BACKGROUND Considering that multiple aneurysms carry a high risk for fatal rupture, there is a need for complete treatment of all lesions in one surgical session using either unilateral-contralateral or bilateral approaches. Contralateral approaches have been used mainly for small anteriorly projecting middle cerebral and medially expanding ophthalmic types of aneurysms. They are limited by the narrow space for surgical manipulation, forced elevation of frontal lobes, and stretching of the olfactory nerves. These problems might result in damage to structures along the unusually long intracranial way of the approach. The complications associated with the unnecessarily large conventional fronto-temporal and bifrontal craniotomies, and the developments in visualization, neuroanaesthesia, microneurosurgery, cerebrospinal fluid (CSF) drainage, and brain protection have led to less invasive methods in cerebral base surgery. These achievements have supplied the background for the supraorbital keyhole approach to aneurysms of the anterior circulation or basilar tip. Because the supraorbital keyhole approach offers several advantages over the classic fronto-temporal craniotomies to the anterior skull base, it was extended for both sides in one surgical session to treat bilateral multiple aneurysms as well. METHODS Out of a series of 150 patients harboring 188 saccular aneurysms operated on via a supraorbital keyhole approach with a superciliar skin incision, 36 had multiple aneurysms. Thirty patients with multiple aneurysms underwent surgery for their ruptured aneurysms (17 cases in the acute phase and 13 patients during the chronic stage); in 6 cases silent aneurysms were operated on. The multiple aneurysms were managed from one side in 18 cases. A bilateral supraorbital keyhole approach was performed during one surgical session in 11 patients, and in 7 cases the unilateral supraorbital keyhole approach was combined with contralateral fronto-temporal (3 cases), suboccipital (2 cases), or frontal-parasagittal (2 cases) exploration. The operations were carried out through an approximately 2.5 × 3 cm supraorbital keyhole craniotomy following a skin incision just above the eyebrow. The roughly 4 cm superciliar skin incision begins medial to the supraorbital nerve and ends 3 to 10 mm beyond the lateral edge of the eyebrow. The technical details of the method are presented, and the benefits, limitations, and complications are discussed. RESULTS In the 36 patients operated on via the supraorbital keyhole approach 74 aneurysms were clipped successfully. In 2 cases premature intraoperative rupture of the aneurysms occurred, but these events were managed successfully. Despite the small size of the craniotomy the approach allows enough room for intracranial manipulation with maximal protection of the brain and other intracranial structures. One patient died because of pulmonary embolism. There were no craniotomy-related complications in the present series. CONCLUSION The supraorbital keyhole approach together with the advent of the modern neuroanaesthesia, CSF drainage, and microsurgical techniques is a safe approach in the hands of experienced neurosurgeons for the treatment of supratentorial or basilar tip aneurysms. Because the approach is simple and swift, the bilateral single-session craniotomy does not have any disadvantages compared to two-stage procedures. However, the one-sitting surgery reduces the high risk of fatal rupture in the perioperative period associated with multiple aneurysms.
