Backgrounds Vein of Galen aneurysmal malformation (VGAM) is a rare congenital vascular malformation representing <1% of all arteriovenous malformations. In the newborn period treatment is done for untreatable CHF. There have been reports of transvenous coil embolization either trans-tuorqualar, or tran-femoral, although effective in controlling the high output failure, the results are less than optimal, and has lost popularity. The combined transarterial and transvenous ‘trapping’ of the fistula, is challenging and few reports as to seafty and curative are available. We have used the transumbilical arterial approach in newborns with good results. The concept of devascularization in a staged fashion over a period of time, has permit us to get a total or near total obliteration in 80% of cases. There is however a group of patients in whom the residual arterial supplies is through small perforators and in whom transvenous embolization (TVE) is technichally the easiest for cure. We assessed outcomes of our vein of Galen malformation cases treated with TVE.

Materials and Methods We retrospectively reviewed 141 consecutive patients with VGAM treated in our institute between 2004 and 2019. Thalamic AVMs were excluded. 9 patient underwent TVE.

Results Among 9 TVE, 1 underwent partial TVE for palliative measures and excluded from this analysis. The other 8 underwent TVE. All of them had undergone more than 3 transarterial nBCA embolizations. 4 out of 8 patients had complete obliteration of the VOGM. 2 patients underwent stereotactic radiosurgery for the residual fistula and complete obliteration was confirmed (prior to 2000). The outcome 6 out of 8 patient head total obliteration, and achieved normal development without neurological deficit. On the other hand, two hemorrhagic complications occured, 1 imediatelly after the procedure (2013), and the 2nd within 2 days after TVE (2018), where there was a small residual. Of them, the 1st expired and the 2nd had significant neurological impairment. Both had coils embolization. 2 patients with coils embolization were cured. This difficulty in predicting the risk of hemorrhage, prompted us to improve our ability to close the shunt, and the small remaining arterial supply by using the Chapot ‘Pressure cooker’ (CHPC) technique in 2 with compleat obliteration.

Discussion There has not been any report before, about the TVE to cure the VGAM after multiple sessions of TAE. In this study, two issues can be brought up. One, there is a chance to close the fistula compleatelly or incompletely only using coils. In addition there is the concern of imparing drenage of the normal brain. To improve these two issues, complete closure of the fistula using the CHPC technique with liquid embolic material in TVE, which we performed recently with great success, seems to be a solution.

Conclusion In endovascular treatment of the vein of Galen malformation, TVE is feasible option, once the dilated vein of Galen becomes small enough. To prevent incomplete occlusion or post procedural hemorrhagic complication, the use of the Chapot ‘Pressure cooker’ technique using liquid embolic material is considered to be necessary.

Disclosures T. Shigematsu: None. A. Berenstein: None.