Ahmed M. El-Emam, MD; Hanan M. Hassan, MD; Ahmed S. Youssef, MSc
Pulmonary arteriovenous malformations (PAVMs) are abnormal communications directly between pulmonary arteries and pulmonary veins without formation of a capillary bed; it is a rare anomaly of the cardiovascular system.[1,2]
The PAVMs consist of three anatomical components: one, or more than one, feeding artery(ies), an aneurysmal sac and one or more draining vein(s). PAVMs may be simple or complex; simple PAVMs have a solitary feeding artery, a bulbous, aneurysmal, non-septated communication to one or more draining veins. Complex PAVMs have two or more feeding arteries opening into a septated aneurysmal sac to two or more draining veins. Diffuse PAVMs are AVMs involving minimally one segment diffusely included.
FIGURE 1 Pulmonary artery angiography in AP view showing large complex PAVM in the left lowerposterior lung lobe, supplied by multiple feeding arteries (A), and in lateral view (B).
PAVMs are mostly congenital, frequently associated with hereditary hemorrhagic telangiectasia (HHT). Isolated cases have also been reported. Diffuse PAVMs are rarely found with unoperated congenital heart diseases like Polysplenia Syndrome. Acquired causes of PAVMs include: tuberculosis, trauma, juvenile hepatic cirrhosis and schistosomiasis. Glenn operation is a documented acquired cause of PAVMs. PAVMs may clinically present with findings such as: dyspnea, hemorrhage, chest pain and desaturation. Neurological complications may occur due to: impaired capillary bed filtration including cerebral abscess, ischemic strokes, migraine headaches, myocardial infarctions and pregnancy-related deaths.
To read the full article, please go to the October 2020 Issue of CCT.