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Background/Aim: Brain arteriovenous malformations (AVMs) are vascular malformations characterized by dysmorphic, aberrant vasculature. During previous surgeries of compact nidus brain AVMs (representing the majority of cases), we have observed a "shiny" plane between nidal and perinidal AVM vessels and the surrounding grey and white matter and hypothesized that preoperative neuroimaging of brain AVMs may show a neuroradiological correlate of these intraoperative observations. Patients and Methods: We retrospectively reviewed and analyzed multiplanar and multisequence 3-Tesla magnetic resonance (3T MR) imaging in five consecutive brain AVMs with special attention on imaging characteristics of the brain-AVM interface, i.e., the perivascular and perinidal regions. Results: In all five patients, we identified T2-hypertinense perivascular perinidal spaces, which were predominantly observed around the AVM nidus and less prominently around the feeding arteries or draining veins. Conclusion: The identification of T2-hypertinense perivascular spaces surrounding brain AVMs on neuroradiological imaging may provide insights into the anatomico-radiological relationships of brain AVMs and the surrounding grey and white matter parenchyma. These findings could have future implications for our understanding of brain AVM biology and may influence neurosurgical approaches to these lesions. [ABSTRACT FROM AUTHOR]

Brainstem cavernoma is a challenging neurosurgical pathology and microsurgery remains the only treatment option. Although the decision-making between interventional and conservative approach to this disease may be complex, malformations presenting multiple bleedings are usually good candidates for surgery. 1 On the other hand, microsurgical resection of cavernomas can offer an effective resolution with acceptable morbidity. In this video, we present a case of pontine cavernoma with multiple hemorrhages in a young patient. The anatomical characteristic of the lesion defines the best suitable craniotomy for surgery. In this case, an anterior petrosal approach 234 was used to access the peritrigeminal area and safely perform the resection. Anatomical considerations are described on this skull base approach along with the rationale and benefits of this exposure. Electrophysiological neuromonitoring is essential for this kind of procedure and preoperative tractography also enabled the best understanding of the disease. Finally, we also discuss alternative managements and potential complications. 5 With the patient's consent, we also show the excellent clinical evolution after few weeks of recovery and the restoration of the corticospinal tract, previously displaced by the cavernoma, to its original position. [ABSTRACT FROM AUTHOR]

We present a case of a 37-year-old female, with progressive left eye proptosis and an extensive ipsilateral en plaque spheno-orbital meningioma, with diffuse involvement of the lateral wall of the cavernous sinus and the orbit. A cranio-orbital zygomatic approach was performed to reach all extension of the lesion. We made an extradural clinoidectomy and an extensive bone removal of the orbit, exposition of the superior and lateral walls of the cavernous sinus, unroofing of the optic canal, superior orbital fissure, foramen rotundum, and foramen ovale. We performed the peeling of the lateral wall of cavernous sinus with total removal and preservation of the cranial nerves anatomy and function. In this video, we illustrate the importance of the first time aggressive removal of such tumors. We also demonstrate the concept that secondary invasion of the cavernous sinus are suitable for removal with cranial nerve preservation. The link to the video can be found at https://youtu.be/GJmkqVa6jSs. [ABSTRACT FROM AUTHOR]

A 47-year-old woman was referred to the neurological surgery department after a self-limiting episode of dizziness and headache. Magnetic resonance imaging showed an extra-axial mass in the right petrous apex, suggesting a meningioma. We chose the anterior petrosal approach (APA) because meningioma is a benign tumor with brainstem compression, and our goal was total removal for potential cure of the disease. The APA is appropriate for lesions located in the superior petroclival region with a narrow dural tail, above cranial nerves VII and VIII. The posterior petrosal approach is for large petroclival meningiomas that cross the midline, involving the basilar artery and perforating branches, extending below cranial nerves VII and VIII and above the jugular foramen. The retrosigmoid approach is for lesions located in the petrous apex and petroclival regions. Limitations include working between the posterior fossa cranial nerves and removing extensions of the tumor to Meckel cave and middle fossa. The endoscopic endonasal approach is for petroclival lesions. Limitations are the longer distance, nasal disturbances, middle fossa dural tail removal, and cerebrospinal fluid fistula. 1-8 We performed the APA through a suprapetrous craniotomy, which exposes the petrous temporal portion, to drill the posteromedial triangle of the middle fossa to create a surgical corridor to the posterior fossa after splitting the tentorium. 1-8 Removal of the tumor through the APA leads to a direct route to the petrous apex, with short distance and predominant extradural dissection. We achieved gross total removal. The patient presented with transient cranial nerve IV and V disturbances, but recovered entirely in 6 weeks, returning to her professional activities with preserved quality of life (Video 1). [ABSTRACT FROM AUTHOR]

Dural arteriovenous fistulae at the craniocervical junction are rare. When present together with spinal and cranial venous reflux they can have an aggressive natural history with hemorrhage or progressive myelopathy from venous congestion. In this operative video we demonstrate key steps in the surgical ligation of a dural arteriovenous fistula supplied by meningeal branches of the V4 segment of the vertebral artery.  Informed consent was obtained. The patient was positioned prone with chin tucked. Utilizing a midline suboccipital craniotomy and removal of the arch of C1, the vertebral artery was identified at its V4 segment at it transitions from extra to intradural. The video illustrates how a midline approach can be used to access this lesion and a far lateral approach is not required to access the vertebral artery and its dural branches at the craniocervical junction. Division of the denticulate ligaments and mobilization of the spinal accessory nerve allows visualization of the proximal portion of the draining vein. Important anatomy in this region is demonstrated. The critical use of indocyanine green (ICG) dye is demonstrated as the first 2 clip applications were not proximal enough to obliterate the proximal draining vein and persistent early venous reflux was still seen on ICG. The importance of access to and obliteration of the proximal draining vein is shown. An intraoperative ICG and postoperative angiogram demonstrates complete occlusion of the dural arteriovenous fistula.  In this case the patient had minor sensory deficits postoperatively which were resolved by 6 wk postoperatively., (Copyright © 2019 by the Congress of Neurological Surgeons.)

Cavernous malformations (cavernomas) of the brain stem with recurrent hemorrhage may be amenable to microsurgical resection if they are present close to the surface. The risks of surgery need to be balanced with the natural history of the lesion and the accumulation of neurological deficits and risk to life with multiple hemorrhages. In this 3D operative video, we illustrate the technique for the resection of a dorsally located midbrain cavernous malformation. Informed consent was obtained for this procedure. The cavernoma is accessed with the use of a supracerebellar infratentorial approach. The infratentorial craniotomy and coagulation of the superior vermian veins is shown. A description is provided of the use of hemosiderin staining and the intercollicular relative "safe zone"1 as landmarks for the neurotomy. The technique of cavernoma dissection from the surrounding gliotic plane is shown and described. In this case, the patient required prolonged rehabilitation but fully recovered without residual deficit 1 yr following surgery., (Copyright © 2019 by the Congress of Neurological Surgeons.)

Cavernomas presenting with seizures refractory to medical treatment may require surgical excision for seizure control. If superficial, they can be surgically accessible but can pose additional risks when located in or near eloquent cortex. In this 3D operative video we illustrate the technique for the resection of a left temporal cavernoma located near eloquent cortex for speech with awake surgery and cortical mapping to avoid a speech deficit postoperatively. Informed consent was obtained for this procedure. Navigation is used to localize the cavernoma following which a large craniotomy is performed exposing the temporal lobe, frontal lobe, and sylvian vein. Bipolar stimulation is used to localize speech with the patient awake until speech arrest occurs. The cavernoma is situated immediately inferior to the sulcus over which speech arrest occurs. The sulcus immediately above the cavernoma is opened and adjacent arteries are carefully preserved. The glial plane around the cavernoma is used to dissect the cavernoma from the surrounding cortex. Care is taken to remove the haemosiderin as this can act as a precipitant for ongoing seizures. In this case the patient had no neurological deficits following surgery and was seizure free., (Copyright © 2018 by the Congress of Neurological Surgeons.)

Training is a process that requires patience and constant practice. The execution of microscopic procedures is present in the day-to-day of several surgical specialties, but unfortunately experimental models are not easy to access in our environment. We propose a bovine heart model used by residents and young surgeons in the training of microscopic dissection and microanastomoses. It is described the assembly of this model, which can be performed individually and with accessible material to the surgical departments. Our experience in the preparation of the pieces, as well as tips for the process, are described in the text. The bovine myocardial model can be reproduced in any center with benches and surgical instruments. Low cost, fast preparation, and wide availability of the used tissue are among the advantages of this model. We consider the project useful in the training of surgical residents and young surgeons.