Cylindrical Bronchiectasis - Causes, Symptoms, Diagnosis, and Treatment

Introduction

Bronchiectasis is a condition that refers to the enlargement of parts of the airways of the lungs. It results in frequent lung infections. It damages the walls of the bronchial tubes. It can be congenital or acquired. It often occurs as a secondary infection. It results in abnormal and permanent distortion of the bronchi.

What Is Bronchiectasis?

The main airway, the trachea (windpipe), branches off into the right and left bronchial tubes. The bronchial tubes further branch into smaller tubes called bronchioles which lead to air sacs (alveoli) in the lungs. Bronchiectasis is an uncommon lung condition that damages the bronchial tubes. It results in the widening and thickening of the bronchial tubes.

What Is Cylindrical Bronchiectasis?

Cylindrical bronchiectasis is a type of bronchiectasis. Bronchiectasis is divided into three types based on the damage to the airway.

• Cylindrical Bronchiectasis: It is the common form of bronchiectasis, also called tubular bronchiectasis. It results in uniform enlargement of the bronchial tubes. The normal distal tapering of the airways is not present.

• Varicose Bronchiectasis: It is also called saccular bronchiectasis. It distorts the airway and results in increased mucus production. Some bronchi may appear in beaded form.

• Cystic Bronchiectasis: It is the least common and severe form of bronchiectasis. The bronchial walls become thicker than the blebs seen in emphysema. It shows a honeycomb appearance in the CT (computed tomography) scan.

More than one form of bronchiectasis may be present in some individuals.

What Are the Causes of Bronchiectasis?

Various conditions can cause bronchiectasis.

This includes:

• Autoimmune Diseases - Autoimmune diseases like rheumatoid arthritis and Sjogren's syndrome cause bronchiectasis. Other autoimmune inflammatory bowel diseases like ulcerative colitis and Crohn's disease are also associated with bronchiectasis. Graft-versus-host disease in stem cell transplantation patients can lead to bronchiectasis.

• Impaired Host Defense Mechanism - Cystic fibrosis is an autosomal recessive disorder that affects the pancreas, liver, kidneys, and intestine. A gene mutation causes it. It leads to bronchiectasis in the later stages. In addition, other immunocompromised conditions like primary ciliary dyskinesia, primary immunodeficiency, job syndrome, and AIDS (acquired immunodeficiency syndrome) can cause bronchiectasis.

• Lung Infections - Bacterial, mycobacterial, and viral lung infections can cause bronchiectasis. Bacterial infections that cause bronchiectasis are Pseudomonas aeruginosa, Haemophilus influenzae, and Streptococcus pneumoniae. Mycobacterial infections like tuberculosis can lead to bronchiectasis. Nontuberculous mycobacterial infections like Mycobacterium avium complex are associated with bronchiectasis. Endobronchial tuberculosis causes bronchial stenosis or traction from fibrosis and results in bronchiectasis. Traction bronchiectasis affects the peripheral bronchi.

• Congenital - Congenital conditions are also associated with bronchiectasis. Cystic fibrosis is the most common congenital condition associated with bronchiectasis. Other congenital disorders like tracheobronchomegaly, Marfan syndrome, Williams-Campbell syndrome, young's syndrome, and alpha-1 antitrypsin deficiency can cause bronchiectasis.

• Hypersensitivity Reactions - Allergic bronchopulmonary aspergillosis is a hypersensitivity reaction to the fungus Aspergillus fumigatus. It causes inflammation of the airway. It results in bronchiectasis.

• Airway Obstruction - Airway obstruction caused by a tumor, foreign body, or lymphadenopathy leads to inflammation. It results in bronchiectasis.

• Malignant Conditions - Malignant conditions like chronic lymphocytic leukemia are associated with Bronchiectasis.

• Other Conditions - Pneumonia, chronic aspiration, ammonia inhalation, smoke inhalation, radiation-induced lung diseases, and yellow-nail syndrome are associated with bronchiectasis.

How Does Bronchiectasis Develop?

Injury to the lungs, autoimmune destruction of the lung tissues, or other destructive lung disorders leads to impaired mucociliary clearance, obstruction, or a defect in host defense. This initiates an immune response from neutrophils, reactive oxygen species, and inflammatory cytokines.

This results in the progressive destruction of the normal lung tissues and the elastic fibers of the bronchi. This leads to abnormal dilation and destruction of the bronchi and bronchioles. Disordered neutrophil function is associated with severe bronchiectasis. Lung injury leads to impaired mucociliary clearance and mucous stasis.

Mucous stasis results in bacterial colonization and activation of neutrophils. This further results in tissue destruction, impaired mucociliary clearance, mucus stasis, and the continuation of the vicious cycle.

What Are the Symptoms of Bronchiectasis?

The symptoms include:

• Cough with green or yellow sputum.

• Difficulty breathing.

• Wheezing.

• Chest pain.

• Fever.

• Chills.

• Night sweats.

• Fatigue.

• Weight loss.

• Coughing up blood if sputum is not present.

Exacerbations include worsening cough, increased sputum, worsening shortness of breath, exercise intolerance, fatigue, and the development of hemoptysis.

What Are the Complications of Bronchiectasis?

The complications include:

• Respiratory failure.

• Atelectasis.

• Lung abscess.

• Empyema.

• Cor pulmonale.

How Is Bronchiectasis Diagnosed?

The diagnosis is based on radiographic imaging, laboratory, and lung function testing.

• Chest X-Ray - A chest X-ray is done to confirm the presence of bronchiectasis. It shows the presence of airway dilation and bronchial wall thickening. CT scan is used to identify the type of bronchiectasis.

• Nasopharyngeal Swab - It is done to test the presence of the bacteria. Sputum cultures are done to identify bacteria, Mycobacteria, and fungi.

• Blood Tests - Blood cultures, complete blood count, and electrolyte analyses are required.

• Lung Function Tests - This includes spirometry and walking tests to assess and monitor lung impairment.

How to Prevent Bronchiectasis?

Bronchiectasis can be prevented by preventing lung infections. Immunization against measles, pertussis, pneumonia and other respiratory infections is required. Inhalation of smoke and other chemicals should be avoided.

How Is Bronchiectasis Treated?

Treatment requires controlling infections, and bronchial secretions, relieving obstructions and preventing complications.

• Airway Clearance - Inhalation agents like hypertonic saline loosen the secretions and clear the airway. Mucolytic agents like Dornase alfa are given but not recommended for non-cystic fibrosis bronchiectasis. Airway clearance improves breathing difficulty and clears the mucus plugs. Physiotherapy procedures like high-frequency chest wall oscillation help to alleviate the secretions.

• Anti-inflammatories - Macrolides and corticosteroids are given to suppress the inflammation. Inhaled corticosteroids reduce sputum production and decrease constriction.

• Antibiotics - Antibiotics are given to suppress bacterial colonization. Inhaled antibiotics like aerosolized Tobramycin, inhaled Ciprofloxacin, aerosolized Aztreonam, and aerosolized Colistin are given.

• Bronchodilators - Inhaled bronchodilators are given to improve dyspnea and cough.

• Surgery - It involves the removal of diseased segments of the lung to control hemoptysis.

Conclusion

Bronchiectasis is a condition that affects the bronchi. Cylindrical bronchiectasis is a type of bronchiectasis that causes tubular widening of the airway. Severe symptoms may result in respiratory failure. However, early diagnosis and treatment can prevent the risk of complications.