A Rare Neurologic Complication of Coronary Artery Bypass Graft Surgery: Occipital Infarction with Binocular Amaurosis Fugax

Abstract

Herein, we report a major but transient neurologic complication occurring early after coronary artery bypass grafting with cardiopulmonary bypass. In June 2010, a 63-year-old male patient with a history of unstable angina pectoris and severe coronary stenosis was admitted for surgery. He also had a past medical history of hypertension, hyperlipidemia and smoking for 38 years. Preoperative neurological examination was normal with no visual disturbance or orbital motor dysfunction. Physical examination of other organ systems were also normal. During the early postoperative hours, the patient was clinically stable. Direct and consensual light reflexes were normal bilaterally. Following extubation, bilateral total loss of vision developed. Computed tomography of the brain at postoperative day 1 revealed a cerebral infarction with surrounding tissue edema in the occipital lobes. Following the anti-edematous treatment, a gradual improvement of vision occurred in both eyes. Despite the dramatic improvement in visual functions, a computed tomography of the brain at postoperative day 12 showed the persistence of initial radiological findings, suggesting amaurosis fugax, which is generally defined as a transient monocular visual loss and blindness. Binocular amaurosis fugax associated with bilateral total blindness due to postoperative ischemic optic neuropathy has also been described, with an incidence of less than 0.5%. Some other studies have reported a prevalence rate of 1.3-2% among patients undergoing open-heart surgery. In any case, bilateral amaurosis fugax developing as a transient postoperative neurological complication after coronary artery bypass grafting represents a rare condition. Radiological imaging studies may sometimes fail to detect the condition and complete restoration of visual functions may be achieved by appropriate anti-edema therapy.