Orbital Infarction Syndrome Following Mechanical Thrombectomy Secondary to Embolization in New Territory

Background: Orbital infarction syndrome (OIS) is a rare entity defined as ischemia of all intraorbital and intraoccular structures including the optic nerve, extraocular muscles, and orbital fat. This entity is rare due to rich anastomotic orbital vascularization from both the internal carotid artery and external carotid artery. We report a case of a patient who suffered emboli to previously nonaffected territories to the ophthalmic artery and external carotid artery, which resulted in orbital infarction syndrome, and describe techniques to avoid such complications. Case Description: A 66-year-old male presented to our institution with an acute ischemic stroke secondary to occlusion of the internal carotid artery terminus and M1 segment. The vessel was revascularized after 1 pass using a stent retriever. Postoperative angiography demonstrated sluggish flow in the distal right ophthalmic artery, as well as occlusion of the distal external carotid artery. Twenty-four hours following the procedure, the patient was noted to have complete ophthalmoplegia of the right eye, proptosis, and conjunctival chemosis. Computed tomography angiography demonstrated persistent occlusion of the distal right ophthalmic artery and external carotid artery. The right optic nerve was swollen, as were all extraocular muscles. A final diagnosis of orbital infarction syndrome was made given the clinical presentation, imaging findings, and occlusion of all vascular supply to the orbit on both conventional angiography and 24-hour computed tomography angiography. Conclusions: OIS is a rare entity that has not been previously described as a complication of mechanical thrombectomy for acute ischemic stroke. OIS should be considered when patients present with blindness, orbital pain, and total ophthalmoplegia post thrombectomy.