Clipping of Bilateral Ophthalmic Artery Aneurysms Through a Single Craniotomy

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.

Transpetrosal Approach to a Ruptured Distal Basilar Perforating Artery Aneurysm

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.

Quality of YouTube Videos on Laparoscopic Pyeloplasty in Children: An Independent Assessment by Two Pediatric Surgeons

Background YouTube (YT) is the most common video platform accessed by surgical trainees for the preparation of surgery. However, the quality of the YT videos has been questioned time and again. This study was performed to comprehensively assess the quality of the available YT videos on pediatric laparoscopic pyeloplasty (LP). Materials and Methods The term "laparoscopic pyeloplasty in children" was searched in YT on June 3, 2021, and ten most-viewed videos on LP were included. The percentage video power index (%VPI), the Journal of American Medical Association (JAMA) benchmark criteria, and the laparoscopic surgery video educational guidelines (LAP-VEGaS) video assessment tool were used to assess the video popularity, the quality of medical information, and the overall quality of the included videos respectively. Videos were defined as acceptable (score of 11 or more) or poor quality (score <11) based on LAP-VEGaS scores. The inter-observer agreement, in terms of the LAP-VEGaS scoring, was observed among two surgeons using the kappa statistics. Results The median values of the %VPI and JAMA scores of the included YT videos were 68.1 (range 0-13570) and 2 (range 1-2) respectively. The median LAP-VEGaS score of these videos was 6.75 (range 2-16.5) with only two videos having acceptable quality. The quality of these videos was poor in 7/9 domains of the LAP-VEGaS tool. A moderate inter-observer agreement (kappa=0.542) was observed in terms of the LAP-VEGaS scores assigned to the videos (p<0.0001). Conclusion A comprehensive assessment of the ten most-viewed YT videos on pediatric LP revealed poor overall quality. The included videos depicted sub-optimal presentation of the medical information and weak conformity to the LAP-VEGaS guidelines.

Clamshell thoracotomy for en bloc resection of a 3-level thoracic chordoma: technical note and operative video

The clamshell thoracotomy is often used to access both hemithoraxes and the mediastinum simultaneously for cardiothoracic pathology, but this technique is rarely used for the excision of spinal tumors. We describe the use of a clamshell thoracotomy for en bloc excision of a 3-level upper thoracic chordoma in a 20-year-old patient. The lesion involved T2, T3, and T4, and it invaded both chest cavities and indented the mediastinum. After 2 biopsies to confirm the diagnosis, the patient underwent a posterior spinal fusion followed by bilateral clamshell thoracotomy for 3-level en bloc resection with simultaneous access to both chest cavities and the mediastinum. To demonstrate how the clamshell thoracotomy was used to facilitate the tumor resection, an operative video and illustrations are provided, which show in detail how the clamshell thoracotomy can be used to access both hemithoraxes and the mediastinum.

Endoscopic Endonasal Transclival Odontoidectomy for Basilar Invagination: Operative Video and Technical Nuances

Basilar invagination is a congenital or acquired craniovertebral junction abnormality where the tip of the odontoid process projects through the foramen magnum which can cause severe symptomatic compression of the brainstem and spinal cord. If left untreated, patients can develop progressive quadriparesis. Traditionally, basilar invagination can be treated with cervical traction and posterior stabilization. However, in irreducible cases, anterior decompression via a transoral or endonasal approach may be necessary. In this operative video, we demonstrate an endoscopic endonasal transclival approach for odontoidectomy to successfully treat a 37-year-old female with severe basilar invagination causing symptomatic compression on the cervicomedullary junction resulting in unsteady gait and motor weakness. The patient had Klippel–Feil syndrome where the C1 arch was assimilated to the foramen magnum and transclival drilling was needed to adequately access the odontoid process for removal. A second-stage posterior occipitocervical stabilization and fusion was performed the following day. Immediate postoperative imaging showed excellent decompression of the cervicomedullary junction. Postoperatively, the patient had significant improvement in gait and motor strength in all extremities, and was ambulating independently without assistance at 1 year after surgery. The endoscopic endonasal transclival odontoidectomy is a useful strategy to treat severe irreducible basilar invagination causing symptomatic neural compression. The surgical technique and nuances are described in a step-by-step fashion in this illustrative operative video.

The link to the video can be found at: https://youtu.be/HL4K7KqJEJM.

Midline Suboccipital Subtonsillar Approach in Semisitting Position for Resection of Jugular Tubercle Meningioma: 2-Dimensional Operative Video

We present a case of a large jugular tubercle meningioma that was removed through a midline suboccipital subtonsillar approach in semisitting position. The patient is a 49-year-old woman with chronic, medication-resistant cephalgias but devoid of any subjective focal neurological deficit. On magnetic resonance imaging (MRI), an extra-axial lesion, originating from the left jugular tubercle was discovered. There was significant obliteration of the peripontine cisternal space, and compression of the adjacent pontomedullary junction; the lesion also extended into the left jugular foramen.

On physical exam, an absent gag reflex was noted on the left, as well as a moderate deviation of the uvula to the contralateral side (partial Vernet's syndrome).

A gross-total resection was achieved, histopathology confirmed a World Health Organization (WHO) grade I angiomatous meningioma with a low-proliferation index. The patient was discharged home 4 days after surgery with intact function of the lower cranial nerves (CN) following immediate and complete resolution of the preexisting partial CNs IX and X deficits. At 2-year follow-up, there was no indication of intradural residual or recurrence.

In summary, the midline suboccipital subtonsillar approach is a simple and effective tool with limited morbidity in the armamentarium for the microsurgical management of pathologies residing in the posterior cranial fossa or the craniocervical junction.

Major limitations exist for lesions extending above the internal acoustic canal or those of fibrous consistence featuring widespread adhesion to the ventral brainstem or vascular encasement. Provided the necessary anesthesiological precautions and intraoperative procedures the semisitting position is safe and effective.

The link to the video can be found at: https://youtu.be/bbVXagwhDCo .

Endoscope-Assisted Retromastoid Intradural Suprameatal Approach for Trigeminal Schwannoma

Background and Introduction

Dumbbell trigeminal schwannoma is the second most common type of intracranial schwannomas.

Objective

Herein, we are describing and presenting a video of left trigeminal dumbbell schwannoma with a predominant posterior fossa component (modified Samii's grade C1), operated through left Retromastoid Intradural Suprameatal Approach (RISA). We demonstrate a step by step technique of a previously defined procedure for educational purpose.

Surgical Technique

The patient was placed in the right lateral position, and left retromastoid craniotomy was done. Dura was opened based on transverse and sigmoid sinus to expose tumors in the suprameatal region. The tumor removed piecemeal under the microscope, and later endoscope was introduced to identify and remove the residual tumor in the superolateral part of Meckel's cave.

Results

The patient had an uneventful recovery.

Conclusion

Trigeminal schwannoma with a predominantly posterior fossa component can be excised through retromastoid sub-occipital craniotomy. Endoscopic-assisted microsurgery should be considered in all skull base tumors. Aim for complete excision, but safe maximal resection with GKRS for residual can be considered in difficult cases.

Retrosigmoid Approach for Resecting a Giant Lateral Pontine Ependymoma: Two-Dimensional Operative Video

Ependymoma is one of the most common pediatric tumors in central nervous system, for which gross total resection has been the most favorable prognostic factor. 12 However, surgery of ependymomas located in brain stem is significantly challenging. This video demonstrates the microsurgical removal of an ependymoma originating from ependymal cells of the lateral recess of fourth ventricle via retrosigmoid approach in an 11-year-old female. The patient presented with a 6-month history of continues headache and vomiting. On examination, she had a walking instability and an emaciated body. Neuroimaging revealed a right lateral pontine lesion extending to the cerebellopontine angle region. The patient underwent a suboccipital craniotomy, followed by excellent exposure for the tumor. Petrosal vein encased by the tumor mass and close adhesion of the tumor and the initial segments of facial and acoustic nerves adjoined brain stem could be seen operatively. While preserving trigeminal nerve, facial and acoustic nerves, posterior cranial nerves, anterior inferior cerebellar artery, labyrinth artery, posterior inferior cerebellar artery, and petrosal vein, gross total resection was achieved under the careful operation along arachnoid spaces together with intratumoral decompression. The patient tolerated the procedure well without any neurological deficits. Histological examination confirmed the tumor as an ependymoma (WHO II). The cytology measurement of the cerebrospinal fluid did not find any tumor cells. Postoperative computed tomography and magnetic resonance imaging scan depicted complete resection of the tumor, and adjuvant radiotherapy was recommended. She remained symptom-free without any evidence of recurrence during the follow-up period of 1 year. Informed consent was obtained from the patient.

The link to the video can be found at: https://youtu.be/sZ9GhUeltwc .

Lateral Suboccipital Approach in Semisitting Position for Resection of Vagal Schwannoma: 2-Dimensional Operative Video

We present a case of a sizeable vagal schwannoma that was resected through a lateral suboccipital approach in semisitting position. An extra-axial lesion, occupying the left cerebellomedullary cistern and extending from the pontomedullary junction to the jugular foramen was incidentally discovered in a 40-year-old woman afflicted with secondary progressive multiple sclerosis during repeated magnetic resonance imaging ( Fig. 1 ). On physical examination, a mild deviation of the uvula to the right and a diminished gag reflex were observed. The patient was referred to our department after considerable growth of the lesion was noted and a broad interdisciplinary consensus was reached to treat the lesion surgically. A gross total resection was achieved, histopathology confirmed a WHO I schwannoma with a low proliferation index. Postoperative dysphonia resolved completely within a few weeks, there was no collateral neurological deficit and especially no functional dysphagia. At 3-year follow-up, there was no indication of residual or recurrence. This 2-dimensional video demonstrates pre- and postoperative imaging, positioning and set-up of operating room, anatomical and surgical nuances of the skull base approach, and the operative technique for microdissection of the schwannoma from the critical neurovascular structures ( Fig. 2 ). In summary, the lateral suboccipital approach in semisitting position is a powerful tool in the armamentarium for the microsurgical management of various pathologies residing in the posterior cranial fossa, especially large and vascularized schwannomas. Provided the necessary anesthesiological precautions and intraoperative procedures the semisitting position is safe and effective. The link to the video can be found at: https://youtu.be/-9o_qJGkQhg .

C1 Hemilaminectomy for Resection of Foramen Magnum Meningioma: 2-Dimensional Operative Video

We present a case of a sizeable foramen magnum meningioma that was resected through a C1 hemilaminectomy in prone (concorde) position. The patient is a 51-year-old woman with a 3-month history of progressive paresthesia of the upper and lower extremities, followed by gait disturbance, and hand apraxia. There was no complaint of nuchal pain.

On magnetic resonance imaging (MRI) a briskly enhancing extra-axial, intradural craniospinal lesion, extending from the basion of the lower clivus, over the tectorial membrane to the middle of the axis' body was discovered. There was significant transposition and compression of the medulla and corresponding focal hyperintensity on T2-weighted imaging.

On physical examination, the patient was ambulatory independently, notwithstanding a pronounced spinal ataxia. There were deficits in sensation and proprioception, as well as urinary retention, but preserved function of the lower cranial nerves.

In view of the profound transposition of the medulla, utilization of the corridor created by the tumor seemed feasible and we felt that a limited C1 hemilaminectomy would provide sufficient microsurgical access thus obviating a more extensive and invasive approach to the craniocervical junction.

A gross-total resection was achieved; histopathology confirmed a World Health Organization (WHO) grade I angiomatous meningioma with a low-proliferation index. The patient was discharged home 3 days after surgery and her spinal ataxia resolved completely within 3 months of out-patient rehabilitation. At 3-year follow-up, there was no indication of residual or recurrence.

The link to the video can be found at: https://youtu.be/WyShbfr-xi0 .

Midline Suboccipital Subtonsillar Approach with C1 Laminectomy for Resection of Foramen Magnum Meningioma: 2-Dimensional Operative Video

We present a case of a medium-sized foramen magnum meningioma that was resected through a midline suboccipital subtonsillar approach with C1 laminectomy in prone (Concorde) position. The patient is a 77-year-old woman with a 6-month history of intermittent vertigo, moderate gait instability, and slight decline of memory. On magnetic resonance imaging (MRI) an extra-axial intradural lesion was discovered that originated from the right epicondylar region just inferior to the jugular tubercle and occupied the anterolateral aspect of the foramen magnum. There was moderate transposition and compression of the medulla at the level of the cerebellar tonsils. On physical examination the patient was ambulatory independently without motor weakness but exhibited some gait instability. The function of the lower cranial nerves was preserved. A gross-total resection was achieved, histopathology confirmed a WHO grade-I meningothelial meningioma with a low-proliferation index. The patient was discharged home 5 days after surgery, her gait instability improved significantly immediately after surgery and had resolved completely after 2 weeks of inpatient rehabilitation. There was no other neurological deficit. At 3-month follow-up MRI, there was no indication of meningioma residual or recurrence. In summary, the midline suboccipital subtonsillar approach is a powerful tool with limited morbidity in the armamentarium for the microsurgical management of a variety of pathologies residing in the posterior cranial fossa and the craniocervical junction. Oftentimes the space created by the pathology opens up corridors that can be exploited for microsurgical access to avoid more extensive surgical approaches. The link to the video can be found at: https://youtu.be/0uUxs13ze7w .

Resection of a Meningioma at Craniocervical Junction through Far Lateral Approach: Two-Dimensional Operative Video

Tumors located in the craniocervical junction region are significantly challenging for surgical resection. We shared our experience of a meningioma at craniocervical junction resected through far lateral approach in a 68-year-old female. The patient presented with intermittent headache with discomfort in the neck and shoulders for 3 years without any positive signs. Magnetic resonance imaging (MRI) revealed a tumor of 3.6 cm × 3.0 cm × 2.5 cm lying at the ventral side of medulla oblongata, with T1 hypointensity, T2 hyperintensity, and a significant enhancement on T1-contrast image. The far lateral approach on the right side was planned to resect the tumor with a park-bench position. The patient underwent a standard craniotomy using a lazy S -shaped incision. The transposition of vertebral artery was performed carefully therein, followed by removal of part of the arches of atlas and axis. After exposure of the tumor, vertebral artery (VA) and posterior inferior cerebellar artery (PICA) adhesive to the lesion could be seen operatively. Truncating the supplying blood vessels of the tumor was taken as the first step, followed by resecting the tumor mass in a piecemeal manner. While preserving VA, PICA, posterior nerves, medulla oblongata, and cervical cord, gross-total resection was achieved under the careful operation. The patient tolerated the procedure well without any neurological deficits. Histological examination confirmed the tumor as a meningioma (World Health Organization [WHO] grade I). Postoperative MRI scan depicted complete resection of the tumor. The patient remained symptom free without any evidence of recurrence during the follow-up period of 1 year. Informed consent was obtained from the patient. The link to the video can be found at: https://youtu.be/i9H-wS4fF10 .

Anterolateral Approach with Endoscopic Assistance for Resection of a Craniovertebral Junction Chordoma

Craniovertebral junction chordomas can represent a surgical challenge, especially when intradural extension and contact with neurovascular structures is involved. To date, there is still controversy on the choice of optimal surgical corridor for such lesions, with endoscopic endonasal, far lateral and anterolateral corridors being those most commonly used. In this operative video, we present a case of craniovertebral junction chordoma with significant bone destruction and intradural extension ( Fig. 1 ). The tumor was safely removed using an anterolateral approach with transposition of the vertebral artery to gain access to the lateral craniovertebral junction. The endoscope is demonstrated to help with intradural tumor removal, providing a wide angle of view through a relatively narrow dural opening ( Fig. 2 ). In this video, nuances of the anterolateral approach, chordoma removal strategies and closure technique are presented in detail. A gross total resection was achieved, and the postoperative course was uneventful. In summary, the anterolateral approach with endoscopic assistance can offer a safe and effective corridor for the surgical management of craniovertebral junction chordomas.

The link to the video can be found at: https://youtu.be/pC0YxKgNoMY .

CPA Epidermoid Cyst with Rare Anatomic Variant: Anterior Inferior Cerebellar Artery Embedded in the Subarcuate Fossa: Operative Video and Technical Nuances

Intracranial epidermoid cysts are considered benign tumors with a good general prognosis; however, their radical removal, including tumor capsule, is associated with significant morbidity, especially when the capsule is attached to neurovascular structures. We show an operative video describing main steps and surgical nuances in the resection of a large right cerebellopontine angle (CPA) epidermoid cyst in a 42-year-old male patient who presented with intractable trigeminal neuralgia. Craniectomy was performed to exposure the transverse-sigmoid sinus junction. A mold for a polymethylmethacrylate (PMMA) bone flap was built before opening the dura to avoid potentially neurotoxic effects on the cerebellum. The video illustrates the management of the rare anatomical variant of the anterior inferior cerebellar artery (AICA). Its loop was embedded in the dura, covering the subarcuate fossa where it gives off the subarcuate artery. Near total removal of the epidermoid cyst was achieved, leaving only a tiny capsule remnant adhering to the abducens nerve. Postoperatively the patient's trigeminal neuralgia was fully relieved and medications were discontinued. The patient's hearing was preserved per audiometry at the preoperative level (Gardner-Robertson II). Postoperative magnetic resonance imaging (MRI) revealed no signs of residual tumor. In this case, it was not possible to obtain optimal surgical exposure of the CPA without handling a rare anatomical anomaly of the AICA in the dura of the subarcuate fossa, which demanded coagulation and transection of the subarcuate artery and transposition of AICA with the dural cuff. This manipulation enabled optimal surgical removal of the epidermoid and didn't cause any neurological deficit. The link to the video can be found at: https://youtu.be/lLZqBHlu-uA .

Suboccipital Lateral Approach for Resection of Cerebellopontine Angle Meningioma: Operative Video and Technical Nuances

We present the case of a 34-year-old woman, who presented to our department with a 4 months history of dizziness, hearing loss, and tinnitus on the right side. MRI (magnetic resonance imaging) scan demonstrated a large extra-axial lesion, suggestive of a meningioma, with dural attachments to the petrosal bone surface and tentorium, closely related with the trigeminal, abducens, facial, vestibulocochlear, and lower cranial nerves in the right side. Treatment options were discussed with the patient, and surgical resection was selected to remove the lesion, and decompress the cranial nerves and brainstem. The surgery was performed with a patient in a semi-seated position with head placed in a flexed, nonrotated position. A right lateral suboccipital approach was performed, exposing the right transverse and sigmoid sinuses. After dura opening, microsurgical dissection was used to open the cisterna magna, and obtain cerebellum relaxation. That was followed by identification of cranial nerves VII-XII and then identification of the tumor itself. Tumor debulking was then performed with use of suction and ultrasonic aspirator. After extensive resection, the tumor margins were dissected away from brainstem, cerebellum, and cranial nerves. Finally, the tumor attachment to the tentorium was coagulated and cut and the tumor was completely removed. Postoperative MRI confirmed complete resection of the tumor. The patient was discharged on the 1st week after surgery, with no additional postoperative deficits or complications. The link to the video can be found at: https://youtu.be/aZ3jhZTAeAA .

Combined Frontotemporal Transbasal Approach for the Resection of a Giant Rathke's Cleft Cyst: Operative Video and Technical Nuances

We present a case of a giant Rathke's cleft cyst with significant superior extension into the third and right lateral ventricles and lateral extension into the left Sylvian fissure and over the anterior clinoid process. An extended modification of the frontotemporal approach was performed using a combined frontotemporal transbasal approach. This allowed wide exposure to both transsylvian and subfrontal corridors to the retrochiasmatic space. This video atlas demonstrates the operative technique and surgical nuances of the skull base approach, microdissection of the tumor, and safe handling of the neurovascular structures. A gross total resection was achieved and the patient was neurologically intact with improved visual acuity. In summary, the combined frontotemporal transbasal approach is an important strategy in the armamentarium for the surgical management of giant Rathke's cleft cysts.

The link to the video can be found at: https://youtu.be/UjhnUZVi03I .

Surgery of Tuberculum Sellae Meningioma: A Technical Purview on Pterional Approach

Objective  Amidst the raging debate between transnasal and transcranial approaches, the critical factor that dictates success lies in the meticulous dissection of the tumor from the optic apparatus, anterior communicating artery complex, and the pituitary stalk. In this surgical video, we describe the resection of a tuberculum sellae meningioma through the pterional approach highlighting dissection through the appropriate arachnoidal plane.

Case Description  The patient is a 75-year-old female who presented with optic nerve compression with bitemporal hemianopia and endocrine function abnormalities. A transcranial approach was done to effectively decompress the optic nerve. The video includes a detailed discussion on the surgical techniques including working between the different surgical corridors, working in the arachnoid plane to dissect the neurovascular structures away from the tumor, identification, and preservation of pituitary stalk. Postoperatively, the patient's visual field deficit improved with a remaining isolated right temporal field defect at 2 months follow-up. Her endocrine function improved after the surgery.

Conclusion  In the era of endoscopic surgery, transcranial approaches for suprasellar tumors like tuberculum sellae meningiomas still have a distinct surgical role. Our discussion extends to reiterate the strengths and weaknesses of the transcranial approach to this region as compared with the endoscopic approach. We believe decompression of optic nerves, separation of Acom complex from the tumor, and preservation of pituitary stalk are better achieved through a transcranial approach.

The link to the video can be found at :https://youtu.be/kw5eP3oUd6Q .

Modified One-Piece Extended Transbasal Approach for Endoscopic-Assisted Microsurgical Resection of Tuberculum Sellae Meningioma: Operative Video and Technical Nuances

The optimal approach for surgical resection of tuberculum sellae meningiomas remains controversial. Approach selection is largely based on a variety of factors, such as tumor size, extent and location relative to the optic canal and internal carotid artery, the presence of vascular encasement, and surgeon's preference. In this operative video manuscript, the authors demonstrate the importance of an open transcranial approach when the tumor extends lateral to the optic nerve over the internal carotid artery into the opticocarotid triangle, which is a difficult region to safely access with a purely endoscopic endonasal approach. We present a case of an endoscopic-assisted microsurgical resection of a tuberculum sellae meningioma using a modified one-piece extended transbasal approach in a patient with unilateral visual loss. The approach allows both interhemispheric and subfrontal routes to the suprasellar region. Early optic nerve decompression and division of the falciform ligament is critical to optimize visual outcomes. This video atlas demonstrates the operative technique and surgical nuances of the skull base approach, optic nerve decompression, tumor-arachnoid dissection, and safe handling of the neurovascular structures. A gross total resection was achieved and the patient had restoration of normal vision with normal pituitary function. In summary, the modified one-piece extended transbasal approach with endoscopic assistance is an important strategy in the armamentarium for surgical management of tuberculum sellae meningiomas.

The link to the video can be found at: https://www.youtube.com/watch?v=jKNtRzMSFVE .

Combined bi-occipital suboccipital transsinus transtentorial approach for resection of a pineal region falcotentorial meningioma: operative video and technical nuances

Large deep-seated meningiomas of the falcotentorial region present a formidable surgical challenge. In this operative video, the author demonstrates the combined bi-occipital suboccipital transsinus transtentorial approach for microsurgical resection of a large falcotentorial meningioma. This approach involves division of the less dominant transverse sinus after assessment of the venous pressure before and after clipping of the sinus with continuous neurophysiologic monitoring. Mild retraction of the occipital lobe and cerebellum results in a wide supra- and infratentorial exposure of extensive pineal region tumors. This video atlas demonstrates the operative technique and surgical nuances, including patient positioning, supra- and infratentorial craniotomy, transsinus transtentorial incision, and tumor removal with preservation of the vein of Galen complex. In summary, the combined bi-occipital suboccipital transsinus transtentorial approach provides a wide supra- and infratentorial surgical corridor for removal of select falcotentorial meningiomas. The video can be found here: https://youtu.be/3aD8h2uwBAo .

Endoscopic-assisted posterior interhemispheric retrocallosal transfalcine approach for microsurgical resection of a pineal region falcotentorial meningioma: operative video and technical nuances

Falcotentorial meningiomas are rare tumors of the pineal region that arise from the dural folds where the falx and tentorium meet and are often intimately related to the vein of Galen and straight sinus. These lesions often present with signs and symptoms related to hydrocephalus and brainstem compression. Surgical resection of falcotentorial meningiomas remains the definitive treatment, with a variety of surgical approaches used to resect these lesions. The choice of approach depends on several factors, including the size and location of the tumor relative to the vein of Galen complex. Falcotentorial meningiomas can be technically challenging to remove with significant risk of morbidity because of the close proximity to and occasional invasion of the vein of Galen and straight sinus. In this operative video, the authors demonstrate an illustrative step-by-step technique for endoscopic-assisted microsurgical resection of a falcotentorial meningioma using the posterior interhemispheric retrocallosal transfalcine approach for a superiorly positioned falcotentorial meningioma. The surgical nuances are discussed, including the surgical anatomy, gravity-assisted interhemispheric approach in the lateral position, retrocallosal dissection, transfalcine exposure, tumor removal, and preservation of the vein of Galen complex. In summary, the posterior interhemispheric retrocallosal transfalcine approach is a useful surgical strategy for select superiorly positioned falcotentorial meningiomas. The video can be found here: https://youtu.be/d8mdunsRacs .

Direct suction decompression and fenestrated clip reconstruction of complex paraclinoid carotid artery aneurysm: operative video and nuances of skull base technique

Direct microsurgical clipping of complex paraclinoid carotid artery aneuryms remains a formidable technical challenge due to the auneurysm's deep location at the skull base, with adjacent bony anatomy, large size, wide neck, and complex neuroanatomical relationships. In this operative video atlas manuscript, the author demonstrates a step-by-step technique for microsurgical clip reconstruction of a large complex ventral paraclinoid carotid artery aneurysm, using a trapping and direct suction decompression strategy followed by multiple fenestrated clip reconstruction of the internal carotid artery (ICA) via a modified orbitozygomatic approach. The nuances of skull base techniques are illustrated including extradural optic nerve decompression, extradural anterior clinoidectomy, incision of the falciform ligament to untether the optic nerve, and release of the distal durai ring to obtain proximal control. Reconstruction of the ICA and preservation of the anterior choroidal artery were achieved with multiple fenestrated clips. Aneurysm obliteration and patency of flow through the ICA was confirmed on video indocyanine green and catheter angiography. Although novel endovascular strategies continue to evolve, these microsurgical skull base techniques should remain in the surgical armamentarium for treating these complex cranial base vascular lesions. The video can be found here: http://youtu.be/IPS6lslk1ds.