RIGID BRONCHOSCOPY
In 1897, Gustav
Killian published his success in removing a pork bone from the right mainstem
bronchus using a rigid esophagoscope and an external light source. Killian went
on to lecture throughout the world, ushering in the era of modern bronchoscopy.
Chevalier Jackson perfected the technique of rigid bronchoscopy as we now know
it. Much of today’s expertise in endoscopy is based on his original methods or
modifications of them.
Although the use of the flexible
bronchoscope largely replaced the rigid bronchoscope for diagnostic purposes,
rigid bronchoscopy remains an indispensable therapeutic tool. The rigid
bronchoscope lacks the maneuverability of the flexible bronchoscope, but it is
able to provide an airway for oxygenation and ventilation and allows the
passage of large-bore suction catheters as well as multiple other tools such as
large forceps and lasers. Silicone airway stents can only be placed via a rigid
bronchoscope, and the bronchoscope itself can be used to “core out” tumors
invading the airway. Because the flexible bronchoscope can be easily passed through
the rigid barrel, the two methods of airway visualization should be regarded as
complementary.
Instruments
The bronchoscope is basically an
open steel tube. Some rigid bronchoscopes have a proximal or distal lighting
source, but others use an optical telescope. The external diameter of the adult
rigid bronchoscope ranges from 9 to 14 mm and is usually 40 cm long. There is a
distal beveled end to allow for lifting of the epiglottis and safer insertion
through the vocal cords. The diameter of the bronchoscope used depends on the
patient’s size and degree of airway obstruction. Fenestrations are present at
the distal third of the bronchoscope to allow for contralateral lung
ventilation when the bronchoscope is inserted into a mainstem bronchus. A variety
of instruments such as suction catheters and biopsy forceps should be available
for use.
Procedure
Rigid bronchoscopy is generally
performed in the operating suite under general anesthesia, which can be delivered
via inhalational or total intravenous techniques.
Correct positioning of the head is
important to bring the mouth, larynx, and trachea in line with each other. The
head is typically extended and sometimes dropped posteriorly to facilitate this
alignment. As such, patients with cervical spine instability or ankylosing
spondylitis may not be able to be intubated with the rigid bronchoscope.
Dentures should be removed, and the upper teeth should be protected, with
particular attention to avoid leverage against them.
The bronchoscope is introduced
gently with one hand while the other hand keeps the mouth open and maintains
head position. The bronchoscope is passed over the base of the tongue, and its
tip used to lift the epiglottis anteriorly. The arytenoepiglottic folds, arytenoids,
and vocal cords are then visualized. At this point, the bronchoscope is rotated
90 degrees clockwise. The left vocal cord becomes centered in the visual field,
and the tip of the bronchoscope is brought between the two cords. With gentle
progression and continued clock-wise rotation, the bronchoscope will pass into
the trachea. At no time should its passage be forced; if there is
difficulty, a smaller sized bronchoscope may be needed. Ventilation is then
initiated, and inspection of the tracheobronchial tree is continued under
direct vision.
To examine the left-sided airways,
the head is turned toward the right, and to examine the right-sided airways,
the head is turned left. The use of oblique or lateral viewing telescopes is
helpful for full visualization of the upper lobes, although this technique has
largely been replaced by passing the flexible bronchoscope through the rigid
bronchoscope.
Withdrawal of the bronchoscope
requires similar care to that used during insertion. If the patient remains
anesthetized, an endotracheal tube or laryngeal mask airway ca be placed until
the effects of anesthesia are reversed.
