A Method to Expose Paraclinoid Internal Carotid Artery Aneurysms with Minimal Risk.

We describe a useful method to avoid injury to an optic nerve and an internal carotid artery during intradural bone resection in the paraclinoid region. A semicircular dural flap is turned with 2 threads over the anterior clinoid process. The flap is extended over the underlying structures with tapered spatulas to create a space for drilling the bone. The site for drilling was adequately exposed, and bone was drilled away smoothly without damaging the underlying artery and optic nerve in 18 patients with paraclinoid aneurysms. Advantages of this “protective dural flap” method include wide exposure for drilling, protection of the underlying structures from the drill head and suction tubes, and availability of their intermittent inspection during bone resection.