Idiopathic Tracheopathies: An Overview

Introduction:

The trachea, also known as the windpipe, is a long tube that connects the larynx to the lungs. It is an essential organ of the respiratory system, responsible for carrying oxygen to and out of the lungs. Diseases affecting the trachea are referred to as tracheopathia or tracheopathies, which can cause serious respiratory issues and compromise the quality of life of the affected individuals. Idiopathic tracheopathia is one of these conditions that are more challenging because of their complex character and unknown origin. These include tracheobronchopathia osteochondroplastica, tracheomalacia, tracheobronchomegaly (Mounier-Kuhn syndrome), and idiopathic tracheal stenosis. This article will focus on idiopathic tracheopathia.

What Are Idiopathic Tracheopathies?

Idiopathic tracheopathies are a group of diseases that affect the trachea. The term “idiopathic” means that the exact cause of these diseases is unknown. Neoplasms or infections either cause the majority of tracheal diseases. However, in several rare cases, the cause is unknown. This can be challenging for pulmonologists (lung specialists) because the symptoms of this idiopathic tracheopathia can present with nonspecific symptoms that are easily missed.

What Are the Types of Idiopathic Tracheopathies?

Some of the common causes of idiopathic tracheopathies are as follows:

1. Tracheobronchopathia Osteochondroplastica (TO):

TO is an uncommon non-cancerous disease characterized by bony and cartilaginous growth in the trachea. The growth occurs in the anterior and lateral walls of the trachea, and the back part is unaffected. Most of the patients are asymptomatic. Those individuals who are symptomatic may present with the following symptoms:

• Cough.

• Shortness of breath on exertion.

• Wheezing (whistling sound during breathing).

• Recurrent respiratory infection.

• Hemoptysis (coughing up blood) can occur in rare cases.

Diagnosis:

• Chest X-ray: Chest X-rays are not very sensitive but can occasionally reveal calcified deposits that constrict and deform the trachea. Chest X-rays alone do not provide a definitive diagnosis.

• Computed Tomography (CT) Scan: This provides more detailed images than chest X-rays. A CT scan may reveal calcified nodules in the anterior and lateral balls of the trachea.

• Pulmonary function tests.

• Bronchoscopy: A flexible tube with a camera is inserted through the mouth to visualize the trachea. It can usually directly visualize the nodules and confirm the diagnosis.

• Biopsy: During bronchoscopy, if nodules are firm and calcified tissue, biopsy is not necessary for diagnosis. In some cases, a biopsy can be done to confirm the presence of cartilage and bone formation.

2. Idiopathic Tracheal Stenosis:

Idiopathic tracheal stenosis is a condition with a narrowing of the trachea that causes difficulty in breathing. Symptoms of idiopathic tracheal stenosis include:

• Persistent cough.

• Dyspnea (shortness of breath during exertion).

• Hoarseness of voice.

• Increased mucus production.

• Stridor (wheezing sound during breathing in and out).

Diagnosis:

Diagnosis of idiopathic tracheal stenosis may involve chest X-rays, CT scans, MRI (magnetic resonance imaging), and bronchoscopy to check the extent of airway narrowing.

3. Tracheomalacia:

This condition is characterized by weak or floppy tracheal cartilage. This causes the trachea wall to fall in or collapse, which may cause various breathing problems. All individuals with tracheomalacia do not have symptoms; some patients remain asymptomatic. Symptoms may worsen during respiratory infections and sleep.

Common symptoms include:

• Wheezing.

• Shortness of breath.

• Difficulty in swallowing.

• Frequent respiratory infections sometimes lead to bronchiectasis (damage of airways).

• Severe cough, which may occasionally result in cough-induced syncope.

Diagnosis:

• Chest X-ray: X-rays are usually not helpful to diagnose tracheomalacia. Suppose an X-ray shows some abnormalities; further tests are done.

• CT Scan: CT scan leads to misdiagnosis if only done during inhaling. Dynamic CT scan is a valuable tool for diagnosing tracheomalacia. It measures the airway diameter and extent of collapse during exhale. A CT scan shows a ‘frown’ sign (narrowing in front to back direction) and a ‘saber sheath’ trachea ( narrowing in side to side direction).

• Pulmonary Function Tests: This test shows the severity of airflow obstruction.

• Bronchoscopy: It is a gold standard test for diagnosing tracheomalacia.

4. Tracheobronchomegaly:

This, also known as Mounier-Kuhn syndrome, is a rare disease characterized by abnormal enlargement of the trachea and bronchial tubes. The disease is frequently diagnosed in early adulthood, typically in the 30s or 40s. Some patients may present symptoms, and others may remain asymptomatic. Symptoms may include:

• Persistent cough with sputum.

• Difficulty in breathing.

• Recurrent respiratory infections such as bronchitis or pneumonia.

• Bronchiectasis (scarring of airways).

• Hemoptysis (episode of coughing up blood).

Diagnosis:

• Chest X-ray: A chest X-ray may indicate the condition, but a chest CT scan is necessary for confirmation.

• Chest CT Scan: Chest CT scan shows enlarged central airways exceed standard cutoff values. The diameter of the trachea exceeds 1.18 inches, the right main stem bronchus diameter exceeds 0.94 inches, and the left main stem bronchus diameter exceeds 0.91 inches.

• Pulmonary Function Test: It typically shows airflow obstruction.

What Is the Treatment of Idiopathic Tracheopathies?

The goal of treating idiopathic tracheopathia is to improve the airflow, reduce symptoms, and prevent complications. The treatment depends on the specific type and its severity. The following are the treatment approaches:

• Medications: Some medications are given to manage certain symptoms and reduce airway inflammation, such as anti-inflammatory medicines.

• Stent Placement: The placement of stents can help keep the airway open and reduce discomfort in patients with severe tracheal collapse or stenosis (narrowing).

• Surgical Treatment: In case of severe tracheal constriction or tracheomalacia, surgical procedures like tracheal resection with end-to-end anastomosis and tracheobronchoplasty might be required to improve airway function.

• Tracheostomy: Tracheostomy is done for temporary or permanent solutions. In some cases, it bypasses airway blockage and makes breathing easy.

• Laser Treatment: To enhance airflow and decrease discomfort, laser therapy may be utilized to treat particular tracheal lesions or other abnormalities such as TO.

• Lung Transplantation: It may be considered in very severe cases of tracheobronchomegaly in order to enhance respiratory function and quality of life.

Conclusion:

Idiopathic tracheopathia are a group of complex disorders characterized by abnormalities in the trachea (windpipe) without known cause. Even with improvements in treatment strategies and diagnostic imaging, these disorders still pose difficulties for doctors and researchers. To improve the patient outcome and quality of life, proper diagnosis and early treatment are necessary.