BACKGROUND: Microvascular conflicts in hemifacial spasm typically occur at the facial nerve\'s root exit zone. While a pure microsurgical approach offers only limited orientation, added endoscopy enhances visibility of the relevant structures without the necessity of cerebellar retraction.
METHODS: After a retrosigmoid craniotomy, a microsurgical decompression of the facial nerve is performed with a Teflon bridge. Endoscopic inspection prior and after decompression facilitates optimal Teflon bridge positioning.
CONCLUSIONS: Endoscope-assisted microsurgery allows a clear visualization and safe manipulation on the facial nerve at its root exit zone.

BACKGROUND: Resection remains the optimal treatment for hemangioblastomas, highly vascular tumors commonly located in the cerebellum or spinal cord. Preoperative embolization can be used with caution to reduce intraoperative blood loss and promote gross-total resection while reducing neurological morbidity.
METHODS: The authors report a case of a 44-year-old male who presented with worsening dizziness, gait imbalance, and diplopia. Imaging revealed a large vascular cerebellar mass with brainstem compression and hydrocephalus, concerning for hemangioblastoma. The patient underwent preoperative embolization of the main arterial supply from the right superior cerebellar artery, which devascularized the tumor and reduced the early venous shunting, followed by gross-total resection of the tumor. Preoperative embolization helped to facilitate safe microsurgical resection because this main arterial supply was deep to the planned surgical approach, and the Onyx cast served as a landmark of the dorsal midbrain and remaining arterial supply. This resulted in minimal intraoperative blood loss. At 2-year follow-up, the patient\'s diplopia and vertigo had resolved, and his gait continues to improve.
CONCLUSIONS: Despite controversy regarding the use of preoperative embolization for hemangioblastoma resection, the authors emphasize its safety and utility during resection of a large cerebellar hemangioblastoma. Onyx embolization provided benefit in both reducing the tumor blood supply and serving as intraoperative visual guidance.

BACKGROUND: Petroclival meningiomas are challenging tumors. Several skull base approaches have been proposed in the last decades, with variable rates of postoperative morbidity and extent of resection.
METHODS: We herein reported the step-by-step microsurgical resection of a large petroclival meningioma through an extended retrosigmoid approach. Detailed surgical technique has been accompanied by a 2D operative video.
CONCLUSIONS: The extended retrosigmoid approach allowed for a safe gross total resection of the tumor, as confirmed by the postoperative MRI. The patient did not experience any new postoperative deficit, despite a transient diplopia, and was discharged on postoperative day 7.

Bilateral ophthalmic aneurysms are rare and involve two aneurysms in the ophthalmic arteries, one on each, leading to potential symptoms such as vision loss and headaches. The treatment options for aneurysms, ranging from surgery and endovascular embolization to observation, depend on various factors, including aneurysm size and the patient\'s health. Microsurgery, while presenting complexities due to the intricate anatomy of the anterior clinoid region, offers potential advantages such as enhanced decompression rates and reduced aneurysm recurrence. The presented surgical video illustrates the treatment of bilateral ophthalmic artery aneurysms via a single craniotomy. This method reduces surgical duration and trauma, facilitating quicker patient recovery. However, this method bears potential risks, especially to both optic nerves. As underscored in the video, the utmost anatomical understanding in the anterior clinoid area is pivotal for successful outcomes and reduced complications.

暂无摘要。

Endoscopic third ventriculostomy (ETV) is an effective treatment for hydrocephalus in carefully selected patients.1 Studies have shown that larger ostomy size may be associated with higher ETV success and reduced ostomy closure in pediatric and adult patients.2-5 Therefore dilation of the ostomy is a key step in this procedure, which is traditionally accomplished with a balloon catheter, leaving behind loose redundant tissue at the ostomy site. In this 2-dimensional endoscopic operation (Video 1), we demonstrate the technique of using an aspiration device to enlarge the ETV ostomy in a controlled and efficient manner while eliminating redundant tissue. The patient is a 6-month-old girl with newly developed triventricular hydrocephalus seen on head ultrasound, manifested as upward gaze palsy, fontanelle fullness, and rapidly increasing head circumference. We chose to treat her with an ETV, given an ETV success score of 70.6,7 She underwent an ETV augmented with the NICO Myriad aspirator (NICO Corporation, Indianapolis, Indiana, USA) and achieved excellent clinical outcome. No intraoperative or postoperative complication occurred. Postoperative magnetic resonance imaging demonstrated an 8.4-mm ostomy on the third ventricular floor, nearly twice the size of a typical ETV ostomy.5 The key considerations in using this device include setting a low aspiration limit to avoid oversuction and using only mediolateral motion to avoid damage to the basilar artery. Future comparative studies are needed to investigate the efficacy, safety, and long-term outcome in aspirator-assisted ETV versus traditional techniques, as well as to evaluate ostomy size as an independent variable for long-term ETV success.

We present the case of a 17-year-old male, who complained of a 1-year onset of pulsatile headache, dysphagia, speech changes, and emotional lability. Neuroimaging revealed a large left-sided contrast-enhancing tumor located at the infratentorial space consistent with a large trochlear nerve schwannoma. The tumor was compressing the brainstem, obstructing the outflow of the third and lateral ventricles causing hydrocephalus, and disturbing the cortico-bulbar pathways bilaterally leading to the diagnosis of pseudobulbar palsy. After the patient consented the surgical procedure, he was operated through a subtemporal transtentorial approach placed in the lateral position. A lumbar drain was used for brain relaxation during the procedure and image guidance to define the limits of surgical exposure. A microsurgical technique was used, aiming to preserve the cranial nerves and the vascular structures running through the perimesencephalic cisterns. Gross total resection was achieved and clinical course remained uneventful aside from a transient third nerve palsy. Symptoms improved and the three-month follow-up revealed an almost complete function of the oculomotor nerve (Video 1). Trochlear nerve schwannomas are the rarest variety of the cranial nerve schwannomas. Depending on tumor size, clinical and neuroimaging signs of mass effect and brainstem compression, treatment can be observation, microsurgical resection through cranial base approaches or radiosurgery.1-5.

Basilar perforating artery aneurysms are rare and underreported vascular anomalies in the cerebrovascular literature. Various open and endovascular treatment approaches can be employed to treat these aneurysms based on several patient- and aneurysm-specific factors. Some authors have even advocated for conservative, nonoperative management. Here, we report a case of a ruptured distal basilar perforating artery aneurysm secured by an open transpetrosal approach. A 67-year-old male presented to our institution with a Hunt-Hess grade 2, modified Fisher grade 3 subarachnoid hemorrhage (SAH). Initial cerebral digital subtraction angiography (DSA) did not identify an intracranial aneurysm or other vascular lesions. However, the patient had a re-rupture event several days after presentation. DSA at this time revealed a posteriorly projecting distal basilar perforating artery aneurysm. Initial attempts with endovascular coil embolization were unsuccessful. Thus, an open transpetrosal approach was taken to gain access to the middle and distal basilar trunk to secure the aneurysm. This case underscores the unpredictability of basilar perforating artery aneurysms and the challenges encountered when considering active treatment. We demonstrate an open surgical approach with an intraoperative video for definitive management after failed attempted endovascular treatment.

In this illustrative operative video, the authors demonstrate a Teflon bridge technique to achieve safe transposition of a large, tortuous ectatic basilar artery (BA) and anterior inferior cerebellar artery (AICA) complex to decompress the root entry zone (REZ) of the trigeminal nerve in a 61-year-old woman with refractory trigeminal neuralgia via an endoscopic-assisted retractorless microvascular decompression. Postoperatively, the patient experienced immediate facial pain relief without requiring further medications. The Teflon bridge technique can be a safe alternative to sling techniques when working in narrow surgical corridors between delicate nerves and vessels. The operative technique and surgical nuances are demonstrated. The video can be found here: https://youtu.be/hIHX7EvZc1c.

In this illustrative video, the authors demonstrate retrosigmoid resection of a giant cystic vestibular schwannoma using the subperineural dissection technique to preserve facial nerve function. This thin layer of perineurium arising from the vestibular nerves is used as a protective buffer to shield the facial and cochlear nerves from direct microdissection trauma. A near-total resection was achieved, and the patient had an immediate postoperative House-Brackmann grade I facial nerve function. The operative nuances and pearls of technique for safe cranial nerve and brainstem dissection, as well as the intraoperative decision and technique to leave the least amount of residual adherent tumor, are demonstrated. The video can be found here: https://stream.cadmore.media/r10.3171/2021.7.FOCVID21128.