Visible – 380-760 nm
Argon 488-514 nm blue colour, KTP 512nm
blue green colour
Invisible
UV zone – 1-380nm
Infrared - > 760 nm - Nd:Yag 1064 nm, C02 –
10600 nm
4. Argon laser
Can be delivered by optic fibres
Vascular lesions - haemangioma,
telengectasia
Ear – stapedotomy, lysis of middle ear
adhesions, tympanoplasty graft
Diode laser
600-1000 nm
Cheaper
Turbinate reduction, DCR, tonsillar ablation
Can be delivered through optic fibres
5. KTP 532 laser – Potassium-Titanyl-Phosphate
Use in endoscopic surgery through hand held
probe, delivered through optic fibres
Ear – stapedotomy
Nose – FESS, epistaxis, turbinate reduction,
telengectasis
Oral cavity – leukoplakia, erythroplakia, T1
lesions, advanced tumours for debulking, SMF for
treating trismus, UPPP
Larynx – MLS, T1 ca, laryngocele, stenosis
Bronchoscopy – to temove tracheobronchial
secretions
6. Nd:Yag laser
Neodymium:Ytrium-Aluminium-Garnet
Colourless, can pass through optic fibres
Coagulative, but poor precision – can cause
damage to surrounding tissue
Can be used along with CO2 laser
Obstructive malignancy trachea, bronchi,
oesophagus
Vascular lesions like telengectasia
Lymphangioma
Turbinate hypertrophy
7. CO2 laser
Carbon dioxide
Medium used – mixture of co2, nitrogen and
helium neon gases
Colour – red light of helium neon
MC in ENT
Good precision
Cant pass through flexible endoscopes so need
articulating arm
Can be attached to microscope making hand free
Vaporizes tissue
8. Ear – stapedotomy, acoustic neuroma
Nose – telengectasia, rhinophyma, choanal
atresia, turbinate hypertrophy
Oral cavity – leukoplakia, erythroplakia,
small sup cancers, debulking of large
tumours
Oropharynx- recurrent tonsillitis, T1 tumours
Larynx – papillomas, webs, stenosis,
leukoplakia of cord, arytenoidectomy, T1 ca
Trachea and bronchi – debulking of malignant
tumours
9. Advantages of lasers
Easy and rapid ablation of tissue
Excellent haemostasis
Little surrounding tissue damage
Minimal post op pain and oedema due to
action on peripheral nerves
Faster post op recovery
Blocks lymphatics so prevent metastasis
10. Disadvantages of lasers
High cost of purchase and maintenance
Need special training
Biopsy cant be taken
Hazards – ET tube fire, electric shock, eye
injury, skin injury
Chemical hazards, plumes (vaporized cell
contents)
Damage to vocal cords
Tracheal perforation
11. Safety precautions
Education and training of staff including
surgeons, anaesthesists, nursing, technicians
Protection of eyes
Eye glasses with side protection and different
colours (Nd:Yag – blue, co2- plain) worn by those
working in OT. Parient eye covered with double
layer of saline soaked eye pads/bands
Protection of patient skin by saline soaked
towels, pads, sponges which are moistened
periodically
Evacuation of smoke produced by laser
vaporization of tissue by using 2 suctions – 1 for
blood and mucus other for smoke and steam
12. Anaesthesia gases and equipments –
prevention of ET tube fires
Use only non inflammable gases like
halothane (safest) or ether
Use red rubber or silicone tube wrapped with
reflective metallic (aluminium) foil,
protected with saline soaked cotton
Cuff of tube inflated with saline water
coloured by methylene blue – warns during
leakage of cuff
Use jet ventilation with no cuff
13. ET tube fire
Immediately stop ventilation, pour saline
with syringe and remove tube.
Restore airway with new tube.
Give IV steroids
Perform repeated bronchoscopies to
ascertain damage
A bowl filled with saline and a syringe should
be kept in table while using lasers
Laser OT should be labelled and isolated
with no entry or exit allowed except ot
staff
14. Principle
Injection of photosensitizing agent – DHE
(dihematoporphyrin ether) IV into malignant site
and exposing the site to lasers (argon laser) ->
activates the agent leading to destruction of
cancer cells and sparing of normal tissue
Indications
Treatment of ca larynx, nasopharynx,
aerodigestive tract and endobronchial region
Recurrent ca after CT/RT/surgery
S/E – photosensitivity so wear sun protective
clothing on exposure to sunlight
15. Principle
Use of electromagnetic waves of high frequency
through a hand held probe which is inserted into
tissues -> cuts and coagulates tissues with
minimal normal tissue damage and scarring
OPD procedures with fewer complications
Indications
Inferior turbinoplasty
Surgery on soft palate for sleep apnoea and
snoring
Surgery on base of tongue for snoring, lingual
thyroid
17. Intermittent inhalation of 100% oxygen in
chamber with pressure above 1 ATA
(atmospheric absolute)
Indications
Adjunct treatment of sudden SNHL – patients
with ssnhl > 41 db within 14 days of onset of
symptoms – 100% oxygen at 2-2.5 ATA for 90
minutes daily for 10-20 sittings (6 sittings/
week) – increases amount of oxygen in
tissues by diffusion
19. Rapid cooling or freezing of tissues at v low
temperature at -30 degree celsius followed
by slow thawing leads to destruction of
tissues
Types
Open system
Direct application of refrigerating chemicals
like liquid nitrogen sparay, co2 snow
Closed system
Using cryoprobe ( available in various sizes
and designs and produces tip temperature of
-70 degree celsius)
20. Based on Joule Thomson principle – rapid
expansion of compressed gas through a small
hole produces healing
Gas used are – liquid nitrogen, nitrous oxide, co2
Indications
Head and neck tumours
Benign vascular lesions
Premalignant lesions
Reduction of turbinates, allergic rhinitis
Tonsillitis
21. Herpetic, apthous ulcers in oral cavity
Meniere’s disease
Rhinosporodiasis
Nasal polyp
Epistaxis
Pathology
Tissue destruction by intracellular dehydration,
denaturation of lipoproteins, thermal shock, vascular
stasis of arterial and venous blood and
cryoimmunisation (formation of antibodies against
tissues)
22. Procedure
Anaesthesia – LA/ sedation/ no anaesthesia as
tissue freezing causes numbness
Cryoprobe applied for 2-8 minutes leading to
rapid freezing
Freezed tissue allowed to thaw slowly
Procedure repeated once or twice
Healing by secondary intention with necrotic
stump fall in 3-6 weeks
23. Advantages
Safe procedure
No need for GA
OPD procedure
No excision needed
Low cost
Minimal side effects
Can be tolerated by elderly
Manage patients with bleeding disorders
No haemorrhage
24. Disadvantages
Excision biopsy not possible
Cant assess margins of tumour
Need multiple sittings
Depth of freezing unpredictable
Causes skin pigmentation and loss of hair –
due to destruction of hair follicles
With lasers decline in use