arteriovenous malformations in osler weber rendu: a...

Arteriovenous

Malformations in Osler Weber‐Rendu:

A Patient StudyKush M Parmar, Harvard Medical School Year III

Gillian Lieberman, MD

Kush M Parmar, HMS IIIGillian Lieberman, MD

September 2008

Objectives


• Learn what an arteriovenous

malformation (AVM) is.

• Learn imaging modalities that can be used to image AVM.

• Learn the typical appearance of AVM.

• Appreciate the clinical manifestations of AVM in Osler‐Weber‐Rendu/HHT.

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Mrs. R: History


3

• 37 y/o

woman w/ R. MCA ischemic stroke

• Coagulation studies were negative/normal

• No ASD/PFO (potential cause of paradoxical embolism)

• “Cryptogenic stroke”

presentation (no known cause)

Mrs. R: AP CXR


Rounded opacity at R. cardiophrenic angle

Linear opacity extending between rounded opacity and hilum

PACS/BIDMC

FINDINGS

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Findings suggestive of PAVM


General Architecture of Arteriovenous

Malformations (AVM)

‐ Dilated, tortuous feeding and draining vessels ‐ A “nidus”

or “serpiginous”

mass of malformed vessels‐ Diminished oxygen diffusion (A‐V shunt); abnormal/absent capillary bed‐ Rapid filling and emptying

http://neuro.wehealny.org

5

Imaging Pulmonary AVM: Menu of Tests


•

Pulmonary angiography•

Used mainly for therapeutic

interventions due to invasiveness

•

MR angiography

•

Chest CT (+/‐

C)

•

Gold standard

•

Chest X‐ray•

Only useful for large AVM

•

Transthoracic

Contrast Echo

•

Shunt quantification

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Features of Pulmonary AVM on Chest X‐Ray

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• Round or oval opacity• Uniform density, noncalcified• Often lobulated

but sharply

defined• Location: frequently in lower lobes• Connection: may

show feeding

artery radiating from hilus

PACS/BIDMC

Features of Pulmonary AVM on CT

• Homogeneous, non‐calcified, circumscribed

nodule or serpiginous

mass

• MUST

have a direct feeding artery

– Dilated efferent draining vein• With contrast:

– Sequential enhancement of feeding artery and

aneurysmal

part– Early filling of draining vein (to differentiate from

highly vascular soft tissue mass)

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Mrs. R: Chest CT

9


feeding branch of pulmonary artery

nidus

of AVM

R. hemidiaphragm

9

C+CT

Mrs. R: Decision to Embolize

With the clear determination of pulmonary AVM on CT, it was decided to proceed with therapeutic embolization.


10

11


L. pulmonary artery

catheter in IVC

PACS/BIDMC

Mrs. R: Digital subtraction pulmonary arteriogram

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(L. Lung, normal)

Mrs. R: Digital subtraction pulmonary arteriogram

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(R. Lung, before therapeutic embolism)

feeding artery

drainingvein

PACS/BIDMC

AVM

R. pulmonary artery

12

Therapeutic Embolism of PAVM

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www.amplatzer.com

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Mrs. R: Post‐embolizationKush M Parmar, HMS IIIGillian Lieberman, MD

Digital subtraction pulmonary arteriogram(R. Lung, post‐therapeutic embolism)

R. pulmonary artery

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15

Mrs. R: Post‐embolizationKush M Parmar, HMS IIIGillian Lieberman, MD

Digital subtraction pulmonary arteriogram(R. Lung, post‐therapeutic embolism)

R. pulmonary artery

pre-embolism

15

AVM nidus

No filling in embolized

AVM

Differential Diagnosis of Pulmonary AVM

Congenital (~90%)

• Hereditary Hemorrhagic Telangectasia(Osler‐Weber‐Rendu)

– Type I –

EDG1 mutations– Type II –

ALK1 mutations– Other

–

unmapped loci

Acquired

• Highly vascular parenchymal

lesion (compare kinetics

with other vascular structure)16


Clinical Manifestations of Pulmonary AVM

• Dyspnea

on exertion• Hypoxemia

• Stroke• Transient ischemic attack • Cerebral abscess

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Primary mechanism

right-left shunt

paradoxical embolism( our patient)

Most PAVM are asymptomatic for years, so many are first encountered incidentally on imaging

Screening for Pulmonary AVM in HHT Patients

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Chest Radiographs

Contrast echocardiography

-

-

+

+

Chest CT

Absence of PAVM

Prophylactic antibioticsto prevent brain abscess from paradoxical emboli

Absence of PAVM Positive PAVM


+-

Hepatic AVM: Menu of Tests

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•

Doppler Color Ultrasound (Echo Color Doppler)•

Low cost

•

No radiation

•

Highly sensitive

•

CT•

Specific, gold standard

Hepatic AVM on CTKush M Parmar, HMS IIIGillian Lieberman, MD

Early Arterial Phase Late Arterial Phase Portal Venous Phase

hepatic veins

AVM• AVM is most apparent in early arterial phase, no longer visible in portal venous phase

• Hepatic veins fill early

Buonamico et al. J Hepatol. 2008 ;48(5):811-2020

C+CT

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•

Heterogenous

opacification

of liver

‐ Due to many small hypervascular

spots (in HHT patients)

• Early arterial phase contrast filling of AVM

• Hepatic vein enhancement in early arterial

phase‐ Caused by AVM shunt

Hepatic AVM Features on CT


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•

Hypervascularization: tortuous hepatic arteries‐Highly visible main intrahepatic

branches of the hepatic artery in the

portal spaces.‐Shunt determines tortuosity

and enlargement of these vessels.

Hepatic AVM Features on US


EPA=hepatic arteryPV=portal vein


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Hepatic AVM Features on US

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• Intrahepatic

“color spots”‐The presence of subcapsular

vascular spots near the hepatic

capsule consisting mainly of arterial blood flow.



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Osler‐Weber‐Rendu/ Hereditary Hemorrhagic

Telangiectasia

(HHT)• One of the most common monogenic diseases (~1 in 5000‐

10000)

• Progressive clinical manifestations over decades

• Epistaxis– Usually 1st

manifestation, ~10 yr of age

• Telangiectasia– Onset at ~3rd

decade of life– Lips, tongue, palate, fingers, and face

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Diagnosis of HHT

• Curacao criteria• Definite diagnosis with 3 out of 4 criteria

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Criterium Description

Epistaxis Spontaneous, recurrent nose bleeds; often first

manifestation

Telangiectasias Multiple, at characteristic sites: lips, oral cavity,

fingers, nose

Visceral lesions Gastrointestinal telangiectasias

(+/‐

bleeding)Pulmonary AVMHepatic AVMCerebral AVMSpinal AVM

Family history A first‐degree relative with HHT according to these

criteria

25

Gossage

et al. Am J Respir

Crit

Care Med 1998; 158: 643‐661

Likely locations of AVM

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‐

lung‐ liver‐ brain‐ spinal cord‐ spleen‐

kidney

‐

spermatic cord

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Osler‐Weber‐

Rendu/HHT

Idiopathic/Other

Imaging AVM: Summary

27

1. Menu of Tests to Image AVM is Organ‐specific• Pulmonary: CT, Angiography (for interventions)• Hepatic: CT, US

2. Typical architecture of AVM:• Entirely vascular structure that ‘shortcuts’

capillaries

• Dilated, tortuous feeding and draining vessels• Rapid filling and draining of contrast


3. Detecting an AVM may provide an opportunity to

pre‐emptively

address it and offer genetic counseling

for Osler‐Weber‐Rendu

patients and their family

27

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References

•

Cottin

V, Dupuis‐Girod

S, Gaetan

L, Cordier

J‐F. Pulmonary Vascular Manifestations of Hereditary

Hemorrhagic Telangiectasia

(Rendu‐Osler Disease). Respiration

2007; 74:361‐378.

•

Gossage

JR, Kanj

G. Pulmonary Arteriovenous

Malformations: A State of the Art Review. Am J

Respir

Crit

Care Med 1998; 158: 643‐661

•

Remy J, Remy‐Jardin

M, Wattine

L, Deffontaines

C. Pulmonary Arteriovenous

Malformations:

Evaluation with CT of the Chest before and after Treatment. Radiology 1992; 182: 809‐816.

•

Buonamico

P, Suppressa

P, Lenato

GM, Pasculli

G, D'Ovidio

F, Memeo

M, Scardapane

A, Sabbà

C.

Liver involvement in a large cohort of patients with hereditary hemorrhagic telangiectasia: echo‐

color‐Doppler vs multislice

computed tomography study. J Hepatol. 2008 ;48(5):811‐20


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Acknowledgements

• Salomao

Paintuch, MD

• Dmitri J Rabkin, MD

• Gillian Lieberman, MD

• Larry Barbaras (webmaster)

• Maria Levantakis

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