Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3644_Библиотеки_им_академика_М_И_Перельмана

With regard to the age at diagnosis,we identified four groups of children: fetuses, neonates, infants (up to the age of 2 years), and children. These groups are used as a point of reference and are matched with the date of first referral and the date of first embolization. These different dates are important, since they outline the delay between diagnosis and endovas­cular possibilities, the role of decisions made prior to the intervention itself and the neurological outcome resulting from this management.The neurological outcome in the surviving group shows 74% neurologically normal children (Table 3.12). Among the 20 out of 193 (10.8%) children with a severe neurological or cognitive handicap,some were already in an irreversible state when referred to us but for others we failed to anticipate a poor outcome.

dressing the associated pial AVM (Lasjaunias 1987b; terBrugge 2001). Even with true VGAMs, sudden closure of the venous end (sometimes without precise control of placement of the embolic material) may put the patient at risk of venous infarction or hemorrhage. Perforation of the venous pouch with the guiding catheter has lead to fatal intracranial he­morrhage in a number of cases (Lylyk et al.1997).Lastly,severe consump­tive coagulopathy has been reported following transvenous treatment (Rosenberg and Nazar 1991; Charafeddine et al. 1999).

In our series, four children had radiotherapy (Al Watban et al. 1995),three before they had been referred to us. In all three patients, a linear acceler­ator had been used with no effect on the lesion; these three patients were subsequently cured by embolization. The other patient completed treatment with a combination of Knife radiotherapy following emboliza­tion of 80% of the lesion (Figs. 3.45, 3.60).

In the search for minimally invasive techniques to cure difficult or un­reachable vascular malformations of the brain, radiosurgery has become a reliable therapeutic alternative,even in the pediatric population (Stein­berg et al. 1990; Steiner et al. 1989; Altschuler et al. 1989; Colombo et al. 1989; Fabrikant et al. 1989; Loeffler et al. 1990). The main problem in ap­plying this technique in VGAM is the vulnerability of the brain in chil­dren and the time needed for progressive endarteritis to completely oc­clude the malformative shunt. During this delay, the hemodynamic and hydrodynamic effects, either on the supratentorial (Zerah et al. 1992) or infratentorial (Girard et al. 1994) spaces created by the VGAM with the concurrent maturing and developing brain, can induce irreversible dam­age and neurocognitive delay. This retardation is one of the most chal­lenging problems and is often overlooked and rarely reported in the liter­ature. It was present in nearly all the infants referred to us, even though they were considered neurologically normal. To avoid irreversible delay, we believe that one should not wait 2 years in any of these cases to obtain occlusion of the shunt. Although theoretically effective, we believe that there is no indication for radiosurgery as the first modality in treatment in VGAM. In a combined approach, radiosurgery is a powerful tool that can be used as soon as most of the lesion has been controlled in terms of size and analyzed in terms of future neurological risks. The time allotted for treatment depends on the hydrovenous status.As a general policy,we do not recommend radiosurgery in children unless a complete morpho­logical result has to be obtained and if other techniques cannot be used. Indications are thus rare and are discussed on an individual basis,and in our experience as late as possible in the child’s development.

until it joins a significant outlet that takes it across the subarachnoid space to the dural sinuses and away from the regional brain vasculature.Along the length of its subpial segment, the venous channel draining the fistula receives drainage from normal venules participating both in blood drainage and CSF homeostasis of normal brain, which are at a lower pres­sure and therefore unable to function properly, with a high chance of in­ducing regional ischemia, which will result in atrophic changes and pro­gressive melting-brain syndrome. Conversely,if the drainage of a lesion is at or near the subarachnoid level,and the subarachnoid transit distance is short, as it tends to be in most CAVFs, the subpial venous congestion will be reduced, and the chances for regional atrophic changes and melting­brain syndrome are therefore reduced.Premedullary posterior fossa AVFs that arise from the distal vertebral arteries or the basilar trunk also tend to fall into this category and have surprisingly few neurological symptoms.

While the arterial feeders, which participate in this direct communica­tion,may be single (Fig. 4.1) or multiple (Fig. 4.2), they will all converge on a single venous channel. The AVFs are always superficial and cortical

Ve n o us pouches are very frequent in children, since thrombosis and high flow are often present.They are characteristic of AVFs seen in HHT children. These pouches behave like any large pulsatile mass and may have neurological manifestations,although the ability of the infant’s head