Unique trajectory of transorbital penetration injury determined by the orbital bone anatomy resulting in the minimum neurological deficit: A case report

•We report a case of a man with penetrating head injury with minimum complications.•The medial side of the right infraorbital region was pierced by a gardening pole.•Imaging revealed hematoma along the preexisting gardening pole trajectory.•Eventually, we performed occipital artery-posterior cerebral artery bypass surgery and endovascular parent artery occlusion. Transorbital penetration injury may lead to severe neurological symptoms due to damage of critical neurovascular structures around penetration paths. We report a rare transorbital penetration injury case where the trajectory of the penetrating object reached the medial aspect of the occipital lobe without penetrating the brain parenchyma. A 52-year-old man, had the medial side of his right infraorbital region pierced by a gardening pole. The patient was brought to the hospital after pulling out the pole. Imaging studies revealed hematoma along the preexisting gardening pole trajectory. The right posterior cerebral artery (PCA) and penetrating object were in contact with the PCA P3 segment. On day 17 of admission, magnetic resonance imaging of the head showed aneurysm formation in the right PCA at the site of contact with the penetration pole; hence, the patient underwent occipital artery-PCA bypass surgery following endovascular parent artery occlusion. Postoperatively, the patient developed left superior homonymous quadrantanopia, which resolved spontaneously within 6 months. This case highlights the importance of understanding neuroanatomical structures surrounding the penetrating object.