Marsupialization as an alternative to reconstruction in endoscopic skull base surgery. How I do it.

BACKGROUND: To treat extradural solid-cystic lesions of the ventral skull base, a pedicled nasoseptal flap (NSF) maintains patency of the marsupialized cavity and prevents restenosis and cyst recurrence. METHODS: The authors provide a step-by-step description of the surgical technique valid in different lesions of the skull base, all treated via the endoscopic endonasal approach (EEA). The application is demonstrated by an operative video. CONCLUSION: In selected lesions, endoscopic marsupialization using an NSF ensures drainage and ventilation of the surgical cavity. Re-epithelialization provided by a pedicled flap is a viable alternative to multilayer skull base reconstruction.

Endoscopic Transpterygoid Approach to Meckel's Cave: Technical Considerations and Retrospective Analysis of a Clinical Series.

OBJECTIVE: Tumors located within the Meckel's cave (MC) pose a significant surgical challenge. Although several corridors to access this complex region have been described, the endoscopic transpterygoid approach (ETPA) and the endoscopic transorbital superior eyelid approach (ETOA) have emerged in recent years, as viable alternatives to traditional microsurgical transcranial approaches (MTA). To date, there is a limited literature on surgical series considering endoscopic-assisted approaches to the MC. METHODS: We conducted a retrospective analysis of patients with primary MC tumors treated at our Institution between 2015 and 2022, specifically those managed via the ETPA assisted by intraoperative Endoscopic Diving Technique (EDT). Lesion resection extent was evaluated using pre- and post-intervention radiological images and surgical videos. Moreover, a literature review on ETPA was performed. RESULTS: This series comprises 7 patients affected by 4 trigeminal schwannomas, 1 benign notochordal cell tumor, 1 dermoid cyst and 1 mesenchymal tumor. In 71 % of cases, trigeminal neuralgia was the presenting symptom. Post-operative clinical improvement was observed in all but one case. Notably, 85.7 % of patients achieved total or near-total resection (NTR), with the remaining case undergoing subtotal resection (STR). No significant intraoperative complications occurred, and no recurrences were observed during the mean follow-up period of 41 months. CONCLUSIONS: In selected cases, the ETPA offers a direct and safe path to lesions located into the MC. This approach circumvents complications and constraints associated with ETOA or MTA. Moreover, the use of the EDT reduces manipulation of critical neurovascular structures, enhancing the efficacy of the ETPA.

Endoscopic Endonasal Excision of a Cavernous Hemangioma of the Orbital Apex with Cryoprobe Assistance: Two-Dimensional Surgical Video.

Cavernous hemangiomas (CHs) represent the commonest benign orbital lesion in adults, accounting for nearly 6% of overall orbital tumors.1The most common presenting symptoms include unilateral visual deficits, diplopia, ocular muscle impairment, and nonpulsatile proptosis. CHs can be asymptomatic until they reach a considerable size, but when lodged deep in the orbital apex, even small masses may cause severe functional deficits.2 If found incidentally, a wait-and-scan policy is advised. Surgical treatment is indicated in patients with visual impairment or in cases of volumetric increase during the follow-up.3 Among the different surgical corridors to the orbital apex, in the last decade, the endoscopic-assisted approaches, both transpalpebral and endonasal, have emerged as minimally invasive and effective techniques in the skull base surgeon's armamentarium.4 If those lesions are located medially to the optic nerve, the endoscopic endonasal approaches (EEAs) offer several advantages compared with standard craniotomies or orbitotomies.5,6 A 45-year-old woman was admitted to our hospital with symptoms of progressive right visual impairment for 10 months, with radiologic finding of an encapsulated small roundish lesion at the right orbital apex. The mass was completely removed by means of EEA with intraoperative use of a dedicated cryoprobe (Video 1). Histopathologic examination confirmed the CH. At follow-up, the patient experienced complete resolution of her symptoms, with no residues or relapses on magnetic resonance imaging. This case sheds light on the advantages of EEA with the assistance of a cryoprobe, including optimal visualization of the target, lack of external incision, no brain retraction, and short hospital stays.

Endoscopic transventricular approach for the resection of a hemorrhagic cavernous malformation of the tectal plate: Operative video.

Background: Cavernomas of the third ventricle are rare entities that provide significant therapeutic challenges. Because of the better view of the surgical field and the possibility to achieve a gross total resection (GTR), microsurgical approaches are more commonly used to target the third ventricle. Endoscopic transventricular approaches (ETVA), on the other hand, are minimally invasive procedures that can afford a straight corridor trough the lesion, avoiding bigger craniotomies. Moreover, these approaches have shown lower infectious risks and shorter hospitalization times. Case Description: A 58-year-old female patient accessed the Emergency Department complaining of headache, vomiting, mental confusion, and syncopal episodes for the past 3 days. An urgent brain computed tomography scan revealed a hemorrhagic lesion of the third ventricle, conditioning triventricular hydrocephalus, so an external ventricular drainage (EVD) was placed in an emergency setting. An magnetic resonance imaging (MRI) showed a 10 mm diameter hemorrhagic cavernous malformation originating from the superior tectal plate. An ETVA was performed for the cavernoma resection, followed by an endoscopic third ventriculostomy. After proving shunt independence, the EVD was removed. No clinical nor radiological complications were assisted in the postoperative period, so the patient was discharged 7 days after. The histopathological examination was consistent with cavernous malformation. An immediate postoperative MRI showed GTR of the cavernoma with a little clot around the surgical cavity, which appeared completely reabsorbed 4 months later. Conclusion: ETVA provides a straight corridor to the third ventricle, excellent visualization of the relevant anatomical structures, safe resection of the lesion, and treatment of the concomitant hydrocephalus by ETV.

Ultrahigh-Definition-3-Dimensional Exoscope-Assisted Clipping of a Right Middle Cerebral Artery Unruptured Aneurysm with Indocyanine Green Video Angiography: Operative Video.

Ultrahigh-definition 3-dimensional exoscopes represent an excellent technologic innovation in contemporary neurosurgery. They combine the advantages of operating microscopes and endoscopes, offering excellent magnification and lighting, maintaining a relatively small footprint and optimal ergonomic features.1-5 One of the most interesting employments of exoscopes in neurosurgery is represented by intracranial vascular surgery. Reports in this field are still limited, but recent experience has shown that ultrahigh definition 3-dimensional exoscopes for aneurysm surgery are noninferior to operating microscopes for surgery duration, complication rate, and patient outcomes.6 In addition, many intraoperative techniques such as the indocyanine green videoangiography (ICG-VA) have been successfully implemented to exoscope-based surgery.7 We present herein the case of a 66-year-old woman that came to our attention for the incidental finding of 3 unruptured brain aneurysms. After neurosurgical consultation, the one located at the right middle cerebral artery bifurcation was considered eligible for surgery.8,9 As shown in Video 1, ICG-VA was employed after permanent clipping to allow immediate quality assurance of occlusion and distal vessel integrity. Postoperative course was uneventful, and follow-up examinations demonstrated the complete occlusion of the aneurysm. This report highlights the feasibility of exoscopic-based ICG-VA in vascular neurosurgery, given its ease of use, ergonomics, and excellent quality of vision provided to both surgeons and operating staff.