PMC7398198_01
Preoperative angiography. a Left vertebral artery angiography (VAG). The left PICA is agenesis (frontal view). b Right VAG (frontal view) The tentorial sinus is shown as the drainage route (arrow). The right PICA perfuses bilateral inferior cerebellar hemispheres. c Three-dimensional rotational angiography (3D-RA, lateral view) shows the distal posterior inferior cerebellar artery aneurysm(DPICAAn) located at the telovelotonsillar segment of the right PICA with a bleb (large arrow), with neck 3.7 mm and the maximum diameter 7.3 mm; in addition, the AVM feeders are from the left SCA and the right PICA (small arrows). The nidus of AVM is about 18 mm
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Fig1
While the left PICA was agenesis, the right PICA perfused the bilateral inferior cerebellar hemisphere (Fig. 1a, b). The lesion in the left upper cerebellar hemisphere was a nidus of the cerebellar AVM fed by the right PICA and the left superior cerebellar artery (SCA), draining to the transverse sinus through the tentorial sinus (Fig. 1a-c).
Reconstructed three-dimensional computed tomography angiography and venography. a, b Three-dimensional reconstructed images, showing the vertebral artery and PICA (red), distal posterior inferior cerebellar artery aneurysm(DPICAAn) (arrow), one feeder from the right PICA of the AVM (yellow), and nidus-drainers-transverse sinus (blue)
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Fig2
Reconstructed three-dimensional computed tomography angiography and venography (CTAV) revealed that the nidus was located medially on the tentorial surface of the cerebellum, and the DPICAAn was located beneath the left biventral lobule near the fourth ventricle (Fig. 2a, b).
Intraoperative and postoperative images. a The nidus and dilated drainers in the left upper cerebellar hemisphere are shown (arrow). b The distal posterior inferior cerebellar artery aneurysm(DPICAAn) is shown (large arrow). The proximal part of the right PICA is also indicated (small arrow). c The operative view after neck clipping of the DPICAAn (arrow). d The postoperative digital subtraction angiography shows the disappearance of the aneurysm and the cerebellar AVM
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Fig3
Next, the nidus was removed after the drainers of the tentorial sinus were cut (Fig. 3a). In addition, the DPICAAn was exposed (Fig. 3b). We successfully performed neck clipping of the DPICAAn with 2 clips (Fig. 3c). AVM (Fig. 3d). After 18 days of the operation, the patient was discharged from the hospital.