Modern advancements in medicine and an increased use of assisted ventilation (breathing) have led to a higher observation of a condition called Tracheal Stenosis.¹ Tracheal Stenosis can directly lead to breathing problems while causing knock-on effects on other systems in the body. This article will provide you with a brief introduction to Tracheal Stenosis and explore the potential problems that can arise.

Overview 

What is tracheal stenosis?

Tracheal stenosis (tray-kee-al sten-osis) is a condition where the trachea (windpipe) is abnormally narrow, restricting your ability to breathe normally and leading to reduced airflow to the lungs.²

The trachea is an essential part of the respiratory system, providing a direct path for air transportation.³ The structure of the trachea consists of a tube leading from the larynx (voice box) to the lungs, supported by a series of C-shaped rings of hyaline cartilage linked together. This cartilage is firm yet flexible, enabling the trachea to move and flex while breathing, helping to maintain its shape to allow oxygen transportation to the lungs.³ Narrowing of the trachea can occur at any point between the top and bottom, causing a variety of complications ranging from mild to life-threatening.

Causes of tracheal stenosis

There are two forms of the condition, each with different causes:

1. Congenital (present at birth)

Developmental problems during pregnancy can lead to an abnormal tracheal structure. For example, rather than the usual C-shaped structure of cartilage mentioned earlier, people born with tracheal stenosis may have fixed, O-shaped rings called Complete Tracheal Rings (CTR).⁵ This results in a rigid, inflexible and narrow trachea as it can’t grow normally, although it is unknown which mechanisms cause this.

2. Acquired (developed)

More commonly, Tracheal Stenosis can develop during childhood or adulthood. It often occurs as a result of medical interventions, such as long-term use of breathing tubes (intubation) or tracheostomy (emergency surgery performed to create a hole in the trachea so you can breathe). This can cause scarring and narrowing of the trachea. Other causes include:⁶

• Injury or trauma to the throat or chest
• Viral or bacterial infections that affect your respiratory system
• Autoimmune disorders, such as Granulomatosis with polyangiitis (GPA)
• Inflammatory conditions (e.g. Pulmonary Sarcoidosis)
• Tumours (benign: non-cancerous and malignant: cancerous)
• Radiation therapy directed towards your neck/chest

Signs and symptoms

Symptoms can occur shortly after birth (congenital) or following an acute injury to the trachea. These can include:⁷

• Difficulty breathing after everyday activities, like walking
• Noisy breathing (stridor), which may sound like whistling or wheezing
• Cyanosis (blue-spells)
• Apnea (breathing pauses)
• Persistent cough
• Chest congestion
• Frequent cases of pneumonia

Complications of tracheal stenosis 

Why is it important to understand the complications?

While mild Tracheal Stenosis can often go unnoticed, more severe cases can lead to many direct and indirect complications that can cause serious breathing problems and affect daily life. It is important for us to gain knowledge and understand these complications to improve patient outcomes and quality of life by developing effective treatments and prevention strategies. 

Tracheal Stenosis can result in many complications, some of which may be potentially life-threatening. These complications stem from the obstruction (blocking) of airflow, inflammation and the effects of treatment. 

Respiratory complications

The main role of the trachea is to provide a path for airflow. Airflow obstruction limits the amount of space available for the air to pass through, creating resistance and increasing the effort required to breathe.⁸ The increased resistance explains the high-pitched, wheezing sound known as stridor. Wheezing symptoms can often be mistaken as asthma, especially in the early stages and can delay diagnosis and appropriate treatment, increasing the risk of worsening symptoms and further complications.^9,10

Moreover, when the amount of air that can pass through to the lungs is reduced, you may experience a chronic (long-term) sensation of dyspnea, meaning you feel short of breath. Dyspnea can gradually worsen over time, and you may find it hard to breathe and feel fatigued, even during simple activities or at rest. 

In severe cases, you may not be able to get enough air into your lungs, which is referred to as acute respiratory distress syndrome (ARDS). An individual experiencing acute (sudden) respiratory distress may experience a choking or suffocating sensation, causing rapid breathing, gasping for air and feelings of panic.¹¹ These symptoms can be extremely distressing to experience and can impact your quality of life significantly. Respiratory distress is more common in advanced stages of Tracheal Stenosis and requires immediate emergency medical attention, such as surgery or intubation (breathing tubes).¹

Infections

The inner lining of the trachea is composed of mucus-producing cells and cells with tiny hair-like projections called cilia.¹² When harmful particles are inhaled, these two types of cells work together as a team: the mucus-producing cells produce sticky mucus to trap these particles, and the cilia move these particles up to be coughed out or swallowed.¹² This powerful combination of cells is important for lung protection and preventing infections. A narrow trachea can trap mucus, as there is less space for normal clearance to occur, creating a favourable environment for respiratory infections to occur, such as bronchitis and pneumonitis.¹³ The build-up of mucus also further worsens symptoms of stridor and dyspnea previously mentioned. 

Hypoxia and hypoxemia

When the airflow is restricted, hypoxia and hypoxemia can occur. Hypoxia is when the tissues of your body do not have enough oxygen, whereas hypoxemia refers to low oxygen levels in the blood. Symptoms include:¹⁴

• Bluish skin/lips (cyanosis)
• Confusion
• Rapid breathing (tachypnea).
• Restlessness
• Dyspnea

While the body is equipped to deal with temporary dips in oxygen, prolonged oxygen deprivation can cause damage to other organs, such as cerebral hypoxia, causing brain cell death and potential coma or fatality.¹⁴

Cardiovascular (heart) complications 

Long-term hypoxia can also lead to cardiovascular problems; to compensate for the lack of oxygen delivered to tissues from the blood, the heart works harder to pump blood around the body, leading to a faster heart rate and higher blood pressure.¹⁵ Also, hypoxemia can affect the pulmonary arteries, making them constrict (become narrower) and squeezing the blood into a smaller space, elevating blood pressure and causing pulmonary hypertension.¹⁶ This can add further strain on the heart and cause cor pulmonale (enlargement of the right ventricle of the heart) and eventual failure. 

Voice changes and swallowing difficulties

Depending on the location and extent of the stenosis, patients may experience changes in their voice, such as hoarseness, which may be worsened by surgery. Narrowing of the trachea near the vocal cords can also interfere with swallowing, increasing the risk of aspiration (inhaling food or liquid into the lungs), which can lead to aspiration pneumonia.¹⁷

Treatment-related complications

Treating Tracheal Stenosis often involves surgeries that cut away the tissue causing the narrowing and join both ends of the trachea together, a process called resection. Non-surgical interventions such as dilation and stent placement are also used to widen the trachea.⁶ While these procedures may be helpful, they carry risks; stents or surgical repairs can become infected or irritated, creating further swelling or scarring that can cause restenosis (the re-narrowing of the trachea). However, complications from tracheal reconstruction are relatively uncommon, occurring in approximately ~20% of patients.¹⁸ If you are anxious about the risks associated with treatments for tracheal stenosis, you should seek advice from a medical professional to improve the chance of achieving positive outcomes, as treatments can vary in effectiveness based on the severity and location of the narrowing.⁶

Psychological and social impacts

Beyond physical health, Tracheal Stenosis can have negative impacts on your psychological health and well-being. The constant sensation of dyspnea and struggling to breathe can lead to mental health problems, such as anxiety, depression and an overall diminished quality of life. People experiencing chronic dyspnea may also find it difficult to engage in exercise and physical activities, contributing to a sedentary lifestyle, which may lead to conditions related to an unhealthy lifestyle. This may also cause social isolation and an avoidance of physical activities and public spaces due to symptoms, potentially creating a strain on personal relationships and further causing mental health problems. Furthermore, vocational complications may occur due to disruptions to work life and lowered productivity levels.

Management and prevention of complications 

While these complications may seem daunting, the good news is that there are many treatment options and prevention strategies to reduce the chance of these complications! Research and guidelines on effective intubation techniques serve as helpful tools for medical professionals to perform these procedures properly and prevent further problems.¹⁹ Furthermore, techniques such as cuff-pressure monitoring are implemented; to avoid preventable scarring and narrowing of the trachea, practitioners monitor the cuff (seal) of the breathing tube, making sure it doesn’t over-inflate.²⁰ Surgical interventions have also improved, finding promising benefits when combined with the use of airway-opening devices.²¹

Diagnosing and treating Tracheal Stenosis at an early stage is important to reduce the risk of complications. Healthcare professionals should provide education on the likelihood of risks and monitor any treatments, taking a multidisciplinary approach to deal with all aspects. 

Summary

Tracheal Stenosis is a complex condition with potentially severe complications, involving direct respiratory distress or problems to secondary organ systems. Some complications pose an immediate threat to life, while some lead to chronic symptoms that reduce the impact on overall physical and mental health. While advances in diagnosis and treatment have improved outcomes for many patients, this article sheds light on the importance of early detection and appropriate care. It is also paramount that treatment should address both physical and psychological needs of the patient. Further research into the mechanisms that cause these complications is needed in order to discover new minimally invasive treatments, improve diagnostic methods and implement preventative measures.