Treatment of vein of Galen aneurysmal malformation

Transcription

1 J Neurosurg70: , 1989 Treatment of vein of Galen aneurysmal malformation PERRE LASJAUNAS, M.D., PH.D., GEORGES RODESCH, M.D., PHLLPPE PRUVOST, M.D., FRAN~OSE GRLLOT LAROCHE, M.D., AND PERRE LANDREU, M.D. Neuroradiology Unit and Neuropediatric Service, Hbpital de Bicbtre, Paris, and Pediatric Service, CHR de Gien, Gien, France v, The authors report the case of a vein of Galen aneurysmal malformation in a 1-year-old baby presenting with an enlarging head. The lesion was a direct arteriovenous fistula in a dilated vein of Galen and was treated by complete embolization in one session. Four months after occlusion of the shunt, the ectatic vein of Galen and torcular were normal, and the head circumference had stabilized. This case serves as an opportunity to emphasize the quality of results that can be obtained with endovascular techniques. Proper analysis of the vein of Galen angioarchitecture allows planning for appropriate treatment with the lowest possible risk of morbidity and mortality. KEY WORDS ~ vein of Galen 9 embolization 9 aneurysm 9 arteriovenous malformation 9 endovascular treatment A VEN of Galen aneurysmal malformation is a rare anomaly principally affecting the pediatric population.12 This disorder represents less than 1% of all intracranial arteriovenous malformations (AVM's)J 2 The natural history of the disease is associated with high mortality and morbidity rates. 7 Active therapy is required to avoid or minimize its early systemic complications, as well as its early and late nervous system complications. The case of an infant with a vein of Galen aneurysmal malformation is reported. The lesion was successfully treated by embolization with rapid secondary shrinkage of the aneurysmal dilatation. To our knowledge, correction of both the shunt and mass effect has not previously been reported following embolization. Case Report Following a normal pregnancy and delivery, this first baby of a Caucasian family presented with a progressively increasing cranial size. The head circumference was 38 cm at 3 weeks and 44 cm at 3 months, associated with a divergent strabismus. No additional ocular abnormalities or signs of intracranial hypertension could be detected. The patient was fitted with sectorized glasses and the strabismus improved. At 12 months of age the baby's weight was 11.0 kg, his length was 78.5 cm, and his head circumference was 51 cm (+ 2 standard deviations). Admission. Neurological examination was normal, as was cardiac function. An intracranial bruit was de- tected at physical examination. No facial venous collateral circulation could be assessed. Because of the increasing head circumference, a plain skull x-ray film was obtained and showed a craniofacial dysmorphism without radiological signs of intracranial hypertension. No pathological calcification was detected. The pituitary fossa and coronal sutures were normal. Computerized tomography and magnetic resonance imaging showed a dilated vascular structure corresponding to the vein of Galen draining into the straight sinus (Fig. 1 left). No perforating vessel (artery or vein) could be visualized. Cerebral angiography via the right femoral approach revealed a direct single-vessel arteriovenous fistula to the vein of Galen, fed by a long circumferential artery arising from the distal basilar trunk (Fig. 2A). FG. 1. Magnetic resonance images of the patient before (left) and 4 months after (right) embolization. 746 J. Neurosurg. / Volume 70~May, 1989

2 Vein of Galen aneurysmal malformation FG. 2. A: Preoperative selective injection of the left vertebral artery. B: Superselective injection of the embolization mixture into the arterial feeder to the fistula. C: Plain skull x-ray film following embolization. The arteriovenous shunting was located on the left side of the venous ectasia near the superior colliculus, and the area of venous narrowing was located at the junction of the vein of Galen and the straight sinus. There was no evidence of an arterial steal. The normal venous drainage of the brain was via the superior sagittal sinus and both transverse sinuses. There was no evidence of venous reflux from the vein of Galen into the deep veins. The deep venous drainage seemed to converge bilaterally to both cavernous sinuses. Operation. One week after diagnosis, the child was treated by an endovascular approach in a 90-minute procedure. Following left femoral puncture and left vertebral artery catheterization, the feeding pedicle was easily superselectively catheterized with a mini-torquer* (Fig. 2B) and embolized with 0.3 ml of a 20% mixture of isobutyl cyanoacrylate and Lipiodol (Fig. 2C). mmediate control angiography with a left vertebral artery injection showed complete occlusion of the embolized vessel, with a significant reduction of flow into the vein of Galen and slight improvement in the venous drainage of the healthy brain. The embolic material was visualized in the feeder and partially in the ectatic vein (Fig. 2C). The sagittal and remaining dural sinuses were patent. Postoperative Course. Control angiography via a right femoral approach obtained 4 months after the therapeutic procedure confirmed the disappearance of * Mini-torquer manufactured by ngenor Co., Paris, France. the arteriovenous fistula, demonstrated the normal veins of the deep system draining into the petrous veins, and showed shrinkage of the torcular dilatation. From a clinical point of view, the baby was doing well, and the head circumference had slightly diminished to 50.5 cm. Neurological examination was normal except for the previously noted ocular and gaze abnormalities. Magnetic resonance imaging also confirmed the effect of the occlusion, with shrinkage of the vein of Galen ectasia and the normal appearance of the vermis (Fig. 1 right). Discussion Dilatations of the vein of Galen distal to an arteriovenous shunt can be of congenital or acquired origin. Two major types must be differentiated: true aneurysmal malformation of the vein of Galen and AVM of the brain with dilatation of the vein of Galen. True aneurysmal malformations of the vein of Galen are rare congenital AVM's constituted during the 3rd month of fetal life. 14 n such cases, the aneurysmal sac is not formed by the vein of Galen itself, but probably by a venous structure (the medial vein of the prosencephalon), which usually disappears at the 12th week of gestation.~4 For this reason, no vessels afferent to the ectatic vein can be expected. n this variety, one or more fistulas can be detected, localized directly in the wall of the vein of Galen or in the choroid fissure. They are all extracerebral. The vessels feeding the arteriovenous shunt(s) are usually predictable in this type, and include the medial and lateral choroidal, circumferen- J. Neurosurg. / Volume 70/May,

3 P. Lasjaunias, et al. TABLE 1 Aneurysmal malformations of the vein of Galen (VG)* Vascular Anatomy dural DVA + + "acquired" dural venous obstacle - - cerebral parenchymatous shunt (nidus or fistula) - - transcerebral vascularization - -~ direct AV shunt within VG wall + - dural AV shunt at VG-straight sinus junction + or - + or - choroidal arterial supply +w + VG AVMt Brain AVM + VG Direct ndirect Ectasia + (pediatric) + (adult) + + thalamotectal AVM's~ possible, if previous hemorrhage in choroidal AVM * AVM = arteriovenous malformation; DVA = developmental venous anomaly. + = present; - = absent. t Dorsal prosencephalic vein AVM'sJ 4 ~: Beware of the subependymal arteries in the third ventricular choroid plexus AVM. w Associated arteriovenous shunt. DVA + VG VG Dural Varix AVM D CONGENTAL AGENESS DURAL SNUS OBSTRUCTON (with venous ectasia) ACQURED OCCLUSON witla ] an AV shunt* i with with with angiogenesis direct indirect a deep an b / i (mural AVF) (choroidal shunt/ DVA AV shunt$ mural intraluminal Mural Choroidal VG Secondary Dural AVM False dural AVM VG AVF VG AVM varix VG AVM of the VG of the VG FG. 4. Aneurysmal malformation of the vein of Galen (VG) classified in relation to the dural sinus obstruction. AV = arteriovenous; AVF = arteriovenous fistula; AVM = arteriovenous malformation; DVA = developmental venous anomaly, so-called "venous angioma." * = Dorsal prosencephalic vein AVM. 14 t = choroidal or parenchymatous shunt (AVF or AVM). FG. 3. Schematic representation of the true aneurysmal malformation of the vein of Galen (VG). Open arrows point to the true choroidal or VG wall arterial feeders. 1: VG wall feeder (circumferential artery); 2: medial choroidal artery; 3: lateral choroidal artery; 4: anterior choroidal artery; 5: posterior pericallosal artery. The asterisks represent areas of arteriovenous shunting in this type of VG aneurysmal malformation. The solid arrows represent accessory feeders, arising from perforating vessels and joining the choroidal fissure via subependymal anastomosis. tial, mesencephalic, anterior choroidal, and meningeal arteries (Fig. 3). 7'9'14 Additional vessels can be seen (subependymal anastomosis) but they are not a dominant feature. The congenital venous impediment responsible for the venous dilatation takes the form of an obstruction distal to the aneurysm (Fig. 4), which might include agenesis of the straight sinus with persistence of embryonic dural sinuses (falcine or occipital) 9'14 or a jugular vein stenosis. This type of abnormality is usually diagnosed at an early age due to the presence of the systemic symptoms. 9 n the case of brain AVM's with dilatation of the vein of Galen, the AVM is choroidal or parenchymatous (supra- or infratentorial) in position. The venous ectasia expresses the secondary or acquired occlusion of the venous outlet (for example, by thrombosis or plicature). n this variety, the vein of Galen confluence exists as such, and reflux into its patent afferent vessels for venous outflow 1'9 can be observed. This group of abnormalities is usually diagnosed at a later age because of neurological manifestations. 2 Both types of anomaly represent a therapeutic challenge, not only because of their deep location and difficult surgical access, but also because of their severe clinical symptomatology, especially in the newborn. Although differentiation of the arterial anatomy has rarely been made in such cases, the clinical data have been described in the literature, l'3,4,6,7,9'l~ Spontaneous thrombosis of the malformations may occur and was present in 10% in our series; 9 however, the natural history of the disease is dismal, with high mortality and morbidity rates. 5"7A 1,16 These AVM's can be treated by surgery, embolization, or a combination of these two methods. 1.9 Radiotherapy has little to offer therapeutically to these patients; however, either combined with 748 J. Neurosurg. / Volume 70/May, 1989

4 Vein of Galen aneurysmal malformation FG. 5. Drawings showing several venous connections in aneurysmal malformations of the vein of Galen (VG). A: Direct mural arteriovenous (AV) fistula; no connection with the usual afferents to the VG. B: Adjacent AV shunt; occluded connection with the usual afferents to the VG. C: Adjacent AV shunt; reflux into the usual afferent to the VG. D: Common VG and normal cerebral venous drainage into the posterior sinuses. E: Common VG and normal cerebral venous drainage into the superior sagittal sinus anteriorly. F: Separate VG and normal brain venous drainage. partial embolization or alone in selected cases, it may produce satisfactory results (L Steiner, personal communication, ). Even with the use of the surgical microscope and improvement in anesthetic and surgical techniques the operative mortality associated with vein of Galen aneurysms is high; 6 a limiting factor is acute heart failure: in cases where surgery becomes complicated with heart failure there is a 91.4% death rate in the newborn and 38% in infants. TM n the past, most surgery consisted of incomplete clipping of some reachable feeding vessels. Embolization offers a therapeutic approach which in an emergency can diminish the arteriovenous shunt and stabilize cardiac function. A delay with medical treatment may then be proposed before a more radical treatment is undertaken, regardless of its type. ~5 From our experience with 25 vein of Galen malformations (20 in the pediatric population), embolization is a better primary treatment modality than surgery. ~5 The successive occlusion of all vessels feeding the fistula or nidus favors the thrombosis of the AVM. Proper angioarchitectural analysis of both arteries (Table 1) and venous connec- tions (Fig. 5) is the clue to proper therapeutic management of these lesions. 1'9'~5 The best indication of this endovascular therapy is represented by the direct arteriovenous fistulas in the wall of the vein of Galen or in the adjacent choroid fissure. Results in our group have been satisfactory with a low morbidity rate. 15 The present case illustrates in a unique fashion the effectiveness of endovascular treatment. Research to improve endovascular procedures in children has offered the possibility to catheterize from the femoral puncture site with or without balloon catheter systems through a No. 4 French sheath? n this particular case, we did not use a balloon system but applied direct catherization from a femoral approach with a mini-torquer. Arterial embolization should be considered in each of these cases. A venous approach (by femoral vein or transtorcular coil deposit 13) should be reserved for true aneurysmal malformations of the vein of Galen (Fig. 3). That approach is contraindicated in the other groups 9 (Table 1). Only 15% of our patients were managed by a venous approach. ~5 J. Neurosurg. / Volume 70/May,

5 P. Lasjaunias, et al. References 1. Berenstein A, Lasjaunias P: Surgical Neuroangiography, Vol V. Endovascular Treatment of Brain, Spine and Spinal Cord Lesions. Heidelberg: Springer-Verlag (n press, 1989) 2. Clarisse J, Dobbelaere P, Rey C, et al: Aneurysms of the great vein of Galen. Radiological-anatomical study of 22 cases. J Neuroradiol 5:91-102, Diebler C, Dulac O, Renier D, et al: Aneurysms of the vein of Galen in infants aged 2 to 15 months. Diagnosis and natural evolution. Neuroradiology 21: , Gold AP, Ransohoff J, Carter S: Vein of Galen malformation. Acta Neurol Scand 40 (Suppl 11):5-31, Grossman R, Bruce DA, Zimmerman RA, et al: Vascular steal associated with vein of Galen aneurysm. Nenroradiology 26: , Hoffmann H J, Chuang S, Hendrick EB, et al: Aneurysms of the vein of Galen. Experience at the Hospital for Sick Children, Toronto. J Neurosurg 57: , Johnston H, Whittle R, Besser M, et al: Vein of Galen malformations: diagnosis and management. Neurosurgery 20: , 8. Lasjaunias P, Terbrugge K, Chiu M: Coaxial ballooncatheter device for treatment of neonates and infants. Radiology 159: , Lasjaunias P, Terbrugge K, Piske R, et al: Dilatation de la veine de Galien. Formes anatomo-cliniques et traitement endovasculaire fi propos de 14 cas explor6s et/ou trait6s entre 1983 et Nenrochirugie 33: , 10. Litvak J, Yahr MD, Ransohoff J: Aneurysms of the great vein of Galen and midline cerebral arteriovenous anomalies. J Neurosnrg 17: , Maheut J, Santini JJ, Barthez MA, et al: Anrvrysme de l'ampoule de Galien. Rrsultats thrrapeutiques de l'rtude multicentrique nationale. Neurochirurgie 33: , 12. Maheut J, Santini J J, Barthez MA, et al: Symptomatologie clinique de l'anrvrysme de l'ampoule de Galien. Rrsultats d'une enqurte nationale. Neurochirurgie 33: , 13. Mickle JP, Quisling RG: The transtorcular embolization of vein of Galen aneurysms. J Neurosurg 64: , Raybaud CA, Hald JK, Strother CM, et al: Les anrvrysmes de la veine de Galien. Etude angiographique et consid6rations morphog6n6tiques. Neurochirugie 33: , 15. Rodesch G, Lasjaunias P, Terburgge K, et al: Lesions vasculaires art6rio-veineuses intra-cr~niennes de l'enfant. Place des technique endovasculaires & propos de 44 cas. Neurochirurgie 34: , Ya~argil MG: Microneurosurgery, Volume b. AVM of the Brain, Clinical Considerations, General and Specific Operative Techniques, Surgical Results, Nonoperated Cases, Cavernous and Venous Angiomas, Neuroanesthesia. Stuttgart: Georg Thieme, 1988, pp Manuscript received June 30, Accepted in final form January 9, Address reprint requests to: Pierre Lasjaunias, M.D., Ph.D., Unit6 de Neuroradiologie Vasculaire, Hrpital de Bic~tre, Universit6 Paris X, 78 rue du Grnrral Leclerc, Le Kremlin Bic6tre, France. 750 J. Neurosurg. / Volume 70~May, 1989