Microsurgical resection of a large petroclival meningioma through an extended retrosigmoid approach: how I do it

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.

CONCLUSION

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.

Aspirator-Assisted Endoscopic Third Ventriculostomy in an Infant: 2-Dimensional Operative Video

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.

Microsurgical Resection of a Giant Trochlear Nerve Schwannoma: 2-Dimensional Operative Video

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.

Spinal arachnoid web-a distinct entity of focal arachnopathy with favorable long-term outcome after surgical resection: analysis of a multicenter patient population

BACKGROUND CONTEXT

Spinal arachnoid web (SAW) is a rare condition characterized by focal thickening of the arachnoid membrane causing displacement and compression of the spinal cord with progressive symptoms and neurological deficits. Recent reports and clinical experience suggest that SAW is a distinct entity with specific radiological findings and treatment strategies distinguishable from other arachnopathies and potential differential diagnoses.

PURPOSE

To better define the diagnostic and clinical features, treatment options and outcomes of surgically treated SAW.

STUDY DESIGN

Multicentric retrospective cohort study.

PATIENT SAMPLE

Twelve cases of SAW surgically treated at three different centers.

OUTCOME MEASURES

Self-reported and neurological outcome measurements (pain, sensory-motor deficits, vegetative dysfunctions) were assessed at follow-up timepoints.

METHODS

Retrospective review of prospectively collected data on all patients surgically treated for SAW from three participating neurosurgical centers between 2014 and 2020. Clinicopathological data, including neurological presentation, radiological and histological findings and outcome data were analyzed.

RESULTS

Twelve radiologically and surgically confirmed cases of SAW were analyzed. Mean patient age was 54.7 [±12.7], 67% were male. All SAWs were located in the posterior thoracic dural sac. On magnetic resonance imaging (MRI), the "scalpel sign" - a characteristic focal dorsal indentation of the spinal cord resembling a scalpel blade - was identified in all patients. A focal intramedullary syrinx was present in 83%. Preoperative clinical symptoms included signs of myelopathy, pain, weakness and sensory loss, most commonly affecting the trunk/upper back or lower extremities. Laminectomy or laminoplasty with intradural excision of the SAW was the surgical treatment of choice in all cases. Intraoperative ultrasound was valuable to visualize the cerebrospinal fluid (CSF) flow obstruction, confirm the SAW location before dura incision and to control adequacy of resection. After surgery, sensory loss and weakness in particular showed significant improvement.

CONCLUSIONS

The present study comprises the largest series of surgically treated SAW, underscoring the unique clinical, radiographic, histopathological, and surgical findings. We want to emphasize SAW being a distinct entity of spinal arachnopathy with a favorable long-term outcome if diagnosed correctly and treated surgically. Intraoperative ultrasound aids visualizing the SAW before dural incision, as well as verifying restored CSF flow after resection.

A Type II Split Cord Malformation in an Adult Patient: An Operative Case Report

BACKGROUND AND IMPORTANCE

Split cord malformations (SCMs) are rare conditions in which the spinal cord is split into two hemicords within either a single thecal sac or two separate thecal sacs. The hemicords are typically split by a bony or fibrous structure. We present an adult patient who presented with a type II SCM with tethered cord. This is the first case of such a presentation with an accompanying intraoperative video. Unusual features of the case were the presence of an incomplete fibrous septum and lack of a discrete filum terminale.

CLINICAL PRESENTATION

A 50-yr-old woman presented with back pain, radiculopathy, urinary urgency, and episodic fecal incontinence. Her exam was notable for weakness of the right extensor hallicus longus. Imaging showed an SCM extending from L3 to S1, a fibrous septum located at L4-5, and a low-lying conus at S4. She was treated with a decompressive L3-S4 laminectomy and disconnection of all the dural attachment points. She required lumbar drain placement postoperatively and reoperation for wound dehiscence and persistent pseudomeningocele. At the time of last follow-up, she was neurologically intact with improvement in bowel/bladder function.

CONCLUSION

SCM is an uncommon presentation in adults and is often accompanied by findings of skin stigmata, tethered cord, and other central nervous system/skeletal anomalies. Obtaining full multimodal imaging is critical to understanding subtle anatomic variations that can pose operative challenges. We report the treatment of an adult patient with type II SCM, and provide an intraoperative video demonstrating the removal of an incomplete midline fibrous septum.

3-Dimensionally Printed Biomimetic Surgical Simulation-Operative Technique of a Transforaminal Lumbar Interbody Fusion: 2-Dimensional Operative Video

We present a surgical video highlighting the technical demonstration and microsurgical anatomy of an L4-5 transforaminal lumbar interbody fusion utilizing a combination of thermoplastic polymers and 3-dimensional printing technology to create a biomimetic lumbar spine surgical simulator. The posterior elements of L4-5 and the inferior portion of L3 are exposed in their entirety, including the transverse processes in order to identify the appropriate landmarks for pedicle screw insertion. The interspinous ligament of L4-5 is removed, and an interlaminar spreader is used to distract the facet joint. An inferior L4 facetectomy is performed for local autograft harvesting. The L4 and L5 pedicles are skeletonized to completely open the foramen in order to ensure that the exiting nerve root will not be compromised during cage insertion. The ligamentum flavum is then removed, exposing the common thecal sac and L5 traversing root. The L4 exiting nerve root is then identified, completing Kambin's triangle and location of the disc space. The disc is incised, and a combination of punches and curettes are used to completely remove the disc. After an interbody trial is used to assess the proper cage size, the cage is packed with graft and inserted into the midline of the disc space. Pedicle screws are then placed using an anatomic freehand technique, and intraoperative fluoroscopy is performed in order to evaluate the instrumentation and interbody position. If a contralateral decompression is required, a facet-sparing technique is performed in order to preserve bony surface for the fusion. Patient consent was not required for this simulation video.

Multiple Subpial Transections in Eloquent Cortex for Refractory Epilepsy: 2-Dimensional Operative Video

Although the epilepsy refractory to medical therapy can potentially be cured by the resection of epileptogenic tissue, many patients do not qualify for surgery, because epileptogenic tissue can arise from eloquent areas of the brain, where surgical resection would result in severe neurological deficits. Palliative surgical treatments currently used in these situations include deep brain stimulation, responsive neurostimulation, and vagal nerve stimulation.1 A previously developed technique, multiple subpial transections (MSTs), although used infrequently, is another effective tool.2 Our patient, a 34-yr-old man, had epilepsy that was refractory to medical management. His preoperative work-up demonstrated a potential seizure focus in the left pars opercularis and left superior temporal gyrus, which was verified using invasive stereoelectroencephalography. Functional magnetic resonance imaging demonstrated a significant verbal and motor function in this region. After informed consent was obtained, the patient underwent a left-sided craniotomy. The central portion of the seizure focus was resected using the subpial technique. The surrounding presumed epileptogenic cortex, which was considered functionally eloquent, was then horizontally disconnected with MSTs. For each transection, a small puncture incision was made in the pia, and a vertical cut was completed using Morrell dissectors.2 MSTs were performed circumferentially around the entire resection cavity in 5-mm increments. All hemostasis was achieved with irrigation instead of electrocautery, although noncauterizing hemostatic agents are also acceptable. The patient was neurologically intact after the operation and was discharged home on postoperative day 2. He was free of seizures at 11-month follow-up. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.

Surgical Treatment of Intracranial Anterior Ethmoidal Aneurysm: Case Report, Literature Review, and Surgical Video

BACKGROUND

Anterior ethmoid aneurysms are rare with 5 cases of intracranial rupture and 3 cases of life-threatening epistaxis described in recent literature. We present a case of an intracranial ruptured anterior ethmoid aneurysm treated surgically with a favorable outcome.

CASE DESCRIPTION

A 64-year-old male presenting with a headache was found to have a right frontal intracranial hemorrhage with an associated 1.5 cm length × 1.8 cm maximal width anterior ethmoidal artery aneurysm. No definitive etiology of the aneurysm was identified. The aneurysm was treated using a bifrontal craniotomy with interhemispheric microdissection, clip ligation, and resection of the aneurysm dome for pathologic analysis, which ruled out a mycotic etiology. He recovered uneventfully and returned to work with no identifiable neurologic deficit.

CONCLUSIONS

Consistent with prior reports, an intracranial, anterior ethmoidal artery aneurysm can occur in isolation without an associated vascular malformation. On the basis of a literature review and this case, surgical ligation is considered effective and possibly superior over endovascular treatment due to the risk of injury to the orbital vascular supply with transarterial treatment.

Microsurgical Clipping of an Anterior Communicating Artery Aneurysm Using a Novel Robotic Visualization Tool in Lieu of the Binocular Operating Microscope: Operative Video

INTRODUCTION

The binocular operating microscope has been the visualization instrument of choice for microsurgical clipping of intracranial aneurysms for many decades.

OBJECTIVE

To discuss recent technological advances that have provided novel visualization tools, which may prove to be superior to the binocular operating microscope in many regards.

METHODS

We present an operative video and our operative experience with the BrightMatterTM Servo System (Synaptive Medical, Toronto, Ontario, Canada) during the microsurgical clipping of an anterior communicating artery aneurysm. To the best of our knowledge, the use of this device for the microsurgical clipping of an intracranial aneurysm has never been described in the literature.

RESULTS

The BrightMatterTM Servo System (Synaptive Medical) is a surgical exoscope which avoids many of the ergonomic constraints of the binocular operating microscope, but is associated with a steep learning curve. The BrightMatterTM Servo System (Synaptive Medical) is a maneuverable surgical exoscope that is positioned with a directional aiming device and a surgeon-controlled foot pedal. While utilizing this device comes with a steep learning curve typical of any new technology, the BrightMatterTM Servo System (Synaptive Medical) has several advantages over the conventional surgical microscope, which include a relatively unobstructed surgical field, provision of high-definition images, and visualization of difficult angles/trajectories.

CONCLUSION

This device can easily be utilized as a visualization tool for a variety of cranial and spinal procedures in lieu of the binocular operating microscope. We anticipate that this technology will soon become an integral part of the neurosurgeon's armamentarium.

Embolization and Open Decompression of a Giant Aneurysm Involving the P2 Segment of the Posterior Cerebral Artery

A 5-year-old girl was brought to the clinic because of chronic intermittent left-sided headaches. The patient underwent computed tomographic angiography, which demonstrated a giant aneurysm that involved the P2 segment of the left posterior cerebral artery. Before treatment proceeded, consent was obtained from the patient's legal guardian. A trapping-evacuation technique was used for proximal control and decompression so that a clip could be placed on the proximal inflow artery of the aneurysm. First, embolization was performed for aneurysm trapping and for sacrifice of the parent vessel. Two days later, the patient was taken to the operating room for open surgical decompression, clipping, and reconstruction. Heparin was administered during the embolization stage of the operation. The patient did well postoperatively and was discharged home. The 3-month follow-up evaluation demonstrated a right superior homonymous quadrantanopia and no other neurologic deficits. The patient's clinical course is summarized in Video 1.

Video-Assisted Bilateral Thoracoscopic Sympathotomy for Palmar Hyperhidrosis

In this video, we demonstrate a case of a 21-year-old right-handed man who presented with palmar hyperhidrosis. His symptoms started at the age of 4 years and progressively worsened throughout his life. Multiple medical treatments were used without significant benefit. His symptoms worsened to the limit that it affected his work and lifestyle. The patient was taken to the operating room in a supine position with both arms abducted 90°. The right and left chest were prepped and draped in a sterile fashion. The skin incision was done on the left side first, the left lung was isolated, and two 5-mm thoracoports were placed in the sixth and third intercostal spaces, respectively. Carbon dioxide insufflation was used to a pressure of 6 mm Hg for exposure. The chest was visualized, and the sympathetic chain was identified. Ribs were counted and then cautery at a low setting was used. The sympathetic chain was transected at the level of the head of the second rib. Accessory nerves of Kuntz were identified and resected. Carbon dioxide was then evacuated from the left chest using a bronchial tube exchanger and Valsalva maneuver. The lung was completely reinflated and skin was closed in a normal fashion. The same procedure was repeated on the right side. A chest radiograph was obtained intraoperatively, and no pneumothorax was observed. At the end of the procedure, both upper extremity temperature probes showed a significant increase from baseline. Informed patient consent was obtained.

Surgical Management of Idiopathic Thoracic Spinal Cord Herniation

BACKGROUND

Idiopathic spinal cord herniation is a rare condition that involves spinal cord herniation through a defect in the ventral dura.

CASE DESCRIPTION

We present a case of a 61-year-old woman who initially presented in 2016 with an approximately 1-year history of burning right lower extremity pain and gait instability. Her neurologic examination was consistent with thoracic Brown-Sequard syndrome, and spinal magnetic resonance imaging showed a focal defect in the ventral dura at the superior aspect of T4 with the left aspect of the cord herniating into the defect. In 2018, she underwent a T3-T4 laminectomy with T3 pedicle take down and medial facetectomy, with reduction of the herniated cord.

CONCLUSIONS

Idiopathic spinal cord herniation is an uncommon spinal cord disorder with a paucity of data reported. Our case report of a classic case of idiopathic spinal cord herniation presenting as Brown-Sequard syndrome and managed surgically will contribute to the data in this field.

Posterior Cervical Laminoplasty for Resection Intradural Extramedullary Spinal Meningioma: 2-Dimensional Operative Video

This operative video demonstrates a posterior cervical laminoplasty for the resection of a cervical intradural extramedullary meningioma. In addition, the natural history, treatment options, and potential complications are discussed. The patient is a 68-yr-old male who presented with left-hand grip weakness and paresthesias. Magnetic resonance imaging (MRI) demonstrated an enhancing mass that displacing the spinal cord anteriorly and causing severe flattening of the cord at C4 and C5. The patient underwent a posterior cervical laminoplasty for tumor resection. Removal of the dorsal elements with a high-speed drill was performed at C3, C4, and C5. A midline durotomy was performed and a large extra-axial intradural tumor was encountered. The tumor was resected en bloc and specimens were sent for permanent pathological analysis. The dura was closed in a watertight fashion using 6-0 Prolene sutures. The laminoplasty was performed by using titanium miniplates and screws to reconstruct the dorsal bony elements, and the wound was closed in layers using sutures. There were no complications. Final pathology was consistent with a WHO grade I meningioma. Postoperative MRI demonstrated gross total resection. The patient's perioperative course was uncomplicated and his preoperative weakness completely resolved by time of discharge.

Transclinoid-Transcavernous Approach to a Giant Cavernous Sinus Hemangioma: 2-Dimensional Operative Video

This surgical video demonstrates a transclinoid-transcavernous approach for the resection of a cavernous sinus hemangioma (Video 1). The patient is a 42-year-old woman who presented with headache and blurred vision. Magnetic resonance imaging (MRI) demonstrated an enhancing mass in the right-side cavernous sinus and sella. The patient underwent an orbitozygomatic craniotomy, extradural anterior clinoidectomy, and transcavernous approach for tumor resection. Removal of the orbital roof, lateral orbital wall, zygomatic arch, and anterior clinoid process with a high-speed drill was performed. The lateral wall of the cavernous sinus was opened via interdural dissection, and a large reddish tumor was encountered. The tumor was resected after circumferential dissection and coagulation. The cranial nerves III, IV, and V were found and preserved. The surgical cavity was closed with abdominal fat to prevent cerebral-spinal fluid leak. The bone flap was put back and fixed with titanium mesh, plates, and screws; the wound was closed in layers using sutures. The blurred vision relieved immediately after surgery. The patient suffered temporary right-side oculomotor nerve palsy, which was partially resolved after 6 months. There were no other complications. Final pathology was consistent with a cavernous sinus hemangioma. Postoperative MRI demonstrated near total resection except for a small piece of residual in the sella, which was stable in 6-month follow-up MRI scan without further treatment. The patient has been back to normal life and work.