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3.8 Natural History of Vein
of Galen Aneurysmal Malformations
Similar to other types of vein of Galen AV lesions,VGAMs are not hereditary. In our series, two cousins presented with vein of Galen-type AV
shunts diagnosed at neonatal and infant age, but upon analysis they did
not seem to represent true VGAMs. Neither in our series of children with
hereditary hemorrhagic telangiectasia (HHT) disorder, nor in the group
of adult patients with cerebral localizations of HHT was there a VGAM
present. Boynton and Morgan (1973) reported a case of a neonate with a
rapidly lethal vein of Galen AVM fed by posterior, anterior, and middle
cerebral arteries and a family history of HHT.In 1987, Salazar reported a
similar case, but from the description in both cases we doubt that the
AVM was a true VGAM.Despite the male dominance in this type of AVM
(it is the only arteriovenous malformation with a sex dominance), there
is presently no convincing evidence to suggest a hereditary genetic influence on the development of VGAM (Scheme 3.1A).
The natural history of VGAM is unclear from what is documented in
the literature. In particular, since many classic descriptions were not actually VGAMs but were descriptions of VGADs, much of the so-called
natural history of the surviving children was learned from babies who
had undergone shunting procedures.The need for emergency treatment
in many patients certainly represented an acceptable explanation for the
delay in appreciating the associated negative effects of ventricular
drainage on the neurological progression in these children.In particular,
the onset of seizures traditionally described in the late phase of VGAMs
reflects this progressions in babies who had been shunted. Most neurological symptoms and hemorrhages reported in the literature are in mistakenly diagnosed VGAMs or are the result of changes in angioarchitecture, which in turn alter the consequences of the initial lesion. All these
141Natural History of Vein of Galen Aneurysmal Malformations
Fig. 3.30. Infant boys presenting with VGAM and maxillofacial midline disorders:
A cleft palate; B tip-of-the-nose
hemangioma
phases are predictable,and most prodromes are recognizable; early management does not necessarily mean emergency interventions. Finally,
endovascular management of this population has given us a chance to
observe the anatomic and clinical progression in nonsurgical circumstances.
Several papers (Andeweg 1989; Del Bigio et al. 1985; Girard et al. 1992;
Larroche 1977a; Le Gros Clark 1920; Quisling and Mickle 1989; Saliba et
al. 1987b; Schroth and Klose 1992a; Seidenwurm et al. 1991; Weed 1923)
provide crucial insights into the physiology and vasculature of the prenatal brain. They serve as a basis for us to better understand the original
material that we were able to collect (Garcia-Monaco et al.1991b; Girard
et al. 1994; Lasjaunias et al. 1991b, 1995; Rodesch et al. 1994; Zerah et al.
1992) and to improve our interpretation of the literature.
We have chosen a diagrammatic presentation of the natural history
of VGAM to highlight the path followed by each individual case. Thus,
once previous stages have been identified, the subsequent ones can be
more easily anticipated. The therapeutic window outlines the optimal
moment for the endovascular approach. this has become the objective of
our decision as to therapeutic timing and points to the treatment and
clinical goals to be targeted. We will concentrate only on the clinical aspect in this section and will consider the technical management and
global results later. The reader is referred to Chap. 2 to gain a broader
prospective with regard to the diagnostic challenge in the different age
groups.
3Vein of Galen Aneurysmal Malformation142
Scheme 3.1A. Natural history of vein of Galen aneurysmal malformations
3.9 Cardiac Manifestations
Cardiac manifestations were reviewed for neonates (Garcia Monaco
1991b) and have been prenatally diagnosed in VGAMs (Rodesch et al.
1994). In contrast to the cardiac failure observed in large hemangiomas,
where they occur in infancy at the proliferative stage of the disease,
the congestive cardiac failure (CCF) in VGAMs can be present during
the neonatal period (see Chap. 11, this volume) (Scheme3.1B).
In his series of 18 antenatally diagnosed VGAM patients, Rodesch
noted that 17 were born with cardiac failure and only one without.
During prenatal ultrasound examination, some cardiac enlargement
was noted in four out of 17 patients. In all four of the patients in which
this finding was demonstrated, the neonatal score was low (<8/21)
either because of the significant peripheral effect of systemic failure
or because of an already demonstrable encephalomalacia. Treatment
was withheld in four patients and they soon died. The others were
medically managed, carefully followed,and embolized between 2 and
13 months transarterially. A total of 30% of them had slight retardation (of less than 20%), which resolved in a few months after completion of embolization treatment.
As far as the prognosis of an prenatally diagnosed VGAM is concerned,
22% of such babies have irreversible cerebral damage at birth and soon
die; the remaining babies should undergo embolization at various times,
143Cardiac Manifestations
Scheme 3.1B. Systemic disorders
depending on their individual response to medical treatment, and their
late neurological outcome is excellent at 2-year follow-up. Therapeutic
termination of pregnancy can be discussed in cases in which cardiac failure and or cerebral brain damage is noted in utero),while the presence of
macrocrania in utero has no negative significance in our experience.
It is of interest to note that, when comparing the series of prenatally
diagnosed cases with our overall series of VGAMs, the amount of irreversible cerebral damage is the same (22% vs 25%), but the capacity to
determine the correct therapeutic moment improves the neurological
outcome (88% normal neurological examination in the prenatal group vs
78% in the entire series).
In a twin pregnancy, the prenatal diagnosis of VGAM was made in one
fetus, while no abnormality was present in the other baby. Prenatal diagnosis (Fig. 3.31) is not an indication for emergency embolization at
neonatal age, but rather gives an opportunity to prepare the team that is
to treat the child, monitor the degree of systemic disorders to be managed, and choose the best moment at which to handle them.
Premature babies with VGAM are an additional challenge. In two
patients, we performed angiography because of doubt regarding the
nature of the lesion, the presence of a convulsion, the absence of encephalomalacia, and a score of 11 with an unstable CCF in both patients.
A moyamoya type of network was noted in both in addition to typical
features of true VGAM (Fig. 3.20). In such children, treatment should be
withheld, since the neurological outcome no longer depends on the CCF
and the VGAM, but is mainly related to diffuse arterial angiopathy.On the
other hand, a premature 2-kg neonate, born at 36 weeks gestation and
part of a twin pregnancy, presented with progressive CCF but otherwise
good scores and was managed successfully with early arterial embolization and had a good neurological outcome.
With regard to the spontaneous evolution of the CCF, the following
observations can be made. After a brief period of stabilization, in most
cases the CCF worsens during the first 3 days of life, then stabilizes again
to then improve with appropriate medical management.
3Vein of Galen Aneurysmal Malformation144
Fig. 3.31A,B. Prenatal MR
diagnosis of VGAM with
enlarged ventricles mostly
related to subependymal
atrophy
145Cardiac Manifestations
Fig. 3.32A–E. Legend see p. 146
In none of the babies referred to us with the diagnosis of VGAM did
cardiac failure develop de novo after the 2nd week of life. However, it
can decompensate at 3 weeks or recur later following lung infections or
other concurrent diseases. In infants, CCF never constitutes the presenting symptom, nor does it worsen at that age if already present. An
increased cardiac index is often noted when the diagnosis of VGAM is
made because of macrocrania.
Cardiac manifestations have been reviewed for neonates (Garcia
Monaco et al. 1991a; Chevret et al. 2002; Frawley et al. 2002) and the degree of failure is variable from one child to another,but seems to be independent of the characteristics of the shunt (Fig. 3.32). This is also noted
in other neonatal CAVSs (Rodesch et al. 1994). Some obvious high-flow
lesions are well tolerated, while conversely some apparently small ones
may lead to multiorgan failure (Fig. 3.33). The intracranial hemodynamic parameters available do not provide us with any definitive information
concerning the timing or even the end point of AV shunt correction.
Some babies, while presenting with severe CCF and responding well to
medical treatment, may already reveal CT evidence of venous infarction
(Figs. 3.34,3.35). Cerebral insult had presumably already started in utero.
In one autopsy case of severe systemic failure with cerebral encephalomalacia, the cranial vault was already thick (8 mm) and the fontanelles
closed (Landrieu, unpublished data; Figs. 3.4, 3.33), pointing to the early
onset of melting-brain syndrome (see Chap. 2,this volume).
Renal and hepatic damage may further aggravate CCF, and their
function can be transiently impaired (oliguria, increase of enzymes) or
become rapidly unstable despite intensive medical care. Ventilation,
although important in stabilizing some life-threatening situations,
3Vein of Galen Aneurysmal Malformation146
Fig. 3.32. A–C MR and MRA
with 3D reconstructions
accurately demonstrating the
cerebral condition, the lesion,
and its feeders. Color Doppler
ultrasound with morphological
(D, E) and hemodynamic (F)
analysis of a VGAM case
147Cardiac Manifestations
Fig. 3.33A,B. A 2,650-g female neonate presented with severe cardiac failure. Head
circumference was 31.5 cm and neonatal score 8. A Ultrasound and B CT examinationsdemonstrated diffuse brain damage; progression was rapidly fatal
Fig. 3.34. A Chest X-ray in a
male neonate who presented
with severe cardiac failure
and a single convulsive episode.
B, C Although the neonatal
score is 13,CT demonstrates
severe bilateral infarct with
some degree of melting-brain
syndrome already,indicating
its onset in utero
is often overused and may create additional difficulties when extubation
is required once the decision is made not to embolize the child.
The cause of CCF is not fully understood. In fetal life, the effects of
heart rate on the combined ventricular output (CVO) (Rudolph 1976)
suggest that the heart is functioning near its maximum performance
(Marcelletti 1992).
It seems that volume loading increases output to a limited extent. The
fetal myocardium has less contractile tissue, as shown by its myofibrillar
contents (Friedman 1993). Several major events change the fetal circulation at birth: (a) removal of the low-pressure circuit (placenta) from the
systemic circulation, (b) reversal of the relative pressure between the
right and the left atrium,leading to closure of the foramen ovale,(c) muscular contraction of the ductus arteriosus (its closure occurs 10–15 h
after birth with a rise of PO
2
the systemic level,but also neurological and
vasoactive interferences), and (d) decrease in pulmonary vascular resistance.Transitional circulation takes place.This leads to change in cardiac
output from 150 ml/min per kg in the fetus to 3–400 ml/min per kg postnatally.Since the reduced reserve for increased CVO is observed, the aug-
3Vein of Galen Aneurysmal Malformation148
Fig. 3.35A–C. Male neonate
weighing 3,200 g. Immediate
cyanosis requiring intubation
and ventilation with 100% O
2
.
Under NO and dopamine, he
had transient anuria and two
convulsions.A–C CT performed
the same day demonstrates
periventricular encephalomalacia associated with neonatal
calcification, particularly in
the frontal region.Even though
the score was 10,the child was
not embolized. He had two
additional generalized seizures
and rapidly died
mentation in output might be obtained from a transitory gain in cardiac
contractility,which disappears after the 1st week (Marcelletti 1992). Temperature is also an important parameter at this age; it is maintained by
peripheral vasoconstriction and secondary oxydation of triglycerides
and free fatty acids. Further changes are seen during growth of the child.
Our interventional strategy and medical support in neonatal CCF are
in accordance with these physiological changes,and medical treatment is
based more on diuretics and inotropic drugs than on the use of digitalis.
CCF is mainly encountered in the choroidal forms of VGAMs, which
are the most frequent AV shunts diagnosed at that age (cause or consequence?). Severe forms of CCF are associated with persistence of the fetal
type of circulation. Septal communications and ductus arteriosus are
often noted during cardiac ultrasound; they should not be considered as
associated cardiac malformations, even if they increase the systemic insufficiency. Like most of the disorders encountered in these circumstances, they either disappear spontaneously or following endovascular
management of the AV shunt itself. They should be followed with special
attention if embolization is not to be done early, and they may induce a
failure-to-thrive condition.
In our series, two neonates presented with an associated cardiac malformation and an aortic coarctation for which they were first operated on; embolization was then carried out at the age of 1 and 2 months.
Five and 10 years later,the children had satisfactory clinical progression and a score of 4. In two other patients, we decided to clip a ductus arteriosus before embolizing the VGAM in neonates with severe
CCF and a score of 12.
After VGAM is suspected by clinical examination,a pretherapeutic evaluation should be obtained, including the following information: (a) clinical evaluation of the baby and documentation of all the possible events
that have occurred since birth (convulsions,for example,do not occur in
VGAM at that age unless brain damage has already taken place); (b) evaluation of renal and liver function; (c) transfontanel ultrasound to evaluate possible encephalomalacia; (d) cardiac ultrasound to assess cardiac
tolerance and to diagnose any associated cardiac malformation that
might require specific treatment; (e) good-quality MRI to provide all the
necessary morphological information regarding the lesions (the diagnosis of a CAVM at this age would have completely different therapeutic
consequences) and the status of myelinization; (f) electroencephalogram
(EEG) only if the baby is in an intensive care unit (ICU), intubated, and
sedated. Angiography in the neonatal work-up is not indicated and not
recommended; only if embolization is contemplated will the angiographic procedure be performed at the same time. All the information listed
above is necessary to make management decisions.The baby’s weight and
the head circumference constitute frequently omitted information that
needs to be carefully documented and collected in the weeks that follow.
The decisions made at this stage follow a strict protocol and involve
many specialists.Neurological assessment is difficult in neonates and the
presence of systemic disorders has prognostic implications, while cere-
149Cardiac Manifestations
bral damage may go undetected on imaging, either because of the quality of the examination obtained or because of the early nature of changes
present in the neonatal age group.We have designed a specific neonatal
score that documents the significant non-neurological manifestations in
this age group in addition to assessing the gross neurological status (see
Ta ble 3.2). A score of less than 8/21 results in a decision not to treat; a
score of between 8 and 12/21 entails emergency endovascular intervention (Fig. 3.36); a score of more than 12/21 leads to the decision to manage with medical treatment as long as possible until the child is 5 months
of age, providing there is no failure to thrive. At this time, a decision is
made to proceed with endovascular treatment no matter what the symptoms are. In our experience,angiography and treatment at 5 months has
shown to best balance the maximum efficacy of embolization against the
minimum risk of cerebral maturation delay.
The first few months of clinical assessment are crucial to be able to predict the future and neurological status of the child. The goal is to have a
baby that is (a) stable on medication for cardiac insufficiency; (b) easier
to manage from a technical point of view; (c) not showing significant
developmental delay; (d) not developing a significant macrocrania. Pediatric follow-up criteria therefore include monthly head circumference,
weight, and developmental assessment as well as MRI at 3-month intervals. Obviously, alteration in any of these parameters will prompt endovascular management.A postnatal decrease in the head circumference is
probably the worst finding to be noted, since it indicates the loss of brain
substance and early suture fusion.
The next phase in the progression of the disease is marked by hydrovenous disorders (see Chap. 2,this volume).
3Vein of Galen Aneurysmal Malformation150
Ta ble 3.2. Bicêtre Neonatal Evaluation Score
PointsaCardiac function Cerebral function Respiratory function Hepatic function Renal function
5Normal Normal Normal – –
4Overload,noSubclinical isolated Tachypnea, – –
medical treatment EEG Abn’s finishes bottle
3Failure:stable with Nonconvulsive Tachypnea, does No hepatomegaly, Normal
medical treatment intermittent not finish bottle normal function
neurologic signs
2Failure:not stable Isolated convulsion Assisted ventilation, Hepatomegaly, Transient
with medical normal saturation normal function anuria
treatment FIO
2
<25%
1Ventilation Seizures Assisted ventilation, Moderate or Unstable
necessary normal saturation transient hepatic diuresis with
FIO
2
>25% insufficiency treatment
0Resistant to Permanent neuro- Assisted ventilation, Abn coagulation, Anuria
medical treatment logical signs desaturation elevated enzymes
a
Maximal score: 5 (cardiac) + 5 (cerebral) + 5 (respiratory) + 3 (hepatic) + 3 (renal) = 21.
Abn, abnormal; FIO
2
,inspired fraction of oxygen.
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