The Combined Pterional/Anterior Temporal Approach for Aneurysms of the Upper Basilar Complex

Abstract

A technique for achieving a combined pterional (subfrontal) and anterior temporal exposure for aneurysms of the upper basilar complex is described. The technique is not new, but it does involve several modifications not previously described. A standard pterional skin incision that extends below the zygoma just anterior to the tragus is used. The skin flap is separated from the temporal fascia down to the fat pad over the zygoma; at this point, the superficial layer of the temporalis fascia is incorporated and retracted with the skin flap to expose the zygomaticofrontal process and the zygomatic arch. The muscle is cut anteriorly and inferiorly and is retracted posteriorly over the ear. The bone flap includes the anterior temporal squama down to the temporal floor anteriorly. The pterion and the sphenoidal wings are drilled so as to expose completely the dura over the anterior temporal pole. After opening the dura on a flap centered on the sylvian fissure, the medial cisterns are opened widely and the fissure is opened all the way to the middle cerebral bifurcation. Posterolateral temporal retraction and, when necessary, subpial resection of the anteromedial portion of the uncus enhance the exposure posterolateral to the oculomotor nerve. The advantages of this combined approach are as follows: it combines the more anterior angle of vision offered by the pterional approach with the lateral line of vision offered by the subtemporal approach; it eliminates the need for temporal lobe elevation and it allows simultaneous clipping of other aneurysms of the ipsilateral anterior circle of Willis; and it also reduces the frequency and severity of oculomotor palsy, when compared with the subtemporal approach.