Microlaryngoscopy and Brochoscopy (Evaluation of
Airway Problems)
The airway as discussed in the above topic refers to the breathing
tube starting from the lower throat (larynx) to the tubes going
into the lungs (bronchi and bronchioles). Please see WHAT
IS THE AIRWAY? for more detail.
The airway can be evaluated in some cases by looking at pictures
taken using x-rays (chest x-rays, or CT scans) or magnets (magnetic
resonance imaging or MRI). However, sometimes this is not enough.
In these cases, the airway can be examined directly by using a
tube called an endoscope. The specific endoscopes used to look
at the airway are called laryngoscopes and bronchoscopes.
Laryngoscopes are used to look at the upper throat and vocal cords
(voice box or larynx). Bronchoscopes are used to look at the windpipe
(trachea) and the tubes that go into the lungs (bronchi and bronchioles).
What are reasons the airway may need to be
looked at directly?
There are two main reasons to look at the airway directly.
MICROLARYNGOSCOPY
What is a Microlaryngoscopy?
Laryngoscopy is a procedure that allows your physician to look
at your larynx (voice box) using a laryngoscope. "Micro"
refers to getting a very close (magnified) view of the area to
see every tiny detail. This can be done with a special telescope
or operating microscope.
What are the indications for Microlaryngoscopy?
Microlaryngoscopy is especially useful for conditions in which
evaluation or treatment of the vocal cords or immediate surrounding
airway needs to be performed. Problems involving the VOCAL
CORDS result in varying degrees of HOARSENESS,
breathing or speech abnormalities, and laryngoscopy is commonly
used to evaluate these symptoms. Microlaryngoscopy gives the surgeon
the ability to view the larynx in detail. This is vitally important
because minute (very small) changes can produce large changes
in a person's voice.
What is involved with Microlaryngoscopy?
Microlaryngoscopy does not usually require an overnight stay
in the hospital. It is generally performed under general anesthesia
(the patient is asleep during the procedure) with the patient
lying on the back.
With the head tilted back (to make the airway as straight as
possible), a laryngoscope is placed in the mouth to look at the
larynx (voice box). It also pushes the tongue out of the way.
If the patient is old enough to have upper teeth, they are protected
with a tooth guard. The involved area is then visualized and the
view is magnified (enlarged) using an endoscope (telescope). This
is usually attached to a small video camera.
Procedures that may be performed during microlaryngoscopy are
numerous, and include removal of polyps or masses on or around
the vocal cords or to correct deformities of the vocal cords themselves.
These procedures involve the use of special tools and techniques,
and may include use of the CO2 laser. Please see VOCAL
CORD SURGERY in "Surgeries We Perform" for more
information on this topic.
The length of surgery depends on the reason the procedure is
being performed (to simply evaluate the area, or to actually remove
bumps or masses). The procedure usually does not last more than
an hour.
What are the risks and complications of microlaryngoscopy?
The more common risks include chipping a tooth or a temporarily
numb tongue (from pressing on the tongue during the procedure).
Other possible risks include excessive bleeding or breathing difficulties
after the procedure.
If a laser was used during this procedure, additional risks may
be present. These are discussed in VOCAL
CORD SURGERY.
BRONCHOSCOPY
What is Bronchoscopy?
Bronchoscopy is the name for the procedure using a bronchoscope
(hollow metal tube) to directly look at the airway. The bronchoscope
contains a telescope to better visualize all parts of the airway
under magnification.
There are two types of bronchoscopes: rigid and flexible.
What are the indications for rigid bronchoscopy?
Usually by the time rigid bronchoscopy is considered, other tests
may have already been performed that suggest a respiratory (breathing
related) problem. Other times, respiratory symptoms continue to
be present, although no reason can be found. Rigid bronchoscopy
is very valuable in helping to diagnose these various respiratory
symptoms and problems. Examples of these include STRIDOR
(noisy breathing), chronic cough, HOARSENESS,
asthma with unexpected symptoms (atypical asthma), and suspected
foreign body evaluation. STRIDOR, depending on the type, is evaluated
with rigid bronchoscopy to look at the anatomy, and flexible laryngoscopy
to evaluate function.
The rigid bronchoscope is more effective when removing lesions,
performing biopsies (getting a sample of tissue), foreign body
removal, and removing thick airway secretions (fluids) than the
flexible bronchoscope. CO2 laser surgery must be performed with
a laryngoscope or rigid bronchoscope. (Please see VOCAL
CORD SURGERY for information on the CO2 laser).
What is involved with a rigid bronchoscopy?
Rigid bronchoscopy is almost always performed with the patient
under general anesthesia (fully asleep). The patient's head is
tilted back to straighten the airway as much as possible. If teeth
are present, a tooth guard is usually placed along the upper teeth
to help prevent chipping. A laryngoscope (an instrument that holds
back the tongue) is inserted that helps the surgeon visualize
the voice box (larynx). A longer metal tube (the bronchoscope)
in then inserted into the airway. Through the bronchoscope, the
surgeon can then use telescopes, special tools, laser beams, and
small cameras, among other things, depending on the reason the
procedure is being performed.
The entire airway is carefully evaluated, as the telescope is
moved further and further along the airway, looking for any abnormalities.
Many times the size of the airway is measured to determine improvement
in a condition.
What are the complications of this procedure?
With an experienced surgeon, bronchoscopy is a very safe procedure.
The most common complications are due to irritation to the airway
and vocal cords from the bronchoscope itself. Other complications
can include bleeding, temporary breathing problems during and
after the procedure, and problems with the heart rhythm. Rarely,
air can leak out around the windpipe (trachea) (called a pneumomediastinum)
or the lung (called a pneumothorax).
What are the indications for flexible bronchoscopy?
Flexible bronchoscopy is more commonly used for the evaluation
of wheezing or chronic cough. This is usually done by a pediatric
pulmonologist (lung doctor for children)
It is also preferred in patients who cannot tolerate rigid bronchoscopy.
Among these are patients who cannot tolerate general anesthesia
(being put fully to sleep) or those with upper spine disorders
(because their necks can not be positioned appropriately for rigid
bronchoscopy). Other indications for this procedure include patients
with a tracheotomy (breathing tube inserted through a hole in
the neck), recurrent lung infections, and the evaluation of coughing
up blood (hemoptysis).
What is involved with flexible bronchoscopy?
Flexible bronchoscopy does not require the use of general anesthesia.
This procedure is performed by giving the patient a sedating (relaxing)
medication, so that they continue to breathe on their own. This
is important when evaluating conditions where the patient's natural
breathing movements must be observed. In contrast to rigid bronchoscopy,
the head does not need to be tilted back. Although, the flexible
bronchoscope can be inserted into the mouth, it is usually inserted
into the patient's nose. The nasal passages and upper throat are
sprayed with a numbing spray, the bronchoscope is inserted, and
the patient's nasal (nose) structures are then examined. The larynx
(voice box) can then be examined fully. After this, more numbing
medication can be applied to the larynx, and the bronchoscope
is then advanced further down the airway, all the way to the bronchi
(breathing tubes in the lungs) if required.
What are the complications of flexible bronchoscopy?
Since the flexible bronchoscope is inserted through the nasal
passages, occasionally bleeding from the nose (epistaxis) can
result. Otherwise, the flexible and rigid bronchoscopes can result
in similar types of complications; however, both are very safe
procedures and rarely result in complications.