Pulmonary arteriovenous malformation

THE CASE

A 68-year-old female was referred to our hospital for the evaluation of persistent dyspnea. Her comorbidities included hypertension, Type II diabetes mellitus, and uncontrolled asthma. She had a cerebrovascular accident nearly 20 years back and had a recurrence of stroke, a couple of weeks prior to presentation to our hospital. Clinical examination revealed the presence of polyphonic wheezes. She did not have clubbing or cyanosis. Her oxygen saturation in room air was 90%. Computerized tomography (CT) done elsewhere had suggested the presence of a vascular malformation in the left lower lobe and hence a multiphasic CT pulmonary angiogram using volume helical shuttle was done, which demonstrated the presence of an arteriovenous shunt in the left lower lobe with early venous drainage into the left inferior pulmonary vein consistent with pulmonary arteriovenous malformation (PAVM) [Figures 1-3]. In view of the recurrence of stroke, she was advised to undergo percutaneous embolotherapy to close the shunt.

Figure 1.

Axial computerized tomography pulmonary angiogram demonstrating the arteriovenous shunt (orange arrows) consistent with pulmonary arteriovenous malformation

Figure 3.

Volume rendered technique computerized tomography reconstruction of the pulmonary angiogram, demonstrating the pulmonary arteriovenous malformation and the feeder vessel from the pulmonary artery (red arrow) and the draining vessel into pulmonary vein (blue arrow)

Figure 2.

Coronal contrast-enhanced computerized tomography in pulmonary arterial phase, maximum intensity projection demonstrating the pulmonary arteriovenous malformation between the feeder inferior medial basal segmental branch of the pulmonary artery (red arrow) and draining into inferior pulmonary vein (blue arrow) and the left atrium

PAVMs are very rarely encountered in clinical practice. PAVMs can be solitary or multiple, and the most common site of involvement is the left lower lobe. The afferent supply is from the branches of the pulmonary artery, and the efferent vessel drains into the branches of the pulmonary vein. The classical clinical presentation is the triad of dyspnea, cyanosis, and clubbing, although a majority of the patients can be asymptomatic.[1] Complications include hypoxemia, cerebrovascular accidents, brain abscess, paradoxical embolism, intrabronchial rupture causing hemoptysis, and intrapleural rupture producing hemothorax. Although chest radiograph is important in the diagnosis, contrast-enhanced CT is a very valuable tool not only for diagnosis but to delineate the vascular anatomy, grade the complexity of the malformation and plan treatment as well.[2] In younger patients, PAVMs are frequently associated with various syndromes such as hereditary hemorrhagic telangiectasia and Osler-Weber-Rendu disease. Treatment options include surgical resection, but the preferred treatment today is percutaneous embolotherapy using coils, microvascular plugs or detachable balloons.[3] Percutaneous interventions are safe, effective, and carry lesser complication risks compared to surgery especially with advancements in embolization technology and hardware.

This case is being presented to highlight the advancements in imaging which can render a three-dimensional reconstruction of the vascular anomaly and thereby help understand the nature and extent of anatomical involvement in a better way.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.