Bronchoscopy

In 1968, Ikeda introduced the first flexible bronchoscope, and over the decades, flexible bronchoscopy has largely supplanted rigid bronchoscopy for diagnostic procedures. Previously, rigid bronchoscopy was the only way to visualize and access the tracheobronchial tree directly. Now, however, the flexible bronchoscope provides access to a greater extent of the airway, can be performed with minimal sedation, and can be routinely performed in the intensive care unit (ICU) as well as the regular patient ward in many hospitals.

Endobronchial Ultrasound

The recent addition of endobronchial ultrasound (EBUS) technology has increased the sensitivity of transbronchial needle biopsies. This special bronchoscope includes the additional feature of a linear ultrasound probe at the end of the scope, which facilitates visualization of lymph nodes outside the airway. Color flow Doppler images also help differentiate lymph nodes from vascular structures. A working channel directs the passage of a transbronchial needle through the region imaged by the ultrasound, to biopsy discrete lymph nodes. EBUS is most frequently used for mediastinal lymph node staging of patients with known or presumed lung cancer. The diagnostic accuracy is similar to that of mediastinoscopy for this indication; two recent prospective studies show a similar diagnostic accuracy of EBUS and mediastinoscopy. Clearly, either procedure has great diagnostic value when performed by experienced clinicians.

Navigational Bronchoscopy

Previously, fluoroscopy was used to assist in directing the bronchoscope and biopsy forceps toward indeterminate peripheral lung lesions. The two-dimensional nature of fluoroscopy and the inability directly to “steer” the biopsy forceps were serious drawbacks of this modality. Navigational bronchoscopy using electromagnetic guidance was recently introduced to improve the yield of bronchoscopic lung biopsies. This technology depends on the construction of a virtual three-dimensional airway using CT images. An electromagnetic field created over the patient’s chest helps to locate and direct a small endoscopic probe toward the lesion in airways beyond visualization with standard bronchoscopy. This technology can be used in combination with a small, radial ultrasound probe to help determine when the bronchoscope has reached the lesion of interest.

Currently the two most common applications of navigational bronchoscopy are to place fiducial markers or to obtain a tissue diagnosis of small lesions located in airways that are distal to the range of visualization. This technology is most useful for lung lesions within the inner third of the lung parenchyma. Lesions located closer to the periphery of the lung can be biopsied using computed tomography (CT)–guided techniques.

Rigid Bronchoscopy

Rigid bronchoscopy is mostly used for therapeutic airway interventions such as airway dilation, laser debridement, tumor debulking, placement of airway stents, or foreign body retrieval (Figure 74-1). The use of the rigid bronchoscope continues to be an important diagnostic tool in special circumstances, such as those requiring a better tactile sense when assessing for possible extrinsic tumor invasion of the airway, or when larger biopsies are sought. It is also indispensable when airway control is in question because of hemoptysis or tumor invasion.

Figure 74-1 Rigid bronchoscopy equipment. Top to bottom, Bronchoscope with light cable, straight and right-angled surgical telescopes, biopsy forceps, suction cannula.

Rigid bronchoscopy requires general anesthesia with a muscle relaxant and specific ventilatory strategies. The options most often used include jet ventilation and continuous or intermittent insufflation. In patients with airway control as an overwhelming concern because of an obstructing airway lesion, muscle relaxants are avoided to maintain spontaneous breathing.