Bronchiectasis

BronchiectasisBronchiectasis strictly defined is abnormal dilation of the bronchi, but common usage expands the definition to denote the syndrome marked by dilation of bronchi, a paroxysmal cough that produces variable amounts of fetid, mucopurulent sputum, recurrent pulmonary infections. Bronchiectasis was at one time a common problem frequently complicated by hemoptysis, lung and brain abscesses, empyema, respiratory failure, and death. Since the introduction of vaccination programs, antibiotics, and antituberculous medications, however, it is reported commonly only in isolated geographic locations.

Although congenital diseases (Kartagener’s syndrome, immunoglobulin deficiencies, and 1-antitrypsin deficiency) can lead to the development of bronchiectasis, most cases are related to acquired disorders and are caused by two factors: infection and bronchial obstruction. Viral and bacterial pneumonias in infancy and childhood — pertussis, measles, influenza, tuberculosis, and bronchopneumonia—were common predisposing conditions that led to bronchiectasis in the past. Either a single severe bout of pneumonia or repeated moderate infections can cause progressive destruction of bronchial cilia, mucosa, musculoelastic tissue, and even cartilage. Healing with fibrosis of the peribronchial tissues subsequently produces bronchial dilation. Retention of secretions resulting from destruction of normal mucociliary action leads to repeated bouts of infection and progressive scarring and bronchial dilation. Aspirated foreign bodies, endobronchial neoplasms, and hilar lymphadenopathy (see middle lobe syndrome below) also can cause retention of secretions, infections, and progressive bronchiectasis. The presence of true established bronchiectasis, however, must be distinguished from pseudobronchiectasis, which is a cylindric bronchial dilation that is associated with acute bronchopneumonia. When left untreated, true bronchiectasis progresses, while pseudobronchiectasis reverses completely after weeks to months.

Since the original description of bronchiectasis by Laennec in 1826, the disorder has been divided into two main types based on pathologic appearance: saccular and cylindric. Saccular bronchiectasis follows most infections while the cylindric variety is associated with posttuberculosis bronchiectasis. A third type of bronchiectasis is distinguished by alternating saccular and cylindric areas and is referred to as mixed or varicose bronchiectasis. In general, bronchiectasis involves the second-order to fourth-order branches of the segmental bronchi, and its distribution is largely characteristic of the underlying pathology. Congenital disorders, for example, are associated with diffuse bilateral bronchiectasis, while tuberculosis and granulomatous diseases are characterized by unilateral or bilateral disease, most commonly limited to the upper lobes. Furthermore, bronchiectasis following pyogenic and viral pneumonias usually involves only the lower lobes, middle lobe, lingula, and postobstructive bronchiectasis is generally limited to the obstructed segments (see also middle lobe syndrome, below). Common pathogens in patient with bronchiectasis include H influenzae, S aureus, K pneumoniae, E coli, and, in the chronic setting, pseudomonas species. Mycobacteria, fungi, and legionella should also be cultured.

Clinical Findings & Diagnosis of Bronchiectasis

Patient with a history of recurrent febrile episodes often complain of a chronic or intermittent cough that is productive of variable amounts of foul-smelling sputum. Hemoptysis occurs in 41–66%, but rarely is it massive. Bronchiectasis associated with granulomatous disease may not be associated with a productive cough (so-called “dry” bronchiectasis). Exacerbations and advanced disease are manifested by increased sputum production, fever, dyspnea, anorexia, fatigue. A history of sinus problems, infertility, or a family history of similar problems suggests the presence of an inherited disorder associated with bronchiectasis. Physical examination may reveal cyanosis, clubbing, pulmonary osteoarthropathy, evidence of malnutrition, and, in advanced disease, signs of cor pulmonale. Although bronchiectasis is suspected, an imaging study is usually required for confirmation. Bronchograms were at one time required, but high-resolution, fine-cut (1.5–5 mm) CT scans are now the imaging procedure of choice to document bronchial dilation, particularly with saccular disease. Even with the bronchiectasis, however, endobronchial neoplasm or foreign body must be excluded by flexible fiber optic bronchoscopy.

Treatment of Bronchiectasis

In nearly all patients, conservative medical therapy is indicated and generally is sufficient. This includes broad-spectrum antibiotics, bronchodilators, humidification, expectorants, mucolytics, and effective routine postural drainage. In patients with continued infection, bronchoscopy with bronchoalveolar lavage should be considered to obtain more accurate culture results. Other adjunctive therapies includes influenza and pneumococcal vaccines and, in some patients, chronic “prophylactic” antibiotic administration with trimethoprim-sulfamethoxazole, erythromycin, or ciprofloxacin. A recent advance in controlling underlying bacterial (especially pseudomonas) infection, symptoms associated with bronchiectasis has been the use of antibiotics. In the cystic fibrosis and chronic bronchiectasis population, nebulized tobramycin or gentamicin has proved effective in controlling infection, sputum production, and symptoms in a significant proportion of patients.

Patients who fail intensive medical therapy may be candidates for surgical resection if the following criteria are met:

  • the disease must be localized and completely resectable;
  • pulmonary reserve must be adequate;
  • the process must be irreversible (not pseudobronchiectasis, bronchial stricture, foreign body, etc);
  • significant symptoms must persist.

Preoperative assessment requires a high-resolution fine-cut CT scan, though some surgeons still prefer a bronchogram as a “road map.” Pulmonary function studies generally are not necessary since the involved segments do not function. The goals of surgery are to remove active disease and to preserve as much functioning lung parenchyma as possible. The surgical approach includes complete segmental resection of the involved areas. Partial resection almost always ends in recurrence. Resection most commonly involves all basal segments (unilaterally or bilaterally) along with the middle lobe. During surgery, meticulous maintenance of a clear airway devoid of mucopurulent secretions and blood is essential. Careful dissection of the bronchovascular structures is difficult in patient with chronic inflammation and scarring but is essential to avoid complications.

Prognosis

Although most patients are successfully treated with medical therapy, some require surgery. The results of surgical resection depend on the cause and type of pulmonary involvement. Success with elimination of symptoms occurs in up to 80% of patients with limited localized disease but only 36% of those with diffuse disease. Prognostic factors include

  • unilateral disease restricted to the basal segments,
  • young age,
  • absence of sinusitis and rhinitis,
  • history of pneumonia,
  • no major airway obstruction.

Overall morbidity rates are surprisingly low at 3–5% and < 1%, respectively.

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