Epidemiology
- Associated With: congenital heart disease (such as PDA/VSD/tetralogy of Fallot/pulmonic valve stenosis) in 40-50% of cases
Etiology
1) Penetrating Chest Trauma:
2) Necrotizing Pneumonia:
3) TB:
4) Bacterial Endocarditis:
5) Pulmonary HTN (especially with congenital heart disease):
Etiology:
1) Trauma (especially penetrating stab wounds to chest): may produce pseudoaneurysms
2) Swan-Ganz catheterization (probably most common traumatic cause): can cause pseudo-aneurysm if catheter lacerates PA wall with local containment/ can cause true aneurysm if balloon is inflated in a small PA branch
3) Infection (associated with syphilis/ TB/ bacterial, fungal pneumonia/ endocarditis): Rasmussen aneurysm is a PA artery aneurysm associated with TB (forms in old TB cavity)
4) Atherosclerosis of PA
5) Cystic medial necrosis (Marfan syndrome): may produce pseudoaneurysms
6) Pulmonary vasculitis (Giant cell arterides/ Behcet’s syndrome/ Hughes-Stovin syndrome)
Physiology
- Pulmonary HTN due to dilatation of wall of PA with aneurysm formation
- Fusiform PA aneurysm: localized dilatation of entire circumference of vessel wall
- Saccular PA aneurysm: localized dilatation of only partial circumference of vessel wall
Diagnosis
- CXR/Chest CT: usually demonstrate a mass lesion (that may mimic cancer, etc.)
Chest MRI: probably a useful imaging procedure for aneurysm
Pulmonary angiogram: best procedure for imaging aneurysm
-Allows therapy to be performed with imaging procedure
ECHO: useful to image aneurysm
Clinical
Symptoms/signs (most are aymptomatic, being discovered at autopsy):
-Dyspnea/chest pain (if aneurysm is large): may mimic PE
-Signs of right-sided CHF
-Hemoptysis:
Complications: pulmonary artery rupture (with massive hemorrhage)
Treatment
- Catheter embolization of aneurysm: preferred for aneurysms that do not involve the proximal PA
- Surgical resection of aneurysm: may be used due to risk of rupture (especially in presence of hemoptysis)
Prognosis
- Autopsy series demonstrate that 33% of patients die due to aneurysm rupture/ 66% die due to RV failure, PE, or an unrelated cause
References
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