| Definition |
- A localized, abnormal dilation of a bronchial artery (diameter > 2mm is dilated; aneurysm implies focal sac).
- Usually mediastinal or intrapulmonary in location.
- Rare entity, reported in <1% of routine autopsies.
- {Yoon W, Radiology 2002} — https://pubmed.ncbi.nlm.nih.gov/12147755/
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| Cause |
- Chronic Inflammation (Most Common): Bronchiectasis, Tuberculosis, Chronic bronchitis.
- Systemic Vascular Disease: Atherosclerosis, Hypertension.
- Hereditary: Hereditary Hemorrhagic Telangiectasia (HHT/Osler-Weber-Rendu).
- Trauma/Iatrogenic: Post-bronchoscopy or surgical injury.
- Idiopathic: No underlying lung or vascular disease found.
- {Tanaka K, Thorax 1994} — https://pubmed.ncbi.nlm.nih.gov/10513521/
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| Pathophysiology |
- Chronic pulmonary inflammation triggers release of angiogenic factors (VEGF).
- Results in hypertrophy and neovascularization of the bronchial circulation (systemic supply).
- Increased blood flow + systemic pressure + weakened vessel wall (from inflammation or atherosclerosis).
- Leads to focal vessel wall dilation (aneurysm formation).
- Risk of rupture into the bronchus (hemoptysis) or mediastinum/pleura.
- {Deffebach ME, Am Rev Respir Dis 1987} — https://pubmed.ncbi.nlm.nih.gov/3555310/
|
| Structural result |
- Location: Usually within the mediastinum (along the path of the bronchial artery) or hilum.
- Morphology: Saccular or fusiform dilation.
- Size: Variable; rupture risk increases with size, but even small BAAs can bleed.
- Compression: Large aneurysms may compress the esophagus (dysphagia) or SVC.
- {Castañer E, Radiographics 2006} — https://pubmed.ncbi.nlm.nih.gov/16473939/
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| Clinical features |
- Hemoptysis: The hallmark symptom; can be massive and life-threatening.
- Chest Pain: Retrosternal pain mimicking angina or aortic dissection.
- Dysphagia: Due to extrinsic compression of the esophagus.
- Asymptomatic: Often an incidental finding on CT done for other reasons.
- Shock: Sudden collapse if rupture occurs into the pleural space (hemothorax).
- {Kalangos A, J Thorac Cardiovasc Surg 1997} — https://pubmed.ncbi.nlm.nih.gov/9375613/
|
| Imaging |
- CTA Chest (Gold Standard): Enhancing nodule contiguous with a bronchial artery.
- Enhancement: Follows the blood pool of the aorta (arterial phase).
- Chest X-ray: Non-specific; may show a mediastinal or hilar mass/widening.
- Angiography (DSA): Definitive diagnosis and simultaneous treatment; shows contrast pooling/puddling.
- Differential: Must distinguish from hypervascular lymph nodes or aortic aneurysm.
- {Remy-Jardin M, Radiology 2004} — https://pubmed.ncbi.nlm.nih.gov/15550369/
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| Labs / Physiology |
- CBC: May show anemia (if recent bleeding) or leukocytosis (if active infection).
- Coagulation Panel: Assess for coagulopathy prior to intervention.
- Sputum Culture: To identify underlying infectious drivers (TB, Pseudomonas).
- Pulmonary Function Tests: Reflect underlying lung disease (e.g., obstructive in bronchiectasis).
- {Shao H, J Vasc Surg 2015} — https://pubmed.ncbi.nlm.nih.gov/25827971/
|
| Treatment |
- Bronchial Artery Embolization (BAE): First-line therapy; minimally invasive.
- Uses coils, particles, or glue to occlude the aneurysm.
- Surgery: Reserved for failed embolization, unstable rupture, or giant aneurysms.
- Medical: Control of hypertension and treatment of underlying lung infection.
- {Sopko DR, J Vasc Interv Radiol 2004} — https://pubmed.ncbi.nlm.nih.gov/15466808/
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| Prognosis |
- Untreated: High risk of rupture with significant mortality.
- Treated (Embolization): High technical success rate (>90%).
- Recurrence: Possible due to collateral vessel formation; re-imaging often required.
- Complications: Spinal cord ischemia (spinal artery origin) is the most feared complication of embolization.
- {Zhang X, Ann Thorac Surg 2020} — https://pubmed.ncbi.nlm.nih.gov/31862253/
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