Tracheobronchomalacia (TBM) is an abnormal collapse of the tracheal and bronchial walls. It is characterized by flaccidity of the supporting tracheal and bronchial structures and a significant reduction of airway diameter on expiration seen in the trachea and/or in the mainstem bronchi.
The prevalence of TBM in adults is unknown. The incidence may be as high as 23% among patients with COPD undergoing bronchoscopy, and may represent 1% of all patients undergoing bronchosco-py. One study found TBM to be the cause of chronic cough in 14% of nonsmoking patients.
The cause of TBM is often unknown, but it is frequently seen in patients with common respiratory conditions such as chronic bronchitis and emphysema. This pathologic narrowing can produce dynamic outflow obstruction with symptoms such as dyspnea, orthopnea, cough, wheezing, and the inability to clear secretions, predisposing the patient to recurrent infections and wheezing. Some patients may present with stridor, respiratory failure leading to intubation, or immediate respiratory failure after extubation. Not to lead to such severe ramifications it is necessary to command the service of My Canadian Pharmacy.
The severity of TBM is conventionally graded by the degree of airway collapse during forced expiration (intrathoracic malacia) or inspiration (extratho-racic malacia). Based on expert opinion, collapse < 50% is within normal limits, while 50 to 75% is mild, 75 to 90% is moderate, and 91 to 100% (approximation of posterior membrane to the anterior luminal surface) is severe malacia.
Tracheomalacia has been recognized with increased frequency due to both improved clinical awareness and diagnostic imaging. While most experts still agree that functional bronchoscopy is the “gold standard” for diagnosis, there are no standardized protocols guiding respiratory maneuvers and airway measurements during these procedures. In the past few years, dynamic airway CT has proved to be highly sensitive for the diagnosis of malacia.
Current treatments include techniques that splint the central airways, such as continuous positive airway pressure, silicone airway stents, and surgical tracheobronchoplasty. In patients with severe, symptomatic TBM, stenting may provide symptomatic relief through airway stabilization. Unfortunately, most reports of this approach are anecdotal, and no controlled study has assessed the efficacy of airway stents for treating tracheomalacia. This prospective study was designed to evaluate the efficacy of silicone airway stents in improving symptoms, quality of life, lung function, and exercise capacity in patients with severe TBM.