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Tr an s ve n ous embolization of cavernous sinus lesions can be discussed
in some cases; however, considering the quality of the results obtained by
the arterial route and the need to use an arterial approach even in preparation for the transvenous approach,makes us favor the arterial route as
the primary approach in children.The transvenous approach through the
femoral vein or after direct approach to the sinus can be proposed if the
analysis of the cerebral venous drainage has been done correctly
(Fig. 7.18). It is unlikely that immediate complete exclusion of the DAVS is
necessary in all cases.
The long-term result of transvenous stent placement in order to preserve brain venous drainage in the presence of progressive jugular stenosis is still unsatisfactory despite its temporary early benefit (Vilela et al.
2001).
In our experience, surgical management of such situations is required
in exceptional cases,for example to remove spontaneous hematomas that
are poorly tolerated. Ventricular shunting carries the same hazards as
mentioned in Chap.3 of this volume; and anticipation of ventricular
enlargement should lead to early endovascular treatment to eliminate the
risk of active hydrocephalus.
We tend to use heparin for 1 week and low-molecular-weight heparin
for 8 weeks until the next angiographic follow-up in order to preserve the
patency of a (partially) malformed sinus. In some instances, the treatment is decided even before angiography has been performed. Progression is satisfactory if the exclusion of the initial AVS and malformed lakes
results in remodeled patent cerebral venous pathways.
The tools now available allow us to treat almost any type of circulation
shunt to reduce or exclude it completely. The size and weight of patients
are only relative limiting factors for any team accustomed to performing
endovascular procedures in neonates and infants. The major problem is
actually not a technical one, but a conceptional one.As seen for VGAMs,
prediction of the natural history and anticipation of the next pathophysiological stage in a given patient constitute the ultimate goal for the specialist involved in the management of such different entities. The world
(published) experience for such diseases (21 cases prior to 1995; Morita
et al. 1995) shows the confusion that can result from reviewing a succession of anecdotal successful or failed management strategies. In such
meta-analyses, reference to various hypotheses that mix incompatible
analyses in an attempt to be consensual adds further to the mystery and
fatalism accompanying dural vascular lesions in children. Reference to
adult DAVS and inclusion of VGAM in this group is a dangerous academic exercise if they form the basis for heroic or inappropriate therapeutic
management strategies. One can even question the academic value of a
successful treatment based on the wrong concept and the result of an
incomplete analysis.
Over the past 18 years, we have been consulted in 52 cases of DAVS in
children. The distribution in each group does not reflect the true occurrence of the disease, but rather our specific interest and referral patterns.
The outcome of pediatric DAVS management even by experienced teams
is still far from satisfactory.
7Dural Arteriovenous Shunts452
However, our recent capacity to separate the different forms of progression of the disease in children with DAVS is helping us with their
management in a dramatic fashion.The diagnostic tools (scores),clinical
understanding, and therapeutic window concept developed in VGAM
and CAVM patients are also applicable to pediatric DAVSs,as the mechanisms of clinical eloquence and progression are similar in the same age
groups, regardless of etiology (see Chap. 2, this volume). The evidence
that some of these DAVS are lethal 10 years after onset indicates the caution with which we must approach our decisions. The results of longterm follow-up should discourage unrealistically optimistic case reports
advocating novel aggressive endovascular approaches.
453General Remarks on Treatment7.3 Dural Sinus Malformations
8.1 Developmental Venous Anomalies 455
8.1.1 Single Abnormalities 455
8.1.2 Associated Features 459
8.1.3 Associated Cavernomas 473
8.2 Segmental and Nonsegmental Cerebro-orbito-facial Venous Lesions 478
8.2.1 Sturge-Weber Syndrome 478
8.2.2 From SWS to Cerebrofacial Venous Metameric Syndrome 485
8.2.3 Orbitofacial Venous Lesions 496
8.3 Complex Pseudo-metameric Cerebrofacial Venous Syndrome 499
8.4 Blue Rubber Bleb Nevus (Bean Syndrome) 503
8.4.1 The Association of BRBN with DVA 504
8.4.2 Cerebral Venous Malformations in BRBN 507
8.4.3 BRBN and HHT1 507
8.1 Developmental Venous Anomalies
Developmental venous anomalies (DVA), the so-called venous angiomas,
have baffled clinicians for many years (see Vol. 1, Chap. 7). Courville
(1963) suggested that they constituted a “compensatory venous drainage”
in the cortex, in what he described as a malformation. This compensatory
system does not demonstrate increased incidence of rupture and is an adequate drainage mechanism. Courville made the same observation
regarding the deep venous system and subependymal collectors, and his
precise descriptions discuss the characteristic features of DVA, which,
although rare, should therefore not be considered as vascular malformations. In the subsequent literature, most of the confusion arose from the
misnomer and improper use of the term “angiomas” as a synonym for
both arterial and venous malformations.
8.1.1 Single Abnormalities
DVAs must be considered as nonpathological normal venous pattern; therefore the term “developmental venous anomaly” (DVAs) was introduced
(Lasjaunias et al. 1986a). The deep and superficial types of DVA (Valavanis
et al. 1983) constitute the limits of variability of the transcerebral venous
system (Saito and Kobayashi1981; Senegor 1983; Lasjaunias et al. 1986a;
Jimenez et al. 1989; Rothfus et al.1984).The deep varieties of DVAs drain the
normal subcortical areas of the superficial medullary veins into the deep venous collectors (Fig. 8.1).The superficial group of DVAs occur in the super-
8Venous Anomalies and Malformations
ficial medullary veins, which drain the deeper medullary regions into the
cortical veins (Fig. 8.2).In both cases,visualization of the medullary venous
system is not pathological, despite being unusual.This arrangement is compatible with the normal functioning of the area, as shown by the fortuitous
manner in which most are discovered, i.e., in anatomic dissections or as incidental findings during CT, MRI,and angiography.
8Venous Anomalies and Malformations456
Fig. 8.1. Ty pi cal appearance
of deep-seated developmental
venous anomaly (DVA) draining most of the cortical veins
of the right hemisphere
Fig. 8.2. Ty pi cal appearance
of the cortical drainage of the
subependymal region of the
left frontal horn.Angiography
is not needed to confirm the
diagnosis in such a typical
situation
According to other theories, an early (in utero) acquired venular occlusion,or regression,maintains the intrinsic venous anastomoses within the
white matter; the DVA expresses an early collateral adaptation, but develops on a preexisting venous system that has been transformed. Both theories seem valid,but most DVAs are not associated with any sort of neural
tissue damage or dysfunction. Thus the venous system remains adequate
and the causal disorder,if it exists, is functionally negligible. It can hardly
be imagined that a significant venous disorder (such as thrombosis) at an
early stage of development would not be associated with some tissue abnormality (see melting-brain syndrome; see Chap. 2,this volume).
To further exclude DVA from the group of malformations, it should be
remembered that DVAs do not exist in the diencephalon, brain stem, or
spinal cord, and they are only encountered where tectum derivatives
exist (rhombencephalic, mesencephalic, telencephalic; Lasjaunias 1990;
Berenstein 1992; Vol. 1). In children, in particular, thrombotic episodes
may lead to DVA-like patterns,but DVAs can easily be distinguished from
collateral circulations in the central nervous system (CNS) and venous
system (see below). Although the former recruit pathways that have the
greatest potential for enlargement and produce DVA-like patterns, they
are never similar enough to cause misdiagnosis.The venous collectors of
the DVAs follow a transcerebral course that can be demonstrated by CT or
MRI examinations (Augustyn et al. 1985; Olson et al. 1984). Some DVAs
are not detected with CT (Koussa et al.1985) or MRI,but they are not angiographically occult.DVAs are opacified at the usual venous phase of angiography. Certain sites in the frontal or parietal regions show some capillary phase staining, which is sometimes wrongly considered to be abnormal (Hirata 1988; Simard et al.1986; Lasjaunias and Berenstein 1990).
These DVAs represent the sum of both the significant venular convergence (which is specific to DVAs) and the usual early drainage of the frontoparietal brain compared to the remaining brain.
The analysis of intracerebral hemorrhage caused by a DVA in autopsy
series shows a very low tendency to bleed when compared with true cerebral vascular malformations (arterial, capillary, arteriovenous, or cavernomas; Berenstein 1992).The discovery of a DVA during the investigation
of a cerebral hemorrhage should raise the question of their etiological
relationship (Gomori et al.1986). DVAs undergo changes common to the
aging process of the entire venous system.As an extreme anatomic variation,a DVA has a reduced flexibility (adaptability) that may lead to various venous ischemic manifestations (Figs. 8.3–8.5),including the following clinical symptoms:
Seizures
Tr a ns i ent neurological deficit
Headaches
Macrocrania
Mental retardation
Cosmetic problems
These early ischemic signs (Berenstein and Lasjaunias 1992a; Burke et al.
1984; Kutscher et al. 1987; Pelez et al. 1983) may secondarily transform
into hemorrhagic infarction (Fig. 8.3). This is an additional mechanism
457Single Abnormalities
8Venous Anomalies and Malformations458
Fig. 8.3A–F. Legend see p. 459
for the association of DVA and cerebral hemorrhage. This discussion is
typical of the adult population, but does not constitute a common problem in pediatric practice.
Bouchacourt et al. (1978) reported a well-documented case of thrombosis of a DVA that produced extensive venous hemispheric ischemia in
a 37-year-old woman.Although the patient later (while under anticoagulation therapy) had a proximal iliofemoral venous thrombosis, the coagulation factor profile was not analyzed.
Thus,despite all the clinical suspicions,DVA should be accepted as representing normal structures and should be treated neither by surgery nor
by radiation. During a hemorrhagic episode, a cavernous malformation
or other associated vascular malformation should be searched for and
the DVA respected and preserved because of its role in draining normal
brain tissue, even if its appearance is particularly unusual (Fig. 8.37). In
case of an intracerebral hematoma associated with a large area of surrounding hypersignal on MR, a possible intra-DVA arteriovenous shunt
should be looked for, in particular when investigations demonstrate no
evidence of associated ruptured cavernoma or venous thrombosis.
8.1.2 Associated Features
DVAs may also be associated with tumors and other tumoral masses
(Beers et al. 1984).Handa et al.(1984) reported a case of a deep DVA with
an intracranial varix, discovered following a head injury. The varix
seemed to result from an associated anomaly of the venodural junction,
producing a secondary upstream ectasia of the venous collector of the
DVA (Meyer et al. 1983; Handa et al. 1984).
459Associated Features
Fig. 8.3A–H. A 7-year-old child presented with an acute cerebellar syndrome in relation to an intraparenchymatous hematoma (A,B).Angiography demonstrated a focal
AV Fopening in a large DVA (C, D). Selective catheterization of the fistulous point
allowed its elective embolization (E–H)
▲
8Venous Anomalies and Malformations460
Fig. 8.4A–D. A young child presenting with a ruptured temporal DVA (A,B) associat-
ed with an upper parietofrontal AVM that has also produced an intracerebral
hematoma (C,D).E–G Angiographic aspect of both unrelated lesions.E-G see p.461
461Associated Features
Fig. 8.4E–G. (continued) E–G Angiographic aspect
of both unrelated lesions
8Venous Anomalies and Malformations462
Fig. 8.5A–C. A young child presenting with a focal melting-brain syndrome in relation to a DVA with no evidence of associated AVM. (A–D).E–G see p 463.
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