Rigid bronchoscopy: Instrumentation

INTRODUCTION — Rigid bronchoscopy is a technique that visualizes the trachea and proximal bronchi. It is usually performed in the operating room under general anesthesia [1].

Rigid bronchoscopy is most commonly used to manage patients who have obstruction of either their trachea or a proximal bronchus, since the rigid bronchoscope's large lumen facilitates suctioning and the removal of debris, or for interventional procedures such as insertion of airway stents [2,3]. (See "Clinical presentation, diagnostic evaluation, and management of malignant central airway obstruction in adults" and "Airway stents".)

Rigid bronchoscopes, equipment for visualization, and accessory instruments are reviewed here. Techniques of rigid bronchoscopic intubation are described separately. (See "Rigid bronchoscopy: Intubation techniques".)

RIGID BRONCHOSCOPES — The rigid bronchoscope is also known as an open tube bronchoscope, open tube, straight bronchoscope, or ventilating bronchoscope. It is a rigid, straight, hollow metal tube that is available in several sizes. Its purpose is to provide access to the airways.

The external diameter of a rigid bronchoscope varies from 2 to 14 mm, wall thickness ranges from 2 to 3 mm, and length varies from a very short tube (for pediatric cases) to a long or extra-long tube (for adults). Tubes with an extra-large diameter have been developed for exceptional cases of tracheobronchomalacia, but they are not readily available.

Most rigid bronchoscopes are the same diameter from the proximal to the distal end, although some have a beveled or tapered tip to lift the epiglottis during intubation (see "Rigid bronchoscopy: Intubation techniques"). Variations in the tip design also facilitate the dilation of airway strictures. Most rigid bronchoscopes are round when visualized in cross-section, with external side ports that permit the introduction of suction catheters, laser fibers, and ventilation (picture 1 and picture 2). A few are almost oval. A small internal channel exists in some rigid bronchoscopes, through which the rigid telescope passes. Others are simply an empty tube that allow passage of a separate rigid telescope. Some rigid bronchoscopes can analyze exhaled gases.

Some bronchoscopists use only a single manufacturer's rigid bronchoscope, which comes in one or two varying sizes. Other bronchoscopists prefer to have a set of rigid bronchoscopes with multiple different lengths and diameters (picture 3 and figure 1 and picture 4). Such bronchoscopists generally have long rigid bronchoscopes with distal side ports that facilitate ventilation of the contralateral lung when working within a main bronchus (ie, ventilating rigid bronchoscopes), as well as short rigid tracheoscopes without ventilating side ports that are used solely when working in the trachea (ie, non-ventilating rigid bronchoscopes) [2,4].

VISUALIZING EQUIPMENT — During rigid bronchoscopy, a rigid telescope and light source are generally inserted through the rigid bronchoscope to visualize the airways. However, a few systems allow direct visualization through the rigid bronchoscope using light conducted through a tube that extends the length of the rigid bronchoscope or through a prism at the proximal end. A flexible bronchoscope inserted through the rigid bronchoscope is a reasonable alternative. (See "Flexible bronchoscopy in adults: Overview".)

Rigid telescopes — Rigid telescopes visualize the airways at angles of 0, 30, 40, 50, 90, 135, and 180 degrees with respect to the axis of the telescope. This facilitates visualization of the upper lobes, lower lobes, and mainstem bronchi bilaterally (figure 2). The Hopkins lens rigid telescope is the most popular type of rigid telescope. The Hopkins rod telescope is an alternative type of rigid telescope that provides superb visualization of the airway and is available in multiple lengths and diameters [5].

Light source — Illumination is extremely important during rigid bronchoscopy, since visualization tends to be poor due to the pinkish-red color of the airway mucosa, the presence of blood, and/or the presence of distal airway abnormalities. A cold light source (ie, xenon and halogen lamps) is the most frequently used illumination device in rigid bronchoscopy. Newer light sources have devices that regulate the amount of applied light (ie, automatic light intensity regulators, automatic irises), thereby minimizing glare.

Video equipment — As with many surgical procedures and flexible bronchoscopy, the use of video supplements rigid bronchoscopy. It is ideal for teaching and documenting procedures, as well as allowing viewing by multiple individuals. Video imaging is enhanced by the high quality of the optics in a rigid telescope. Single chip or three-chip video cameras can be easily connected to the proximal aspect or eyepiece of a rigid telescope via direct connection devices, Snap-on lenses, or standard C- mounts. Alternatively, a flexible bronchoscope with digital video capability can be used.

ACCESSORY INSTRUMENTS — Accessory instruments that may be used during rigid bronchoscopy include forceps for biopsy, forceps that facilitate foreign-body removal, suction tubing, and instruments used to insert and remove airway prostheses (eg, stents).

SUMMARY AND RECOMMENDATIONS

●Rigid bronchoscopy is a technique that visualizes the trachea and proximal bronchi. It is most commonly used to manage patients who have obstruction of either their trachea or a proximal bronchus, since the rigid bronchoscope's large lumen facilitates suctioning and the removal of debris, or for interventional procedures such as insertion of airway stents. (See 'Introduction' above.)

●During rigid bronchoscopy, a rigid telescope and light source are generally inserted through the rigid bronchoscope to visualize the airways. However, a few systems allow direct visualization through the rigid bronchoscope using light conducted through a tube that extends the length of the rigid bronchoscope or through a prism at the proximal end. A flexible bronchoscope inserted through the rigid bronchoscope is often used in a complementary fashion. (See 'Rigid bronchoscopes' above and 'Visualizing equipment' above.)

●Accessory instruments may be necessary during rigid bronchoscopy. (See 'Accessory instruments' above.)