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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3644_Библиотеки_им_академика_М_И_Перельмана
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ing vasculature in the clinical expression of a given lesion. In addition, the
importance of the parallel maturation of the surrounding brain in children
created the concept of optimal therapeutic timing. Finally, the fact that lesions may not be present at birth certainly further questions the desire to
obtain eradication of the AV shunt as the only guarantee of a return to a normal state and protection over time. Such an approach in children is not
based on any evidence and on the contrary has often resulted in improper
treatment decisions,particularly in young children.The preeminence of the
technical challenge to erase any risk and the consequent aggressiveness of
the treatment performed has obscured the fact that it might not always be
needed immediately and might perhaps be more safely achieved later. Several years ago,staged treatment procedures entered the interventional arena. This represented a progression from palliative to secondarily completed
surgery and subsequently to planned staged procedures.Little attention was
paid to the recovery of the vascular system, and the challenge to achieve total eradication precluded recognition of the reconstructive results obtained.
Interventional neuroradiological experience with CAVM management has
demonstrated the validity of the following concepts:
There is more than a semantic difference between staged, partial, and
palliative treatment.
The desire to rapidly obtain a complete exclusion of the AVM is often
a compulsory objective, which may indicate a failure of analysis to
understand and predict the spontaneous outcome in a given patient.
Incomplete exclusion does not mean the absence of treatment.
Postsurgical remnants do not have the same significance as partially
embolized lesions.
5Cerebral Arteriovenous Malformations332
Fig. 5.25E. Legend see p. 331
333Complete Exclusion
Fig. 5.26A–D. A 14-year-old boy presenting with a brutal left hemiplegia associated
with IVth nerve palsy and Parinaud syndrome. CT and MRI (A, B) disclosed a right
quadrigeminal hematoma. Although the images are suggestive of cavernoma, the axial cut demonstrates a small network on the tegmental portion of the mesencephalon.
Selective arteriography demonstrates an arteriovenous malformation (C, D).E–G see
p. 334
5Cerebral Arteriovenous Malformations334
Fig. 5.26E–G. (continued) Selective injection into the feeder allowed glue deposition
(E). Postembolization follow-up after a few months demonstrates complete stable occlusion of this mesencephalic AVM (F, G )
The endovascular approach to CAVMs provides a wider range of op-
tions,both in the degree of completeness and the timing of treatment,
and more so than any other traditional treatment modality.
The complete disappearance of a lesion at imaging follow-up is reliable.
To t al stable exclusion of an AVM does not require secondary removal
for preventive purposes.
Embolization is a generic name that encompasses many different prac-
tices,objectives,and results.
335Complete Exclusion
Fig. 5.27. A, B A 6-year-old child presenting with an intracerebral hematoma resulting in an incomplete hemiparesis.B–D Following embolization in one session,the entire lesion was excluded.Clinical recovery has started
5.6.2 Partial Treatment
In our practice,the goal of treatment in children has become the preservation of normal neurocognitive maturation as well stable protection
from acute episodes. In most instances,the morphological goal can be superimposed on the clinical goal. In babies, however, as seen in VGAM,
these objectives can be separate in time or even contradictory, if the attempt to obtain a cure compromises neurological outcome. Staged treatment is the planning of steps to reach a more favorable situation and to
achieve an exclusion with lower morbidity than if it was accomplished in
a single session. Palliative treatment is an incomplete exclusion of a lesion
in order to stabilize a critical situation.Partial targeted treatment is an incomplete exclusion motivated by a clinical concern requiring improvement and directed toward a specific portion of the lesion when complete
exclusion cannot be offered with an acceptable level of risk.It has a clinical objective and, in contrast to the palliative objective, its results are
morphologically and clinically identifiable and can therefore be evaluated (Fig. 5.28).
A certain group of patients have not yet completed the embolization
treatment, making up a new population of patients who did not exist as
such in the past.Some are still under treatment (staged),and one may ask
why the treatment is not continued more rapidly. The decision to stage a
procedure carries some significant advantages, particularly in children,
where the length of the procedure is limited by puncture time or fluid
volumes. In addition,with the hemodynamic triggers being modified,the
correction of some disorders induces a normal, although delayed maturation. In this group, the problem is the time between two consecutive
sessions. There is no definitive optimal schedule; however, with experience each interventional neuroradiologist knows whether a better technical result can be achieved by waiting for a few weeks or months. This
strategy will permit a rearrangement of the remaining anatomy, and
some areas of induced angiogenesis may regress, whereas some smaller
feeders may enlarge, permitting easier catheterization. This will have to
be balanced with the hemodynamic changes induced by embolization
and hemodynamic needs, to ensure a proper or preserved maturation
process.
There are a number of patients who cannot be cured even with the current treatment options and capabilities, either because the lesion cannot
be reached or because the disease is multifocal. In this subgroup, treatment is partial and is repeated in time with long intervals between sessions. We do not perform palliative embolization in children with AVM.
The aim of partial treatment is to eliminate dangerous portions of the
AVM (intranidal aneurysms, false aneurysms seen following a hemorrhagic episode, and venous ectasias [Figs. 5.24,5.28]) or its effects on the
adjacent brain (venous congestion, venous thrombosis) or to reduce
seizure activity, progressive deficits, or headaches (Figs. 5.29, 5.30). In
some instances,this targeted embolization deals with a dangerous part of
the lesion prior to the irradiation of the remainder, to avoid repeated hemorrhage during the 2-year interval and to reduce the size of the target
further (Figs. 5.33,5.34).In our experience, partial targeted embolization
5Cerebral Arteriovenous Malformations336
337Partial Treatment
Fig. 5.28. A, B An 8-year-old boy presented with sudden intracerebral hematoma resulting in right-sided hemiparesis and hemianopia.C,D The presence of an intranidal
aneurysm prompted partial targeted embolization prior to discussing further management.Clinical recovery is incomplete
5Cerebral Arteriovenous Malformations338
Fig. 5.29. A–C A 5-year-old
child had had a progressive
motor deficit in relation to
large multifocal AVMs located
in the brain stem since the age
of 2 years.Following four distal
glue deposits in three sessions
(D–F), although the angiographic changes were not
spectacular, the clinical
improvement was dramatic
339Partial Treatment
Fig. 5.30A–E. Legend see p. 340
is an acceptable therapeutic objective only if a complete cure cannot be
obtained at a satisfactory level of risk and if the procedure is performed
with a permanent agent,such as NBCA.This means that we aim to obtain
– by endovascular or other techniques – total exclusion if a good neurological outcome can be guaranteed.The fact that most lesions in patients
referred to us are large or multifocal explains the small number of complete cures in our series.
5.6.3 Neonates and Infants
Tr eatment objectives in this age group are the same as in VGAM; however,the insult to the cerebral tissue is more rapid,as the venous drainage is
usually impaired, and collateral venous circulation is compromised,
using as alternative drainage toward subpial veins in most instances.
The poor neurological prognosis forces us to try to achieve a significant reduction of the shunting more rapidly. Early management
is, therefore, not so much motivated by the CCF, which is usually mild
to moderate, but by the possibility of ensuing irreversible cerebral
damage. The patients should be evaluated without angiography in order
to assess the degree of interference between the AVM and the brain tissue, while rapidly scheduling the first embolization session, almost regardless of the existing symptoms. If the CCF is severe, the prognosis is
extremely poor, since it combines both systemic and subpial effects
(Fig. 5.17).
5Cerebral Arteriovenous Malformations340
Fig. 5.30. A, C Deep-seated AVM located in the head of the caudate nucleus and revealed with an intraventricle hemorrhage (A frontal,B early,and C late lateral views).
D Distal selective catheterization of the Heubner artery allowed the embolization,
thus disconnecting 90% of the lesion (E–G)
Convulsion is a major symptom and should point to the need for rapid
treatment, even if the convulsion remains isolated and without permanent clinical effect (Tables5.2, 5.3).
In the series of Rodesch et al. (1995a), CAVSs had a poorer prognosis
than VGAMs when the onset of symptoms was at neonatal and infant age.
Sixteen neonates or infants were embolized as the primary modality of
treatment and four of these eventually died. One died due to multiorgan
failure, one following a complementary surgical approach, one from hemorrhage after incomplete treatment (three sessions) for a multifocal
perimesencephalic AVM,and one from a posterior fossa hemorrhage despite complete occlusion of the AVM.Eight out of 12 had a normal neurological status (scores of 5, 4, or 3), and the remaining four had a score of
2. Eight patients had surgical resection of their CAVS as the first (and
only) treatment modality; seven of them were older than 2 years of age at
the time of surgery. All patients had their AVM removed and all are still
alive; two out of eight have moderate permanent neurological deficits.
5.6.3.1 Hydrodynamic Disorders
Possible hydrodynamic disorders should be managed early through reduction or occlusion of the AV shunt. Even if pial lesions in infancy present features that simulate the VGAM pattern, symptoms are significantly different, rarely causing hydrodynamic disorders, but frequently focal
neurological symptoms and hemorrhage. CAVMs rapidly produce local
brain atrophy (focal melting-brain syndrome) (Fig. 5.17). This atrophy
represents the subacute local effect of abnormal hydrodynamics induced
by surrounding pial venous congestion.Dural sinus hyperpressure (Quisling and Mickle 1989; Zerah et al. 1992) can induce reversible tonsillar
prolapse (Girard et al. 1994), which expresses the posterior fossa hydrovenous disorders (Andeweg 1989). Special attention must be paid to the
venous drainage of the brain at each session in order to follow the maturation of the various outlets and their patency.
3415.6.3.1 Hydrodynamic Disorders
Ta ble 5.2. Pial AVMs in children (<16 years): clinical presentation in neonates
Cardial overload 50%
Hemorrhage 37.5%
Incidental 12%
Ta ble 5.3. Pial AVMs in children (<16 years): clinical presentation in infants
Hemorrhage 30%
Macrocrania 26.6%
Cardiac overload 23.3%
Deficit 6.6%
Epilepsy 6.6%
Incidental 6.6%
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