The Supraorbital Keyhole Craniotomy through an Eyebrow Incision: Its Origins and Evolution

In the modern era of neurosurgery, the use of the operative microscope, rigid rod-lens endoscope, and neuronavigation has helped to overcome some of the previous limitations of surgery due to poor lighting and anatomic localization available to the surgeon. Over the last thirty years, the supraorbital craniotomy and subfrontal approach through an eyebrow incision have been developed and refined to play a legitimate role in the armamentarium of the modern skull base neurosurgeon. With careful patient selection, the supraorbital “keyhole” approach offers a less invasive but still efficacious approach to a number of lesions along the subfrontal corridor. Well over 1000 cases have been reported in the literature utilizing this approach establishing its safety and efficacy. This paper discusses the nuances of this approach, including the benefits and limitations of its use described through our technique, review of the literature, and case illustration. 1. Introduction Numerous neurosurgical approaches have been developed to operate on lesions of the frontotemporal skull base. These approaches include frontal, bifrontal, frontotemporal, pterional, orbitozygomatic, and other variations [1]. The evolution of these approaches from Dandy’s frontotemporal “macrosurgical approach,” to Yasargil’s microsurgical pterional approach, and finally to the supraorbital keyhole approach through an eyebrow incision all have served to give the neurosurgeon the exposure they needed to safely address various pathologies [2]. The goal of “keyhole” surgery was not to perform a small incision and craniotomy for the sake of a small opening. The goal of this approach was to permit adequate access to skull base lesions while limiting trauma to surrounding structures such as the skin, bone, dura, and, most importantly, the brain [3–5]. The supraorbital craniotomy and subfrontal approach have been used to access a number of pathologies including tumors (meningiomas, craniopharyngiomas, etc.) and vascular abnormalities (e.g., aneurysms, arteriovenous malformations, and cavernous hemangiomas) [1, 2, 5–35]. Surface lesions typically require craniotomies as large as the lesion. Deep-seated lesions, however, can be accessed through a much smaller craniotomy since the intracranial field widens with increasing distance from the skull [2, 3, 5, 36–38]. Utilizing this principle, surgeons can access lesions in the subfrontal, suprasellar, Sylvian fissure, and posterior fossa regions of the brain [2–6, 21]. When considering any approach to a pathological entity, it is important to understand the