The Role of the Pterional Approach in the Surgical Treatment of Olfactory Groove Meningiomas: A 20-year Experience

Abstract

Background Olfactory groove meningiomas remain surgically challenging. The common microsurgical approaches suffer from late exposure of the neurovascular structures. Conversely, the pterional approach has the advantage of early dissection of the posterior neurovascular complex. Methods We reviewed the records of patients treated for olfactory groove meningioma in our department between 1991 and 2010. A total of 61 patients underwent removal of olfactory groove meningiomas via the pterional approach. These included 58 primary and 3 recurrent tumors. Mean overall follow-up time was 122 months. Results Early exposure and dissection of the internal carotid artery, middle cerebral artery, anterior cerebral artery, and optic nerve was feasible in all cases. Complete tumor removal was achieved in 60 patients. Morbidity and mortality rates were 26% and 1.6% respectively. Postoperative complications included epileptic seizures (five patients) and cerebrospinal fluid (CSF) leak (two patients). During follow-up, we recorded three tumor recurrences. Conclusions The pterional approach appears to be an excellent solution for the treatment of olfactory groove meningiomas. Its foremost advantage is early visualization of the posterior neurovascular complex. Moreover, it allows frontal sinus preservation and timely tumor devascularization and avoids excessive brain retraction. The pterional view is familiar to most neurosurgeons and therefore the transition to this technique is fairly straightforward.

Keywords: meningioma removal; olfactory groove meningiomas; pterional approach; surgical treatment.

Fig. 1

(A) Typical olfactory groove meningioma. Note the close proximity of the posterior tumor border to the neurovascular complex. The pterional craniotomy extends from the lateral part of the greater sphenoid wing to the lateral frontal skull base (dotted line). The frontal sinus remains intact. (B) The posterior tumor surface is addressed first (white arrows); this allows early dissection of the middle cerebral (MCA), anterior cerebral (ACA), internal carotid artery (ICA), and optic nerves/chiasm (CN II) (curved arrows). With the crucial structures out of harm's way, the posterior tumor parts are debulked. On the right: dotted line denotes operative line of sight. The angle in the diagram is exaggerated since retraction during operation is not as extensive as in the diagram, although after extraction of a great tumor the sight can be so extensive without brain retraction. (C) Tumor hollowing continues anteriorly; the tumor nidus is devascularized and hyperostotic bone is drilled away. Diamond drill and bone wax is used to control the hemorrhage. (D) The crista galli is removed and the falx is incised (dotted line); this enables access to the contralateral tumor parts. (E) The final step of the procedures addresses the contralateral tumor borders. The tumor is gently pulled downwards and inwards. The contralateral ACA is dissected away (curved arrow).