A pulmonary arteriovenous malformations (PAVM) is a rare vascular abnormality of the lung. Most cases tend to be simple AVM's (single feeding artery) although up to 20% of cases can have complex (2 or more) feeding vessels 7. They can be multiple in ~ 1/3 of cases.
Demographics and clinical presentation
There is a recognized female predilection. Despite most patients being asymptomatic, the connection between the venous and arterial system can lead to dyspnea (due to right-to-left shunting), as well as embolic events (due to paradoxical emboli). Although it is assumed that the vascular defects are present at birth, they are seldom manifested clinically until adult life until when the vessels have been subjected to pressure over several decades. Clinically a murmur or bruit may audible over the lesion (especially if peripheral).
In congenital cases they are considered to result from a defect in the terminal capillary loops which causes dilatation and the formation of thin-walled vascular sacs.
These are often unilateral. Although can potentially affect any part of the lung, there is a recognised predilection towards the lower lobes (50-70%) 7.
PAVMs have been described in association with a number of conditions.
- hereditary haemorrhagic telangiectasia (HHT) frequently have PAVMs 1. It is reported that at least 33% of those with a single PAVM and at least 50% of those with multiple PAVM's have HHT 6.
In addition PAVMs have been found in
- hepatic cirrhosis (as part of the hepatopulmonary syndrome)
- mitral stenosis
- previous cardiac surgery (e.g Glenn and Fontan procedures for cyanotic congenital heart disease) 7
- actinomycosis - thoracic actinomycosis infection
- Fanconi syndrome
- metastatic thyroid carcinoma
- tuberculosis (Rasmussen aneurysm)
A number of modalities are available for the diagnosis of PAVMs, including contrast echocardiography, radionuclide perfusion lung scanning, computed tomography (CT), magnetic resonance imaging (MRI), and, the gold standard, pulmonary angiography 2.
CT is often the diagnostic imaging modality of choice. The characteristic presentation of a PAVM on non-contrast CT is a homogeneous, well-circumscribed, non-calcified nodule up to several centimeters in diameter or the presence of a serpiginous mass connected with blood vessels 3. Occasionally associated phleboliths may be seen as calcifications. Contrast injection demonstrates enhancement of the feeding artery, the aneurysmal part, and the draining vein on early-phase sequences.
- cyanosis (due to the right to left shunt)
- high out put congestive cardiac failure
- paradoxical cerebral embolism 5
Treatment and prognosis
Treatment options include
- trans-catheter coil embolisation
Once successfully treated (embolotherapy, surgical resection), prognosis is generally good for an individual lesion.
- 1. Gossage JR, Kanj G. Pulmonary arteriovenous malformations. A state of the art review. Am J Respir Crit Care Med. 1998; 158(2): 643-61. PubMed
- 2. Guttmacher AE, Marchuk DA, White RI Jr. Hereditary hemorrhagic telangiectasia. N Engl J Med. 1995; 333(14): 918-24. PubMed
- 3. Remy J, Remy-Jardin M, Wattinne L, Deffontaines C. Pulmonary arteriovenous malformations: evaluation with CT of the chest before and after treatment. Radiology. 1992; 182(3): 809-16. PubMed
- 4. Sloan RD, Cooley RN. Congenital pulmonary arteriovenous aneurysm. Am J Roentgenol Radium Ther Nucl Med. 1953; 70(2):183-210. PubMed
- 5. Todo K, Moriwaki H, Higashi M et-al. A small pulmonary arteriovenous malformation as a cause of recurrent brain embolism. AJNR Am J Neuroradiol. 2004;25 (3): 428-30. AJNR Am J Neuroradiol (citation) - Pubmed citation
- 6. Suchin CR, Whitman GJ, Chew FS. Pulmonary arteriovenous malformation. AJR Am J Roentgenol. 1996;167 (3): 648. AJR Am J Roentgenol (citation) - Pubmed citation
- 7. Lee EY, Boiselle PM, Cleveland RH. Multidetector CT evaluation of congenital lung anomalies. Radiology. 2008;247 (3): 632-48. doi:10.1148/radiol.2473062124 - Pubmed citation
- 8. Gossage JR, Kanj G. Pulmonary arteriovenous malformations. A state of the art review. Am. J. Respir. Crit. Care Med. 1998;158 (2): 643-61. doi:10.1164/ajrccm.158.2.9711041 - Pubmed citation
Synonyms & Alternative Spellings
|Synonyms or Alternative Spelling||Include in Listings?|
|Pulmonary arteriovenous fistula||✓|
|Pulmonary arteriovenous aneurysm||✓|
|Cavernous angioma of the lung||✗|
|Haemangioma of the lung||✗|