Perioperative visual loss (POVL) is a well-documented yet uncommon complication of nonocular surgery. Patients undergoing cardiac and spinal surgery are at the greatest risk, though POVL may occur during other neurosurgical and vascular procedures as well. The most common causes of POVL are central retinal artery occlusion (CRAO) and ischemic optic neuropathy (ION),1-3 though cases of orbital compartment syndrome (OCS) have also been reported.4-7
We describe a case of POVL during a temporal meningioma excision using the pterional approach. Though the etiology is not fully understood, the patient’s clinical course was complicated by a third cranial nerve (CN III) palsy and CRAO, which, together with the patient’s presentation, were consistent with previously documented cases of OCS. The goals of this case report are to increase awareness of this surgical outcome, identify practices that may have contributed to its development, and delineate methods to minimize its occurrence.
Informed consent regarding this research was obtained from the patient and an institutional Health Insurance Portability and Accountability Act authorization form was completed. This manuscript adheres to the applicable Enhancing the Quality and Transparency of Health Research guideline.8
Case Presentation
A 47-year-old woman underwent a left temporal craniotomy for resection of a sphenoid wing meningioma discovered during a workup for persistent headaches. She had no medical history of diabetes, hypertension, coronary artery disease, or ophthalmic disease. Two months before her scheduled surgery, the patient reported bilateral blurry vision and underwent ophthalmologic evaluation. Her intraocular pressure (IOP) was normal, and she had no pupillary or retinal disease. She showed evidence of decreased vision in her left eye, suggesting a possible mass effect from her meningioma. Subsequent imaging of the optic nerve and retina had unremarkable physiology (Figure 1). Preoperative magnetic resonance imaging (MRI) demonstrated a stable enhancing mass involving the left great sphenoid wing and left cavernous sinus(Figure 2). There was a superior mass effect on the left middle cerebral artery, but all vessels were patent without evidence of thrombosis.
The patient underwent general anesthesia with invasive hemodynamic monitoring used throughout the procedure. She was induced with fentanyl, propofol, and rocuronium; anesthesia was maintained with isoflurane and a remifentanil infusion. Hypotension was treated with phenylephrine and intravenous fluids. Intraoperative neuromonitoring with electroencephalogram (EEG) and somatosensory evoked potentials was performed. During the surgery, the patient was positioned supine in a Mayfield 3-point head fixation system. All pressure points were padded appropriately and continually checked. A standard left pterional craniotomy was performed, and the scalp was reflected anteriorly and secured using fish hooks with rubber bands. The operation did not violate the cavernous sinus or orbital compartment. There was no evidence of active bleeding upon inspection nor with the Valsalva maneuver. No changes were noted in EEG or somatosensory evoked potentials; blood pressure remained within 20 mm Hg of the patient’s baseline. She was extubated at the end of the 10-hour case and was hemodynamically stable upon transport to the surgical intensive care unit. Postoperative imaging confirmed the successful removal of the left sphenoid wing meningioma.
The patient’s postoperative examination demonstrated a 5 mm dilated, nonresponsive left pupil, though the patient did not report visual loss at that time. Defects were noted in the inferior oblique, superior, inferior, and medial rectus muscles, consistent with CN III palsy. The surgery included manipulation of CN III, which made this a possible outcome, but an alternate causative pathology like OCS was not immediately suspected. Postoperative computed tomography (CT) showed an expected pneumocephalus and left scalp swelling without evidence of mass effect or midline shift.