Abstract
Purpose
To describe acute and chronic retinal ischemic changes following an internal carotid artery pseudoaneurysm stenting procedure, and to review current evidence for risk factors and management of post-procedural retinal ischemic events.
Observation
A 50-year-old man presented with a 3-month history of pulsatile tinnitus, headache, and intermittent blurry vision. A CT angiogram of head and neck showed bilateral cervicopetrous internal carotid artery (ICA) pseudoaneurysms. The patient underwent successful repair with angioplasty and stenting of the flow-limiting high-grade (>95%) stenosis of his left high cervical ICA. On post-operative day 1, the patient reported monocular vision loss with a large central scotoma. He was found to have a central macular area of retinal whitening and multiple areas of perivascular retinal whitening on exam, concerning for retinal artery occlusions secondary to peri-procedural emboli. Dual antiplatelet therapy was started and a stroke evaluation was performed. Two months later, his visual acuity in the affected eye was counting fingers and his left eye fundus examination was notable for multiple areas of scattered hemorrhages, microaneurysms, and retinal exudates in the distribution of prior retinal ischemia. OCT imaging revealed atrophic changes in the left macula. Subsequently, the patient completed stage-2 repair of the left ICA pseudoaneurysm followed by uncomplicated repair of the right ICA. Four months later, his left eye visual acuity and retinal findings remained stable.
Conclusions and Importance
Post-procedure retinal emboli and ischemia are important, vision threatening possible ocular complications for patients undergoing carotid vascular and endovascular procedures.
1
Introduction
Internal carotid artery (ICA) pseudoaneurysms are rare, but can result from carotid dissections secondary to blunt or penetrating trauma, infection, or underlying conditions like fibromuscular dysplasia or connective tissue disease. , A pseudoaneurysm is defined by the loss of integrity of all three layers of the arterial wall (intima, media, adventitia), in contrast to a true aneurysm, in which the arterial wall is intact but expanded. Pseudoaneurysm formation has been reported in approximately 10–40% of cases with carotid artery dissection. , These lesions can cause mass effect on adjacent structures, or potentially result in distal thromboembolism. , Endovascular treatment is the most common technique for management of these lesions, with the goal of providing symptomatic relief and minimizing the risks of stroke and hemorrhage. However, cerebral or retinal emboli can result as a potential complication of this intervention, leading to stroke or vision loss. We present a case of retinal emboli and ischemia following internal carotid artery pseudoaneurysm stenting.
2
Case report
A 50-year-old man with a history of bipolar disorder, hypertension, and polysubstance use presented with a 3-month history of bilateral pulsatile tinnitus, headache, and intermittent blurry vision. He was found to have bilateral cervicopetrous ICA pseudoaneurysms on CT angiogram imaging of the brain and neck; given their location, these lesions were attributed to prior trauma. Intermittent blurry vision was thought to be most consistent with intermittent emboli arising from the pseudoaneurysms or associated stenoses. The decision was made to perform staged stent-assisted coiling of the left and then the right ICA in order to prevent further embolic phenomena.
The patient underwent successful repair with angioplasty and stenting of the flow-limiting high-grade (>95%) stenosis of his left high cervical ICA ( Fig. 1 A) under general anesthesia. Intra-operative angiography demonstrated delayed outflow into the left petrous, cavernous, and supraclinoid internal carotid artery as well as the middle cerebral artery prior to stenting. The left ophthalmic artery was also noted to be small in caliber. The patient was heparinized during the procedure (with therapeutic elevation of activated clotting time from 108 seconds at baseline to 261 seconds following IV heparin) and was already on aspirin and clopidogrel in preparation for intervention. Use of a mechanical distal embolic protection device was not possible due to the skull base location of the stenosis. Following stenting, angiography demonstrated improved intracranial blood flow and no intracranial arterial branch occlusions ( Fig. 1 B). Trans -stent coiling was deferred until a later date in order to allow the Enterprise stent (Johnson & Johnson) to endothelialize in place and reduce the chance of stent displacement by the coiling catheter.
On post-operative day 1, the patient had a generalized tonic-clonic seizure in the ICU and also reported monocular central vision loss in the left eye, which, in retrospect, he had noted since the night before. On bedside examination with a near card, the patient’s visual acuity was 20/30 in the right eye (OD) and 20/30 in the left eye (OS) with eccentric fixation. Without eccentric fixation, the left eye was counting fingers at approximately 7 feet. Intraocular pressures were within normal limits, and there was no relative afferent pupillary defect in either eye (the left pupil was fixed and asymmetric with posterior synechiae, which were presumably pre-existing and unrelated). Confrontational visual fields were full OD, but there was a central scotoma OS. Ocular motility was normal, and the anterior segment exam with portable slit lamp was otherwise unremarkable. Dilated fundus exam was normal in the right eye. The left posterior segment was notable for a large central macular area of retinal whitening and multiple scattered areas of perivascular retinal whitening along the superior and inferior arcades (particularly at terminal branches) ( Fig. 2 ). There were no obvious intra-vascular emboli. These findings were concerning for likely multiple branch retinal artery occlusions or a cilioretinal artery occlusion from peri-procedural emboli, which may have occurred during or shortly after angioplasty and stenting of the high-grade stenosis just distal to the pseudoaneurysm. The patient underwent aspirin (ARU) and platelet reactivity (PRU P2Y12) testing, with values of 552 and 10, respectively, indicating therapeutic effect of both aspirin and clopidogrel. A CT angiogram of the brain and neck was obtained, which was negative for acute infarct or intracranial hemorrhage. The patient was discharged on dual antiplatelet therapy.
