Apollo microcatheter-assisted transvenous embolization for brain arteriovenous malformation with a tortuous stenotic drainage vein and "Caput Medusa" sign: a case report.

INTRODUCTION AND

IMPORTANCE

Transvenous embolization (TVE) for brain arteriovenous malformations (AVMs) typically requires two microcatheters or a dual-lumen mini-balloon catheter in the draining vein. A single Apollo microcatheter can replace these devices, offering a novel TVE alternative for AVMs with the "Caput Medusa" sign. This case report describes the technique, as such reports remain limited.

CASE PRESENTATION: A 34-year-old male patient suffered intracranial hemorrhage and developed right-sided hemiplegia and aphasia. Angiography revealed a left corpus callosum AVM supplied by the left anterior cerebral artery and lenticulostriate artery, with drainage into a thick vein exhibiting the "Caput Medusa" sign. After navigating the tortuous, stenotic distal draining vein using an Apollo microcatheter, TVE was performed through the following sequential steps: coiling of the left distal anterior cerebral artery, temporary occlusion of the left internal carotid artery, maintenance of blood pressure below 100 mm Hg, and injection of Onyx-18 via the Apollo microcatheter to achieve complete AVM obliteration. Postoperatively, no new neurological deficits were observed. On postoperative day 40 follow-up, he could walk with right muscle strength grade 4 and had normal speech function.

CLINICAL DISCUSSION: The "Caput Medusa" sign of the AVM is produced by the convergence of multiple shunts into a thick proximal draining vein, making the draining vein system clearly visible. The Apollo microcatheter is soft and can navigate through the tortuous and stenotic drainage vein.

CONCLUSION

The "Caput Medusa" sign of the AVM facilitates TVE visualization. TVE may be feasible in selected AVMs when a single Apollo microcatheter is used.