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SECTION VII — Diseases of Oesophagus
Figure 70.1. Foreign body food passage. (A) PA view showing 50 paisa coin. (B) Lateral view of the same.
3. Dysphagia. Obstruction to swallowing may be partial
or total. Partial obstruction becomes total with time
due to oedema.
4. Drooling of saliva. It is seen in cases of total obstruction. Saliva may be aspirated causing pneumonitis.
5. Respiratory distress. Impacted foreign body in the upper oesophagus compresses posterior wall of trachea
causing respiratory obstruction especially in children.
Laryngeal oedema can develop.
6. Substernal or epigastric pain. It may occur due to oesophageal spasm or incipient perforation.
7. In partial obstruction, patient may still be taking
normal food with little or no discomfort for a few
days. Even X-rays may be normal. No complacency
should be observed and an endoscopic examination
performed when history and physical examination
strongly suggest a foreign body.
SIGNS
1. Tenderness in the lower part of neck on the right or left
of trachea.
2. Pooling of secretions in the pyriform fossa on indirect
laryngoscopy. They do not disappear on swallowing.
3. Sometimes a foreign body may be seen protruding
from the oesophageal opening in the postcricoid
region.
bones, pieces of wood or plastics are radiolucent. Barium
swallow is avoided as it may spill over into the larynx
and thus delay the subsequent endoscopic procedure and
also make it more difficult. Also look for multiple foreign
bodies (as coins). A disc battery may elude as it may cast a
double shadow or stacked coin appearance.
MANAGEMENT
1. endoscopic remoVal. Most of the foreign bodies in
oesophagus can be removed by oesophagoscopy under
general anaesthesia. Both rigid and flexible scopes have
been used to remove foreign bodies from the oesophagus.
Rigid oesophagoscope, appropriate for the size of patient
with proper type of forceps is preferred. Soft (meat pieces
without bone, vegetable matter) and blunt objects can be
removed with flexible scopes (see Table 70.1 for comparison of the two procedures).
A hypopharyngeal speculum resembling a laryn-
goscope with long blade is less traumatic and more
INVESTIGATIONS
Posteroanterior and lateral views of neck and similar
views of the chest including abdomen are taken. They reveal most of the radio-opaque foreign bodies and their location (Figures 70.1–70.3). Foreign bodies of the oesophagus lie in the coronal plane in PA view and edge on in the
lateral view. It is just the reverse in tracheal foreign bodies
because of orientation of vocal cords. Radiolucent foreign
bodies may show as an air bubble in cervical oesophagus
in X-ray soft tissue lateral view of neck. Failure to see a
foreign body on X-ray does not rule it out as small fish
Figure 70.2. A fish bone in the oesophagus. Also note the presence
of a bubble of gas (arrow).
Figure 70.3. Two metallic foreign bodies. A large ring at cricopharyn-
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geal area and a small piece in abdomen (arrows).
convenient to use for foreign bodies lodged near the upper sphincter.
Chapter 70 — Foreign Bodies of Food Passage
397
the passage of foreign body. Operative interference is required when:
(a) Patient complains of pain and tenderness in abdo-
men.
(b) Foreign body is not showing any progress on periodic
X-rays taken at a few days interval.
(c) Objects are sharp and likely to penetrate or get ob-
structed, e.g. nails, pins, needles, sharp bones, denture fragments, razors and long thin wires.
(d) Foreign body is 5 cm or longer (e.g. hair pin) in a
child of 2 years; it is unlikely to pass through turns
of duodenum. A disc battery larger than 1.5 cm in a
child of 6 years and remaining in stomach for 48 h.
(e) There is pyloric stenosis.
COMPLICATIONS OF OESOPHAGEAL
FOREIGN BODY
1. Respiratory obstruction. This is due to tracheal compression by the FB in the oesophagus, or laryngeal
oedema especially in infants and children.
2. Perioesophageal cellulitis and abscess. It occurs in
the neck.
3. Perforation. Sharp objects may perforate the oesophageal wall, setting up mediastinitis, pericarditis or empyema. They may perforate the aorta and prove fatal.
4. Tracheo-oesophageal fistula. Rare.
5. Ulceration and stricture. Overlooked foreign bodies
may cause slow ulceration and stricture formation.
2. cerVical oesophagotomy. Impacted foreign bodies
or those with sharp hooks such as partial dentures located
above thoracic inlet may require removal through an incision in the neck and opening of cervical oesophagus.
DISC BATTERIES
Ingestion of disc batteries is becoming common because
of their widespread use in hearing aids, toys, calculators
and other electronic devices. They contain sodium hy-
3. transthoracic oesophagotomy. For impacted foreign bodies of thoracic oesophagus, chest is opened at the
appropriate level.
A foreign body which has passed the pylorus of stomach may pass through rest of gastrointestinal tract without difficulty; stool should be examined daily for 3–4 days
for spontaneous expulsion. Patient should take a normal
diet and no purgative should be administrated to hasten
droxide, potassium hydroxide and mercury which leaks
through them to cause oesophageal injury. Prolonged
sojourn at one place causes complications like stricture,
perforation, tracheo-oesophageal fistula, mediastinitis
and death.
It is observed that a disc battery causes damage to mucosa in 1 h, muscle coat in 2–4 h and perforation of the
oesophagus in 8–12 h, therefore it should be removed
TABLE 70.1 COMPARATIVE ADVANTAGES AND DISADVANTAGES OF RIGID AND FLEXIBLE OESOPHAGOSCOPY
Rigid Flexible
Anaesthesia General Topical or topical with sedation
Route Oral Oral (nasal for transnasal oesophagoscopy for diagnosis)
Jaw-neck abnormalities Cannot be done due to technical difficulty Can be done
Structures seen Up to oesophagus Oesophagus, stomach, pylorus and duodenum
Admission Requires admission Mostly an outdoor procedure
Foreign bodies removal Easy, various types of forceps can be used; end
of oesophagoscope helps to ensheath sharp
objects
Accessories May require telescopes for magnification.
Documentation is difficult
Cost Cost is more, requires admission to hospital.
Charges of anaesthesia and operation theatre
also raise the cost
Only soft small foreign bodies can be removed. Limited
numbers of forceps that can pass through the channel
can be used. Ensheathing of FB not possible. Overtube
may be required. Difficult to remove impacted FB
Inbuilt facility of camera, bright light, magnification and
easy documentation
Reduced cost
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SECTION VII — Diseases of Oesophagus
promptly from the oesophagus. If lodged in stomach, a
radiographic follow up is conducted every 4–7 days and
parents instructed to observe stools daily for spontaneous
passage. If patient is a child under 6 years and battery size
is 1.5 cm or more, follow-up X-ray examination is done
after 48 h of ingestion and if the battery is still in stomach, it is removed endoscopically.
SOME CAVEATS IN OESOPHAGEAL
FOREIGN BODY
• It is not recommended to remove oesophageal foreign
bodies by Foley’s or balloon catheter, as they can be
aspirated when pulled up into the pharynx. Removal
under direct vision is always preferable.
• Do not try to push foreign bodies down into the stom-
ach for spontaneous expulsion later.
• Use of papain, a meat tenderizer, is not recommended
if a bolus of meat is stuck up. It can digest the oesophageal wall. Also sometimes meat contains bone which is
not digested.
• Do not use glucagon to relax lower oesophageal
sphincter for foreign body to pass. It does not relax a
stricture or oesophageal ring if foreign body is held due
to that.
SECTION VIII
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Recent Advances
S e c t i o n o u t l i n e
71 Laser Surgery, Radiofrequency Surgery, Hyperbaric Oxygen Therapy and Coblation, 401
72 Cryosurgery, 409
73 Radiotherapy in Head and Neck Cancers, 411
74 Chemotherapy for Head and Neck Cancer, 419
75 HIV Infection/AIDS and ENT Manifestations, 421
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Chapter 71
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Laser Surgery, Radiofrequency Surgery,
Hyperbaric Oxygen Therapy
and Coblation
I. LASER SURGERY
A. LASERS
LASER is an acronym for Light Amplification by Stimulated
Emission of Radiation.
principle. Normally, an atom is in a stable form, i.e. the
electrons, equal to the number of protons, are revolving
around the nucleus in a fixed orbit. When given energy,
electrons change their orbits away from the nucleus and
the atoms are then called “excited” but this excited state
of atoms does not last long. The atoms soon release their
absorbed energy automatically (spontaneous emission)
and return to their original state. If photons are made to
strike these excited atoms, the decay of the atoms is accelerated and both the incident and the absorbed photons
are released (stimulated emission). This stimulated radiation is amplified with the help of mirrors. Thus, lasers
are electromagnetic radiations. They have specific wavelength, which depends upon the type of lasing medium
such as argon, carbon dioxide, Nd:YAG, helium, etc.
TYPES OF LASERS
Depending upon the lasing medium, various types of
lasers with differing wavelength can be created. Lasing
medium can be solid (ruby, Nd: YAG or potassium titanyl
phosphate); gas (CO2 or Helium–Neon) or liquid (pumped
inorganic dye in a glass tube). Various types of lasers are
given in Table 71.1.
EFFECTS OF LASER ON TISSUES
When a laser hits the tissue it can meet the following
fates (Figure 71.1):
1. Reflection. Part or whole of laser light is reflected back.
2. Absorption. Laser energy is absorbed by the tissue. It
is the absorbed energy which produces its effect on
tissues.
3. Scatter. Laser energy scatters in the tissues and its pen-
etration deep into the tissues becomes limited. Shorter
the wavelength, more of the energy is scattered.
4. Transmission. The light is transmitted through the tissue
without causing any effect on tissues through which it
passed. Argon laser has been used to coagulate retinal ves-
sels without any damage to cornea, lens or the vitreous.
Lasers which are reflected or transmitted through the
tissue do not cause any effect on tissues.
Effect of laser on the tissues depends on the absorbed
energy. At a temperature of 60 °C, there is protein denaturation but tissues can recover. At 80 °C there is degradation
Figure 71.1. Effect of laser beam on tissue: (a) reflection, (b) transmission, (c) scatter and (d) absorption with tissue destruction.
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SECTION VIII — Recent Advances
of collagen tissue and at 100 °C, cells and their pericellular
water convert into heat that causes tissue ablation. Thus
lasers can be used to cut (make incision), coagulate blood
vessels or vaporize the tissue. When a burn is created by laser beam, it always causes some degree of collateral damage.
Zones of tissue damage can be divided into (Figure 71.2):
1. Zone of vaporization. A crater is created due to tissue
ablation and vaporization leaving behind only a few
flakes of carbon.
2. Zone of thermal necrosis. This is just adjacent to the
above zone. There is tissue necrosis. Small blood vessels, nerves and lymphatics are sealed.
3. Zone of thermal conductivity and repair. This zone
recovers with time.
TABLE 71.1 VARIOUS TYPES OF LASERS
AND THEIR WAVELENGTH
Type of laser Wavelength
• Argon
• KTP(Potassiumtitanylphosphate)
• Nd:YAG(Neodymium:yttriumaluminium
garnet)
• CO2 (Carbon dioxide)
• Ho:YAG(Holmium:YAG)
• Er:YAG(Erbium:YAG)
• Diodelaser
• Tunabledyelasers
488–514 nm
532 nm
1060 nm
10,600
2100 nm
2960 nm
600–1000 nm
577 nm
PROPERTIES AND EFFECTS OF LASERS
Depending on the wavelength, laser energy produces the
following effects:
1. Photothermal. It produces heat energy which is used
to cut, coagulate or vaporize tissues.
2. Photoacoustic. It can be used to break stones and has
been used in lithotripsy.
3. Photochemical. Ultraviolet lasers with wavelength of
248 and 312 nm can ionize DNA and RNA, respectively
and are carcinogenic. This effect of specific lasers (e.g.
argon tunable dye laser) has been used in photodynamic therapy to selectively destroy cancerous tissue.
4. Photodissociation (LASIK lasers). Photodissociation
breaks C–C bonds, divides collagen without heating it,
e.g. excimer laser used in LASIK procedures to reshape
cornea for refractive errors.
ELECTROMAGNETIC SPECTRUM
AND LASERS (FIGURE 71.3)
Visible lasers. Visible light has a wavelength of 400–
700 nm (more precisely 380–760). Lasers falling in this
range of wavelength are visible lasers. They have different
colours from violet to red (VIBGYOR). As the laser light
is visible, they do not require a separate aiming beam to
focus them. Argon laser (488–514 nm) has a blue colour.
KTP laser (512 nm) has a blue–green colour (Table 71.2).
Figure 71.2. Zones of tissue destruction caused by lasers.
inVisible lasers. Lasers in ultraviolet zone (1–380 nm)
and infrared zone (>760 nm) are not visible. Infrared
lasers are further divided into near-infrared lasers (760–
2500 nm) and mid-infrared lasers (2500–50,000 nm). There
are no far-infrared lasers (50,000–1,000,000 nm).
Lasers which can be transmitted through optical
fibres.
• Argon
• KTP
• Nd: YAG
• Er: YAG
• Ho: YAG
• Diode laser
Figure 71.3. Electromagnetic spectrum.
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403
TABLE 71.2 DIFFERENT TYPES OF LASERS WITH
THEIR WAVELENGTH, ZONE AND SPECTRUM
Laser wavelength (nm) Zone Visibility Example
1–380 Ultraviolet Invisible Excimer laser
(193 nm)
380–760
(400–700)
760–2500 Near-infrared Invisible Nd: YAG
2500–50,000 Mid-infrared Invisible Er: YAG (2960 nm)
50,000–
1,00,000
Visible zone
(VIBGYOR)
Far-infrared
No such
lasers exist
Visible
Colours
Argon
(488–514 nm)
KTP (532 nm)
(1060 nm)
Ho: YAG
(2100 nm)
CO2 (10,600 nm)
LASERS FOR USE IN EAR SURGERY
Lasers approved by FDA for otological work include:
• Argon – 514 nm
• KTP – 532 nm
• CO2 – 10,600
• Er: YAG – 2960
Otologic lasers have been used to vaporize small glomus tumours, acoustic neuromas, small A-V malformation, granulation tissue or adhesions in the middle ear.
Lasers have also been used to do a myringotomy, drilling
a hole in incus or malleus for ossicular reconstruction,
welding of grafts in tympanoplasty or coagulating membranous posterior semicircular canal in benign paroxysmal positional vertigo and in stapes surgery to make a
hole in stapes footplate.
OPERATIONAL PARAMETERS OF LASERS
They are important when operating with lasers.
1. Wavelength of laser. Properties of lasers depend on
their wavelength.
2. Power. It is the output from the machine and is meas-
ured in Watts. Higher the power, more is the energy
delivered to tissues.
3. Exposure time. It is measured in seconds.
4. Spot size. It is the area exposed to beam. Spot size is
minimum at the focal length. Focused beam is used
for cutting and decofocussed beam for coagulation or
ablation of tissues.
5. Power density. It is power delivered per unit area of
spot size and is measured in Watts/cm2. It indicates in-
tensity of beam.
Powerdensity (measuredinwatts percm)
=
Area of spot size in cm
6. Fluence or radiant exposure. It is power density mul-
tiplied by duration of exposure in seconds and meas-
ured in joules/cm2. It indicates total energy delivered
to tissues per unit area.
2
Powerinwatts
2
Fluence(measuredin joules)
Powerdensity(measuredinwatts)Time(seconds)
Mode
1. Continuous mode. It provides constant stable energy;
as the active medium is continuously kept in a stimulated mode.
2. Pulsed mode. Gives interrupted beam as the active
medium is intermittently activated for a short time.
3. Q-switched mode. Provides very short pulses in a controlled manner. Pulses range between 10 ns and 10 µs.
Delivery System
Articulated arm is used for CO2 laser as it does not pass
through optical fibres.
• Optical fibres require micromanipulator or a hand
piece at the end of an articulated arm containing reflective mirrors to direct the light when working through a
microscope.
• Optical fibres. Near-infrared (Nd: YAG) and visible
lasers (argon and KTP 512) can pass through optical
fibres. Invisible lasers require an aiming beam (e.g. He–
Ne) of visible light to locate the spot.
ADVANTAGES AND DISADVANTAGES
OF LASERS
Advantages include precise incision, easy and rapid ablation of tissues, excellent haemostasis, and minimal postoperative pain and oedema of tissues.
Some lasers can be passed through optical fibres and can
thus be used through flexible endoscopes, straight or curved
tubes to ablate tumours situated in difficult locations in the
tracheobronchial tube or nasal crevices or clefts.
Disadvantages include high cost in the purchase of
equipment and its maintenance, special training in operating with lasers, hazards in the use of laser requiring
special precautions, and safety measures and special anaesthesia requirements to avoid fires.
CLINICAL APPLICATIONS
OF INDIVIDUAL LASERS
Clinical use of lasers is determined by:
1. Wavelength of laser
2. Selective absorptive property of tissues
3. Ability of laser to pass through flexible optical fibre
4. Mode of delivery (continuous wave mode or pulsed
mode)
argon laser. It lies in the visible spectrum, wavelength
488–514 nm, blue–green in colour, easily transmitted
through clear fluids, e.g. cornea, lens and vitreous humour. It is absorbed by haemoglobin and pigmented tissues, and thus it is used to treat port–wine strain, haemangioma and telangiectasias. When focused on a small
point, it can vaporize the target tissue. It has been used
to create a hole in stapes footplate but requires a drop of
blood for its absorption at that site so that it is not reflected by white bone of stapes footplate. It can be delivered
by optical fibres.
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SECTION VIII — Recent Advances
ktp laser. It lies in visible spectrum, wavelength
532 nm, properties are similar to Argon laser, absorbed
by haemoglobin, can be delivered through optical fibres.
Clinically it has been used in stapes surgery, endoscopic
sinus surgery to remove polyps or inverted papillomas
and vascular lesions, microlaryngeal surgery for excision
of polyps, cysts, papillomas, contact ulcers, laryngoceles
and early malignant lesions. It has also been used to remove tracheobronchial lesions through bronchoscope.
nd: YA G . It has a wavelength of 1064 nm (double that
of KTP), lies in near-infrared zone of electromagnetic spectrum and is invisible; thus it requires a separate aiming
beam of visible light and can pass through flexible optical
fibres. It can pass through clear fluids but is absorbed by
pigmented tissue and thus has been used in the eye and
urinary bladder. It creates nearly 4 mm zone of necrosis and
thermal coagulation both in depth and laterally, therefore
useful for coagulation of blood vessels or control bleeding.
Clinically it has been used to debulk tracheobronchial
and oesophageal lesions for palliation, hereditary hemorrhagic telangiectasia and turbinectomy.
co2 laser. Wavelength 10,400 nm, invisible, requires an
aiming beam of helium–neon laser, cannot pass through
flexible optical fibres, and requires articulated arm with a
series of reflective mirrors to direct the beam to the target
area. Requires a micromanipulator if working through an
operating microscope, can be absorbed by water or clear
glass. Ordinary glass or lenses of the microscope can also
absorb the rays as well as the glasses worn by the operator.
It is absorbed by tissues high in water and is not colour dependent. Reflection and scatter through tissues is
minimum. It causes minimal effect on adjacent tissues in
depth and laterally. CO2 laser is the workhorse laser and
has been widely used in ENT. It can cut precisely, coagulate bleeders and vaporize tissues.
Clinically it has been used in laryngeal surgery to excise vocal nodules, polyps, cysts, granulomas or juvenile
laryngeal papillomas. It cuts precisely and a spot size of
0.3 mm can be achieved; lesion is first delineated and
then dissected with microlaryngeal instruments. Microflaps can be raised to treat Reinke’s oedema. It is also used
for leukoplakia, T1 lesion of vocal cord or localized lesions
of supraepiglottis and infraepiglottis. Transverse cordotomy and endoscopic partial or complete arytenoidectomy
can also be done in bilateral abductor paralysis.
In the oropharynx, it has been used to excise benign
or malignant lesions. Laser tonsillectomy can be done in
patients with coagulopathies.
Plastic surgeons have used it to remove benign and malignant lesions of skin and to vaporize naevi and tattoos.
diode laser. It has a wavelength of 600–1000 nm. It can
be delivered by optical fibres. It is moderately absorbed by
melanin and haemoglobin. Diode lasers have been used
in turbinate reduction, laser-assisted stapedectomy and
mucosa-intact tonsillar ablation.
SAFETY PRECAUTIONS IN THE USE OF LASER
It is important to observe safety precautions in the use of laser as they can cause damage to eyes (retina, cornea or lens),
skin and airways or cause endotracheal tube fires which can
be catastrophic. The measures to be taken include:
1. Education of the staff. All personnel working with
lasers, doctors, nurses and technical staff of the operation theatre should be educated about the safe use of
lasers and their hazards.
2. Protection of eyes and skin. All the staff working in
the operation theatre should use wavelength-specific
glasses. Glasses should also have side protectors to
avoid damage by any reflected rays. Plain glasses for
CO2 laser, blue–green for Nd: YAG and amber coloured
for Argon laser are used. Wavelength-specific glasses
are available with all the lasers. Lasers with visible or
near-infrared range of electromagnetic spectrum (400–
1400 nm) damage the retina and those with ranges
less than 400 nm and more than 1400 nm damage the
cornea and sometimes even the lens causing corneal
opacities or cataracts. Patient’s eye should be protected
by double layer of saline-soaked cotton eye pads. All
other exposed parts of face should be covered by saline-soaked wet towels.
3. Endotracheal tubes. Wavelength-specific endotracheal tubes are available. Rubber tubes are better than
PVC ones; the latter are less resistant to laser beam
and also produce more damage if accidental fires take
place; also their breakdown products are more toxic.
Tubes can be wrapped with reflective aluminium foils
to avoid burns. Colourless or silicon tubes can be used
with Nd: YAG laser but they should not have any black
or dark lettering or a lead-lined marking along the side.
4. Anaesthetic gases. Halothane or enflurane are used
as they are noninflammable. Nitrous oxide gas, being
oxidizing, is not used.
5. Evacuation of smoke. In addition to suction tube
being used by the surgeon to aspirate blood and secretions, another suction tube should be available to
remove smoke and steam created by vaporization of
tissues. It should not spread into the OT and be inhaled by OT staff. Smoke may be mutagenic and has
also been shown to contain virus particles from tissue
vaporization of viral papillomas.
6. Tube fires. This is a dreaded complication and several
cases are on record. In case of tube fire, stop ventilation
immediately, pour saline with a syringe and withdraw
the tube simultaneously. Re-establish the airway with a
new endotracheal tube. Perform a bronchoscopy to assess the degree of damage to the tracheobronchial tube
and give intravenous steroids. Carefully follow the patient postoperatively with repeat bronchoscopies.
PRECAUTIONS IN THE USE OF LASERS
1. Display a sign outside OT “Lasers In Use.”
2. Close the OT door. No entry or exit of staff permitted.
3. Protective glasses, specific for the wavelength of laser,
being used should be worn by the surgeon, nurses and
other OT personnel. Glasses should have side protectors.
(a) CO2 laser. Plain clear glasses. Optics of microscope
are also protective.
(b) Argon or KTP lasers. Amber colour or orange–yel-
low glasses.
(c) Nd: YAG. Blue–green glasses.
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405
4. Wet saline pads are placed on the eyes.
5. Wet saline-soaked towels for face or exposed parts of
skin.
6. Use wavelength specific endotracheal tube or wrap the
tube with aluminium foil.
7. Use methylene blue-coloured saline for cuff of endotracheal tube.
8. Use noninflammable gases such as enflurane. Oxygen concentration in inhaled gases should not exceed
40%. Do not use N2O.
9. Keep a bowl and a syringe filled with saline in readiness in case of tube fires.
B. PHOTODYNAMIC THERAPY
It is an upcoming newer modality of treating cancer of
skin, larynx, nasopharynx, tumours of aerodigestive tract
and endobronchial tumours. It is based on the principle
of injecting a photosensitizing agent which is taken up
preferentially by the tumour cells and then exposing the
site to a specific wavelength of the laser. Laser activates the
photosensitizing agent which brings about destruction of
cancer cells but spares the normal tissues. Photodynamic
therapy has also been used for recurrences after surgery,
radiation or chemotherapy. Photosensitizing agents used
intravenously include haematoporphyrin derivative (for
head and neck cancers) and photosan-3 (for endobronchial tumours). Topical sensitizer, delta aminolevulinic
acid, has been used for skin cancers (basal cell carcinoma
and Bowen disease).
Laser often used in photodynamic therapy is argon
tunable dye laser with a wavelength of 630 nm. It also has
the advantage of delivery through flexible fibres. Also, by
changing the dye, lasers with different wavelengths can
be produced. Patients receiving photodynamic therapy
should avoid exposure to sunlight and use sun-protective
clothing to avoid photosensitive skin reactions which
may continue for several weeks.
II. RADIOFREQUENCY SURGERY IN ENT
Radiowaves have been used surgically to reduce the volume of tissues. It has been used on inferior turbinates to
relieve nasal obstruction; on soft palate to relieve primary
snoring, upper airway resistance and sleep apnoea; and
on the base of tongue to relieve sleep apnoea. It has also
been used for the treatment of lingual thyroid.
The radiofrequency (RF) device generates electromag-
netic waves of very high frequency between 350 kHz and
4 MHz. Usually 460 kHz is used. RF is delivered through
various probes according to the site of ablation. The
probe, inserted into the tissues, causes ionic agitation,
heats up the tissues which result in protein coagulation
and tissue necrosis but no charring. Later scar formation
occurs in 3 weeks with reduction in size of tissue. Usually the temperature is controlled between 80 and 85 °C.
The essential parameters of radiofrequency are the power
(in Watts), temperature (degrees of Celsius), resistance
(in Ohms), treatment time (in seconds) and total energy
delivered in joules (i.e. Watt × seconds); they can all be
controlled in the device.
Using different types of electrodes, radiofrequency has
also been used to perform tonsillotomy, microlaryngeal
surgery (to remove granulomas, papillomas, cysts), myringotomy, uvulopalatoplasty, correction of rhinophyma
and cosmetic removal of skin lesions. Radiofrequency is
used to cut and coagulate tissues with minimal lateral tissue damage and charring. It is a minimally invasive technique and surgery can be performed as an outdoor procedure. Complications are few. The procedures are cost
effective.
III. HYPERBARIC OXYGEN
THERAPY IN ENT
Hyperbaric oxygen therapy (HBOT) is a treatment modality involving the intermittent inhalation of 100% oxygen in chambers pressurized above 1 atmosphere absolute (ATA). ATA is the unit of pressure and 1 ATA is equal
to 760 mm of mercury or pressure at sea level. When all
pressures to which a person is exposed are summed up,
the result is called atmospheres absolute. (Committee on
Hyperbaric Medicine, Undersea & Hyperbaric Medicine
Society 1976).
HBOT has been used as an adjunctive therapy for sudden sensorineural hearing loss (SSNHL) as it raises the
amount of oxygen in the inner ear by diffusion, which
activates cell metabolism leading to restoration of ionic
balance and electrophysiological functions of cochlea.
Due of lack of definite cause of SSNHL, its treatment
is largely empirical and includes use of a wide variety of
therapies like systemic and intratympanic steroids, vasodilators, antiviral and anticoagulants to counteract possible inflammatory mechanism modifying hydrostatic
pressure and improving cochlear blood flow. The possible
final goal of any treatment modality of SSNHL is the restoration of oxygen tension in the cochlea to encourage
healing and return of hearing to normal levels.
The high spontaneous recovery rate of SSNHL and its
low incidence make validation of empirical treatment
modalities difficult. HBOT in recent years has gained
relevance for treating SSNHL in combination with other
agents. The Undersea & Hyperbaric Medicine Society (UHMS)
after a review of data available across the world has approved
the use of HBOT in SSNHL in October 2011.
INDICATIONS FOR HBOT
Over the last two decades, animal studies and clinical trials have produced reasonable scientific evidence or wellvalidated clinical experience. This has led to a renaissance
of HBO and produced a set of indications for which HBO
is beneficial (Figure 71.4).
Evidence-based Indications
(Approved by UHMS)
1. Healing in problem wounds, diabetic or venous
2. Necrotizing soft tissue damage including malignant
otitis externa
3. Radiation tissue damage
4. Carbon monoxide poisoning
5. Crush injury and other acute traumatic ischaemia
6. Decompression sickness
7. Air/gas embolism
8. Compromised skin grafts and flaps
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