case_images: PMC6357536_01
case_images: (a-c) CT showed a hematoma at the pons and midbrain with intraventricular hemorrhage and acute hydrocephalus. (d) 3D-CTA showed a large and multiple venous ectasia. (e) The shunting point was at the right cerebellar tent near the petrosal bone (black arrow)
case_images: SNI-10-2-g001.jpg
case_images: PMC6357536_01_SNI-10-2-g001.jpg
case_images: F1
case_images: Computed tomography (CT) revealed a very large high-density mass lesion on the pons, midbrain, and cerebellopontine (CP) angle with subarachnoid and intraventricular hemorrhage and acute hydrocephalus [Figure 1a-c]. Three-dimensional CT angiography (3D-CTA) revealed large and multiple venous pouches invaginating the brainstem [Figure 1d]. TDAVF, Borden type III and Cognard type IV. The shunting point was located at the right cerebellar tent near the petrosal bone [Figure 1e].
case_images: (a) Lateral view on a right external carotid angiogram. The MMA (arrow) and Max. A (arrowhead) are feeding the TDAVF. (b) Anteroposterior view on a right vertebral angiogram. The SCA (arrow) and AICA (arrowhead) are feeding the TDAVF. Lateral view on carotid angiogram (c: right, d: left) showing dilated tentorial arteries (arrows). (e) Simplified scheme relationship among feeing arteries (red), draining veins (blue) and shunting point (asterisk). (f) 3D-CTA after endovascular treatment. The venous pouches of the midbrain became smaller (asterisk). The venous pouch of the CP angle did not change (arrowhead)
case_images: SNI-10-2-g002.jpg
case_images: PMC6357536_01_SNI-10-2-g002.jpg
case_images: F2
case_images: A), and ascending pharyngeal artery [Figure 2a]. A right vertebral angiogram also showed multiple feeders, including the right superior cerebellar artery (SCA), right anterior inferior cerebellar artery (AICA), and right posterior inferior cerebellar artery [Figure 2b]. A bilateral internal carotid artery angiogram revealed tentorial arteries from the meningohypophyseal trunk [Figure 2c and d], and large and multiple venous pouches invaginating the midbrain, pons, and right CP angle. The simplified schema was showed in Figure 2e in order to comprehend the relationship among feeding arteries, draining veins, and the shunting point on dura matter of cerebellar tent. The venous pouches of the midbrain became smaller after embolization, but the size of the pouches in the operative route of the CP angle did not change [Figure 2f].
case_images: Intraoperative photographs show a venous pouch in the operative route (arrow) and coagulation of the cerebellar tent (arrowheads). (b) The shunting point (asterisk) was in the rostral portion of the trigeminal nerve (v). (c) After clipping of the draining vein
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case_images: PMC6357536_01_SNI-10-2-g003.jpg
case_images: F3
case_images: TAE used for other meningeal arteries, were coagulated to shrink the size and pressure of venous pouches to the maximal extent before reaching the shunting point. This maneuver was able to reduce the pressure of the venous pouch and then resulted to visible the shunting point, which was just rostral to a portion of the trigeminal nerve [Figure 3b]. An interruption procedure was performed, and successful obliteration of the shunting point was achieved [Figure 3c].
case_images: Lateral view on a right common carotid angiogram (a), anteroposterior view on a right vertebral angiogram (b), and lateral view on a left common carotid angiogram (c) showing no vascular abnormalities. (d) Postoperative 3D-CTA was also showing no vascular abnormalities
case_images: SNI-10-2-g004.jpg
case_images: PMC6357536_01_SNI-10-2-g004.jpg
case_images: F4
case_images: Postoperative 3D-CTA and cerebral angiograms showed no abnormal vasculature [Figure 4].