Several surgical techniques have been documented for approaching and repairing superior semicircular canal dehiscence syndrome (SCDS). These techniques encompass the trans-middle cranial fossa, transmastoid, endoscopic approaches, and round window reinforcement (RWR). RWR entails the placement of connective tissue with or without cartilage and around the round window niche, restricting the round window\'s movement to minimize the 3rd window effect and restore the bony labyrinth closer to its normal state. We employed the multilayer RWR technique, resulting in significant postoperative improvement and long-lasting effects for 3.7 years in 2 cases. Here, we present the clinical findings, surgical procedures, and the effectiveness of multilayer RWR. This technique can be the initial choice for surgical treatments of SCDS due to its high effectiveness, longer-lasting effect, and minimal risk of surgical complications.

UNASSIGNED: Dural arteriovenous fistulas (DAVFs) involving superior petrosal sinus (SPS) and superior petrosal vein (SPV) are extremely rare. The pathogenesis of these fistulas remains unclear. We are illustrating 2 cases of DAVFs involving the superior petrosal sinus and veins associated with venous sinus thrombosis with a literature review.
UNASSIGNED: We reviewed the literature using the PRISMA (preferred reporting items for systematic reviews and meta-analyses) guidelines focusing on DAVFs involving the SPS and/or SPV. Additionally, we searched for additional articles through the reference lists of the included studies.
UNASSIGNED: Our review yielded 20 articles from 1997 until 2022 involving 33 patients with 34 fistulas, including our 2 patients. The mean age was 55.1 ± 12.9 years (range 25-85), 54.5% were males (n = 18). The patients presented with hemorrhage in 36.4% (n = 12), and progressive myelopathy in 30.3% (n = 10). Most fistulas often had arterial supply from MMA, MHT, and/or OA. The fistulas had infratentorial drainage in 64.71% (n = 22), supratentorial drainage in 23.53% (n = 8), and both supra and infratentorial drainage in 11.76% (n = 4). In 27.3% (n = 9), cerebral venous thrombosis was mentioned or identified. Endovascular treatment was performed in 47.1% of cases (n = 16), surgery in 29.4% (n = 10), and combination of treatments in 23.5% (n = 8). A total of 30.3% (n = 10) of cases had incomplete recovery or poor result.
UNASSIGNED: DAVFs involving the SPS and/or SPV are associated with aggressive natural history, requiring early diagnosis and prompt treatment, leading to good prognosis. These fistulas may be acquired in origin, probably secondary to cerebral venous thrombosis.

Isolated superior petrosal sinus dural arteriovenous fistula (SPSdAVF) is a rare condition for which transvenous embolization is a safe treatment, even if accessing the isolated sinus can be challenging. A 39-year-old female patient with dizziness and right facial palsy underwent magnetic resonance imaging, revealing a venous infarction at the posterior fossa and a dural arteriovenous fistula. Digital subtraction angiography showed an isolated SPSdAVF. The shunt point was posterior to the isolated superior petrosal sinus, and the shunt flowed only through the petrosal vein. Contrast-enhanced magnetic resonance imaging showed thrombosis at the anterior segment of the superior petrosal sinus. Transvenous embolization was successfully performed via the thrombosed anterior segment of the superior petrosal sinus without associated complications. This case shows that transvenous embolization through a thrombosed superior petrosal sinus is an alternative treatment option for isolated SPSdAVF.

Transvenous embolization for cavernous sinus (CS) dural arteriovenous fistulas (CS-DAVFs) with limitations of the major access routes to the CS is challenging.
A 74-year-old woman presented with left-sided conjunctival injection and exophthalmos. Cerebral angiography showed a left CS-DAVF draining into the left uncal vein and superior ophthalmic vein, with the fistulous point located in the posterosuperior compartment of the left CS. The left inferior petrosal sinus and internal jugular vein were occluded, and no drainage route from the left superior ophthalmic vein was seen. The anterior segment of the left superior petrosal sinus (SPS) was occluded, but the posterior segment was not. Microangiography from the posterior segment of the left SPS showed a beak-like orifice in the anterior segment of the left SPS toward the left CS. A micro-guidewire was guided through the beak-like orifice, and the microcatheter was advanced into the left CS. The left CS was packed and the DAVF was occluded.
Transvenous embolization through an occluded SPS may be an option in the endovascular treatment of CS-DAVFs. Penetration along the beak-like orifice of the occluded SPS visualized by venography at the blind end of the SPS may be useful in reaching the CS via the SPS.

The presigmoid approach classically includes the ligature and section of the superior petrosal sinus to get a wider visibility window to the antero-lateral brainstem surface. In some cases, the separation of this venous structure should not be performed.
We present our experience getting safely to a pontine cavernous malformation through a conventional mastoidectomy presigmoid approach preserving an ingurgitated superior petrosal sinus because the association with an abnormal venous drainage of the brainstem.
When sectioning the superior petrosal sinus in classical presigmoid approaches is contraindicated, its preservation could also offer good surgical corridors to get to small-medium anterior and lateral brainstem cavernous malformations.

The superficial middle cerebral vein (SMCV) commonly drains in the cavernous sinus. Its different drainage variants include preserved segments of the primitive tentorial sinus. In any of these variants, the terminal venous segment of SMCV passes on the base of the skull. The archived computed tomography angiograms of a 58-year-old female case were documented anatomically. On the left side was found the sinus of the lesser sphenoidal wing converging with the middle meningeal vein to form a venous channel located within the Sylvian fissure at 4 mm laterally to the cavernous sinus and trigeminal cavum. That venous channel was thus termed the \'laterocavernous vein\'. It drained posteriorly within the superior petrosal sinus. This aberrant vein could interfere unpleasantly with pterional neurosurgical approaches for the Sylvian fissure, cavernous sinus or trigeminal ganglion.

Petroclival meningiomas represent the most complex lesions in skull base surgery, being closely related to critical neurovascular structures. The combined petrosal approach allows a wide exposure of the petroclival region and provides multiple angles of attack, limiting brain retraction. The authors present the case of a 54-year-old man with a large left petroclival meningioma responsible for headaches, dysphagia, and trigeminal neuralgia. The lesion was resected using a combined petrosal approach. A progressive improvement of the preoperative symptoms was observed. Postoperative MRI showed a near-total resection of the tumor, along with reexpansion of the brainstem. The video can be found here: https://stream.cadmore.media/r10.3171/2022.1.FOCVID21226.

Trigeminal schwannomas are benign tumors amendable to curative surgical resection.1 Excellent outcomes, with preservation and improvement of cranial nerve function, including trigeminal nerve function, have been reported with microsurgical resection through skull base approaches.2 Dumbell shaped tumors, involving the middle and posterior fossa, are more challenging.3 They are resected via a middle cranial fossa approach with the expanded Meckel cave providing access to the posterior fossa. However, tumors with a large caudal extension below the internal auditory meatus typically cannot be adequately accessed with this approach and the posterior petrosal approach is utilized.2 Specific venous anatomy might deter from cutting the tentorium. This article describes the surgical resection of a trigeminal schwannoma with a large posterior fossa component through a petrosal approach without cutting the tentorium.4 The patient is a 34-yr-old man who presented with headaches and gait disturbance. Neurological exam revealed hypoesthesia and hypoalgesia in the left V1 and V2 distributions. Magnetic resonance imaging (MRI) revealed a large dumbbell-shaped schwannoma causing brainstem compression. Magnetic resonance venography (MRV) demonstrated temporal lobe venous drainage into the superior petrosal sinus and tentorium proximal to the transverse sigmoid junction. A single temporal-suboccipital bone flap and a retro-labrynthine mastoidectomy were performed. The petrous apex was drilled and Meckle\'s cave opened. The presigmoid dura was opened and extended toward the petrous apex region beneath the tentorium. This provided access to and safe resection of the tumor. A gross total tumor resection was achieved. The patient remained stable neurologically and was without tumor recurrence at 3 yr postoperatively. The patient had consented to the procedure. Figures in video at 4:06 from Jafez et al, Preservation of the superior petrosal sinus during the petrosal approach, J Neurosurg. 2011;114(5):1294-1298, with permission from JNSPG.

Petroclival region dural arteriovenous fistulas (DAVFs) are rare and difficult lesions to manage. They often have very complex anatomical structures and can be further divided into the superior petrosal sinus, petrous apex, inferior petrosal sinus, upper clival, and upper clival epidural-osseous DAVFs. Most petroclival region DAVFs should be treated due to their high Cognard grades. Currently, endovascular treatment (EVT) has become the first-line therapeutic option for petroclival region DAVFs. But not all the petroclival region DAVFs could be cured with EVT. When the arterial feeders are large or the DAVF is adjacent to the venous sinus, the success rate may be higher. In petroclival region DAVFs, if EVT can be performed successfully, satisfactory outcome can be anticipated. However, there are some inadvertent complications, which include cranial nerve palsy, subsequent sinus thrombosis, and migration embolization of the internal carotid artery and vertebral artery. Currently, a review of the EVT of petroclival region DAVFs is lacking. In this article, we performed a review of the relevant literature on this issue. In addition, some illustrative cases would be provided to elaborate these specific entities.

An adult male was found to have a variation of the left basal vein of Rosenthal after presenting with complaints of headache and balance issues. In this case, the vein drained directly into the left superior petrosal sinus (SPS) instead of the great vein of Galen. Anatomical variation of the basal vein is likely due to embryonic development of the deep cerebral venous system as primitive structures either differentiate regress or further with age. These changes may result in the uncommon presentation seen in this case. To our knowledge, this is the first case that shows the basal vein drains into the SPS. The normal and variant anatomy of this vessel are discussed.