CASE REPORT

Prenatal ultrasonographic diagnosis of vein of Galen aneurysms – reportof two cases

SUSANA SANTO, LUISA PINTO, NUNO CLODE, EDITE CARDOSO,

JOAO PAULO MARQUES, ANTONIETA MELO, CONCEICAO CARDOSO, &

LUIS MENDES GRACA

Department of Obstetrics, Gynecology and Reproductive Medicine, Hospital Santa Maria, Lisbon, Portugal

(Received 12 December 2006; revised and accepted 5 August 2007)

Abstract

Aneurysms of the vein of Galen (AVG) represent less than 1% of all intracranial arteriovenous malformations. Two cases ofprenatal diagnosis made by color Doppler ultrasonography at 32 weeks of gestation are reported. Both cases presented withantenatal mild cardiomegaly and both developed severe cardiac failure in the neonatal period. Embolization wasunsuccessful and both infants died. These cases highlight the need for a careful evaluation of the time and mode of delivery;embolization must be performed after a fully informed decision.

Keywords: Vein of Galen aneurysm, prenatal diagnosis, heart failure

Introduction

Aneurysms of the vein of Galen (AVG) are rare

vascular anomalies, representing less than 1% of all

intracranial arteriovenous malformations [1]. Pre-

natal diagnosis is usually made during the third

trimester by color Doppler ultrasonography.

Case reports

Case 1

A 30-year-old woman, gravida 3, para 2, had an

uneventful pregnancy until 32 weeks of gestation

when an ultrasound scan revealed an anechoic,

supratentorial, median and left paramedian mass,

with a keyhole shape and regular borders (Figure 1).

Color Doppler showed turbulent arterial and venous

flows suggesting the diagnosis of AVG (Figure 2);

enlargements of the straight sinus and jugular veins

were also noticed. Mild cardiomegaly was present.

Magnetic resonance imaging (MRI) confirmed the

sonographic diagnosis; no other brain anomalies

were identified. An ultrasonographic examination

was performed every 2 weeks until delivery and no

other signs of cardiac failure were noticed.

After a multidisciplinary discussion, delivery by

cesarean section at 38 weeks was decided. A 3670 g

male infant with Apgar scores of 9 and 10 at 1 and

5 min respectively was delivered. During the first

24 h the newborn developed a high-output cardiac

failure. The echocardiogram revealed significant

enlargement of the right chambers, superior vena

cava and pulmonary artery; there were also signs of

tricuspid insufficiency. The MRI showed an aneur-

ysm of the vein of Galen fed by several posterior

basal arteries and by the pericallosal artery; a

supratentorial mild hydrocephaly was also seen.

Cardiac failure was unresponsive to medical therapy

and arterial embolization of the aneurysm was per-

formed on day two. The procedure was complicated

by intraventricular and posterior fossa bleeding with

subsequent coma. The newborn died on day nine.

Case 2

A 32-year-old woman, nulliparous, had an unevent-

ful pregnancy until 32 weeks of gestation when an

Correspondence: Susana Santo, Rua Camilo Pessanha N811 R/C Esq, 1700-084 Lisboa, Portugal. Tel: þ35 1966507377. E-mail: sf_santo@sapo.pt

The Journal of Maternal-Fetal and Neonatal Medicine, March 2008; 21(3): 209–211

ISSN 1476-7058 print/ISSN 1476-4954 online � 2008 Informa UK Ltd.

DOI: 10.1080/14767050801924357

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ultrasound scan revealed an anechoic, supratentorial,

median mass with regular borders. Color Doppler

showed turbulent arterial and venous flows suggest-

ing an AVG and the 3D scan demonstrated the

afferent vessels (Figure 3). There was also evidence

of mild cardiomegaly, mild triscuspid insufficiency

and significant foramen ovale shunting. MRI de-

monstrated that the aneurysm was supplied by

branches of the anterior and posterior cerebral

arteries; no other brain anomalies were identified.

An ultrasonographic examination was performed

every two weeks until delivery and no other signs of

cardiac failure were noticed.

After a multidisciplinary discussion, a vaginal

delivery was allowed. Spontaneous labor occurred

at 40 weeks but a cesarean section was performed

due to secondary arrest of labor. A 3150 g male

infant with Apgar scores of 6 and 10 at 1 and 5 min

respectively was delivered. On day six, a severe

impairment of heart function was noticed. Since it

was refractory to medical therapy an attempt for

aneurysm embolization was done. The procedure

was not completed due to technical difficulties; the

infant died on day 16 from irreversible cardiac

failure.

Discussion

AVG is a rare congenital vascular malformation that

shunts the arterial blood flow into an enlarged vein.

It results from an arteriovenous connection between

the primitive choroidal vessels and the median

prosencephalic vein of Markowski occuring between

the 6th and the 11th week of gestation; this

determines an abnormal flow, which prevents the

involution of the embryonic vein and the subsequent

development of the vein of the Galen [2].

A classification of AVG defines two subtypes:

choroidal and mural. The former has multiple

feeders from the choroidal and other deep midbrain

arteries that converge to the anterior wall of the

aneurysm. The latter is characterized by the presence

of a fistula inside the vein’s wall, typically has fewer

feeding arteries and has been associated with lesser

degrees of heart failure [2]. Both cases reported had a

choroidal AVG and this may have contributed to the

poor prognosis.

Prenatal diagnosis of AVG has become easier with

the improvement of sonographic Doppler techniques

Figure 3. 3D ultrasonography image of the vascular malformation

demonstrating the afferent vessels.

Figure 1. Anechoic, tubular, median lesion of the brain.

Figure 2. Color Doppler demonstrates vascular nature of the

lesion and shows turbulent flow.

210 S. Santo et al.

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that demonstrate the turbulent arterial and venous

flows within the mass. MRI is important to exclude

associated brain anomalies. Differential diagnosis

includes arachnoid, porencephalic or choroids

plexus cysts, pineal tumors, choroid papilloma and

intracerebral hematoma [3].

The cerebral shunt increases the cardiac preload

and, if it exceeds the capacity of the right to left shunt

mechanism, a congestive heart failure will develop.

The severity of the cardiac insufficiency depends on

the magnitude of the cerebral shunt, which increases

with the interruption of the placental low resistance

flow. Intrauterine signs of cardiac failure such as

cardiomegaly, triscuspid insufficiency, polihydram-

nios, pericardial and pleural effusion, edema and

ascites have been detected in prenatal ultrasound

examination [4]. Evidence of progressive cardiac

dysfunction in utero is an ominous sign, indicating a

high flow anomaly that may not respond to therapy

[2]. In fact, heart failure is referred in the literature as

the most determining prognostic factor of AVG. The

two cases reported had prenatal mild cardiomegaly

and one of them had mild triscuspid insufficiency.

Although there were no signs of severe intrauterine

cardiac failure they developed a significant impair-

ment of cardiac function on the first postnatal days.

Embolization is the main therapy for AVG. In

asymptomatic neonates it should be performed after

the 5th or 6th month of life [5]. Before that age,

embolization should only be decided as a life-saving

procedure. In fact, when performed in neonates this

is a difficult and high risk technique – intracranial

bleeding may occur and the persistent venous

insufficiency after embolization may cause hydro-

cephalus, progressive parenchymal atrophy and

calcification. Several clinical evaluation scales have

been proposed in order to identify the cases that will

not respond to treatment avoiding fruitless proce-

dures that may prolong life at the expense of severe

morbidity. Prenatal cardiomegaly and cerebral injury

at birth have been proposed as contraindications to

vascular intervention [2].

The best gestational age for delivery of these

fetuses must be carefully considered. Pregnancy

termination can be tempting because early prenatal

recognition is said to allow early medical treatment

reducing the need for complex neuroradiological

techniques [1]. However, the fetus with cardiac

dysfunction has a poor prognosis [3] and premature

delivery may also alter or delay the normal develop-

ment of intracranial venous drainage in utero which

can be responsible for some unfavorable neonatal

outcomes [2].

Vaginal delivery is suggested in cases of AVG

without signs of heart failure. In cases complicated

by cardiac insufficiency cesarean section does not

seem to reduce the mortality rate and should only be

performed for obstetrical reasons [3].

As a consequence of the poor prognosis of AVG,

careful evaluation and fully informed decision is

mandatory. Parent counseling should include the

information that embolization during the first weeks

of life is a high risk procedure unlikely to result in a

good outcome [2]. Time, mode of delivery and

treatment should always be established on an

individual basis.

New neurosurgical techniques that can really

change the natural history of the fetuses affected by

AVG are expected.

References

1. Sepulveda W, Platt CC, Fisk NM. Prenatal diagnosis of

cerebral arteriovenous malformation using color Doppler

ultrasonography: case report and review of the literature.

Ultrasound Obstet Gynecol 1995;6:282–286.

2. Jones BV, Ball WS, Tomsick TA, Millard J, Crone KR. Vein of

Galen aneurysmal malformation: Diagnosis and treatment of

13 children with extended clinical follow up. Am J Neuroradiol

2002;23:1717–1724.

3. Doren M, Tercanli S, Holzgreve W. Prenatal sonographic

diagnosis of a vein of Galen aneurysm: Relevance of associated

malformations for timing and mode of delivery. Ultrasound

Obstet Gynecol 1995;6:287–289.

4. Mai R, Rempen A, Kristen P. Prenatal diagnosis of a vein os

Galen aneurysm assessed by pulsed and color Doppler

sonography. Ultrasound Obstet Gynecol 1996;7:228–230.

5. Garel C, Azarian M, Lasjaunias P, Luton D. Pial arteriovenous

fistulas: Dilemmas in prenatal diagnosis, counseling and

postnatal treatment. Report of three cases. Ultrasound Obstet

Gynecol 2005;26:293–296.

Vein of Galen aneurysm 211

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