A pterion keyhole approach for the treatment of anterior circulation aneurysms

The supraorbital keyhole approach is most frequently used in treatment for lesions within the anterior cranial base. However, it has some drawbacks, including cosmetically poor appearance of the scar, forehead deformity, and difficulty in dealing with some kinds of middle cerebral artery (MCA) and internal carotid artery (ICA) aneurysms. Therefore, we have developed a small pterion keyhole approach for an alternative access to treat anterior circulation aneurysms. An oblique skin incision about 3-5 cm in length was made just from 1.0 cm anterior to the superficial temporal artery at the level of the zygomatic arch, curved just below the temporal line to the forehead, and stopped at the hairline over the sylvian fissure. Then a small craniotomy (2-3 cm) was made just over the sylvian fissure and the aneurysms were exposed through the lateral cerebral fissure. We used this approach to treat 40 patients with aneurysms located in posterior communicating arteries (n=14), the MCA (n=10), the anterior communicating arteries (n=9), the anterior cerebral artery (n=1), the ophthalmic arteries (n=3), and the ICA (n=3). The general outcome of all patients was good without serious complications from the surgical technique even though 3 cases underwent intraoperative premature rupture of the aneurysms. No approach-related complication occurred except that one patient had vasospasm 2 days after the aneurysm clipping. In conclusion, this pterion keyhole approach can achieve the best operative effect for the treatment of intracranial anterior circulation aneurysms in a selective group of patients with several advantages over traditional craniotomy including minor tissue damage, less brain retraction, a superior cosmetic result, and shorter duration of surgery. Moreover, the operative field becomes wider in the deep area, providing sufficient space for microscope-assisted surgery without the need for highly specialized instruments.