Delayed Visual Loss and Its Surgical Rescue Following Extracranial-Intracranial Arterial Bypass and Native Internal Carotid Artery Sacrifice.
BACKGROUND
High-flow extracranial-intracranial (EC-IC) bypass followed by sacrifice of the native internal carotid artery (ICA) is a recognized treatment option for giant ICA aneurysm and skull base tumor involving the ICA. Distal clipping at the supraclinoid portion of the ICA is technically straightforward, but it can potentially compromise ophthalmic artery (OA) perfusion. Because of the extensive EC-IC anastomoses with the OA, visual symptoms are fortunately uncommon. We report a patient who developed complete blindness after distal trapping of the supraclinoid ICA; it was reversed after emergency clip removal.


CASE DESCRIPTION
Our patient is a 47-year-old man with recurrent nasopharyngeal carcinoma in close proximity to the left petrosal ICA. The first stage of the procedure involved an EC-IC bypass using radial artery graft, followed by a second stage with combined craniofacial excision. Trapping of the native ICA was achieved using a permanent aneurysm clip placed at the supraclinoid ICA distal to the origin of the OA. He complained of a new onset of complete left eye visual loss approximately 6 hours after the distal aneurysm clip was applied. He was immediately sent to the operating theatre for the removal of the supraclinoid aneurysm clip. On the next day, his vision improved and left pupil became reactive again.


DISCUSSION
OA flow following ICA trapping is complicated and precarious. Delayed onset of visual loss is possible. Prompt action by direct exploration and clip removal is needed and can be effective in reversing blindness.
['Li|Lai-Fung|LF|', 'Leung|Gilberto Ka-Kit|GK|', 'Lui|Wai-Man|WM|']
D015901:Angiography, Digital Subtraction D002277:Carcinoma D002343:Carotid Artery, Internal D002548:Cerebral Revascularization D006801:Humans D021621:Imaging, Three-Dimensional D018810:Magnetic Resonance Angiography D008279:Magnetic Resonance Imaging D008297:Male D008875:Middle Aged D009303:Nasopharyngeal Neoplasms D009880:Ophthalmic Artery D011183:Postoperative Complications D014786:Vision Disorders
Blindness Cerebral revascularization Ischemic Optic neuropathy