Keywords Galen vein aneurysm - prenatal diagnosis - ultrasonography - magnetic resonance -
perinatal outcomes
Palavras-chave Aneurisma da veia de Galeno - Diagnóstico pré-natal - Ultrassonografia - Ressonância
magnética - Resultados perinatais
Introduction
Galen vein aneurysm (GVA) is a rare congenital malformation arising because of the
presence of multiple arteriovenous shunts that drain to a median prosencephalic vein.[1 ] There is usually only a single malformation corresponding to ∼ 1% of all vascular
cerebral malformations. However, it may be associated with congenital heart disease,
hydrops, and cystic hygroma.[2 ] Its etiology is unknown, and there is no described familial inheritance. Heart failure
is the most common symptom in the neonatal period, but seizures and other neurological
signs may also be observed.[3 ]
[4 ]
Because GVA has a low incidence rate but high morbidity and mortality rates, a prenatal
diagnosis is necessary for adequate follow-up, delivery, and parent counseling. In
general, the condition is prenatally diagnosed based on conventional ultrasonography
when a cystic image that confirms dilation of the vein, located either in the middle
region or slightly deviated from the central region, below the third ventricle on
the middle supratentorial line is identified.[5 ] Color Doppler imaging shows a turbulent flow inside the cyst, which may be associated
with secondary ventriculomegaly.[6 ] Magnetic resonance imaging (MRI) helps to confirm the diagnosis and also reveals
complications such as hemorrhagic injury in the white matter of the brain.[7 ] Other prenatal diagnostic methods such as ultrasonography in the 3-dimensional power
Doppler mode have been described, but these have shown no advantages over conventional
ultrasonography and MRI.[8 ]
[9 ] Fetal echocardiography may help detect early signs of heart failure, which, together
with hydrops, is the most common consequence of GVA.
Here we present a series of seven cases of prenatal diagnosis of GVA with their main
findings based on conventional ultrasonography and MRI as well as their postnatal
outcomes.
Methods
A retrospective longitudinal study was performed, analyzing a database of seven cases
of prenatal diagnosis of GVA from February of 2000 to May of 2012 at two Brazilian
institutions: Centro Integrado de Saúde Amaury de Medeiros da Universidade de Pernambuco
(UPE) and Clínica de Diagnóstico por Imagem (CDPI). This study was approved by the
Committee on Ethics in Research of the Universidade de Pernambuco (UPE). Five cases
were from UPE and 2 from CDPI.
The following data were evaluated: gestational age (in weeks) at diagnosis, GVA dimensions
on ultrasonography, associated fetal changes, findings on fetal echocardiography,
gestational age at delivery, type of delivery, birth weight, Apgar score at the 1st
and 5th minutes, neonatal outcomes, and survival with follow-up until 4 years of age.
In addition, we have described the main findings based on color Doppler ultrasonography
and MRI.
Results
The mean gestational age ± standard deviation on prenatal diagnosis of GVA by ultrasonography
was 25 ± 4.9 weeks. The mean length and width of the GVA on diagnosis were 3.2 ± 0.4
cm and 2.2 ± 1.6 cm, respectively. The mean gestational age at birth was 37.5 ± 0.7
weeks, and a cesarean section was performed in 85.7% of cases (6/7). The average birth
weight was 3,070 ± 240.4 g. Mean Apgar scores at the 1st and 5th minutes were 8.5
± 0.7 and 9.5 ± 0.7, respectively. The overall survival rate was 42.8% (4/7), with
three neonatal deaths. Of the four survivors, three presented with normal neuropsychomotor
development until 4 years of age and only one showed serious neurological sequelae.
[Table 1 ] presents the description of the pre- and postnatal data of the seven cases of GVA.
[Fig. 1 ] shows the pre- and postnatal imaging findings of case #7. [Table 2 ] presents the description of the main findings based on conventional color Doppler
ultrasonography and MRI in the seven cases of the prenatal diagnosis of GVA.
Table 1
Prenatal outcomes of fetuses diagnosed with Galen vein aneurysm
Case#
1
2
3
4
5
6
7
GA at diagnosis (weeks)
33
36
32wk, 1d
35
30
24
26
Associated findings
cardiomegaly, slight pericardial effusion
polyhydramnion, ventriculomegaly, cardiomegaly, cervical vascular congestion
Polyhydramnion
ventriculomegaly, cardiomegaly, cervical vascular congestion
ventriculomegaly, pericardial effusion, cardiomegaly, cervical vascular congestion
None
None
Fetal echo .
cardiomegaly,
pulmonary hypertension, heart failure
Normal
cardiomegaly, pericardial effusion, heart failure
cardiomegaly, tricuspid failure, pericardial effusion
Normal
Normal
GVA
(cm)
2.9 × 1.1
3.2 × 1.8
2.2 × 1.8
7.0 × 2.5
4.2 × 2.5
3.0 × 2.3
3.5 × 3.4
Type of delivery
Vaginal
Cesarean
Cesarean
Cesarean
Cesarean
Cesarean
Cesarean
GA at birth
(weeks)
37
39
38
36wk, 1d
34wk, 4d
38
39
Apgar score,
1st & 5th min
8 and 9
3 and 6
7 and 9
5 and 4
6 and 4
8 and 9
9 and 10
Birth weight
(g)
2900
2940
3180
2980
2550
3060
3240
Neonatal outcome
GVA embolization at 6mth
ICU, digoxin, furosemide
discharge 4d after birth
ICU for 28d
heart failure
3wk in the ICU
seizures, hydrocephalus, heart failure 2wk after birth
Survival up to 4yr of age
Normal
death at 48h
spontaneous thrombosis at 4yr, normal development
serious neurologic sequelae
death on 4th day
death during surgery
Normal
Abbreviations: d, day(s); echo., echocardiography ; GA, gestational age; GVA, Galen vein aneurysm; ICU, intensive care unit; mth, month(s);
wk, week(s); yr, year(s).
Fig. 1 (A ) Two-dimensional ultrasonography in the axial plane based on color and power Doppler
ultrasonography at the 28th week of pregnancy, confirming the Galen vein aneurysm.
(B) Fetal sagittal T2 magnetic resonance image confirming the Galen vein aneurysm with
a hypointense signal (arrow). (C) Postnatal sagittal T2 magnetic resonance image confirming the Galen vein aneurysm
(arrow). (D) Angiography performed on the 23rd day after birth. Pre- and post-embolization images,
showing reduction in the Galen vein aneurysm.
Table 2
Findings on magnetic resonance imaging and ultrasonography in our cases of prenatal
diagnosis of Galen vein aneurysm
Case #
Magnetic resonance imaging
Ultrasonography
1
Ellipsoid expansive formation, ∼ 2.0 cm in its largest diameter at the level of the
middle line in the tentorial region, posterior to the pituitary, hypointense T1 and
T2 signals, suggesting a flow void, communicating with the sinus rectus, consistent
with aneurysmal dilation of the Galen vein, with no signs of ventriculomegaly.
An elongated cystic image, measuring ∼ 2.9 × 1.1 cm, was observed in a location posterior
to the thalamus, continuing on the middle line and spreading superiorly between the
hemispheres. On the color Doppler, a low-resistance flow was observed, with an arterial
pattern prevailing. The echographic aspect and the flow pattern are consistent with
Galen vein aneurysm. Enlarged cardiac area and slight pericardial effusion.
2
Slight ventriculomegaly and expansive ellipsoid formation in a middle line location,
spreading to the posterior fossa, consistent with arteriovenous malformation (Galen
vein aneurysm).
Slight ventriculomegaly and an elongated anechoic image in a middle line location,
spreading to the posterior fossa. On the color Doppler, an abundant flow of very low
resistance, consistent with an arteriovenous malformation (Galen vein aneurysm). Enlarged
cardiac area with slight pericardial effusion.
3
Intracranial ellipsoid expansive formation, 3.0 × 2.1 cm in size, located on the middle
cerebral line (supratentorial), consistent with Galen vein aneurysm.
A homogeneous intracranial cystic area, measuring 2.2 × 1.8 cm, localized on the middle
line (supratentorial). On color Doppler, intense arteriovenous flow. Normal heart
size and shape.
4
Ellipsoid expansive formation measuring 7.0 × 2.5 cm, supratentorial, slight dilation
of the posterior horn of the brain ventricle and the 3rd ventricle, consistent with
Galen vein aneurysm associated with ventriculomegaly.
A cystic area with a tubular aspect, measuring 4.1 × 3.7 cm, on the middle line (supratentorial),
being confirmed based on color Doppler as an arteriovenous flow within, consistent
with Galen vein aneurysm. Slight ventricular dilation. Slightly enlarged cardiac area.
Vascular congestion of the cervical region.
5
Ventricular dilation and ellipsoid expansive formation, measuring ∼ 6.0 × 4.0 cm,
on the middle line (supratentorial), consistent with Galen vein aneurysm.
A cystic area with a tubular aspect, measuring ∼ 5.5 × 4.0 cm, on the middle line
(supratentorial), confirmed based on color Doppler as an arteriovenous flow within,
consistent with Galen vein aneurysm. Slight ventricular dilation.
6
Expansive lesion with lobulated contours and well-defined limits, with a hypointense
T2 signal and an iso/hypointense T1 signal, measuring 3.0 × 1.8 × 2.3 cm, interhemispheric,
posterior to the 3rd ventricle, with no compressive effect.
Anechoic image measuring 34 × 28 mm, located posteriorly above the thalamus. Slightly
dilated lateral ventricles. Color Doppler with turbulent flow. Normal 3rd and 4th
ventricles.
7
Expansive lesion with lobulated contours and well-defined limits, with a hypointense
T2 signal and an iso/hypointense T1 signal, measuring 3.5 × 3.4 × 2.6 cm, interhemispheric,
posterior to the 3rd ventricle, no compressive effect.
Anechoic Image measuring 26 × 24 mm, posterior to the 3rd ventricle. Normal lateral,
3rd, and 4th ventricles. Color Doppler with turbulent flow.
Discussion
Here we present a series of cases of prenatal diagnosis of GVA based on ultrasonography
at an average gestational age of 25 weeks; our diagnosis agrees with the findings
reported in most publications.[8 ]
[9 ]
[10 ] Magnetic resonance imaging is used to evaluate associated neurological findings
that may be of prognostic value. In our case series, MRI showed no diagnostic advantages
over ultrasonography. In a series of 18 cases of GVA, MRI identified 3 cases of neuronal
migration abnormalities that had not been identified by ultrasonography.[2 ]
In our series, associated findings were present in 71% of the cases (5/7) and cardiomegaly
was the most frequent finding. However, in only two cases, a therapeutic preterm delivery
was performed owing to congestive heart failure in the fetus. The mean gestational
age at delivery was 37.5 weeks, and the mean birth weight was adequate in terms of
the gestational age. In a series of 21 cases, the mean gestational age at birth was
high (38.7 weeks) and the mean birth weight was also adequate in terms of the gestational
age (3096 g).[2 ] The most frequent type of delivery in our case series was cesarean section (86%),
which is in accordance with the high incidence of this type of delivery in Brazil,
both in public and private institutions, regardless of fetal malformations.[11 ]
Associated anomaly is a proven factor of adverse perinatal outcome in cases of GVA
and termination of the pregnancy is indicated in countries where this procedure is
legal.[2 ] Regarding the type of delivery, in the absence of fetal cardiac dysfunction and
isolated GVA, normal delivery is the best choice. In the presence of fetal cardiac
dysfunction and isolated/associated GVA, there is no consensus in the literature and
the choice should be based on the gestational age and the neonatal intensive care.
Despite advancements in prenatal diagnosis, neonatal mortality is high in GVA, with
three neonatal deaths (43%) observed in our case series, as well as a case of serious
neurological sequelae in the 4-year follow-up (14%). In all these neonatal deaths,
the fetuses showed cardiomegaly in the fetal echocardiography. In a case series in
which termination of the pregnancy was performed in fetuses with GVA, 89% of them
showed cardiomegaly in the fetal echocardiography.[2 ] There are no studies regarding the best fetal echocardiography follow-up in cases
with cardiac dysfunction/cardiomegaly.
In a systematic review of 90 cases of prenatal diagnosis of GVA, the mortality rate
was 54%, and serious neurological sequelae were found in 14% of the cases[2 ]; this was consistent with the findings of our study. Postnatal treatment of GVA
will depend on its size; small GVAs with low flow may undergo spontaneous thrombosis,
as observed in case #3. Patients with neurological and cardiac symptoms must be treated
by a radiological or surgical intervention.[5 ] When GVA is not life threatening, the vascular malformation is best embolized after
5 months from birth,[12 ] as performed in cases #1 and #7, which showed good postnatal outcomes and normal
neurological development in the 4-year follow-up.
In summary, we have presented a series of cases of prenatal diagnosis of GVA based
on ultrasonography and MRI. Because GVA is associated with high rates of neonatal
death, its prenatal diagnosis is essential for parent counseling and follow-up at
tertiary care institutions.
