Pulmonary
Arteriovenous
Malformations
Pulmonary
Arteriovenous
Malformations
Pulmonary AVMs
Etiology
Congenital defect in capillary structure
Acquired in
Cirrhosis
Cancer
Trauma
Surgery
Actinomycosis
Schistosomiasis
Pulmonary AVMs
Etiology
Pathology
Hemangioma of cavernous type
Age
3rd–4th decade
Mostly manifest in adult life
10% in childhood
Pulmonary AVMs
Occurrence
Isolated abnormality=40%
Pulmonary AVMs
Osler-Weber-Rendu Syndrome
Associated with Osler-Weber-Rendu
Syndrome (30-88%)=hereditary hemorrhagic
telangiectasia
Only 15% of Osler-Weber-Rendu syndrome have
pulmonary AVMs
Family history with this disease
Epistaxis common
Telangiectasia of skin and mucus membrane
GI bleeding
Multiple AVMs in Liver in Osler-Weber-Rendu
Syndrome
Pulmonary AVMs
Types
Simple type (79%)
Single feeding artery empties into
bulbous, nonseptated aneurysmal
segment
Single draining vein
Pulmonary AVMs
Types-continued
Complex type (21%)
More than one feeding artery empties
into septated, aneurysmal segment
More than one draining vein
Pulmonary AVMs
Symptoms
Asymptomatic in most until 3rd or 4th
decade if AVM is single and <2cm
Orthodexia
= increased hypoxemia with
PaO
2
<85 in erect position
Epistaxis (79%)
Cyanosis with normal-sized heart (R
L
shunt in 25-50%)
Pulmonary AVMs
Symptoms-continued
Clubbing
Bruit over the lesion which > with
inspiration
Dyspnea on exertion (60%)
Palpitations, chest pain, no CHF
Pulmonary AVMs
Location
Lower lobes (65-70%)
Then, middle lobe
Then, upper lobes
Medial third of lung
Often subpleural
Bilateral (20%)
As opposed to multiple which is 33%
Pulmonary AVMs
X-Ray Findings
Sharply defined mass (90%)
Cord-like bands from mass to hilum
(feeding artery and draining vein)
2/3 single, 1/3 multiple
Enlarge with advancing age
Pulmonary AVMs
X-Ray Findings
Change in size with Valsalva maneuver
(decrease)
Phleboliths (rarely)
CT
Feeding vessels
Rapid enhancement on dynamic CT
Pulmonary AVM – 3D CT
Reconstruction
Heart
Pulmonary AVMs
Complications
CVA
TIA (37%)
Stroke (18%)
Cerebral abscess 2° to loss of
pulmonary filter function (9%)
Pulmonary AVMs
Complications-Continued
Hemoptysis 2° rupture into bronchus
most common presenting symptom
(13%)
Hemothorax 2° rupture of subpleural
AVM
Polycythemia
Pulmonary AVMs
Prognosis
11% mortality
Pulmonary AVMs
DDX
Other causes of solitary or
multiple pulmonary nodule(s)
Ca
Hamartoma, adenoma, granuloma
Mets
Wegener's
Rheumatoid nodules
Pulmonary AVMs
Treatment
Embolization with coils/detachable
balloons