DEFINITION

Therapeutic bronchoscopy consists of airway interventions performed to restore or maintain airway patency, either for palliation or cure of malignant and benign lesions of the upper and lower airways. Procedures are performed using either a flexible or a rigid bronchoscope. Procedures are often referred to as interventional bronchoscopic procedures, and indeed, societies such as the American Thoracic Society, the European Respiratory Society, and the American College of Chest Physicians have offered guidelines pertaining to the practice and training of interventional bronchoscopy as a set of procedure performed by interventional pulmonologists and thoracic surgeons.

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 impacted in the right main bronchus of a 63-year-old gentleman. Rigid bronchoscopy, however, was rarely performed for therapeutic debulking because of the risk of bleeding, and was usually reserved for foreign body extractions until Nd:YAG laser resection became popular in the 1980s.

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  Therapeutic rigid bronchoscopy is always done under general anesthesia, using spontaneous assisted ventilation or jet ventilation. Therapeutic flexible bronchoscopic procedures are also usually performed under general anesthesia with endotracheal intubation but can also be performed using laryngeal mask airways.

  
  
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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.

  
  
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  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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  Therapeutic flexible bronchoscopy is usually performed using moderate sedation or general anesthesia. Many therapeutic procedures can be performed through the flexible scope, including foreign body removal, argon plasma coagulation, brachytherapy catheter placement, photodynamic therapy, Nd:YAG photocoagulation and resection, electrocautery, and balloon dilation, bronchial thermoplasty, and endobronchial valve placement for emphysema. Expandable metal stents can also be inserted using a combination of Seldinger techniques, flexible bronchoscopy, and fluoroscopy.

INDICATIONS

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  Central airway obstruction :

  
  
  
  
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    Fixed central airway obstruction is a frequent indication for therapeutic 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 a radiographic abnormality suggestive of neoplasm or benign strictures. Patients may have a history of previous intubation, tracheotomy, or suspected vasculitic disease. Other etiologies of fixed airway obstruction include idiopathic tracheal stenosis, postintubation strictures, a history of burn or inhalation injury, lung transplantation, tracheal resection and reanastomosis surgery, metal or silicone stent insertion; history of infectious airway disease, including tuberculosis, Klebsiella rhinosleroma, and fungal disease such as coccidiodomycosis, histoplasmosis and aspergillus.

    
    
    
    
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      Results of dilation and other bronchoscopic therapies are often satisfactory in more than 30% of cases initially.

      
      
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      Procedures may be curative or palliative.

      
      
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      Several types of neoplasms may also cause fixed airway obstruction. These include thyroid cancer, esophageal cancer invading the airway, enlarged mediastinal adenopathy from a neoplasm, carcinoid tumors, and adenoid cystic carcinoma.

      
      
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      Segmental obstruction can be caused by malignant and benign disorders, and are usually less amenable to bronchoscopic therapies, although brachytherapy, electrocautery, and photodynamic therapy should be considered.

      
      
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      Fixed strictures should be evaluated for etiology and possible cause. Before embarking on bronchoscopic therapy, particularly for patients with benign etiologies, a multidisciplinary approach is warranted. Surgical consultation is recommended, particularly for patients with potentially respectable airway strictures.

    
    
    
    
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    Dynamic central airway obstruction

    
    
    
    
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      May be associated with fixed airway obstruction.

      
      
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      May be caused by variable extrinsic compression snf also by expiratory central airway collapse (tracheobronchomalacia and excessive dynamic airway collapse).

      
      
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      Should be considered in patients who present weaning difficulties.

      
      
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      Other etiologies include vascular compression, post-pneumonectomy changes, chronic obstructive pulmonary disease (COPD), chronic airway infection, ball-valve airway tumors, including bronchogenic carcinoma, metastases from kidney, colon, breast cancer and malignant melanoma, diseases such as relapsing polychondritis (that may mimic asthma, but is usually refractory to conventional therapies).

    
    
    
    
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    Segmental airway obstruction

    
    
    
    
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      May be caused by a similar variety of benign and malignant disorders:

      
      
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      Can be seen as simple airway mucosal thickening.

      
      
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      May also be associated with or caused by mediastinal and hilar adenopathy.

      
      
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      Careful attention should be paid to adjacent vascular structures when bronchoscopic therapies are considered.

      
      
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      Granulation tissue formation prompted by inhaled foreign bodies can bleed easily.

    
    
    
    
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    Airway-esophageal and bronchopleural fistulas

    
    
    
    
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      Fistulas are troublesome and may cause symptoms such as prolonged airleak, difficulty weaning from mechanical ventilation, recurrent aspiration, dysphagia, and recurrent pneumonia.

      
      
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      Overall prognosis is usually poor.

      
      
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      Single-airway, esophageal, or double-airway and esophageal stents often help palliate symptoms and prolong survival.

      
      
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      Stents may also be helpful to palliate bronchoesophageal fistulas that occur after thoracic surgery or radiation therapy.

      
      
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      Other techniques such as balloon occlusion and administration of fibrin sealants can be attempted.

    
    
    
    
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    Procedure-related strictures

    
    
    
    
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      Insertion of metal or silicone stents can be followed by formation of granulation tissue or tumor overgrowth.

      
      
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      Metal stent rupture or excess epithelialization may cause airway stenosis.

      
      
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      Migration of a covered stent may cover the opening to a bronchus or the origin of a main stem bronchus.

      
      
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      Covering (silicone, polyurethane, polyester mesh) of metal and hybrid stents may rupture and cause airway obstruction. Careful attention is needed in case electrocautery, argon plasma, or laser is used to remove broken wire struts because airway fires can occur.

      
      
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      Electrocautery, cryotherapy, and excessive laser application can each cause collateral damage and recurrent airway strictures.

      
      
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      Vigorous dilation, especially usually overinflated balloons or large rigid bronchoscopes, can stretch airway mucosa and cause increased chance for scar tissue formation, especially in the region of the cricoid cartilage.

      
      
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      Recurrent stenosis is frequently seen after photodynamic therapy, so frequent clean out bronchoscopies are usually warranted to remove necrotic debris after photodynamic therapy (PDT).

    
    
    
    
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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 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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  Systemic diseases:

  
  
  
  
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    Asthma and emphysema

    
    
    
    
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      Symptoms include recalcitrant cough, shortness of breath, respiratory insufficiency which are refractory to treatment, and recurrent intubation.

      
      
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      Bronchial thermoplasty remains “experimental” and should be performed as part of clinical trials and special protocols.

      
      
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      Endobronchial valves can be considered as part of clinical trials and special protocols. This method of bronchoscopic lung volume reduction can cause pneumothorax and recurrent pneumonia. Information pertaining to procedure-related risks should be shared with patients.

    
    
    
    
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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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      Stent trial may be warranted in selected cases, but information pertaining to increased risks of stent-related complications should be shared with patients, families, and referring physicians.

      
      
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      Definitive treatment for malacia is often a tracheoplasty and bronchioplasty, but benefit from stenting may confirm that a patient is a good candidate for tracheoplasty.

    
    
    
    
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    Other illnesses

    
    
    
    
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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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      Bronchoscopic treatment is determined, in part, by measuring length of the stricture as well as distance from the vocal cords, risk of airway perforation, availability of appropriately seized stents, operator experience, risk of bleeding, capacity to control airway compromise, and respiratory failure.

    
    

  
  

CONTRAINDICATIONS

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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, prolonged hypoxemia, bleeding, pneumothorax, fever, procedure-related anxiety).

  
  
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  Preprocedure evaluation includes examination for significant comorbidities, especially cardiac arrhythmias, a 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, 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 done before procedures according to institutional guidelines because of risk of vomiting (cough and gag reflex), and aspiration.

  
  
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  Special precautions are warranted in patients with heart disease, in the elderly, and of course, in case of bleeding diathesis.

  
  
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  Careful examination of teeth, gums, and neck flexion and extension is warranted to avoid injury.

  
  
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  Patients with C-collars, limited neck mobility, and comorbidities such as advanced rheumatoid arthritis or ankylosing spondylitis may be especially difficult to manage, particularly for rigid intubations ( Fig. 9-1 ).

  
  

  
  

  
  

  

  
  

  
  

  Patient with ankylosing spondylitis could not be placed supine for rigid intubation because of cervical spine ankylosis.

  
  
  
  
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  Intubation of patients with congenital deformities may also be especially difficult or impossible to intubate with a rigid bronchoscope.

  
  
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  In patients with evidence of hyperreactive airway disease or COPD, preprocedure bronchodilators and corticosteroids should be administered.

  
  
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  In patients with tracheal strictures or evidence of laryngeal edema, postprocedure corticosteroids are usually administered.

  
  
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  Pregnancy is definitely associated with increased risk for therapeutic bronchoscopy, which should be performed only if absolutely necessary. Careful obstetric consultation is warranted, and often, obstetrics should stand by at the time of the bronchoscopic intervention.

  
  
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  Care should always be taken when rigid bronchoscopy is performed in critically ill patients on mechanical ventilation. Intubation with the rigid tube should probably be done under direct visualization as the endotracheal tube is being removed, so that the rigid tube can be seen entering the upper tracheal.

  
  
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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 resection required in-depth knowledge of laser-tissue interactions, or effects of electrocautery, and knowledge of stent-related complications.

  
  
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  The bronchoscopist and team should be practiced and experienced with techniques for (1) emergency intubation; (2) regaining an airway in case of laryngeal obstruction, laryngeal spasm or inability to intubate; (3) bleeding control using balloons and endobronchial blockers. Some of these techniques can be learned in postgraduate courses, guided reading, and simulation scenarios. All should be practiced by the interventional team before embarking on operative cases.

SUMMARY OF RESULTS OF LASER, STENTS, AND PHOTODYNAMIC THERAPY

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  Risks and benefits of each procedure must be carefully weighed.

  
  
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  Demonstrated survival benefit, improved dyspnea scores, and improved quality-of-life scores directly related to bronchoscopic treatment.

  
  
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  Patients who undergo successful re-establishment of airway patency usually survive longer than those who have continued partial obstruction or in whom attempts at restoring airway patency are unsuccessful.

  
  
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  Pulmonary function has been shown to improve by as much as 300 mL, Karnofsky scores often improve from 40 to 60, but median survival after stent insertion, for example, is only about 5 months. This reinforces the fact that the airway disease is simply one manifestation of an end-stage disease, or that life-threatening symptoms of airway obstruction may occur as a terminal or near-terminal event. However, palliation of airway obstruction is justified to provide improved comfort, diminished breathlessness, and increased ability to interact with family and friends.

  
  
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  In patients with superficial early lung cancer and carcinoma in-situ, potentially curative bronchoscopic treatment should also be considered. Photodynamic therapy may be a valuable treatment for such early in situ cancers (rarely), especially in patients who are not surgical candidates.

  
  
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  PDT may also treat the extension of a lung cancer out of a bronchus so that a standard lobectomy may be performed, rather than a more complex sleeve lobectomy or to shrink a tumor away from the carina.

  
  
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  Procedures are also safe in the elderly and elder elderly, although anesthesia-related events such as hypoxemia and unstable blood pressure must be controlled.

  
  
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  Although surveillance bronchoscopy is probably not necessary, any new or recurrent symptoms in patients with indwelling stents warrant bronchoscopy.

  
  
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  Patients can be given a medical alert document indicating type and location of stent, and also providing instructions in case of emergency. A model is freely downloadable from the www.bronchoscopy.org .

PROCEDURES