Freehand Ventriculoperitoneal Shunt for Idiopathic Intracranial Hypertension: Technical Note for Slit-Like Ventricle Puncture.

Idiopathic intracranial hypertension (IIH) is a syndrome characterized by elevated intracranial pressure, headache, and papilledema. It is frequently associated with obese women and can result in irreversible vision loss. The ventriculoperitoneal (VP) shunt has been proven to be superior to the lumboperitoneal (LP) shunt in IIH patients, with better clinical outcomes. It has been reported that the accurate placement of the ventricular catheter is highly important for shunt survival. However, a slit-like ventricle pattern, typically seen in the disease, has been considered a great concern and challenge for ventricular catheter placement, primarily for freehand technique. Frameless stereotaxy, ultrasound, and endoscopy have been described to improve the accuracy of catheter insertion. However, intraoperative image guidance is not widely accessible, especially in lower-resource countries, due to the high costs associated with its use. Techniques to improve the accuracy of the freehand VP shunt in IIH are scarce in the literature, and any effort to contribute to its development is valuable and helpful.

Large Vestibular Schwannoma: A Two-Stage Surgery.

Treatment of large vestibular schwannoma (VS) has historically centered on total resection of the lesion. Staged surgery has been used for VS that is highly vascularized, unexpected events during surgery, and thinned and stretched facial nerve with serious adherence causing difficult dissection. We present a case of a patient with a large VS resected through a two-stage surgery through the same retrosigmoid craniotomy.

Surgical salvage for recurrent vestibular schwannoma after primary stereotactic radiosurgery.

Background: The management of vestibular schwannoma has evolved over the past hundred years. In the last decades, surgery has been gradually replaced by radiation therapy as a primary treatment modality, particularly for small tumors, due to the less invasive nature and the compared reported outcomes in tumor control and hearing preservation. However, irradiation sometimes fails to stop tumor growth. In a long-term follow-up after primary fractionated stereotactic radiotherapy, the rate of treatment failure was reported as 3% and needed surgical salvage. For single-fraction modality, Hasegawa et al. reported salvage treatment after primary Gamma Knife radiosurgery in 8%, where 90% of these underwent surgery and 50% of those who were treated with a second gamma knife surgery required surgical intervention later. An increase in tumor volume by more than 10-20%, tumor growth after three years, and no return to pretreatment volume after transient swelling have been considered as tumor recurrence rather than pseudoprogression, a transient increase in tumor volume after radiotherapy that occurs up to 30% of cases. It has been reported that microsurgery after radiotherapy is more difficult, with most authors reporting a loss of defined arachnoid planes and worse cranial nerve outcomes, especially for hearing and facial nerve function. Case Description: A 43-year-old female patient was incidentally (asymptomatic) diagnosed on a magnetic resonance imaging (MRI) scan harboring a left vestibular schwannoma, grade T2 (Hannover classification), in 2015. Neurologic examination was unremarkable, and audiometry testing was normal. She was initially treated with observation. Three years later, in 2018, the lesion had enlarged, becoming a grade T3a and reaching the cistern of the cerebellopontine angle. The tumor was then treated with fractionated stereotactic radiosurgery (5 sessions of 5 Gy). MRI scans in 2019 and 2020 showed slight tumor growth. This enlargement was attributed to a pseudoprogression after radiosurgery, and only observation was advocated. In 2022, 4 years later, after radiosurgery, the tumor was still growing, and the patient began to suffer from hearing loss. A failure treatment was considered, and microsurgery was indicated. The patient was counseled about the risk of functional nerve impairment, and surgical consent was obtained. A retro sigmoid approach was planned. A gross total resection was attempted due to the clear subperineural plane during tumor dissection and because it was the only option that would provide a cure for the patient. The adjacent neurovascular structures were firmly adhered to the tumor capsule, which represented a major challenge for microdissection. The tumor was soft, without significant bleeding. A total resection was achieved, and the facial nerve was anatomically preserved. The patient developed facial paresis (House-Brackmann III) in the immediate postoperative period, which improved at the 6-month follow-up. Hearing loss did not improve. Postoperative MRI showed total resection. Conclusion: Microsurgery after radiotherapy for vestibular schwannoma is challenging in terms of indication, when to indicate, resection target, difficulty in dissection due to local changes, and outcome. Gross total resection may be considered, as it is the only treatment that may provide a cure for the patient. However, the patient should be counseled about the risks.

Anterior petrosal approach for petroclival solitary plasmacytoma.

Background: Primary solitary plasmacytoma (PSP) of the skull base is a rare localized monoclonal plasma cell dyscrasia with normal or low plasma cell infiltration. Differentiating from other skull base tumors based on radiologic findings is difficult due to nonspecific features. PSP has a better prognosis after surgical resection and adjuvant radiotherapy, unless the tumor progresses to multiple myeloma (MM). Nonetheless, 50-60% progress to MM within a median time of 2 years. Gross total resection (GTR) for PSP is controversial for improving overall survival. However, if the lesion is easily accessible, for example, nonskull base lesion, GTR is still advocated. Case Description: A 67-year-old male patient presented with right occipital neuralgia and diplopia in the last year. Neurological examination revealed mild abducens paresis on the right side. Brain MRI scan showed a large petroclival bony extradural mass lesion on the right side, with homogeneous enhancement, extending from the dorsum sellae to the ipsilateral occipital condyle and involving the petrous carotid artery. Brain CT scan revealed an osteolytic lesion without intratumoral calcifications, sclerotic border, or periosteal reaction. Anterior petrosal approach was performed and GTR was achieved. The patient had good postoperative outcome and improvement of symptoms. Postoperative MRI revealed GTR. Total body imaging work-up and immunohistochemistry confirmed PSP. Conclusion: Although the extent of resection in the outcome is controversial, maximal safe resection of skull base PSP should be considered to improve symptoms and quality of life.

Orbitozygomatic approach for large orbital cavernous hemangioma.

BACKGROUND: Cavernous hemangiomas, more accurately defined as cavernous venous malformations, constitute the most common primary intraorbital tumors of adults comprising 4-9% of all tumors,[4] and the second most frequent cause of unilateral proptosis after thyroid-related orbitopathy.[3] Over 80% are located within the intraconal compartment, most commonly in the lateral aspect.[1] Surgical treatment for orbital cavernous hemangioma is generally required in symptomatic cases, optic nerve compression, and cosmetically disfiguring proptosis.[2] Transcranial approaches, the most familiar approaches for neurosurgeons, provide wide access to the entire superior and lateral orbit. They usually offer direct visualization, allowing for a safer dissection, while minimizing significant injury to the native neural and vascular anatomy of the orbit.[5] Although transcranial approaches continue to evolve, in many cases, they have been supplanted by endoscopic skull base approaches and modifications to deep lateral orbitotomy approaches.[5]. CASE DESCRIPTION: A 62-year-old male patient presented with slowly expanding left proptosis, which he had first noticed 3 years before presentation. He was already blind in his right eye due to a history of traumatic amaurosis in childhood. The left eye examination revealed severe proptosis with restricted eye movement in all directions and significant visual impairment (visual acuity of 20/300, expressed by Snellen test, with no improvement on correction). MRI of the orbit showed a large left superolateral intraconal cavernous hemangioma compressing and displacing the optic nerve, with the typical feature of slow gradual irregular enhancement with delayed washout on contrast-enhanced image. A one-piece modified orbitozygomatic approach was performed and a total en block resection was achieved. The bone flap was fixed with titanium miniplates and screws, the temporal muscle and the skin were closed in a standard fashion. The patient did not present any new deficit in the postoperative period. The patient had good functional and cosmetic outcomes with resolution of proptosis, restoration of eye movements, and improvement of visual acuity in the 3-month follow-up. Postoperative MRI showed total resection. CONCLUSION: The orbitozygomatic approach for large orbital cavernous hemangioma provides satisfactory orbital decompression and large working space, reduces traction, and increases visualization and freedom to dissect small vessels and nerves that may be tightly attached to the tumor pseudocapsule.

Tailored Anterior Clinoidectomy: Beyond the Intradural and Extradural Concepts.

Anterior clinoidectomy (AC) is a key microsurgical step for the safe and successful management of parasellar pathologies that involve the anterior clinoid process (ACP) and the optic canal. Traditionally, extra and intradural ACs are performed separately according to the surgeon's experience or preference. The objective is to present and discuss the tailored AC concept through illustrative cases. We conducted a retrospective record review of three patients who underwent AC as a surgical step for the treatment of parasellar pathologies that involve the ACP and optic canal. A review of the relevant literature on AC was performed in the PubMed, LILACS, and SciELO databases. In all three cases, the pterional craniotomy was the preferred approach for AC. Case 1, a 47-year-old female patient with type III anterior clinoidal meningioma, underwent a tailored intradural technique (optic canal unroofing) with total tumor resection and complete visual recovery. Case 2, a 63-year-old female patient with a complex type II anterior clinoidal meningioma with extensive hyperostosis of the ACP, underwent a hybrid AC technique with complete removal of the tumor and visual improvement. Case 3, a 62-year-old female, underwent a tailored intradural AC for clipping an incidental carotid-ophthalmic aneurysm. Tailored AC aims to provide adequate exposure with less risk of neurovascular injury, allowing enough space to safely treat parasellar lesions. The type, size, and location of the lesion, as well as the surgeon's experience, should always be considered for surgical planning.

Therapeutic anticoagulation for venous thromboembolism after recent brain surgery: Evaluating the risk of intracranial hemorrhage.

OBJECTIVE: Venous thromboembolism (VTE) is particularly prevalent in neurosurgical patients. A major dilemma arises when a patient needs to be treated with therapeutic anticoagulation during the early days after brain surgery due to the concern of intracranial hemorrhage (ICH). There is still a lack of studies regarding the optimal time to start therapeutic anticoagulation and risk assessment of ICH in this setting. This study aims to assess the risk of ICH for patients with venous thromboembolism treated with therapeutic anticoagulation started within the first 30 days after intracranial neurosurgical procedure. PATIENTS AND METHODS: This study was an analytical observational research based on a retrospective record review of VTE patients submitted to therapeutic anticoagulation started within the first 30 days after intracranial neurosurgical procedure at Paulo Niemeyer State Brain Institute, from September 2013 to February 2020. Patients' clinical and surgical data, anticoagulation drug therapy, time interval between surgery and start of therapeutic anticoagulation, bleeding complications and hemorrhage-related deaths were some of variables evaluated. A p value < 0.05 was considered statistically significant. RESULTS: A series of 53 consecutive patients and 54 intracranial neurosurgical procedures met the criteria. Twenty-nine (53.7 %) patients were treated with warfarin, 21 (38.9 %) with new oral anticoagulant (NOAC) and 4 (7.4 %) only with enoxaparin. VTE diagnosis between the postoperative days 0 and 4 was statistically associated with a delay in starting therapeutic anticoagulation of more than two days (p < 0.001). The frequency of bleeding complication was statistically significant higher in patients treated with warfarin (p = 0.03). Although with no statistical significance, there were a higher rate of ICH in patients receiving warfarin (13.8 % vs. 0% in NOAC group, p = 0.13). There was no statistical difference about ICH incidence between the postoperative intervals from 2nd to 7th, 8th to 14th, 15th to 21 st and 22th to 29th days (p = 0.35). Hemorrhage-related mortality rate was 3.7 %. CONCLUSION: ICH was not statistically associated with the timing of therapeutic anticoagulation after brain surgery between the 2nd and 29th postoperative days, which may encourage the strategy of early treatment considering the life-threatening potential of VTE. However, the risk of ICH should not be ignored in the setting of warfarin use, which had a remarkable incidence of 13.8 %. Warfarin must be used cautiously, especially in high-grade gliomas.