Chapter 18: Diagnostic Flexible Bronchoscopy

INTRODUCTION

Bronchoscopy adds light and color to the study of diseases of the respiratory system. As one of the most important diagnostic procedures in pulmonary medicine, it enables the physician to visually inspect the tracheobronchial tree and to obtain samples from the lungs, including distal air spaces, in a non-invasive fashion. Clinical bronchoscopic procedures date back to Gustav Killian, who in 1897 performed the first inspection and therapeutic intervention within the human tracheobronchial tree. Reports indicate that he used a rigid bronchoscope to successfully remove a foreign body lodged in the patient's right mainstem bronchus. During the early twentieth century, a rigid bronchoscope remained the only tool available to thoracic physicians to diagnose and treat diseases of the respiratory system. Such rigid bronchoscopes consisted of a hollow metal tube plus a light source that allowed for passage of suction catheters and various tools to extract aspirated foreign bodies. The rigid bronchoscope did not allow access to smaller lobar airways or to any airway segment that could not be linearly aligned with the oropharynx. In 1967, Ikeda of Japan developed the flexible fiberoptic bronchoscope, enabling procedures to be performed with greater ease and comfort for awake patients using minimal anesthesia, and giving access to segmental and even subsegmental airways.

CONTEMPORARY BRONCHOSCOPY EQUIPMENT

The modern flexible adult bronchoscope has a diameter of 5-6 mm and is 50-60 cm in length (Fig. 18.1). Most flexible bronchoscopes have a fiberoptic light source as well as a lens for viewing, and a hollow channel for suction that also permits the passage of instruments to and beyond the distal tip of the bronchoscope. Such bronchoscopes are maneuvered manually through the patient's airways by variably deflecting its distal end, using a lever mounted on the proximal portion of the instrument that is held by the physician. Images are generally displayed on a video screen in the bronchoscopy suite or at the bedside of critically ill patients. In addition to providing a means to aspirate tracheobronchial secretions, blood, or other airway debris via suction, the hollow working channel allows for the passage of a wide variety of specially designed tools into the airways. These include small sampling brushes, miniature forceps for obtaining tissue samples and needles for obtaining aspirates. The working channel can also be used to deliver medications such as topical anesthetic and to deliver saline to lavage the airways (see below).