Flexible Bronchoscopy and Bronchoalveolar Lavage (BAL)

Abstract

Flexible bronchoscopy is a commonly utilized endoscopic procedure allowing for direct visualization of the airways, as well as a variety of therapeutic and diagnostic interventions. Common indications of flexible bronchoscopy include evaluation of pulmonary infiltrates, hemoptysis, airway obstruction, foreign body aspiration, tracheal stenosis, bronchopleural fistula, and post-lung transplant. The procedure involves the insertion of a flexible bronchoscope through the vocal cords and into the lumen of the trachea and bronchi. Direct visualization is provided by fiberoptic video imaging. Bronchoalveolar lavage (BAL) further refers to instillation and subsequent recovery of sterile saline into the airways. In this article, we will detail the technique, considerations, and complications of flexible bronchoscopy and BAL.   

Keywords

Bronchoscopy; bronchoalveolar lavage; pulmonology; interventional pulmonology.

Case Overview

Background

Prior to 1968, direct visualization and intervention of the airways could only be achieved via rigid bronchoscopy, whereby a light source and suction was affixed to a rigid bronchoscope.¹ The first flexible bronchoscope became available in 1968 and has largely become the cornerstone of minimally invasive airway intervention.² Bronchoalveolar lavage (BAL) was further introduced in 1974 and allowed for the procurement of material from the lower respiratory tract.³ While it was originally conceived for the purpose of removing aspirated foreign bodies, modern flexible bronchoscopy serves a wide range of applications.¹ The most common diagnostic purposes of basic bronchoscopy are the direct identification of airway abnormalities, including obstruction, endobronchial lesions and masses, sources of bleeding, fistulas and foreign bodies, and collection of airway materials for microbiologic, immunologic, or cytologic analysis.

Focused History of the Patient

History of present illness will vary depending on the underlying etiology and purpose of examination. For example, a typical patient undergoing assessment for a suspected lung malignancy are classically older, former or current smokers, and may report cough, hemoptysis, weight loss, fatigue, and chronic dyspnea. This patient evaluated in the corresponding video was undergoing work up for suspected non-tuberculous mycobacterial infection, and reported chronic nonproductive cough, low grade fevers, and night sweats unresponsive to typical antibiotic treatment courses. Particular attention should be given to any personal history or associated symptoms of hematologic malignancy, bleeding disorders, pulmonary hypertension, bullous emphysema, and myocardial ischemia, which may individually increase the risk of procedural complications.

Physical Exam

Physical exam findings will vary depending on the underlying indication for bronchoscopy. Preoperative assessment should include vital signs with particular attention to hypoxemia or hemodynamic instability, oropharyngeal inspection, and cardiopulmonary auscultation. 

Imaging

Prior to the procedure, a high-resolution CT scan of the chest should be obtained. Imaging is vital for preliminary evaluation of airway anatomy, including anatomic variants, and identification of target lobes and abnormalities for intervention. Depending on the intervention undertaken, a plain film of the chest may be obtained postoperatively to evaluate for procedural complications.

Special Considerations

Absolute contraindications to flexible bronchoscopy include severe hypoxemia, hemodynamic instability, refractory arrhythmias.⁷ Coagulopathy, recent myocardial infarction, pulmonary hypertension, and increased intracranial pressure are generally considered relative contraindications, though bronchoscopy can generally be performed safely in these scenarios with proper precautions and expertise.⁸

Discussion

Flexible bronchoscopy begins with positioning the patient in the supine position. Though this procedure can be safely performed without sedation, the use of sedation has been associated with improved outcomes and is generally recommended.⁴ In the above video, we used a combination of moderate sedation and topical anesthesia. A laryngeal mask airway is placed and affixed with a bronchoscope adapter, allowing for simultaneous mechanical ventilation and insertion of the bronchoscope. First, the bronchoscope is inserted and advanced to the vocal cords, and lidocaine is instilled directly to the vocal cords via the working channel. The bronchoscope is then advanced through the vocal cords and into the trachea, at which point additional lidocaine is instilled to the carina. An airway exam is then conducted starting with the right bronchial tree by convention. As shown in the video, the bronchoscope is advanced in the right mainstem bronchus, where the take-off of the right upper lobe bronchus at the first secondary carina is visualized. Once the right upper lobe bronchial segments are inspected, the bronchoscope is then advanced into the bronchus intermedius, where the second secondary carina is visualized. This can be identified by the trifurcation of the right middle lobe bronchus, right lower lobe bronchus, and superior segment of the right lower lobe bronchus. After inspection of each of the above bronchi and their respective segments, the bronchoscope is then retracted to the tracheal carina and advanced into the left mainstem bronchus, where the secondary carina is identified by the bifurcation of the left upper and left lower lobe bronchi. Inspection of the left upper lobe bronchus will also reveal the take-off of the lingular bronchus. After all of the remaining segments are directly visualized, the bronchoscope is directed to the lobe of interest, and “wedged” into the respective bronchus. Sterile saline is instilled into the bronchial segment via the working channel, and then retrieved through the suction port into either the syringe or a specimen trap. It is generally recommended that at least 100 mL of fluid be instilled, though more may be required depending on indication and yield.⁵ The bronchoscope is then retracted from the patient, and the procedure is concluded.

Patients are typically monitored for a short time postoperatively and discharged home the same day. Significant complications are rare (<1% occurrence), but may include respiratory failure, bronchospasm, bleeding, and pneumothorax.⁶

Airway exploration by flexible bronchoscopy is generally limited to the extent of the subsegmental airways. Recent innovation in diagnostic bronchoscopy, including ultrathin bronchoscopy and robotic bronchoscopy, have allowed for access to the subsegmental airways and periphery of the lung parenchyma.⁶

Equipment

A flexible bronchoscope is the primary tool used for this procedure. As described in the video, the tip of the flexible bronchoscope contains a light source, a video camera, and a working channel. The working channel can be used to instill medications, introduce a variety of instruments, or suction airway material. The bronchoscope tip can be flexed and extended via a lever on the handle, and rotation of the handle is used to guide the bronchoscope directionally.

Disclosures

Nothing to disclose.

Statement of Consent

The patient referred to in this video article has given their informed consent to be filmed and is aware that information and images will be published online.