Tracheobronchomalacia or TBM is a condition characterized by flaccidity of the

trachea The trachea, also known as the windpipe, is a Cartilage, cartilaginous tube that connects the larynx to the bronchi of the lungs, allowing the passage of air, and so is present in almost all air-breathing animals with lungs. The trachea extends ...

l support

cartilage Cartilage is a resilient and smooth type of connective tissue. In tetrapods, it covers and protects the ends of long bones at the joints as articular cartilage, and is a structural component of many body parts including the rib cage, the neck an ...

which leads to tracheal collapse. This condition can also affect the bronchi. There are two forms of this condition: primary TBM and secondary TBM. Primary TBM is congenital and starts as early as birth. It is mainly linked to genetic causes. Secondary TBM is acquired and starts in adulthood. It is mainly developed after an accident or chronic inflammation. Tracheobronchomalacia may also occur in people who have normal cartliginous structure of the trachea, but significant atrophy of the posterior wall, causing significant invagination of the trachea on expiration. In these cases it is more commonly known as Excessive Dynamic Airway Collapse (EDAC).

Signs and symptoms

Initially TBM may be asymptomatic or some patients do not experience symptoms at all. In a progressive TBM case symptoms include: * shortness of breath * a cough * mucus build up * stridor (a wheeze-like sound on breathing out) * difficulty in breathing * bluish coloration to skin around the nose and mouth * Chronic cough Symptoms may become worse if the patient is stressed, sick, lying down, or forcing a cough.

Cause

Congenital TBM is present from birth. Acquired TBM often has no clear cause but is frequently found together with other pulmonary diseases like

asthma Asthma is a long-term inflammatory disease of the airways of the lungs. It is characterized by variable and recurring symptoms, reversible airflow obstruction, and easily triggered bronchospasms. Symptoms include episodes of wheezing, cou ...

and

Chronic obstructive pulmonary disease Chronic obstructive pulmonary disease (COPD) is a type of progressive lung disease characterized by long-term respiratory symptoms and airflow limitation. The main symptoms include shortness of breath and a cough, which may or may not produce ...

, as well as

Gastroesophageal reflux disease Gastroesophageal reflux disease (GERD) or gastro-oesophageal reflux disease (GORD) is one of the upper gastrointestinal chronic diseases where stomach content persistently and regularly flows up into the esophagus, resulting in symptoms and/ ...

. TBM can be caused by damage to the support cartilage or membranous wall of the trachea, this can be the result of physical trauma (such as from prolonged

Tracheal intubation Tracheal intubation, usually simply referred to as intubation, is the placement of a flexible plastic catheter, tube into the vertebrate trachea, trachea (windpipe) to maintain an open airway or to serve as a conduit through which to administer ce ...

) or pathological changes caused by inflammatory diseases like

Relapsing polychondritis Relapsing polychondritis is a multi-systemic condition characterized by repeated episodes of inflammation and deterioration of cartilage. The often painful disease can cause joint deformity and be life-threatening if the respiratory tract, heart v ...

. In patients with TBM in one study, the number of longitudinal elastic fibers in the pars of membranacea was reduced throughout the whole trachea. People with heritable connective tissue disorders like Ehlers–Danlos syndrome seem to have at an increased risk of both congenital and acquired TBM, although the extent of that risk is unknown. There have been studies linking long-term use of inhaled

Corticosteroid Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex of vertebrates, as well as the synthetic analogues of these hormones. Two main classes of corticosteroids, glucocorticoids and mineralocorticoids, are involv ...

s to Tracheobronchomalacia.

Diagnosis

Diagnosis is conducted according to the severity of the symptoms. Initially pulmonary function tests are administered. These tests include the lungs' capability of air intake and outtake, and gas flow of oxygen and carbon dioxide between the body and environment. Following these function tests a special type of Chest CT scan or a

bronchoscopy Bronchoscopy is an endoscopic technique of visualizing the inside of the airways for diagnostic and therapeutic purposes. An instrument (bronchoscope) is inserted into the airways, usually through the nose or mouth, or occasionally through a trac ...

will be ordered. The results of the scan and bronchoscopy will display the status of the condition. A mild case of tracheobronchomalacia would be if the patient's trachea condenses 50% of its normal space when exhaling. Moderate tracheobronchomalacia would be 25% of the normal trachea space constricting and a severe case would be if the walls touch each other. Tracheobronchomalacia is thought to be underdiagnosed as mild cases may be asymptomatic and symptoms are often mistaken for more common respiratory conditions like Athsma and

Treatment

To properly treat a patient with tracheobronchomalacia, the subtype must be determined (primary or secondary). After the type is named, the cause must be identified, whether it is from genetics, a trauma accident, or chronic tracheal illness. If a trauma case or chronic tracheal illnesses were the cause, the first steps of treatment would be to address these underlying issues. If the cause is genetic or the previous underlying issues could not be fixed, other treatments would be assessed. More severe treatments include silicone stenting to prevent tracheal constriction, surgery to strengthen or attempt to rebuild the walls,

continuous positive airway pressure Continuous positive airway pressure (CPAP) is a form of positive airway pressure (PAP) ventilation in which a constant level of pressure greater than atmospheric pressure is continuously applied to the upper respiratory tract of a person. The ap ...

that has a machine blow small amounts of air into the trachea to keep it open (mainly at night), or a

tracheostomy Tracheotomy (, ), or tracheostomy, is a surgical airway management procedure which consists of making an incision (cut) on the anterior aspect (front) of the neck and opening a direct airway through an incision in the Vertebrate trachea, trache ...

, which is surgically inserted into the patient's neck that leads to the trachea to help with breathing. Another form of treatment may include a tracheobronchoplasty which is a specific surgical procedure that helps control the airway by splinting the trachea. The splint helps strengthen the trachea with the hopes that the symptoms improve. People with tracheobronchomalacia who do not experience symptoms do not need treatment and are often undiagnosed. On 28 May 2013, it was reported that a cure had been developed via a

3D printed 3D printing or additive manufacturing is the construction of a three-dimensional object from a CAD model or a digital 3D model. It can be done in a variety of processes in which material is deposited, joined or solidified under computer co ...

windpipe. This cure has currently saved the lives of at least 3

infants An infant or baby is the very young offspring of human beings. ''Infant'' (from the Latin word ''infans'', meaning 'unable to speak' or 'speechless') is a formal or specialised synonym for the common term ''baby''. The terms may also be used to ...

References

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