case_images: PMC10629327_01
case_images: (a) Admission computerized tomography (CT) scan showing subarachnoid hemorrhage involving the prepontine and cerebellopontine cisterns; (b) From the left: CT-angiography coronal view showing a right pontine artery aneurysm (red arrow); magnetic resonance angiography confirming the known aneurysm (red arrow) and a cerebellopontine angle cistern arterial venous malformation (white arrow) (c) admission (left) and 3 weeks (right) digital subtraction angiography demonstrating aneurysm growth from 4.5 mm to 6.5 mm.
case_images: SNI-14-352-g001.jpg
case_images: PMC10629327_01_SNI-14-352-g001.jpg
case_images: F1
case_images: DSAs [Figure 1]. Due to the sharp angle origin of the parent artery from the basilar trunk and a documented vasospasm, two attempts at endovascular treatments were unsuccessful.
case_images: (a) To the left early mid-facial degloving with piezosurgery, in the middle drilling of the clivus (c), and to the right position check under neuronavigation; (b) aneurysm (A) exposure. The brainstem (B) is visualized beyond the aneurysm dome, final clip position, and (right) closure; (c) computerized tomography bone window demonstrates a tailored bone removal and position of the clip (white arrow). Reduced inflow to the distal AVM nidus is still visible (red arrow). Anterior-posterior angiographic view shows clipping of the aneurysm, which appears completely excluded, as the course of the pontine artery itself due to vessel stenosis. To the right final cosmetic result.
case_images: SNI-14-352-g002.jpg
case_images: PMC10629327_01_SNI-14-352-g002.jpg
case_images: F2
case_images: Reduced inflow to the distal AVM nidus was still visible, due to retrograde supply from an ipsilateral superior cerebellar artery (SCA) and anterior inferior cerebellar artery (AICA) [Figure 2].
case_images: PMC10629327_02
case_images: (a) Computerized tomography (CT) and axial magnetic resonance imaging showing basal cisterns subarachnoid hemorrhage (white arrow); (b) from the left: CT-angiography and magnetic resonance angiography (axial view). Aneurysm (black arrow) and arterial venous malformation (AVM) (white arrow); (c) Digital subtraction angiography (anterior-posterior view) outlines the specific characteristics of the vascular malformation; small right cerebellopontine angle cistern AVM (red arrow) with proximal aneurysm (white arrow) whose origin was from a dilated pontine artery. Other minor feeders to the AVM seem to arise from the ipsilateral superior cerebellar artery and anterior inferior cerebellar artery.
case_images: SNI-14-352-g003.jpg
case_images: PMC10629327_02_SNI-14-352-g003.jpg
case_images: F3
case_images: [Figure 3].
case_images: (a) Exposure of the Kawase quadrangle and anterior petrosectomy performed by the use of the piezoelectric osteotome and drilling. On the right, endoscopic close-up view of the arterial venous malformation (AVM) (white arrow); (b) AVM coagulation under microscope and, on the right, final endoscopic assessment of complete AVM exclusion (white arrow); (c) postoperative studies. A baseline computerized tomography scan shows the right anterior petrosectomy. Digital subtraction angiography (anterior-posterior view) performed after 7 days showed complete AVM removal and dimensional reduction of the proximal pontine artery aneurysm. To the right 6-months, magnetic resonance angiography detected no residual vascular anomalies.
case_images: SNI-14-352-g004.jpg
case_images: PMC10629327_02_SNI-14-352-g004.jpg
case_images: F4
case_images: Six months later, the aneurysm itself was no longer visible [Figure 4].