Craniovertebral Junction Surgical Approaches: State of Art.

Surgical approaches directed toward craniovertebral junction (CVJ) can be addressed to the ventral, dorsal, and lateral aspects through a variety of 360° surgical corridors Herein, we report features, advantages, and limits of the updated technical support in CVJ surgery in clinical setting and dissection laboratories enriched by our preliminary surgical results of the simultaneous application of O-arm intraoperative neuronavigation and imaging system along with the 3D-4K EX in TOA for the treatment of CVJ pathologies.In the past 4 years, eight patients harboring CVJ compressive pathologies underwent one-step combined anterior neurosurgical decompression and posterior instrumentation and fusion technique with the aid of exoscope and O-arm. In our equipped Cranio-Vertebral Junction Laboratory, we use fresh cadavers (and injected "head and neck" specimens) whose policy, protocols, and logistics have already been elucidated in previous works. Five fresh-frozen adult specimens were dissected adopting an FLA. In these specimens, a TOA was also performed, as well as a neuronavigation-assisted comparison between transoral and transnasal explorable distances.A complete decompression along with stable instrumentation and fusion of the CVJ was accomplished in all the cases at the maximum follow-up (mean: 25.3 months). In two cases, the O-arm navigation allowed the identification of residual compression that was not clearly visible using the microscope alone. In four cases, it was not possible to navigate C1 lateral masses and C2 isthmi due to the angled projection unfitting with the neuronavigation optical system, so misleading the surgeon and strongly suggesting changing surgical strategy intraoperatively. In another case (case 4), it was possible to navigate and perform both C1 lateral masses and C2 isthmi screwing, but the screw placement was suboptimal at the immediate postoperative radiological assessment. In this case, the hardware displacement occurred 2 months later requiring reoperation.

Why the Funnel in Neurosurgery?

According to Cambridge Dictionary, Funnel is an object that has a wide round opening at the top, sloping sides, and a narrow tube at the bottom, used for pouring liquids or powders into containers with narrow necks.From an semplified anatomic point of view, the skull base along with its offshoot, the spine, replicate a bone funnel as a vessel sustaining the brain, the cerebellum and the spinal cord along with cranial and radicular nerves. Non doubt at all that the knowledge of the embryology, anatomy, physiology, pathophysiology and the more effective surgical pathways to engage and remove surgical diseases is of paramount importance in the surgical cultural heritage to be strongly encouraged and supported in young neurosurgeons.So to the steps that seem to emerge from this Issue of Acta Neurochirurgica suppl are exploratory, strategic, tactical and finally operational. From the skull base to the sacrum we meet a macrosystem of anatomic and functional complex network with a common embryological hystory as well as contiguity. Different skills are necessary to face with a 360° universe of functions and diseases to deal with. Intelligence and culture as knowledge of both anatomy and pathology help to elaborate the STRATEGY while technical and manual supports are part of the TACTIC armamentarium which is proactive and determinant to the final OPERATIONAL step.

New Trends in Neurosurgery: Toward a Future of Integration and Equity Among Male and Female Neurosurgeons.

The gradual rise of women in medical schools and residencies, surpassing men in medical school applications, contrasts with the male dominance in surgical fields, including neurosurgery (only 18% women). Reasons include concerns about work-life balance, traditional childcare roles, and gender biases. In response, Women in Neurosurgery (WINs) was founded in 1989 to address gender disparities. However, WINs sessions at conferences evolved into segregated scientific sessions, deviating from their original purpose. This contradicts the ideal of a unified neurosurgical community. While some support segregated spaces, many advocate against gender-based divisions. Today WINs' existence is deemed outdated, with a call for integration, inclusivity, and equality in the modern era of neurosurgery.

Post-mortem Imaging of Brain/Spine Injuries: The Importance of a Comprehensive Forensic Approach.

In forensic investigations, the limitations of the traditional purely autoptic approach can be overcome through post-mortem imaging (virtopsy). Virtospy has several applications to the investigation of brain and spinal injuries, whose analysis can be of forensic interest, especially in cases of suspected malpractice. In this scoping review, we briefly describe the main applications of the two most common post-mortem radiological techniques (computed tomography (CT) and magnetic resonance imaging (MRI)) to the forensic investigation of brain and spinal injuries in cases of medical malpractice or traumatic (accidental/homicidal/suicidal) deaths. Although CT represents the traditional approach to post-mortem imaging, MRI is proving to be a valuable tool to investigate brain and spinal injuries and lesions. These post-mortem radiological techniques can also be used to guide the surgeons in simulated surgical procedures on corpses in the context of training programs, thus helping operators to improve technical and non-technical skills and to reduce the risk of avoidable errors.

The Funnel: From the Skull Base to the Sacrum. New Trends and Technologies in Anaesthesia for the Adult Patient.

The management of children affected by neurosurgical pathologies is multidisciplinary and should be set on several fronts.The potential need for massive blood components transfusions, the prolonged anaesthesia in paediatric age that may be often complicated by various forms of syndrome-related problems, and airway management are often encountered.The problems may be divided schematically into three large groups: preoperative, intraoperative and postoperative problems.The aim of this work is to optimize and make paediatric neurosurgery safe by highlighting the most important aspects in the various perioperative phases.

Methods and Principles of the Intraoperative Neurophysiologic Monitoring in Neurosurgery.

Intraoperative neurophysiologic monitoring (IONM) is an innovation introduced in neurosurgery in the past decades. It aims to support and guide the neurosurgeon to obtain the best surgical result possible, preventing the occurrence of neurological deficits. The somatosensory evoked potentials (SSEP) assess the integrity of the sensory pathways monitoring the dorsal column-medial lemniscus pathway during spine and cerebral surgery. Motor evoked potentials (MEPs) provide information on the integrity of the motor pathway monitoring the efferent motor pathways from the motor cortex to the muscle through corticospinal (or corticobulbar) tracts. Free-running EMG is the standard technique to monitor peripheral nerves, roots, or cranial motor nerves during surgery. Intraoperative EMG signals are activated during cranial motor nerves damaging or after an irritative stimulus. The duration, morphology, and persistence of EMG reflects the severity of neural injury. Nerve mapping consists of recording muscle activations given by direct nerve stimulation. This technique makes use of a stimulation probe available to the neurosurgeon which allows administering current directly to the nervous tissue (nerves, roots, etc.). Intraoperative neurophysiological monitoring (IONM) represents the standard of care during many procedures, including spinal, intracranial, and vascular surgeries, where there is a risk of neurological damage. Close communication and collaboration between the surgical team, neurophysiologist, and anesthesiologist is mandatory to obtain high-quality neuromonitoring, thus preventing neurologic injuries and gaining the best surgical "safe" results.

Image-Guided Surgery in Complex Skull Base and Facial Fractures: Initial Experience on the Role of Intra-Operative Computer Tomography.

Surgery of fractures involving the skull base and the facial skeleton often presents challenges that should be addressed to prevent secondary brain injuries (i.e., cerebro-spinal fluid leak), preserve visual functioning, and guarantee a good esthetic result. Complex craniofacial reconstruction can be aided by navigation and pre-operative planning. In recent years, computerized planning of surgical reconstruction drastically increased the safety and efficacy of surgery, but the impact of intraoperative high quality image devices such as an intraoperative computed tomography (CT) scan has not been investigated yet. This case-control study reports the institutional preliminary experience of using intraoperative CT scans in the surgical management of complex cranio-facial fractures. The results in terms of accuracy of bony reconstruction and neurological or surgical complications have been analyzed in 12 consecutive patients treated with (6 cases) or without (6 cases) i-CT. Comparative analysis demonstrated a greater accuracy of reconstruction in patients treated with the assistance of i-CT. Intraoperative CT is a useful tool with a promising role in a multidisciplinary surgical approach to complex cranio-facial surgery.

Technologies in Anaesthesia for the Paediatric Patient.

Spine surgery is an increasingly frequent surgery and includes a wide range of procedures, from minor surgeries (removal of herniated discs, simple laminectomies) to major surgeries (arthrodesis, removal of spinal meningiomas, etc.).These surgeries commonly involve complex patients (elderly population, ASA II-III) and are sometimes performed in emergency settings (polytrauma, cauda syndrome, pathological fractures), which require specific positions (pronation or lateral decubitus), whereby there can be difficulty in airway management, especially in surgeries that concern the cervical tract.One of the main peculiarities of spine surgery involves the prone position.Patient positioning on the operating bed is an action that must be carried out under medical supervision, in particular by the anaesthetist who is supposed to supervise the regular positioning of the patient at the very moment in which it is performed. The correct positioning of the patient is one of the most important moments of the patient care process in the operating room, given that an error in this field may cause serious damage to the patient by giving rise to permanent and significant nerve damage.The prone position is associated with a variety of complications (Kwee et al., Int Surg 100(2): 292-303, 2015). The points of greatest compression during pronation are eyes, nose, breasts, genitals and neck veins.Therefore, the main risks that can derive from an incorrect position are visual disturbances from inappropriate orbital compression, brachial plexus stretching, ulnar nerve compression and lateral femur-cutaneous nerve stretching. In addition, an inappropriate compression of the abdominal organs in this position, may cause ischemia and consequent organ failure resulting in hospitalization prolongation, permanent disability and sometimes even death (Edgcombe et al., Br J Anaesth 100: 165-183, 2008).In addition to the mechanical effects on anatomical structures, there are also the physiological effects of the prone position, which can be divided into circulatory and respiratory effects.These effects are even more pronounced in elderly patients, cardiopaths or patients with respiratory diseases.

Pediatric Meningiomas: Current Insights on Pathogenesis and Management.

Meningiomas are rare tumors in children, ranging from 0.4 to 4% of intracranial tumors. Differently from their adult counterpart, pediatric meningiomas (PMs) often show peculiar aspects such as the development of tumoral cysts, the involvement of the intraventricular space, and missing attachment to the dura mater. The most important difference with adults is represented by the high incidence of WHO grade II and III variants, which can account for more than 70% of cases. The prognosis of PMs mainly depends on the initial surgical resection because radiotherapy, which is the main treatment option in the case of tumor recurrence or progression, does not seem to increase the relapse free survival and the overall survival, and chemotherapy still misses specific and effective protocols.On these grounds, the need to better understand these tumors, to favor an appropriate multidisciplinary management, is particularly felt. The present review is focused on the advances on the pathogenesis, the molecular aspects, and the managements of PMs, with the goal to improve the knowledge of these challenging neoplasms.

Tuberculum Sellae Meningioma: Report of Two Cases and Literature Review of Limits of the Transcranial and Endonasal Endoscopic Approaches.

BACKGROUND: Tuberculum sellae (TS) meningioma is one of the most frequent meningiomas of the anterior skull base. Herein we perform a review of the literature concerning the preferred surgical approaches to TS meningiomas; in addition, we describe two explicative cases, operated on by our group using different approaches, with the aim to critically revise surgical indications and contraindications. METHODS: In October 2021, two female patients with tuberculum sellae meningioma were treated at the Policlinico Gemelli of Rome. The patients presented with visual deterioration. Surgery was performed using the fronto-temporal approach and transsphenoidal approach. The visual function before and after surgery was evaluated as the main outcome parameter of the surgical treatment of these tumors. CONCLUSIONS: Tuberculum sellae meningioma can be safely resected using the transcranial approach and the transsphenoidal endoscopic approach with preservation and even improvement of visual function after surgery. The relationship of the tumor with the optic nerves, optic canal, and anterior cerebral artery complex are important issues that have to be considered when dealing with tuberculum sellae meningioma. Both transcranial and endonasal approaches, in experienced hands, can allow complete resection of the lesion.

Petroclival Clinoidal Folds and Relationships with Arachnoidal Membranes and Neural Structures of Anterior and Middle Incisural Spaces: Old Neuroanatomical Terms for a New Neurosurgical Speech in Cadaver Labs with Limited Resources Era. Part I: Osteology and Structural Anatomy of Dura Mater.

Purpose The role of cadaver labs in preparing new generations of effective neurosurgeons is of paramount importance. The Authors describe a personal cadaver lab experience aimed at improving the knowledge of a difficult region of the central skull base. The anterior and middle incisural spaces are regions of remarkable anatomical, and surgical interest due to complex relationships between bony, dural, arachnoidal, and neurovascular structures. The primary purpose of this study is (1) to describe the anatomy of this region with particular emphasis on the relationships between the anterior margin of the free edge of the tentorium and the sphenoid and petrous bone; (2) to identify surgical implications in many different types of neurosurgical procedures dealing with this challenging complex anatomic area.Methods Eight fresh, non-formalin-fixed non-silicon-injected adult cadaver heads and five injected formalin-fixed adult cadaver heads were analyzed in this study.Results The anatomical study was focused on the description of the relationships between bony, dural, arachnoid, and neurovascular structures. Surgical implications are described accordingly.Conclusions Detailed anatomical knowledge of this region finds concrete applications in neurosurgical practice since the anterior and middle incisural spaces are often surgically exposed in neoplastic and vascular diseases.

Petroclival Clinoidal Folds and Relationships with Arachnoidal Membranes of Anterior and Middle Incisural Spaces: Old Neuroanatomical Terms for a New Neurosurgical Speech in Cadaver Labs with Limited Resources Era. Part II: Free Edge of the Tentorium, Petroclinoid Folds, and Incisural Spaces.

BACKGROUND Anatomical dissections play an irreplaceable role in the training of new generations of effective neurosurgeons, especially when addressing skull base lesions is required.The Authors describe an inter-laboratory dissection study aimed at improving the knowledge of a complex region of the skull base. The anterior and middle incisural spaces are of remarkable anatomical and surgical interest due to complex relationships between bony, dural, arachnoidal, and neurovascular structures. The primary purposes of this study are to describe the anatomy of this region with particular emphasis on the relationships between the anterior margin of the free edge of the tentorium and the sphenoid and petrous bone; to identify surgical implications in many different types of neurosurgical procedures dealing with this challenging, complex anatomic area.METHODS Thirteen anatomical specimens, including five injected specimens, were dissected in this study. In the formalin-fixed specimens, vessels were injected with colored silicone.RESULTS The anatomical study was focused on the description of the relationships between bony dural, arachnoid, and neurovascular structures. Surgical implications are described accordingly.CONCLUSIONS Detailed anatomical knowledge of this region finds concrete applications in neurosurgical practice since the anterior and middle incisural spaces are often surgically exposed in neoplastic and vascular diseases. The high-definition pictures reported in this study could represent useful support to understand the anatomy of this complex region.Finally, our study could provide guidance to neurosurgical centers in which resources are limited that are either planning to establish their own cadaver dissection laboratory or failed to do so because of the supposed high-costs.

Petroclival Clinoidal Folds and Relationships with Arachnoidal Membranes of Medial Incisural Space: Old Neuroanatomical Terms for a New Neurosurgical Speech in Cadaver Labs with Limited Resources Era. Part III: Arachnoid Membranes, Cranial Nerves, and Surgical Implications.

BACKGROUND Anatomical dissections play an irreplaceable role in the training of new generations of effective neurosurgeons, especially when addressing skull base lesions is required.The Authors describe an inter-laboratory dissection study aimed at improving the knowledge of a complex region of the skull base. The anterior and middle incisural spaces are of remarkable anatomical and surgical interest due to complex relationships between bony, dural, arachnoidal, and neurovascular structures. The primary purposes of this study are to describe the anatomy of this region with particular emphasis on the relationships between the anterior margin of the free edge of the tentorium and the sphenoid and petrous bone; to identify surgical implications in many different types of neurosurgical procedures dealing with this challenging complex anatomic area.METHODS Thirteen anatomical specimens, including five injected specimens, were dissected in this study. In the formalin-fixed specimens, vessels were injected with colored silicone.RESULTS The anatomical study focused on the description of the relationships between bony dural, arachnoid, and neurovascular structures. Surgical implications are described accordingly.CONCLUSIONS Detailed anatomical knowledge of this region finds concrete applications in neurosurgical practice since the anterior and middle incisural spaces are often surgically exposed in neoplastic and vascular diseases. The high-definition pictures reported in this study could represent useful support to understand the anatomy of this complex region.Finally, our study could provide guidance to neurosurgical centers in which resources are limited that are either planning to establish their own cadaver dissection laboratory or failed to do so because of the supposed high-costs.

Middle Meningeal Artery Embolization for the Management of Chronic Subdural Hematomas: A New-Old Treatment.

Chronic subdural hematoma (cSDH) is defined as a subdural collection of blood on CT imaging that tends to persist and gradually increase in volume over time, with components that are hypodense or isodense compared to the brain. There are no proven guidelines for the management of patients with cSDH. Surgical approaches included burr hole, twist drill hole, and craniotomy-based evacuations. Outcomes after surgical removal is generally favorable, but cSDH tends to recur after the initial evacuation.Middle meningeal artery (MMA) embolization has been gaining increasing popularity among the treatments of cSDH. This is largely due to a growing population of patients with cSDH who are refractory to other treatments or in patients who present with multiple comorbidities or who are taking antiplatelet and anticoagulant medications. The goal of middle meningeal artery (MMA) embolization is to devascularize subdural membranes associated with SDH so that the balance between continued leakage and reabsorption is shifted toward reabsorption.We discuss our clinical and technical approach to cSDH treated with perioperative embolization of the MMA.

Chiari Malformation Type 1 and Syringomyelia: Why Do Patients Claim for International Guidelines? Commentary on the 2021 Chiari and Syringomyelia Consensus Document.

The diagnosis of Chiari malformation type 1 (CM1) and Syringomyelia (Syr) has become increasingly common during the past few years. Contemporarily, the body of literature on these topics is growing, although randomized controlled studies on significant case series to drive guidelines are missing in the pediatric and adult populations. As a result of the different opinions about surgical indications and techniques raised by CM1-Syr, an increasing number of well-informed but disoriented patients is emerging. To bridge this gap, an International Consensus Conference on CM1-Syr held in Milan in November 2019 aimed to find a consensus among international experts, to suggest some recommendations that, in the near future, could lead to guidelines. Here, we comment on the most relevant recommendations about the definition, diagnosis, surgical management, failures and re-intervention, and outcome. We also focus on some "wrong" indications or techniques that, although widely disapproved by the experts, and negatively experienced by many patients, are still largely in use.

Supraorbital Keyhole Versus Pterional Approach: A Morphometric Anatomical Study.

OBJECTIVE: Although the supraorbital (SO) keyhole approach has a wide range of indications, its routine usefulness with the advance of current technology has not been fully evaluated. In an attempt to address this issue, a cadaveric morphometric analysis to the supra- and parasellar regions was performed, comparing the standard Pterional craniotomy (PT) with the SO keyhole. METHODS: ETOH-fixed and silicone-injected human cadaveric heads were used. SO (n = 8) and PT craniotomies (n = 8) were performed. Pre- and post-dissection CT, along with pre-dissection MRI scans were also completed for neuro-navigation purposes, aimed to verify predetermined anatomical landmarks selected for morphometric analysis. RESULTS: Notwithstanding the smaller craniotomy, the SO approach allowed optimal anatomical exposure when compared to the PT approach. With 30° of head rotation, the SO keyhole showed a wider surgical field of the suprasellar region. CONCLUSIONS: Using detailed preoperative image-guided surgical planning, the SO keyhole approach offered an appropriate alternative route to the supra- and parasellar regions, compared to the PT craniotomy.

Percutaneous Balloon Compression for Trigeminal Neuralgia. A Comparative Study Between the Fluoroscope Guided and Neuronavigated Technique.

Percutaneous balloon compression (PBC) is a safe and effective procedure in the treatment of trigeminal neuralgia (TN) due to its simplicity, low cost and the possibility of being repeated in case of pain recurrence. Foramen ovale (FO) cannulation is accomplished with the assistance of intraoperative C-arm fluoroscopy. Recently, several authors have reported successful application of intraoperative CT navigation as well. The reported advantages of CT navigation are linked to better spatial orientation and the low rate of attempts for FO cannulation. However, these advantages should be considered in the face of concerns regarding increased radiation dose to the patient and its possible adverse effects. Here we compared the fluoroscopic guided and neuronavigated PBC techniques in terms of efficacy and radiological exposure. We retrospectively analyzed 37 patients suffering for TN and submitted to PBC. We observed a significant improvement of pain at 1 month FU compared with the pre-operative in both groups (p < 0.0001 and p < 0.0001, respectively). A significant increase in radiation exposure was found in the neuronavigated group compared with the fluoroscopy group (p < 0.0001). We suggest the use of neuronavigated PBC only in selected cases, such as patients with multiple previous operations, in whom a difficult access can be pre-operatively hypothesized.

Use of BoneScalpel Ultrasonic Bone Dissector in Anterior Clinoidectomy and Posterior Fossa Surgery: Technical Note.

BackgroundFirst popularized by Dolenc, anterior clinoidectomies were performed with rongeurs, before the adoption of modern high-speed drills. We describe a novel application of the piezoelectric BoneScalpel™ in anterior skull base and posterior fossa surgeries. In the literature, to date, there are no mentions of anterior clinoidectomies performed with piezosurgical devices.MethodsWe reported a total of 12 patients, 8 affected by posterior fossa tumors and 4 treated for anterior skull base oncologic and vascular pathologies. This study aims to assess the safety and efficacy of the piezoelectric osteotomy in skull base and posterior fossa surgeries. In all patients, an ultrasonic bone dissector (BoneScalpel™ - Misonix) was used to perform the anterior clinoidectomy (AC) and craniotomy.ResultsA successful clinoidectomy was performed in 4 out of 12 patients (33.3%). We did not notice any heat damage to the surrounding soft tissue in critical areas such as paraclinoid structures. We documented only one durotomy in an oncologic patient, while no lesions of SSS or TS were detected.We recorded only a slightly increased surgery duration in the PIEZOSURGERY® and BoneScalpel™ group, compared to standard surgery with an osteotome to perform craniotomies, but no time difference in performing the clinoidectomy between BoneScalpel™ and a conventional high-speed drill.ConclusionWe report the first experience with piezosurgery for anterior clinoidectomy. There is no time difference in performing the clinoidectomy between BoneScalpel™ and a conventional high-speed drill, and this is an undoubted advantage in critical contexts such as clinoid-paraclinoid surgeries, where the risk of dural sinuses tears is common.

The Role of the Anesthesiologist and the Modern Intraoperative Echography in Ventriculoatrial Shunt for Hydrocephalus: From Hakim to Nowadays.

The introduction of US-guided venipuncture in clinical practice has greatly facilitated the surgical approach to patients with hydrocephalus. Especially in infants and children, where it results in a lower technical failure rate, less time and fewer complications than the traditional referral method, this technique has become a clinical protocol. This dynamic or "real time" technique has become one of the anesthetist's tools. This allowed the anesthesiologists to be part of the surgical team, so they not only dedicate themselves to inducing and maintaining general anesthesia but also to performing venipuncture of the central vein of the neck and to locating the tip of the catheter.The anesthetist's tools have made it possible to perform a simple and safe method, and the anesthesiologists have become an active part of the surgical team, charged with a specific role during the positioning of the ventricular atrial shunt.

Spinal Cord High-Frequency Stimulation. The Current Experience and Future Directions.

Spinal cord stimulation (SCS) is a neuromodulation technology that has emerged as a valid treatment for chronic intractable neuropathic pain. After conventional tonic SCS, new waveforms of stimulation, like high frequency (HF), have proved that they can provide safe and effective pain relief. In addition, SCS is now being utilized more broadly as a potential treatment for a range of indications, including motor disorders and spasticity. Our study presents a retrospective analysis of 20 patients with heterogenous aetiologies of neuropathic pain treated with HF stimulation, after a standardized protocol in a temporary trial. We observed a significant improvement in pain relief according to comparisons of numerical rating scale (NRS) scores before the procedure, after the clinical trial and at latest follow-up. Two unusual clinical cases were also reported, and the pertinent literature was discussed.