Bronchomalacia is a condition in which the cartilage supporting the bronchial airways is abnormally soft or weak, allowing the airway walls to collapse during exhalation and restrict airflow. It can affect one or both lungs at the level of the mainstem bronchi or their smaller branches, and it ranges from a barely noticeable finding on imaging to a life-threatening obstruction in critically ill infants. The condition is frequently confused with asthma or chronic bronchitis, which means many people live with it for months or years before getting a correct diagnosis.
What Happens Inside a Malacic Airway
Healthy bronchi stay open during both inhalation and exhalation because semicircular rings of cartilage provide structural rigidity, much like the rings in a garden hose keep it from kinking. In bronchomalacia, those rings are either underdeveloped, damaged, or softened to the point that they can no longer hold the airway open when pressure outside the bronchus exceeds pressure inside it, which happens every time you breathe out. The result is that the airway partially or fully collapses on expiration, trapping air behind the narrowed segment and making it harder to clear mucus.1PubMed Central. Prevalence of tracheobronchomalacia and excessive dynamic airway collapse in bronchial asthma of different severity
An important distinction exists between bronchomalacia and a related but different phenomenon called excessive dynamic airway collapse, or EDAC. In bronchomalacia, the cartilage itself is weak. In EDAC, the cartilage is intact, but the soft posterior membrane of the airway bulges forward into the lumen during exhalation. Both lead to expiratory narrowing, and the two can coexist, but they involve different structures and sometimes call for different treatment approaches.2PubMed. Tracheobronchomalacia and Excessive Dynamic Airway Collapse: Current Concepts and Future Directions
Clinicians define bronchomalacia as a greater than 50% reduction in the airway’s cross-sectional area during quiet breathing. In practice, severity is graded on a simple scale: mild means a 50–75% reduction, moderate means 75–90%, and severe means more than 90% collapse.3European Respiratory Journal. ERS statement on tracheomalacia and bronchomalacia in children Those grades matter because they guide treatment decisions: a child with mild malacia who is growing normally will often be watched, while an infant with near-complete collapse may need surgery within weeks.
Why It Happens
Bronchomalacia falls into two broad categories. Primary (or congenital) bronchomalacia results from a developmental defect in the cartilage itself; the rings simply never formed properly. Secondary (acquired) bronchomalacia develops later when something damages or compresses previously normal cartilage. In children, the most common secondary causes are external compression from abnormal blood vessels, enlarged cardiac structures, or complications from surgeries such as repair of esophageal atresia and tracheoesophageal fistula. Long-term follow-up of children who had esophageal atresia repair frequently reveals airway malacia on bronchoscopy.4Gastroenterology Report. Long-term esophageal and respiratory outcomes in children with esophageal atresia and tracheoesophageal fistula
Vascular rings, a group of congenital anomalies in which blood vessels encircle the trachea and esophagus, are another well-recognized trigger. Even after surgical division of the ring, residual airway malacia can persist and may need separate treatment. Specialists typically recommend bronchoscopy at the time of vascular ring repair to assess the degree of any associated bronchomalacia or tracheomalacia.5PubMed. Vascular rings Imaging studies of children with vascular rings and pulmonary artery slings have detected tracheomalacia or bronchomalacia in over half of cases.6PubMed. Imaging modalities in children with vascular ring and pulmonary artery sling
In adults, the picture shifts. Chronic obstructive pulmonary disease (COPD), recurrent infections, prolonged intubation, and relapsing polychondritis (an autoimmune disease that attacks cartilage) are among the recognized causes. The cartilage damage in these cases accumulates over time, and weakness of the airway walls and supporting cartilage is well documented in both adult and pediatric populations.7Journal of Thoracic Imaging. Tracheobronchomalacia: Current Concepts and Controversies
Symptoms in Children
In infants, bronchomalacia almost always shows up within the first six months of life. The hallmark sound is a harsh, monophonic wheeze loudest over the central airway, often present even between respiratory illnesses. In one case series, every single infant with primary bronchomalacia had initially been diagnosed with reactive airways disease (a clinical stand-in for early asthma) by their primary care physician, and none had bronchomalacia on the radar before referral to a specialist center.8PubMed. Primary bronchomalacia in infants and children
Beyond wheezing, symptoms depend on exactly where the malacia sits. If the malacic segment is in the intrathoracic airways, the child tends to have an expiratory wheeze. During respiratory infections, the picture can worsen to include a barking cough, prolonged cough that lingers well after the infection clears, or croup-like symptoms.9European Respiratory Journal. ERS statement on tracheomalacia and bronchomalacia in children – Section: Clinical symptoms and signs In severe cases, especially in infants with cardiac anomalies, “blue spells” (brief episodes of cyanosis and apnea) and events formerly known as apparent life-threatening events can occur. These are the scenarios that push clinicians toward surgical intervention.
A large retrospective analysis of 459 children with airway malacia found that isolated bronchomalacia was far more common than tracheomalacia or combined tracheobronchomalacia, accounting for nearly 95% of cases. The right lung was affected about five times more often than the left lung alone, though malacia in both lungs was seen in roughly a third of children. All the children in that cohort had been diagnosed with pulmonary infection, highlighting how closely bronchomalacia and recurrent respiratory infections travel together.10PubMed Central. Clinical features of airway malacia in children: a retrospective analysis of 459 patients
Why Adults Often Get Misdiagnosed
Adults with bronchomalacia face a different diagnostic challenge. There is no obvious newborn screen for it, and the symptoms, chronic cough, exercise intolerance, recurrent lower respiratory infections, shortness of breath, are indistinguishable from several far more common conditions. The condition is frequently misdiagnosed as asthma, bronchitis, or simply chronic cough, in part because there are no specific history findings or physical exam signs that point straight to it.11PubMed. Tracheobronchomalacia A useful clinical clue is a patient whose “asthma” does not respond to inhalers the way it should. If bronchodilators and inhaled steroids leave the wheeze unchanged, malacia deserves consideration.
How Bronchomalacia Is Diagnosed
The gold standard for diagnosis is flexible bronchoscopy performed while the patient is breathing on their own (or at least with minimal sedation that preserves spontaneous respiration). The clinician watches the airway during the breathing cycle and visually estimates how much it narrows on expiration. Among adult pulmonologists, inter-observer agreement using this technique has been shown to be favorable, giving confidence that different doctors looking at the same airway will arrive at the same conclusion.12PubMed. Evaluation of tracheobronchomalacia by dynamic flexible bronchoscopy. A pilot study In pediatric patients, however, some research has raised concerns about variability between observers, partly because the procedure is technically harder in smaller airways and sedation levels can influence the degree of collapse seen.13PubMed. Intra-Observer and Interobserver Consistency in the Diagnosis of Lower Airway Malacia Using Dynamic Flexible Bronchoscopy in Pediatric Patients
Dynamic expiratory CT scanning has emerged as a non-invasive alternative. The patient (or, in children, the ventilator circuit) is asked to exhale forcefully while images are captured, and the resulting scans show the airways at their narrowest. In a pilot evaluation comparing dynamic CT to bronchoscopy, CT correctly identified malacia in 28 of 29 patients.14Chest. Comparison of dynamic expiratory CT with bronchoscopy for diagnosing airway malacia: A pilot evaluation A separate study in fragile children found dynamic CT had 100% sensitivity and about 82% specificity compared to bronchoscopy.15PubMed. Dynamic expiratory CT: An effective non-invasive diagnostic exam for fragile children with suspected tracheo-bronchomalacia Specialists have shown substantial agreement when reading these dynamic CT scans for the presence of malacia, though agreement drops to moderate levels when they try to classify the specific subtype of airway collapse.16PubMed Central. Evaluating physician concordance in interpretation of tracheobronchomalacia diagnosis and phenotyping using dynamic expiratory chest computed tomography
For many pediatric patients, particularly those too fragile for sedated bronchoscopy, dynamic CT offers a practical screening tool. When the scan is clearly positive, some teams proceed directly to treatment planning without a confirmatory bronchoscopy, though most still perform a scope before surgery to get a firsthand look at exactly which segments are affected.
Conservative and Non-Surgical Management
Mild bronchomalacia in children often improves with time as the airway cartilage matures and stiffens. The standard approach for these patients is supportive care: airway clearance techniques like chest physiotherapy, bronchodilators during infections, antibiotics when bacterial infection is suspected, and home monitoring with pulse oximetry.17PubMed Central. Management of Bronchomalacia in Infants Post-Cardiac Surgery Using Synchronized Nasal DuoPAP: A Novel Technology Families are typically instructed to check oxygen levels at home at least twice a day and to return for outpatient follow-up at regular intervals.
For more troublesome cases that are not yet severe enough for surgery, continuous positive airway pressure (CPAP) can be a game-changer. The idea is simple: positive pressure stents the airway open from the inside, counteracting the tendency to collapse. In adult patients with severe tracheobronchomalacia unresponsive to routine medical therapy, the addition of intermittent nasal CPAP has been shown to improve exercise tolerance, sputum clearance, and the resolution of areas of collapsed lung (atelectasis), and to reduce the frequency of hospital visits.18American Review of Respiratory Disease. Nasal Continuous Positive Airway Pressure in the Treatment of Tracheobronchomalacia This same principle applies when patients undergo general anesthesia: maintaining continuous positive pressure or positive end-expiratory pressure is the standard recommendation to keep malacic airways from collapsing under sedation.19Anaesthesia Cases. Difficult positive pressure ventilation in an adult with a tracheostomy
Stenting
When conservative measures fall short but the patient is not a good candidate for open surgery, endobronchial stents offer a middle-ground option. The concept dates back decades: a small expandable metal tube is placed inside the malacic bronchus to prop it open. Early reports described self-expanding stents placed endoscopically in infants with life-threatening airway malacia as a way to avoid more complex surgical procedures and prolonged ventilator support.20JAMA Otolaryngology–Head & Neck Surgery. Treatment of Severe Bronchomalacia With Expanding Endobronchial Stents
More recent experience with coronary-type bare metal stents in infants has been encouraging. In one series, the stents were easy to deploy precisely, did not migrate, and provided enough structural support to keep the bronchus open without causing erosion or significant granulation tissue. One stent was successfully removed after twelve months of somatic growth with no loss of bronchial patency afterward.21PubMed. Bronchial stenting in infants with severe bronchomalacia: Technique and outcomes That said, granulation tissue formation remains the most common complication of airway stenting in general. In one older series of balloon-expandable stents in children, granulation tissue led to stent removal in one patient, and there were two deaths in the cohort, one possibly related to stent placement.22JAMA Otolaryngology–Head & Neck Surgery. The Use of Balloon-Expandable Metallic Stents in the Treatment of Pediatric Tracheomalacia and Bronchomalacia Stenting is not a low-risk procedure, and its use in children is generally reserved for patients who have failed other options or who need a bridge to surgery.
Surgical Options
For children with severe or life-threatening bronchomalacia, surgery is often the definitive treatment. The two main approaches are aortopexy (hitching the aorta forward to pull the airway open from the front) and posterior tracheobronchopexy (stitching the posterior membrane of the airway to the spine or surrounding tissue to prevent it from bowing inward). Posterior tracheopexy has shown strong results: in one series, children demonstrated significant postoperative improvements across nearly every symptom category, including cough, noisy breathing, recurrent infections, oxygen dependence, blue spells, and ventilator dependence. Bronchoscopy scores improved across all regions of the trachea and bronchi. About 9% required reoperation for persistent airway issues, usually addressed with the addition of aortopexy.23PubMed. Posterior tracheopexy for severe tracheomalacia
When the left mainstem bronchus is compressed by a descending aorta, a combined approach using descending aortopexy plus posterior tracheopexy has proved effective. One study reported significant improvement not only in the tracheal segments but also specifically in the right and left mainstem bronchi, along with resolution of clinical symptoms including exercise intolerance, ventilator dependence, and oxygen need.24PubMed. Descending Aortopexy and Posterior Tracheopexy for Severe Tracheomalacia and Left Mainstem Bronchomalacia
A large recent series focused on children with esophageal atresia and life-threatening tracheobronchomalacia found that tracheobronchopexy allowed 94% of patients to avoid tracheostomy altogether. Most of these children had near-complete airway collapse before surgery. At a median follow-up of about three years, blue spells had resolved entirely, and ventilator dependence and need for positive pressure ventilation were significantly reduced. Mortality in the cohort was 5%, with most deaths related to underlying comorbidities rather than the airway surgery itself.25PubMed. Tracheobronchopexy to Avoid Tracheostomy in Esophageal Atresia Patients With Severe Life-Threatening Tracheobronchomalacia
Long-Term Outlook
The common reassurance that children “grow out of” airway malacia is true for many mild cases, but the picture is less rosy than parents might hope for moderate and severe disease. A follow-up study of children with tracheobronchomalacia found that at a median age of about nine years, the majority of parents still reported unresolved symptoms. Lung function testing in these children showed that airflow measurements were significantly lower than predicted for their age and size, with mean values below normal for forced exhalation and peak flow.26PubMed. Pulmonary function and long-term follow-up of children with tracheobronchomalacia This doesn’t mean every child with bronchomalacia will have persistent problems, but it does suggest that children diagnosed with more than mild disease should be followed with periodic lung function testing rather than assumed to have recovered.
In adults who undergo tracheobronchoplasty for severe disease, the surgical correction of the malacic airway has been shown to improve objective measures of lung function. Improvement in quality-of-life scores, however, does not always mirror the functional gains. Some patients feel dramatically better; others report only modest subjective improvement despite clearly better airway anatomy on post-operative imaging.27PubMed Central. Quality of life outcomes in tracheobronchomalacia surgery The reasons for that disconnect are not fully understood but likely involve the extent of lung damage that accumulated before the malacia was corrected, as well as coexisting conditions like COPD or obesity.
3D-Printed Airway Splints
One of the more striking developments in bronchomalacia treatment has come from biomedical engineering. Researchers have designed patient-specific, 3D-printed external airway splints made from a bioresorbable polymer. The splint is surgically placed around the outside of the collapsing airway segment, holding it open mechanically. Because the polymer slowly dissolves over a period of years, it provides structural support during the critical window of childhood growth and then disappears, avoiding the need for a second surgery to remove hardware.
The first published cases involved three infants with severe tracheobronchomalacia who were implanted with personalized 3D-printed splints. At the time of publication, all three had resolution of their life-threatening airway disease and continued growth of the primary airways.28PubMed Central. Mitigation of tracheobronchomalacia with 3D-printed personalized medical devices in pediatric patients A subsequent larger case series confirmed the initial clinical effectiveness of the device in a broader cohort of critically ill children.29PubMed Central. 3D-printed, externally-implanted, bioresorbable airway splints for severe tracheobronchomalacia The approach remains investigational and has so far been used only in children for whom conventional treatments were not viable, but it represents a genuinely new paradigm: instead of stitching the airway to surrounding structures or placing a tube inside it, the splint wraps around it from outside and then vanishes once the job is done.
Anesthetic Risks Worth Knowing About
Anyone with bronchomalacia who undergoes general anesthesia faces a specific hazard that is easy to overlook if the surgical team is unaware of the diagnosis. Most anesthetic agents relax the smooth muscle of the airway and reduce the residual tone that helps keep a malacic bronchus at least partially open. Positive pressure ventilation during surgery can partially compensate, but the relationship is not straightforward. In one documented case, a woman with known tracheobronchomalacia and a permanent tracheostomy experienced significant difficulty with ventilation and oxygenation during anesthetic induction despite the use of positive pressure; her condition improved only when spontaneous breathing was restored.30Anaesthesia Cases. Difficult positive pressure ventilation in an adult with a tracheostomy
The practical takeaway is that anyone with a diagnosis of bronchomalacia should make sure every anesthesiologist they encounter knows about it before induction. The airway management strategy may need to be adjusted: keeping the patient spontaneously breathing when possible, using positive end-expiratory pressure, and having a plan for what to do if ventilation becomes difficult. This is one of those situations where a note in the medical record or a brief conversation before surgery can prevent a genuine emergency in the operating room.