The Role of Scalp Flap Retraction during Cerebral Aneurysm Surgery as a Potential Cause of Visual Deficits

ABSTRACT

OBJECTIVE: We recently reported six patients with unilateral visual loss that developed immediately after cerebral aneurysm surgery. This was found to be due to retinal ischemia. PATIENTS AND METHODS: To investigate whether or not this rare occurrence results from focal compression on the ipsilateral globe due to a scalp flap retraction, the authors checked changes of orbital pressure indirectly before and after the flap retraction in seven consecutive aneurysm patients and repeated the measurement in six other patients protected with an eye shield. In addition we have used an eye protector during aneurysm surgery over a next three-year period to determine whether or not an eye shield can prevent this problem. RESULTS: The authors confirmed elevation of indirect intraorbital pressure whenever the flap was retracted, but there was no pressure elevation in the study using an eye shield. In parallel we have not experienced any visual complications since this maneuver. CONCLUSIONS: We think that inadvertent pressure placed on the eyeball with a retracted scalp flap might provoke intraocular and/or retinal ischemia resulting in visual failure after intracranial aneurysm surgery in patients with any conditions that induce marginally ischemic retina.