PMC7193207_01
Non-contrasted head computed tomography obtained on admission. (a-c) Bone window shows the trajectory of the missile entering the right inferior temporal bone, right middle cranial fossa, the right orbit, through the sinonasal cavity, the left maxillary sinus, and exiting through the left orbit. (d-f) Brain window shows the contusion with the associated extra-axial and subarachnoid hemorrhage in the right temporal tip.
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F1
The Sylvian fissures were not involved in the ballistic trajectory [Figure 1].
(a) Computed tomography angiogram (CTA) of the head, obtained on hospital day 1, did not show a vascular abnormality. Specifically, no abnormality is seen at the right middle cerebral artery (MCA) bifurcation. (b) Follow-up CTA of the head, obtained on hospital day 5, demonstrates the interval development of a traumatic aneurysm at the right MCA bifurcation. (c) Diagnostic cerebral angiogram (DCA) performed on hospital day 6 demonstrates previously identified 4 x 3 mm right middle cerebral artery bifurcation aneurysm. DCA also identified a 2 mm right internal carotid artery (ICA) terminus aneurysm as well as severe vasospasm of the right distal ICA and right MCA which were not previously appreciated on the CTA from January 1, 2019.
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F2
A subsequent diagnostic cerebral angiogram (DCA) confirmed the presence of a 4 x 3 mm right MCA bifurcation aneurysm, and also identified a 2 mm right internal carotid artery (ICA) terminus aneurysm, as well as severe vasospasm of the proximal ICA and MCA vessels [Figure 2].
(a) Complete dissection of the (arrow) pseudoaneurysm seen at the right middle cerebral artery bifurcation with distal and proximal control. (b) Removal of the pseudoaneurysm and identification of the (arrow) tear on the vessel wall. (c) Placement of a clip on the tear in the vessel wall.
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F3
Direct clipping of the lacerations in the vessels was successful, although bypass was prepared for, depending on the intraoperative findings [Figure 3].
(a) Placement of Charbel Micro-Flowprobe  (Transonic) on the right A1 segment of the anterior cerebral artery. Placement of the two clips on the previously described traumatic intracranial aneurysms at the right internal carotid artery terminus and the middle cerebral artery bifurcation can be seen. (b) Cerebral blood flow measurements pre and post intervention with papaverine and soft tissue dissection are listed. *The negative value depicted for the right A1 preintervention measurements indicates reverse flow.
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F4
The measurements demonstrated improvement in flow after the therapeutic maneuvers [Figure 4].