Dr Manpreet Singh Nanda

Associate Professor ENT

MMMC&H Solan

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

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

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

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 tracheobronchialsecretions

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

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

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

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

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

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

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

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 otstaff

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

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

Tonsillotomy

MLS

Myringotomy

Treatment of rhinophyma

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

Tinnitus

Noise induced hearing loss/ acoustic trauma

Malignant otitis externa

Non healing wounds

Compromised skin grafts and flaps

Crush injury

CO poisoning

Decompression sickness

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)

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

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)

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

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

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