Introduction
Pulmonary arteriovenous malformation (AVM) is a rare abnormality of the blood vessels in the lungs. It is a problem in which there are abnormal communications between a pulmonary artery and a pulmonary vein. This causes irregularity in the regular gas exchange and filtration of blood.
Aetiology
It can either be congenital or acquired. Usually, congenital cases are secondary to Hereditary Haemorrhagic Telangiectasia.
Acquired causes include prior chest surgery, injury, infections such as schistosomiasis and actinomycosis, heart condition like Mitral stenosis. Rare conditions such as Fanconi's syndrome, hepatic cirrhosis related hepatopulmonary syndrome, and metastatic carcinoma are also acquired.
Pulmonary AV malformations can be present from birth and develop in adulthood. Many individuals with Pulmonary AV Malformations will later develop Hereditary Hemorrhagic Telangiectasia
Hereditary hemorrhagic telangiectasia (HHT) is a genetic disorder characterised by multiple arteriovenous malformations (AVMs) that lack intervening capillaries and result in direct connections between arteries and veins.
The most common clinical manifestation is spontaneous and recurrent nosebleeds, beginning on average at the age of 12 years. Telangiectasis (minor AV Malformations) is characteristically found on the lips, tongue, buccal and gastrointestinal mucosa, face and fingers.
Presentation
Most patients are asymptomatic. The majority of cases often develop by the fourth and sixth decades of life. However, patients with hereditary hemorrhagic telangiectasia develop symptoms by the second decade of life.
However, it can also present with the following symptoms:
- Breathlessness on exertion
- Cough
- Blood-stained sputum
- Bleeding from nose
- Chest pain
- Palpitations
- Shortness of breath
Investigations
Diagnosis of pulmonary AV malformations is as follows:
- Chest X-ray
- Contrast-enhanced CT scan
- MRI with or without MR angiogram
- Radionuclide lung scan
- Pulmonary angiography
- Transthoracic contrast Echocardiogram (TTCE)
Treatment of pulmonary AV malformations
Definite treatment for pulmonary arteriovenous malformations (PAVM) involves therapeutic embolisation or surgical resection. Therapeutic embolisation includes angiographic embolisation with a metal coil or balloon occlusion.
Conclusion
Though the patients present asymptomatically and the findings are incidental, the condition may be life-threatening. Adequate treatment availability and technological advancement play a significant role in bringing the individual back to normalcy.
