DEFINITION

Bronchoscopy is the examination of the upper and lower airways. Procedures are performed using either a flexible or a rigid bronchoscope. Rigid bronchoscopes are a rigid stainless steel tube with a series of mirrors inside to transmit the image to the operator through an eyepiece and connected videocamera. Flexible bronchoscopy is performed using a flexible tube with a series of flexible fiberoptic bundles; however, increasingly, flexible bronchoscopy is performed using a tube with a distal charge coupled device, transmitting the image of the airways onto a videoscreen.

HISTORY

Gustav Killian, an Otorhinolaryngologist at Freiburg, Germany performed the first rigid bronchoscopy on March 30, 1897 in order to remove a piece of bone embedded in the right main bronchus of a 63-year-old man. Until then, the indirect laryngoscope method had been used to visualize only parts of the tracheobronchial tree. A few years later, Professor Chevalier Jackson, a famous North American Otorhinolaryngologist, was instrumental in disseminating the use of the rigid bronchoscope in the United States as well as abroad.

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  Although rigid bronchoscopy can be used for diagnostic procedures, it is most comfortably performed under general anesthesia, and thus is more frequently used for therapeutic procedures such as laser resection, stent insertion, and airway dilation of malignant and benign strictures.

  
  
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  The rigid bronchoscope comes in various diameters and lengths. The external diameter of the rigid bronchoscope may also vary depending on manufacturer. For adults, most tubes are at least 8 mm wide.

Shigeto Ikeda of Tokyo, Japan introduced the first flexible fiberoptic bronchoscope at the Ninth International Congress on Diseases of the Chest held in Copenhagen in 1966.

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  Flexible bronchoscopy is usually performed using moderate sedation, but it can also be safely and comfortably performed in the fully awake and alert individual. The scope can vary in diameter from 3 to 6 mm, and usually it has a working channel of 1.9 to 2.4 mm. An increasing number of ancillary instruments and flexible bronchoscopic procedures are being designed to enhance diagnostic yield for a variety of indications.

INDICATIONS

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  Suspected of known malignancy

  
  
  
  
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    Suspected bronchogenic carcinoma is a frequent indication for diagnostic bronchoscopy. Patients are often referred because of symptoms such as cough, dyspnea, hemoptysis, a history of previous carcinoma potentially metastatic to the lungs and airways, or radiographic abnormality suggestive of neoplasm (mass, lymphangitic-type infiltrate, focal infiltrate, solitary or multiple pulmonary nodules, mediastinal adenopathy).

    
    

    Small cell carcinoma:

    
    
    
    
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      The yield of bronchoscopic procedures is excellent. Tumors are often infiltrative, and diagnosed using washing, brushings, submucosal needle aspiration, and endobronchial biopsies.

    
    
    
    

    Non–small cell carcinoma:

    
    
    
    
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      Tumors can present with normal as well as abnormal tracheobronchial mucosa. When abnormal, appearances include but are not limited to intraluminal mucosal thickening, exophytic lesions, nodules, and friable mucosal changes.

      
      
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      Sometimes there are indirect signs of neoplasm and volume loss represented by focal and extensive airway narrowing, segmental bronchial strictures, extrinsic compression, large airway narrowing, carinal involvement, bronchoesophageal fistula, bronchomediastinal fistula, thickening of posterior pars membranosa, and thickening of mucosal spurs to peripheral bronchi. These changes are also seen in patients with small cell carcinoma and in patients with cancers metastatic to the airways (for example, breast cancer, colon cancer, renal cell carcinoma, malignant melanoma, thyroid cancer, esophageal cancer, adenoid cystic carcinoma, carcinoid tumors, and sarcomas).

      
      
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      Resectability can be assessed by careful measurement of distance from the carina, presence of associated airway strictures, and presence or absence of synchronous or asynchronous ipsilateral or contralateral abnormalities.

      
      
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      Mediastinal staging is possible using transbronchial needle aspiration (TBNA) or endobronchial ultrasound. Diagnostic yield is significantly increased when more than 4 needle passes are made; rapid on-site cytology examination (ROSE) is employed.

    
    
    
    
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    Early lung cancer detection

    
    
    
    
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      Increasingly advocated for patients at risk for new or recurrent bronchogenic carcinoma (patients with chronic obstructive pulmonary disease (COPD), smoking history, history of lung resection for bronchogenic carcinoma, patients with history of head and neck cancer).

      
      
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      Autofluorescence bronchoscopy can be used to increase sensitivity. Numerous biopsies of abnormal areas warranted.

      
      
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      New technologies include optical coherence biopsy, high-magnification bronchoscopy, and confocal endoscopy. Goals for these new technologies are to increase specificity, but further research and technology development are still needed.

    
    
    
    
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    Lymphoma

    
    

    Non-Hodgkin’s and Hodgkin’s Lymphoma:

    
    
    
    
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      Can be seen as simple airway mucosal thickening.

      
      
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      Mediastinal and hilar adenopathy

    
    
    
    
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    Tracheal tumors

    
    
    
    
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      Tracheal tumors are easily diagnosed using bronchoscopic procedures. Distance from the vocal cords and carina is assessed, and resectability can be determined by measuring lesion length, distance from the carina and vocal cords, and the number of cartilaginous rings involved.

    
    
    
    
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    Metastatic tumors

    
    
    
    
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      Tumors of the lung can be diagnosed even in the absence of airway involvement. Brushings, washings, bronchoalveolar lavage, and transbronchial lung biopsy provide diagnostic material when patients have focal or diffused infiltrates or nodular opacities.

    
    
    
    
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    Other malignancies

    
    
    
    
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      Solid tumors with mediastinal nodal metastases (breast cancer most common; thyroid, renal, rectal, and so on) are diagnosed.

      
      
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      Esophageal cancer can cause fistulas, as can esophageal cancer with an associated esophageal stent insertion or radiation therapy.

      
      
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      Surgical complications such as postpneumonectomy or postlobectomy stump fistula can be visualized and determinations made regarding indications for bronchoscopic or open surgical repair.

    
    

  
  
  
  
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  Benign Disease

  
  
  
  
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    Benign tracheal strictures

    
    
    
    
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      Symptoms include cough, shortness of breath, sudden onset of respiratory insufficiency, recurrent intubation of difficulty weaning from mechanical ventilation, adult-onset asthma, or asthma symptoms unresponsive to therapy.

      
      
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      Patients often have a history of difficult intubation, trauma, mechanical ventilation, or tracheostomy.

      
      
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      Airway strictures should also be suspected in patients with vasculitis such as Wegener’s Granulomatosis, as well as in patients with a history of tuberculosis, sarcoidosis, and other granulomatous disorders.

      
      
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      Length, caliber, and type of benign stricture (simple or complex, hourglass or circumferential, focal or multifocal) can be determined.

      
      
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      Resectability is determined, in part, by measuring length of the stricture as well as distance from the vocal cords.

    
    
    
    
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    Tracheobronchial malacia and excessive dynamic airway collapse

    
    
    
    
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      Increasingly recognized, may be primary or secondary with numerous possible etiologies

      
      
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      Dynamic bronchoscopy helps make diagnosis. Patients are examined with the bronchoscope in the sitting and supine positions, and asked to inhale and exhale forcibly. Excessive dynamic airway collapse (significant intrusion of the posterior membrane) can be seen with or without associated malacia (softening of the airway cartilage) ( Fig. 4-1 ).

      
      

      
      

      
      

      

      
      

      
      

      Patient with expiratory central airway collapse (malacia and excessive dynamic airway collapse) moved into lateral decubitus position as part of dynamic bronchoscopy performed using moderate sedation.

      
      

    
    
    
    
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    Other causes of airway strictures

    
    
    
    
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      Postradiation

      
      
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      Foreign body inhalation

      
      
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      Burn and inhalation injury

      
      
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      Brachytherapy, postelectrocautery, cryotherapy, laser resection, stent insertion, or airway photodynamic therapy.

      
      
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      Postsurgical (sleeve lobectomy, resection anastomosis, lung transplantation)

    
    
    
    
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    Lung transplantation

    
    
    
    
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      Bronchoscopy is helpful to inspect anastomoses and to diagnose anastomosis strictures or dehiscence.

      
      
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      Bronchoscopy is used to detect infection and transplantation-related complications including bronchiolitis and infectious lung disease.

    
    
    
    
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    Infectious and inflammatory lung disease

    
    
    
    
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      Greatest yield from combined washings and bronchoalveolar lavage.

      
      
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      Transbronchial biopsy may increase yield in both intact and immunocompromized patients, but the risk/benefit ratio of biopsy must be carefully considered.

      
      
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      Fungal, viral, bacterial diseases diagnosed, including tuberculosis; Mycobacterium avium-intracellulare , Pneumocystis, and Aspergillus infection; coccidioidomycosis.

      
      
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      Patients usually have pulmonary infiltrates, atelectasis, and lobar consolidation, but infection can also be diagnosed by mediastinal sampling using TBNA.

      
      
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      Interstitial lung diseases can be diagnosed by transbronchial lung biopsy. Yield in increased using multiple procedures such as endobronchial biopsy, transbronchial biopsy and TBNA for diseases such as Sarcoidosis. In other illnesses, such as nonspecific interstitial pneumonitis, usual interstitial pneumonitis, and desquamative interstitial pneumonitis, biopsies may be nonspecific, showing only fibrosis. Bronchoalveolar lavage with cell count differential is usually reserved for research purposes. Transbronchial biopsies can be helpful to diagnose bronchiolitis and alveolitis if representative samples are obtained.

    
    

  
  

CONTRAINDICATIONS

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  According to numerous guidelines and surveys, practice patterns differ, but the only contraindication is persistent or refractory hypoxemia.

  
  
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  Risks and benefits of each procedure must be carefully weighed.

  
  
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  Strategy and planning for each procedure includes indication, preprocedure evaluation, allergies, risks (respiratory failure, cough, vasovagal events, bleeding, pneumothorax, fever, procedure-related anxiety).

  
  
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  Preprocedure evaluation includes examination for significant comorbidities, especially cardiac arrhythmias, bleeding or coagulation disorder, medications including anticoagulants, antiplatelet agents, history of narcotic use (may require increased dose of sedation drugs), as well as careful assessment of patient’s preferences (nasal or oral bronchoscope insertion), expectations, and discussion of potential alternative diagnostic procedures.

  
  
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  “Time out” can be valuable in order to ascertain that nursing team, patient, and bronchoscopists agree on procedures to be performed, that appropriate precautions are taken in case of procedure-related complications or adverse events, and that all equipment and ancillary instruments are readily available.

  
  
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  Sedation should be individualized based on comorbidities, response to medication, desire for procedure recall, and need for patient collaboration during the procedure (forced cough, dynamic bronchoscopy). Synergistic effect of combined medications such as benzodiazepines and narcotics should be considered, particularly in patients with airway obstruction or poor ventilatory function.

  
  
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  Feeding should be held before procedures according to institutional guidelines because of risk of vomiting (cough and gag reflex) and aspiration.

  
  
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  Procedures appear safe even after myocardial infarction, in the elderly, and in patients with elevated intracranial pressures or pulmonary hypertension, although routine precautions are warranted. Some investigators suggest that bronchoscopy should be postponed, if possible, at least 4 weeks after myocardial infarction, and increased risk exists in patients with active congestive heart failure and left ventricular dysfunction. Transbronchial lung biopsies should be avoided, unless absolutely necessary in patients with pulmonary hypertension.

  
  
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  Bronchoscopy is usually safe in patients with asthma, although it should probably be avoided in patients with status asthmaticus. In addition, preprocedure bronchodilators and, of course, corticosteroids should be administered and procedures postponed, if possible, in patients with active asthma or exacerbations of COPD, as demonstrated by wheezing, shortness of breath, and pulmonary hyperinflation.

  
  
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  Pregnancy is definitely associated with increased risk for bronchoscopy. This is related to the reduced cardiac preload, decreased lower esophageal sphincter tone, increased oxygen consumption, and the primary respiratory alkalosis associated with pregnancy.

  
  
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  Critically ill patients on mechanical ventilation should be placed on 100% oxygen during the procedure. In nonintubated patients with impending respiratory failure, consideration should be given to use of noninvasive ventilation support and also precautionary intubation (sometimes over the flexible bronchoscope) prior to performing bronchoscopy.

  
  
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  Complications can be readily addressed by careful strategy and planning for each procedure. Also, necessary techniques and equipment should be known. For example, techniques of bronchoscopic intubation, bleeding control using balloons and endobronchial blockers, and emergency techniques for supplemental oxygen administration can be learned through postgraduate courses, guided reading, and simulation scenarios ( Fig. 4-2 ).

  
  

  
  

  
  

  

  
  

  
  

  Supplemental oxygen being connected directly to working channel of flexible bronchoscope using three-way stopcock. This technique allows delivery of supplemental oxygen while maintaining ability to suction using suction valve of the flexible scope.

  
  

PROCEDURES