Resection of Clival Chordoma Through the Anterior Clivectomy: 2-Dimensional Operative Video

Clival chordomas are rare malignant behaving tumors that grow, locally invade, metastasize, and seed, and they have a high recurrence rate.1,2 The longest disease control is achieved by radical resection followed by high doses of radiation therapy, commonly proton beam.3 To achieve radical tumor removal, multiple surgical procedures through different approaches might be required.4 Since the chordoma's origin is, and remains, extradural, an extradural approach is preferred, and can lead to intradural extension. Anterior approach is frequently utilized to remove the midline-located tumor and the eroded clivus.5 Several midline approaches were utilized, including the transbasal, transfacial, transcervical, open door, and Lefort's maxillotomies1; however, the same tumor removal can be achieved with a simple extension of the trans-sphenoidal approach, by resecting the anterior maxillary wall, of the contralateral to the lesion preponderant side.5 This approach coupled with the use of neuronavigation on mobile head and endoscopic-assisted technique allowed to achieve a wide and direct exposure, with the ability to resect extra- and intradural tumors.2,5 Lately, the endonasal endoscopic technique became popular as an alternative4; however, we found a great advantage in the ability to combine the stereoscopic microsurgical technique with the endoscopic dissection, in addition to avoiding the extensive nasal dissection and its complications. We present a case of a 63-yr old woman with an upper clivus chordoma compressing the brainstem who underwent a gross total resection by endoscopic-assisted microscopic techniques through an anterior clivectomy approach. Patient consented to the procedure and publication of her images.

Orbital neuromuscular choristoma of the ophthalmic nerve

Introduction: Neuromuscular choristoma (NC) is a rare tumor composed of striated muscle fibers admixed with nerve fibers that often affects large peripheral nerve trunks in children. To the best of our knowledge, this is the first reported case in the literature of a NC of the ophthalmic nerve in an adult. Case description: A 27-year-old woman presented with a 20-day history of left periorbital headache radiating to the frontotemporal region, with associated tearing, nausea, and vomiting. The examination was normal, except for hypoesthesia in the distribution of the first trigeminal nerve branch (V1). Cranial computerized tomography showed a lesion in the left orbit and cavernous sinus with widening of the superior orbital fissure. On magnetic resonance imaging, the lesion was well-defined with fusiform morphology and showed a central cystic component and peripheral enhancement. An extradural approach was performed with subtotal tumor resection. Biopsy showed proliferation of striated muscle cells admixed with nerve fascicles and Schwann cells. A pathological diagnosis of NC of V1 was determined. Six months after surgery, left hypotropia with limitation of supraduction was observed, as well as hypoesthesia and paralysis of the left forehead with ipsilateral eyebrow ptosis. The rest of the examination remained within normal limits. Conclusion: NC should be considered in the differential diagnosis of a young patient with periorbital headache and hypoesthesia in the V1 region.

Pediatric multicompartmental trigeminal schwannoma: illustrative case

BACKGROUND Trigeminal schwannoma (TS) is an uncommon and histologically benign intracranial lesion that can involve any segment of the fifth cranial nerve. Given its often impressive size at diagnosis and frequent involvement of critical neurovascular structures of the skull base, it represents a challenging entity to treat. Pediatric TS is particularly rare and presents unique challenges. Similarly, tumors with extension into multiple compartments (e.g., middle cranial fossa, posterior cranial fossa, extracranial spaces) are notoriously difficult to treat surgically. Combined or staged surgical approaches are typically required to address them, with radiosurgical treatment as an adjunct. OBSERVATIONS The authors presented the unusual case of a 9-year-old boy with a large, recurrent multicompartmental TS involving Meckel’s cave, the cerebellopontine angle, and the infratemporal fossa. Near-total resection was achieved using a frontotemporal-orbitozygomatic craniotomy with a combined interdural and extradural approach. LESSONS The case report adds to the current literature on multicompartmental TSs in children and their management. The authors also provided a simplified classification of TS that can be generalized to other skull base tumors. Given a lack of precedent, the authors intended to add to the discussion regarding surgical management of these rare and challenging skull base lesions.

Extradural minipterional approach: Evolving indications of the minipterional craniotomy

Background: In this paper, we report a clinical series of skull base lesions operated on trough the MiniPT, extending its application to skull base lesions, either using the classical minipterional or a variant, we call extradural minipterional approach (MiniPTEx). Methods: We describe our surgical technique of operating on complex skull base lesions using a minipterional extradural approach. Anterior clinoidectomy, middle fossa peeling, transcavernous, and Kawase approaches were performed as needed. In total, we carried out 24 surgeries: three skull base tumors, 1 Moyamoya case, and 20 giant/complex intracranial aneurysms. All the patients present good neurological result (mRs < 3). Only two patients had paralysis of any cranial nerve and only one patient had a mild hemiparesis. Results: This surgery series there are 24 cases, 10 patients were treated with exclusive MiniPT. MiniPT extradural approach was made in 14 patients. Twelve were treated using pure MiniPTEx approach, 1 patient using transcavernous approach, and in 1 patient, the anterior clinoid was resected with the combination of a MiniPT, a medium fossa peeling, and the Kawase anterior petrosectomy for skull base surgery. Conclusion: We further advance the indications of the MiniPT by extending it to operate on the cranial base tumors or complex vascular lesions without additional morbidity. MiniPT approach may be safely associated with skull base techniques, including anterior and posterior clinoidectomies, peeling of the middle fossa, transcavernous approach, and anterior petrosectomy. The versatility of the MiniPT craniotomy and the feasibility of performing skull base surgery through the MiniPT technique have been demonstrated in this paper.

A Giant Trigeminal Schwannoma, Posterior Fossa and Middle Fossa Extradural Approach: A Case Report

Trigeminal schwannomas are rare tumors that are located in the posterior and middlecranial fossae in about a quarter of the cases. The presentation pattern is differentaccording to the involved compartment and the goal of surgery is complete removal.We present the case of a 28-years old man who presented with a left sided trigeminalschwannomas extending from the posterior to the middle fossa. Middle fossa part ofthe tumour was removed by extradural subtemporal approach and posterior fossapart was removed by retrosigmoidretromastoid approach Bang. J Neurosurgery 2020; 9(2): 162-167

Endoscopic Endonasal Approach to the Lateral Wall of the Cavernous Sinus: A Cadaveric Feasibility Study

Objective: A transcranial extradural approach to the middle cranial fossa (MCF) requires separation of the dural layers of the lateral wall of the cavernous sinus. The authors tested the feasibility of an endonasal approach for this separation. Methods: A cadaveric feasibility study was conducted on the sides of 14 dry skulls and 10 fresh cadaveric heads. An endonasal, transsphenoidal, transpterygoid approach was taken to the MCF. The maxillary struts and medial greater wing of the sphenoid below the superior orbital fissure were drilled with transposition of the maxillary nerve. The lateral cavernous dural layers were split at the maxillary nerve with separation of the temporal lobe dura and exposure of the MCF bony base. The integrity of the cranial nerves and inner and outer dural layers of the lateral cavernous wall was checked. Different measurements of bony landmarks were obtained. Results: The integrity of the dural layers of the lateral cavernous wall and the cranial nerves were preserved in 10 heads. The mean area of the bony corridor was 4.68 ± 0.97 cm2, the V2-to-V3 distance was 15.21 ± 3.36 mm medially and 18.21 ± 3.45 mm laterally, and the vidian canal length was 13.01 ± 3.06 mm. Conclusions: Endonasal endoscopic separation of the lateral cavernous dural layers is feasible without crossing the motor cranial nerves, allowing better exposure of the MCF.