Chapter 1
Flexible bronchoscopy
Johannes M.A. Daniels
Dept of Pulmonary Diseases, VU University Medical Center, PO Box 7075, Amsterdam, The Netherlands.
Correspondence: Johannes M.A. Daniels, Dept of Pulmonary Diseases, VU University Medical Center, ZH 4F-004, PO Box 7075, 1007 MB Amsterdam, The Netherlands. E-mail: j.daniels@vumc.nl
Flexible bronchoscopy allows visual inspection of the airways and can be used for diagnostic and therapeutic purposes. Indications for diagnostic bronchoscopy are abundant and include evaluation of symptoms such as cough or haemoptysis, evaluation of clinical findings such as suspected malignancy or pneumonia of unknown aetiology and early detection of lung cancer. In addition, several therapeutic modalities are at the disposal of the bronchoscopist and many more are currently under development. Prerequisites for performing flexible bronchoscopy are good knowledge of the patient, equipment and sedation techniques as well as skill in handling the bronchoscope, performing sampling techniques and managing complications. Although bronchoscopy can be performed with only topical anaesthesia, it is an unpleasant examination and sedation should be offered to the patient. Specific precautions are necessary for adequate and safe sedation.
Cite as: Daniels JMA. Flexible bronchoscopy. In: Herth FJF, Shah PL, Gompelmann D, eds. Interventional Pulmonology (ERS Monograph). Sheffield, European Respiratory Society, 2017; pp. 1–18. [https://doi.org/10.1183/2312508X.10002317].
Technological advances have made flexible bronchoscopy a very effective tool in the diagnosis of many diseases of the respiratory tract and paved the way for many more technological breakthroughs, both diagnostic and therapeutic. Breakthroughs through modifications of the flexible bronchoscope (some of which are covered elsewhere in this Monograph) include linear EBUS [1, 2], AFB [3, 4] and NBI [3, 5]. Breakthroughs by adding catheter based techniques (some of which are covered elsewhere in this Monograph) include TBNA [6, 7], laser treatment [8], radial EBUS [9–11] navigation [12], bronchoscopic lung volume reduction [13, 14], bronchial thermoplasty [15–17] and transbronchial cyrobiopsy [18, 19].
This chapter will cover the indications and techniques of flexible bronchoscopy. In addition, we will discuss sedation during bronchoscopy and finally the limitations of flexible bronchoscopy.
Indications
Bronchoscopy can be of value in a wide variety of diseases of the respiratory tract, both in a diagnostic and a therapeutic setting. A good indication for performing bronchoscopy would be any clinical situation in which a clinician expects that bronchoscopy will have a substantial diagnostic or therapeutic impact. Specific indications are listed in table 1.
Table 1. Indications for flexible bronchoscopy
Diagnostic flexible bronchoscopy |
Evaluation of symptoms |
Persistent cough |
Chronic dyspnoea |
Haemoptysis |
Hoarseness |
Stridor |
Evaluation of clinical findings |
Suspected malignancy (central or peripheral) |
Suspected bronchial obstruction (recurrent pneumonia, persisting atelectasis) |
Pneumonia of unknown aetiology or not responding to treatment |
Suspected tuberculosis |
ILD |
Hilar and/or mediastinal lymphadenopathy |
Bronchiectasis |
Inhalation injury (toxic, heat, smoke) |
Trauma with suspected airway injury |
Radiation-induced airway injury |
Suspected bronchopleural fistula |
Dynamic airway obstruction (e.g. TBM, EDAC, RP) |
Suspected lung transplant rejection or infection |
Airway management issues (e.g. evaluation of a difficult airway, obstruction of an artificial airway) |
Early detection of lung cancer |
Therapeutic flexible bronchoscopy |
Mucus impaction |
Foreign body removal |
Blood clot removal |
Endotracheal tube placement in patients with a difficult airway |
Tumour ablation (e.g. electrocautery, cryotherapy, laser, APC, PDT) |
Balloon dilatation |
Airway stenting |
Airway valves in persistent air leak |
Bronchoscopic lung volume reduction |
Bronchial thermoplasty |
Treatment of bronchopleural fistula |
TBM: tracheobronchomalacia; RP: relapsing polychondritis. |
Diagnostic flexible bronchoscopy
Bronchoscopy is often used in the evaluation of common clinical symptoms or the evaluation of specific clinical findings. In most cases, bronchoscopy is part of an elaborate clinical work-up and in each individual case it should be decided whether flexible bronchoscopy is of added value, taking specific guidelines and literature into account.
Evaluation of symptoms
Persistent cough
In patients with chronic cough, flexible bronchoscopy can be performed if extensive clinical evaluation for common causes of cough (pulmonary function testing, imaging, etc.) shows no diagnosis or if history taking reveals a specific suspicion of central airway pathology. It is important to realise, however, that the yield of bronchoscopy in chronic cough is low (≤6%) [20–24]. Occasionally, specific causes of chronic cough can be identified (e.g. foreign body, tracheobronchopathia osteochondroplastica, primary tracheobronchial amyloidosis, congenital defects, broncho-oesophageal fistula) (figure 1). Bronchoscopy with biopsies of normal-appearing mucosa performed in patients with cough might explain the mechanisms of chronic cough as part of a research project, but is of no value in clinical decision making [25]. If flexible bronchoscopy is performed in patients with cough, it is important to carefully inspect the oropharynx and laryngopharynx for signs of post nasal drip, inflammation, neoplasm or gastro-oesophageal reflux, or to refer the patient for otolaryngoscopy [26, 27].
Figure 1. a) Typical appearance of tracheobronchopathia osteochondroplastica in the trachea. Note that the lesions are smooth, covered by normal mucosa and confined to the cartilage rings. This is a spot diagnosis; histological conformation is not required. b) Primary tracheobronchial amyloidosis. Note the characteristic yellowish deposits that seem randomly spread across the airways, while some areas are spared. c) Example of a foreign body, in this case an open safety pin that got stuck in the trachea. A flexible grasping forceps is being positioned for extraction.
Dyspnoea
Flexible bronchoscopy has no place in clinical algorithms for the evaluation of dyspnoea. However, if dyspnoea is suspected to originate from the central airways, bronchoscopy can be of added value. Examples include suspected tracheal stenosis, tracheobronchomalacia, EDAC, malignant airway obstruction or a problem with artificial airways, such as a tracheostomy tube.
Haemoptysis
Haemoptysis can be mild or life threatening. In mild haemoptysis, bronchoscopy can play an important role in localising and identifying the source of the bleeding, even if a CT scan shows no abnormalities [28–30]. If bleeding is significant and the CT scan shows clear location and likely cause (e.g. bleeding at site of bronchiectasis), it is preferable to omit bronchoscopy and proceed directly to bronchial artery embolisation. Massive haemoptysis is a rare but life-threatening emergency. The danger of massive haemoptysis lies in asphyxiation. Management of massive haemoptysis requires advanced airway management skills and often bronchoscopic intervention [31]. The evaluation and management of haemoptysis is discussed in more detail in another chapter in this Monograph [32].
Hoarseness and stridor
Hoarseness and stridor are less common complaints and are often caused by diseases of the oropharynx, larynx and vocal cords. However, diseases of the trachea, especially in close proximity to the vocal cords, are also associated with these symptoms. Examples are web-like tracheal stenosis, neoplasms of the proximal trachea and recurrent respiratory papillomatosis.
Evaluation of clinical findings
Suspected malignancy
Bronchoscopy has an important role in the evaluation central and peripheral masses. The positioning of flexible bronchoscopy in the evaluation of pulmonary masses is dependent of many factors. If tissue procurement for histological diagnosis is the primary goal of the procedure then bronchoscopy with biopsies can be an excellent choice. For visible central lesions, the sensitivity of four to five biopsies is >95% [33]. Biopsy techniques are described elsewhere in this Monograph [6]. If a lesion is located in the periphery of the lung and especially if small in size, more advanced techniques might be required to obtain adequate samples. Techniques such as navigation and radial EBUS are described elsewhere in this Monograph [9]. If lymph node staging is the primary goal then endosonography techniques (EBUS/transoesophageal EUS) [1] or in selected cases TBNA [6] should be used.
Suspected bronchial obstruction
In a patient with persistent atelectasis or recurrent pneumonia, bronchoscopy is an important tool to investigate the cause and, in cases of bronchial obstruction, to re-open the bronchus if possible. Causes of bronchial obstruction causing atelectasis may be mucus plugging, a foreign body, a neoplasm, blood clots, or airway torsion or compression.
In cases of recurrent pneumonia, it is important to analyse the locations of the past pneumonias. If the pneumonia recurs at the same site, bronchial obstruction is suspected, although foreign bodies can sometimes migrate and cause subsequent pneumonias at different sites [34].
Pneumonia of unknown aetiology or not responding to treatment
In the majority of cases, the aetiological agent is not identified and empirical antibiotic treatment is instituted. The patient might not respond to this treatment for several reasons: an unanticipated and untreated pathogen or a non-infectious cause of the pulmonary infiltrate (e.g. malignancy, cryptogenic organising pneumonia, eosinophilic pneumonia). For microbiological testing, BAL can be useful for patients who do not expectorate representative sputum samples [35]. For immunocompromised patients (with AIDS or neutropenia, for example), BAL is standard in the diagnosis of opportunistic pulmonary infections (e.g. Pneumocystis jirovecii, fungi, viruses). For patients with slowly or non-resolving pneumonia, BAL and optional TBLB is advocated [36, 37].
Suspected tuberculosis
Bronchoscopy can be an important tool in the diagnosis of suspected tuberculosis (TB) of the lung parenchyma, the tracheobronchial tree and the hilar/mediastinal lymph nodes. TB located in the lung parenchyma can manifest as localised disease (pulmonary infiltrate, cavernous lesion, granuloma) or diffuse disease (miliary tuberculosis). Where there is involvement of the lung parenchyma, sputum samples should always be examined first. If a patient does not expectorate sputum or the sputum smear is negative for TB, bronchoscopy can be indicated. The same applies to immunocompromised patients where co-infection with other opportunistic pathogens is possible.
Interstitial lung disease
In the analysis of ILD, flexible bronchoscopy can be used to perform BAL or TBLB. BAL is a valuable tool in the diagnosis of several specific forms of ILD if used in conjunction with clinical information and HRCT findings. As an example, a high lymphocyte count, in combination with diffuse ground-glass opacities in the mid and lower lung regions, is highly suggestive of cellular nonspecific interstitial pneumonia [38]. For eosinophilic pneumonia, an eosinophil percentage of >25% is considered diagnostic in the presence of a typical HRCT pattern [33]. In many cases, however, BAL and HRCT findings are less specific. In addition, standardisation of the bronchoscopic procedures, cellular analysis and interpretation of the results is still far from optimal. Tissue diagnosis is still the gold standard in many ILDs. TBLB is a minimally invasive method for obtaining lung tissue. An important limitation of TBLB obtained using flexible biopsy forceps is the small amount of alveolated tissue and the presence of artefacts. Transbronchial cryobiopsy was recently introduced for ILD and is clearly superior to forceps TBLB [39]. This promising technique is discussed in more detail elsewhere in this Monograph [18].
Hilar and/or mediastinal lymphadenopathy
Lymph nodes in close proximity to the airways can be samples with TBNA, with or without endosonographic guidance. Details for TBNA [6] and EBUS-guided TBNA (EBUS-TBNA) [1] are discussed elsewhere in this Monograph.
Bronchiectasis
Indications for flexible bronchoscopy in patients with bronchiectasis may be: the detection of a foreign body; BAL for diagnosis of bacterial, fungal or mycobacterial infection in the absence of representative sputum samples; the removal of sputum plugs; and the diagnosis and management of airway haemorrhage associated with bronchiectasis.
Inhalation injury
Inhalation of heat, smoke or specific chemical substances can cause considerable morbidity and mortality, and airway/lung damage can be permanent [40, 41]. In burns patients, the incidence of inhalation injury is correlated with the size of the skin burn and is associated with poorer outcome, especially if further complicated by pneumonia [42]. Severe inhalation injury is characterised by pulmonary and bronchial oedema and secretions, which can accumulate and cause pneumonia and atelectasis. Bronchoscopic removal of accumulating debris in patients with airway injury is associated with a shorter length of stay in the intensive care unit and a shorter length of stay in the hospital [43].
Trauma with suspected airway injury
Deceleration trauma can cause rupture of the central airways, which is life threatening. Airway rupture can be complicated by pneumothorax, pneumomediastinum or even total loss of airway and death. Only a minority of patients with traumatic airway injury make it to the hospital alive [44]. Bronchoscopic assessment of the exact location, size and extent of the airway injury is crucial. Bronchoscopy should also be used for placement of an endotracheal tube at the correct location (cuff distal to the site of airway defect) [45–48].
Radiation-induced airway injury
High-dose radiation of central tumours is particularly associated with airway injury. Airway injury can include teleangiectatic vascular changes, airway stenosis, airway wall necrosis and airway fistula (figure 2). Airway necrosis or fistula can be complicated by fatal haemoptysis. Prospective data about airway injury in patients who were treated with external beam radiation is scarce. In a retrospective study of 74 patients who underwent SBRT of a tumour in close proximity to the central airways, KARLSSON et al. [49] found atelectasis in 24% of patients. A prospective study of 342 patients who were treated with endobronchial brachytherapy reported an incidence of bronchial stenosis of 12% [50]. A Cochrane review about palliative endobronchial brachytherapy for nonsmall cell lung cancer showed that fatal haemoptysis can occur in up to 20% of cases, with similar numbers observed in external beam radiation and endobronchial brachytherapy [51].
Figure 2. Complications after radiotherapy of the central airways. a) Teleangiectatic vascular changes in the distal trachea. b) Stenosis of the right lower lobe bronchus. c) Tracheo-oesophageal fistula. d) Massive necrosis of the right main bronchus.
Suspected bronchopleural fistula
Bronchopleural fistula most frequently occurs as a complication of stump dehiscence or dehiscence of bronchial anastomosis after lung surgery (figure 3). Timely diagnosis of bronchopleural fistula is crucial to prevent further complications, such as pleural empyema, and to initiate adequate surgical and/or medical management.
Figure 3. Dehiscence of the bronchial anastomosis after sleeve lobectomy of the right upper lobe. Note the sudden stop of bright pink bronchial wall.
Dynamic airway obstruction
Dynamic airway obstruction can be caused by any disease that is associated with loss of stability of the airway. Instability of the airways causes collapse during expiration. The most common cause of airway instability is pulmonary emphysema, where loss of lung parenchyma results in loss of airway tethering. Several rare conditions are associated with instability of the central airways. In tracheobronchomalacia (TBM), which has multiple causes, destroyed or damaged cartilage causes central airway collapse and expiratory flow limitation. EDAC is characterised by excessive bulging of the membranous wall while the cartilage is unaffected [52]. Bronchoscopy is the gold standard for the diagnosis of TBM and EDAC, and can distinguish different causes of TBM (e.g. primary, tracheal injury caused by endotracheal tube or tracheostomy, or relapsing polychondritis).
The role of bronchoscopy in suspected lung transplant rejection or infection and airway management issues is discussed elsewhere in this Monograph [53].
Early detection of lung cancer
Squamous cell lung cancers account for 20–30% of lung cancers and are most common in the central airways. Although a shift toward more peripherally located squamous cancer has been observed in surgical series [54, 55], it is estimated that 15–20% of lung cancers are of the central squamous cell type, which constitutes a major worldwide cancer burden [56]. Regardless of technological improvements that have led to modern video bronchoscopy systems, the sensitivity for detecting early stage central lung cancer is low [57, 58]. AFB uses the spectral differences in fluorescence and absorption properties of normal and dysplastic bronchial epithelium, and enables early detection of centrally located pre-invasive endobronchial squamous lesions [59, 60]. AFB and other early detection techniques are described elsewhere in this Monograph [3].
Therapeutic flexible bronchoscopy
Right from the start, bronchoscopy was also intended for therapeutic use. Some of the first rigid bronchoscopes in the 19th century were used for foreign body removal. Nowadays, there is a great variety of therapeutic bronchoscopic applications for many pulmonary diseases. Most of these techniques can be applied through a flexible bronchoscope. Current and near future therapeutic interventions are described elsewhere in this Monograph [13, 15, 32, 61–67].
Technique
Handling the bronchoscope
The bronchoscope is high-tech and expensive equipment and should be handled with great care. The tip of the bronchoscope should be protected from trauma because it contains essential, fragile and expensive parts, such the lens and the CCD. After positioning the patient, performing a time-out procedure, applying local anaesthesia and sedation if required, the bronchoscope can be introduced through the mouthpiece, nose or artificial airway. Throughout bronchoscopy, several important issues should be kept in mind, as follows.
Left or right hand?
The flexible bronchoscope was originally designed to be held in the left hand, because Professor Shigeta Ikeda (who invented and developed the flexible fibreoptic bronchoscope in cooperation with Olympus Optical Co. and Machida Endoscope Co.) was left-handed. The reason that modern commercially available bronchoscopes are still designed to be held in the left hand is because many techniques have been added that often require more complex skills than handling the bronchoscope. Steering a flexible bronchoscope clockwise and anti-clockwise and flexing and extending the tip with the lever requires only simple motor skills. Advancing and retracting the bronchoscope and operating instruments through the working channel of the bronchoscope (biopsy forceps, TBNA needles, bronchial blockers, etc.) requires fine motor skills (figure 4), which are preferably carried out with the dominant hand. Nevertheless, some bronchoscopists, experts amongst them, prefer to hold the bronchoscope in their right hand. The available literature also shows this to be a matter of controversy [68, 69]. Individual factors such as hand dominance, degree of ambidexterity and existing motor neuron pathways can play an important role in making this choice. Therefore, it makes sense that every bronchoscopist should find out for themselves what works best.
