Simpson Grade I Removal of Tuberculum Sella Meningioma Through the Supraorbital Approach: 2-Dimensional Operative Video

As described by Cushing1 in the chiasmatic syndrome, tuberculum sellae meningiomas induce progressive asymmetrical, incongruous visual loss, which would lead to blindness. The surgical removal of these lesions has been rewarding in regard to visual preservation, or recovery, and has passed the test of time. Optic canal extension, in one or both canals, is a consistent feature of these tumors, and removing the tumor from the optic canals is paramount in the treatment of these lesions.2 Despite the small target volume, radiosurgery is not applicable because of the lack of safe distance from the optic pathways. Tuberculum sella meningioma has been distinguished with good surgical outcomes and low recurrence rates; thus, Simpson grade I removal (tumor, dura, and bone invasion) confers a prospect of cure. Safe and successful resection of tuberculum meningiomas is achieved through the skull base supraorbital approach3 with several critical objectives: (1) visualization of the tumor without brain retraction; (2) 270° opening of the optic canal proximally and distally for safe tumor removal; (3) preservation of the vascular supply to the optic pathways and pituitary; (4) microsurgical dissection under high magnification on a short working distance to the encased carotid and anterior cerebral arteries; (5) complete resection of involved dura and bone at the skull base, particularly laterally; and (6) a robust skull base reconstruction with a vascularized pericranial flap.4 We present the case of a 45-yr-old female with a tuberculum sella meningioma who underwent Simpson grade I removal with an uneventful outcome. The patient consented for surgery. Image at 2:59 reprinted with permission from Al-Mefty O, Operative Atlas of Meningiomas. Vol 1, © LWW, 1998; Image at 9:33 public domain.4

Strategies for Optic Pathways Decompression for Extra-Axial Tumors or Intracranial Aneurysms: A Technical Note

Background Different types of skull base tumors and intracranial aneurysms may lead to compression of the optic pathways. Since most of them are biologically benign conditions, the first aim of surgery is preservation of optic nerves rather than the oncologic radicality. Materials and methods Based on the progressive technical refinements coming from our institutional experience of optic nerve compression from aneurysms and extra-axial tumors, we analyzed the surgical steps to release nerves and chiasm during tumor debulking and aneurysm clipping. Results We distinguished vascular and tumor lesions according to the main direction of optic nerve compression: lateral to medial, medial to lateral, inferior to superior, and anterior to posterior. We also identified four fundamental sequential maneuvers to release the optic nerve, which are (1) falciform ligament (FL) section, (2) optic canal unroofing, (3) anterior clinoid process drilling, and (4) optic strut removal. The FL section is always recommended when a gentle manipulation of the optic nerve is required. Optic canal unroofing is suggested in case of lateral-to-medial compression (i.e., clinoid meningiomas), medial-to-lateral compression (i.e., tuberculum sellae meningiomas), and inferior-to-superior compression (i.e., suprasellar lesions). Anterior clinoidectomy and optic strut removal may be necessary in case of lateral-to-medial compression from paraclinoid aneurysms or meningiomas. Conclusions Preservation of the visual function is the main goal of surgery for tumors and aneurysms causing optic nerve compression. This mandatory principle guides the approach, the timing, and the technical strategy to release the optic nerve, and is principally based on the direction of the compression vector.

Optic pathways and brainstem involvement in posterior reversible encephalopathy syndrome

Posterior reversible encephalopathy syndrome (PRES) is a neurological syndrome manifesting with acute focal signs, and concomitant neuroimaging findings of vasogenic oedema. It affects the parieto-occipital regions in a vast majority of cases, although atypical variants have been described comprising the brainstem, basal ganglia or spinal cord. We report the case of a 41-year-old woman, admitted for persistent headache and inferior altitudinal field defect in the right eye. She presented with severe, non-medicated, hypertension. Brain MRI showed findings compatible with atypical PRES, involving the brainstem and optic pathways. With antihypertensive therapy the headache remitted, although visual field remained and was interpreted in the context of a vascular aetiology—non-arteritic anterior ischaemic optic neuropathy. MRI was repeated 3 weeks later and showed almost complete reversal of the previous changes.

Proton and carbon ion radiotherapy in skull base chordomas: a prospective study based on a dual particle and a patient-customized treatment strategy

Background The aim of this study is to evaluate results in terms of local control (LC), overall survival (OS), and toxicity profile and to better identify factors influencing clinical outcome of skull base chordoma treated with proton therapy (PT) and carbon ion radiotherapy (CIRT). Methods We prospectively collected and analyzed data of 135 patients treated between November 2011 and December 2018. Total prescription dose in the PT group (70 patients) and CIRT group (65 patients) was 74 Gy relative biological effectiveness (RBE) delivered in 37 fractions and 70.4 Gy(RBE) delivered in 16 fractions, respectively (CIRT in unfavorable patients). LC and OS were evaluated using the Kaplan–Meier method. Univariate and multivariate analyses were performed, to identify prognostic factors on clinical outcomes. Results After a median follow-up of 44 (range, 6–87) months, 14 (21%) and 8 (11%) local failures were observed in CIRT and PT group, respectively. Five-year LC rate was 71% in CIRT cohort and 84% in PT cohort. The estimated 5-year OS rate in the CIRT and PT group was 82% and 83%, respectively. On multivariate analysis, gross tumor volume (GTV), optic pathways, and/or brainstem compression and dose coverage are independent prognostic factors of local failure risk. High rate toxicity grade ≥3 was reported in 11% of patients. Conclusions Particle radiotherapy is an effective treatment for skull base chordoma with acceptable late toxicity. GTV, optic pathways, and/or brainstem compression and target coverage were independent prognostic factors for LC. Key Points • Proton and carbon ion therapy are effective and safe in skull base chordoma. • Prognostic factors are GTV, organs at risk compression, and dose coverage. • Dual particle therapy and customized strategy was adopted.