Adenosine-assisted embolization of cerebral arteriovenous malformations: a systematic review and meta-analysis.

BACKGROUND: Cerebral arteriovenous malformations (AVMs) are complex lesions that can cause hemorrhagic stroke and significant neurological disability. Adenosine induces cardiac standstill and hypotension, which are thought to be useful during cerebral AVM embolization. Herein, we conducted a systematic review and meta-analysis of the technique's safety. METHODS: Following PRISMA guidelines, four databases were queried for studies describing the use of adenosine-assisted embolization of cerebral AVMs. Adenosine-related intraoperative complications, permanent neurological outcomes, morbidity, and mortality assessed the technique's safety. Single proportion analysis under a random-effects model was performed. Heterogeneity was assessed using I² statistics, and publication bias was evaluated through funnel plot analysis and Egger's regression test. RESULTS: Ten studies were included, involving 79 patients (55.7% male) with 79 AVMs (54.4% unruptured and 70.9% Spetzler-Martin grade III-V) who underwent 123 embolizations (80.4% and 5.9% under transarterial and transvenous approaches, respectively) with n-butyl cyanoacrylate (80.4%), ethylene vinyl alcohol (14.4%), or both (5.2%). The incidence of transient adenosine-related intraoperative complications was 0% (95% CI 0% to 3%, I2=24%). Besides, the incidence of adenosine-related morbidity, mortality, and permanent outcomes was 0% (95% CI 0% to 3%, I2=0%). During follow-up, good functional outcomes were reported for 64 patients (81%). CONCLUSIONS: Adenosine's effects on blood flow control can facilitate embolization and mitigate the risk of AVM rupture and embolic agent migration. Although current evidence stems from observational studies, the results of this meta-analysis suggest a safe drug profile due to minimal associated morbidity and mortality. Further research from larger randomized and controlled studies is warranted to attain a higher level of evidence. PROSPERO REGISTRY NUMBER: CRD42023494116.

Toward a Frontierless Collaboration in Neurosurgery: A Systematic Review of Remote Augmented and Virtual Reality Technologies.

OBJECTIVE: Augmented reality (AR) and virtual reality (VR) technologies have been introduced to neurosurgery with the goal of improving the experience of human visualization. In recent years, the application of remote AR and VR has opened new horizons for neurosurgical collaboration across diverse domains of education and patient treatment. Herein, we aimed to systematically review the literature about the feasibility of this technology and discuss the technical aspects, current limitations, and future perspectives. METHODS: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, 4 databases (PubMed, Embase, Scopus, and Cochrane Library) were queried for articles discussing the use of remote AR and VR technologies in neurosurgery. Data were collected in various fields, including surgery type, application type, subspecialty, software and hardware descriptions, haptic device utilization, visualization technology, internet connection, remote site descriptions, technical outcomes, and limitations. Data were summarized as counts and proportions and analyzed using IBM SPSS software. RESULTS: Our search strategy generated 466 records, out of which 9 studies satisfied the inclusion criteria. The majority of AR and VR applications were used in cranial procedures (77.8%), mainly in education (63.6%), followed by telesurgical assistance (18.2%), patient monitoring (9.1%), and surgical planning (9.1%). Local collaborations were established in 55.6% of the studies, while national and international partnerships were formed in 44.4% of the studies. AR was the main visualization technology, and 3G internet connection was predominantly used (27.5%). All studies subjectively reported the utility of remote AR and VR for real-time interaction. The major technical challenges and limitations included audiovisual latency, the requirement for higher-fidelity and resolution image reconstructions, and the level of proficiency of the patient with the software. CONCLUSIONS: The results from this systematic review suggest that AR and VR technologies are dynamically advancing to offer remote collaboration in neurosurgery. Although still incipient in development and with an imperative need for technical improvement, remote AR and VR hold a frontierless potential for patient monitoring, neurosurgical education, and long-distance surgical assistance.

Editorial for Brain Sciences Special Issue: "Advances in Skull Base Tumor Surgery: The Practical Pearls".

The field of skull base surgery is unique; it involves the adequate and coordinated multidisciplinary interaction of multiple specialties, such as otorhinolaryngology, maxillofacial surgery, ophthalmology, neuro-anesthesiology, oncology, radiation oncology, neurophysiology, and neurosurgery [...].

Isolated cervical Cutibacterium acnes osteomyelitis in a patient with no primary source of infection - A case report and review of the literature.

Background: Cervical vertebral osteomyelitis (CVO) is a rare pathology that leads to progressive osseous degradation and eventual loss of bone putting the patient at risk of devastating neurological injury in the event of bony collapse or instability. Cutibacterium acnes formerly called Propionibacterium acnes is rare, but within the last two decades has been an increasingly reported cause of osteomyelitis. The majority of C. acnes vertebral osteomyelitis cases have been reported in patients with a history of prior invasive procedures where direct contamination at the time of procedure was suspected as the underlying etiology. Case Description: We report a unique case of an otherwise healthy 39-year-old male with no prior history of invasive procedures who presented with CVO secondary to C. acnes. He underwent surgical debridement and fusion in conjunction with antibiotic treatment. The patient recovered well and a 2-year follow-up with serial imaging showed no evidence of disease recurrence. Conclusion: C. acnes is an under-recognized and under-reported etiology of spine infections. Clinicians should be aware of the pathological potential and atypical presentation of C. acnes vertebral osteomyelitis.

Giant primary intracranial multi-fossa leiomyosarcoma involving the frontal sinus, ethmoid air cells, anterior fossa, middle fossa, and intraventricular space: A case report and literature review.

Background: Leiomyosarcomas (LMSs) is a type of sarcoma that arises from smooth muscle and generally presents in the abdomen. Although intracranial LMS has been identified before, most reported presentations have been in immunocompromised patients. Here, we present an intracranial LMS in an immunocompetent patient. Case Description: A 22-year-old male with a history of an atypical pineal parenchymal tumor of intermediate differentiation resected by suboccipital craniotomy at the age of 12 followed by adjuvant radiation therapy, presented with 3 weeks of decreased appetite, weight loss, and lethargy. He subsequently underwent transbasal approach skull base tumor resection. Histologic examination of the mass along with the patient's history of radiation was supportive of a low-grade, radiation-induced LMS arising from the anterior fossa of the skull or meninges and extends to the frontal sinus and ethmoid air cells. Conclusion: Primary intracranial LMS is an extremely rare diagnosis and presenting symptoms vary with the location and size of the tumor. Due to the poor specificity of clinical symptoms, diagnosis is often based on histology. The most common treatment is surgical resection. Adjuvant chemotherapy with various agents has been found to be somewhat effective outside the central nervous system. When LMS does occur, a history of immunocompromised state or previous radiation exposure is often present. Pathological confirmation is required for an appropriate diagnosis.

Percutaneous high cervical spinal cord stimulation for refractory trigeminal neuralgia.

Background: Trigeminal neuralgia (TN) is a debilitating pain that affects the dermatomes associated with the trigeminal nerve (V1, V2, and V3). Unfortunately, many medical treatments and surgical procedures fail to sufficiently modulate the pain associated with this condition. Case Description: This study presents two extreme cases of refractory TN (RTN) that progressed to atypical facial pain and describes successful mitigation of the neuralgia of said cases by percutaneous implantation of upper cervical spinal cord stimulation (SCS). The SCS was designed to target the descending spinal trigeminal tract. Conclusion: Together, these cases collaborate with the limited literature and further delineate the use and potential advantages of SCS in the treatment of RTN.

Staged Strategies to Deal with Complex, Giant, Multi-Fossa Skull Base Tumors.

Given the complex and multifaceted nature of resecting giant tumors in the anterior, middle, and, to a lesser extent, the posterior fossa, we present two example strategies for navigating the intricacies of such tumors. The foundational premise of these two approaches is based on a two-stage method that aims to improve the visualization and excision of the tumor. In the first case, we utilized a combined endoscopic endonasal approach and a staged modified pterional, pretemporal, with extradural clinoidectomy, and transcavernous approach to successfully remove a giant pituitary adenoma. In the second case, we performed a modified right-sided pterional approach with pretemporal access and extradural clinoidectomy. This was followed by a transcortical, transventricular approach to excise a giant anterior clinoid meningioma. These cases demonstrate the importance of performing staged operations to address the challenges posed by these giant tumors.

Immunoglobulin G4-related disease of the cavernous sinus with orbit invasion - A case report.

BACKGROUND: Immunoglobulin G4-related disease (IgG4-RD) is a rare systemic disease of unknown etiology. It is characterized by tissue infiltration caused by IgG4 plasma cells and sclerosing inflammation of various body organs. At present, there are very few reported cases of IgG4-RD invasion of cavernous sinus and the orbit. CASE DESCRIPTION: A 56-year-old female with a history of rheumatoid arthritis was presented with a gradual onset of right oculomotor, abducens, and trigeminal nerve deficits. Four weeks after the onset of symptoms, the patient developed gradual visual deficit. Following this, a trial of steroids was administered to the patient. However, the treatment did not work as expected and patient's condition worsened. She progressed on to suffer complete visual loss in the right eye. Extensive work-up conducted on her turned out to be nondiagnostic. After this, the patient was referred to us for our evaluation. Neuroimaging revealed a right-sided cavernous sinus and orbital apex lesion. Given the lack of diagnosis and response to steroid treatment, we recommended surgical intervention and performed a modified pterional and pretemporal approach with extradural anterior clinoidectomy and transcavernous approach. We performed a lesion biopsy and cavernous sinus decompression, which helped in the partial recovery of visual function. The pathology report was consistent with IgG4-RD. CONCLUSION: IgG4-RD is a rare disease that occurs even less in combination with cavernous sinus and orbit invasion. The rarity of the disease and the diverse presentation of symptoms have sometimes caused delayed diagnosis and intervention. Patients who failed to respond to conservative management and patients in the fibrotic stage of the disease without other organ involvement may benefit from surgical intervention if amenable. Early suspicion, diagnosis, and intervention can facilitate better prognosis.

The use of exoscope combined with tubular retractor system for minimally invasive transsulcal resection of an ventricular atrium atypical choroid plexus papilloma: Three-dimensional operative video.

BACKGROUND: Choroid plexus papilloma represents 1-4% of pediatric brain tumors, mostly located in the ventricular atrium.[1] Intraventricular tumors represent a challenge due to the poor visualization of the surgical field and damage to surrounding structures.[2] Use of tubular retraction reduces cerebrovascular trauma to the surrounding parenchyma by distributing pressure uniformly, allowing less invasive corticotomy, and more stability on surgical corridors that allow the surgeon to use both hands and external visualization devices.[2-5]. CASE DESCRIPTION: We present the case of a 3-year-old boy with progressive headache, vomiting, and loss of control in the left hand for 3 months, with a history of ventricular shunt placement for acute obstructive hydrocephalus. The MRI revealed large lobulated lesion, which was hypointense on T1, hyperintense on T2, marked enhancement on T1 C+ (Gd) within the atrium of the right lateral ventricle, and spectroscopy with a peak of choline. Written consent for the use of photos and videos on this work was obtained from the patient's mother. A high-definition two-dimensional exoscope (VITOM® Karl Storz, Tuttlingen) was used during the surgical approach and throughout tumor removal, which was aided by ViewSite Brain Access System (VBAS®; Vycor Medical Inc.).[3] We performed a transparietal minimally invasive transsulcal parafascicular approach through the Frazier point for direct access to the ventricular atrium. Histological examination confirmed atypical choroid plexus papilloma. Postoperative imaging shows no residual tumor. The postoperative course was satisfactory with improvement of the headache and control of the left hand, leading to discharge home 1 week after surgery. CONCLUSION: The tubular transparietal minimally invasive approach obviates the need for traditional approaches to the atrium. This technique is safe and effective for the treatment of intraventricular and periventricular lesions, thus making this challenging target in more accessible to neurosurgeons, avoiding structure damage and any associated morbidity or mortality.

The anterior incisural width as a preoperative indicator for intradural space evaluation: An anatomical investigation.

BACKGROUND: The opticocarotid triangle (OCT) and the carotico-oculomotor triangle (COT) are two anatomical triangles used in accessing the interpeduncular region. Our objective is to evaluate if the anterior incisural width (AIW) is an indicator to predict the intraoperative exposure through both triangles. METHODS: Twenty sides of 10 cadaveric heads were dissected and analyzed. The heads were divided into the following: Group A - narrow anterior incisura and Group B - wide anterior incisura - using 26.6 mm as a cutoff distance of the AIW. Subsequently, the area of the COT and the OCT in the transsylvian approach was measured, along with the maximum widths through the two trajectories in modified superior transcavernous approach. RESULTS: The COT in the wide group was shown to have a significantly larger area compared with the COT in the narrow group (38.4 ± 12.64 vs. 58.3 ± 15.72 mm, P < 0.01). No difference between the two groups was reported in terms of the area of the OCT (50.9 ± 19.22 mm vs. 63.5 ± 15.53 mm, P = 0.20), the maximum width of the OCT (6.6 ± 1.89 vs. 6.5 ± 1.38 mm, P = 1.00), or the maximum width of the COT (11.7 ± 2.06 vs. 12.2 ± 2.32 mm, P = 0.50). Clinical cases were included. CONCLUSION: An AIW <26.6 mm is an unfavorable factor related to a limited COT area in a transsylvian approach for pathologies at the interpeduncular fossa. Preoperative identification and measurement of a narrow AIW can suggest the need to add a transcavernous approach.

Combined petrosal approach for resection of petroclival chondrosarcoma: Microsurgical 2-D video.

BACKGROUND: Petroclival lesions pose a significant neurosurgical challenge due to involvement or close proximity to important neurovascular structures. Chondrosarcomas are rare lesions that can affect these areas. CASE DESCRIPTION: A 24-year-old male with 3 months history of poor coordination, imbalance, left-sided face hypoesthesia, facial palsy House-Brackmann Grade 2, and 6th cranial nerve palsy with diplopia. Hearing was preserved. Preoperative images showed a 5.5 cm multilobulated enhancing extra-axial mass centered in the left petroclival region with extension into middle and posterior fossa causing severe (Stage 3) brainstem compression.[1] After a lengthy discussion of treatment options, the patient consented for the procedure. We performed a presigmoid retrolabyrinthine combined petrosal approach. We used cranial nerves monitoring (VII, VIII, IX, X, XI, XII), frameless stereotaxy, and a lumbar drain. Due to the tumor size and location (petroclival region with extension into the posterior and middle cranial fossa), we chose this approach to achieve a maximal safe resection of the tumor and preserve hearing. Alternative approaches of use are expanded middle fossa with transcavernous extension or expanded endonasal approach. The selected approach achieved wide exposure of the tumor which was highly vascular. The tumor was carefully dissected off the brainstem, cranial nerves (IV, V, VI, VII, VIII), and basilar artery trunk. A gross total resection was achieved (Multimedia 1). The patient did well after surgery and was extubated on postoperative day (POD) 1 and the lumbar drain removed on POD 5. Pathology reported low-grade chondrosarcoma (WHO grade I). At 3 months follow-up, the patient improved neurologically, including facial nerve weakness (House-Brackmann Grade 1) except for his left 6th cranial nerve palsy which mildly improved. CONCLUSION: Petroclival chondrosarcomas are rare tumors that are usually treated with surgical resection followed by stereotactic radiosurgery. The tumor size, location, and extension dictate approach selection. For lesions involving the petroclival region with extension into the middle fossa and posterior fossa, the combined petrosal approach is reasonable.

High flow bypass for right giant cavernous internal carotid artery aneurysm with fibromuscular dysplasia of cervical internal carotid artery: microsurgical 2-D video.

BACKGROUND: It is well known that intracranial aneurysms can be associated to fibromuscular dysplasia (FMD). Nevertheless, it is not clear the best treatment strategy when there is an association of giant symptomatic cavernous carotid aneurysm with extensive cervical internal carotid artery (ICA) FMD. CASE DESCRIPTION: We present the case of 63 year-old right-handed female with hypothyroidism, 1 month history of right-sided pulsatile headache and visual disturbances with feeling of fullness sensation and blurry vision. Her neurological exam showed partial right oculomotor nerve palsy with mild ptosis, asymmetric pupils (right 5 mm and left 3mm, both reactive), and mild exotropia, normal visual acuity. Computed tomography angiogram and conventional angiogram showed 2.5 × 2.6 × 2.6 cm non-ruptured aneurysm arising from cavernous segment of the right ICA. She had right hypoplastic posterior communicant artery, and collateral flow through anterior communicant artery during balloon test occlusion and the presence of right cervical ICA FMD. The patient was started on aspirin. After lengthy discussion of treatment options in our neurovascular department, between observations, endovascular treatment with flow diverter device, or high flow bypass, recommendation was to perform high flow bypass and patient consented for the procedure. We performed right-sided pterional trans-sylvian microsurgical approach and right neck dissection at common carotid bifurcation under electrophysiology monitoring (somatosensory evoked potentials and electroencephalography); while vascular surgery department assisted with the radial artery graft harvesting. The radial artery graft was passed through preauricular tunnel, cranially was anastomosed at superior trunk of middle cerebral artery, and caudally at external carotid artery (Video). Intraoperative angiogram showed adequate bypass patency and lack of flow within aneurysm. The patient was extubated postoperatively and discharged home with aspirin in postoperative day 5. Improvement on oculomotor deficit was complete 3 weeks after surgery. CONCLUSION: Nowadays, endovascular therapy can manage small to large cavernous ICA aneurysms even if associated to FMD, although giant symptomatic cavernous carotid aneurysms impose a different challenge. Here, we present the management for the association of symptomatic giant cavernous ICA aneurysm and cervical ICA FMD with high flow bypass. We consider important to keep the skills in the cerebrovascular neurosurgeon armamentarium for the safe management of these lesions.

Current Open Surgical Indications for Revascularization in Cerebral Ischemia.

Cerebral revascularization was pioneered half a century ago. Gradual improvements in microsurgical instrumentation and training in microsurgical techniques have allowed significant changes that improved outcomes in neurosurgery, extrapolating this knowledge to other neurosurgical diseases (brain tumor, aneurysms, and skull base tumor surgery). But the popularity of cerebral bypass procedures was followed by their decline, given the lack of clear benefit of bypass surgery in chronic cerebrovascular ischemia after the EC-IC bypass studies. Over the last couple of decades, the formidable advance of neuro-endovascular techniques for revascularization has lessened the need for application of open cerebral revascularization procedures, either for flow augmentation or flow replacement. However, there is still a select group of patients with chronic cerebral ischemia, for whom open cerebral revascularization with flow augmentation is the only treatment option available, and this will be the objective of our current review.

Retractorless interhemispheric transtentorial approach for large lesions in the posterior incisural space.

BACKGROUND: Surgical resection of lesions in the posterior incisural space presents a significant surgical challenge, which may result in postoperative visual complications and other neurological deficits. We, therefore, describe a retractorless interhemispheric transtentorial approach that avoids surrounding brain structures with positive outcomes and no complications or visual damage. CASE DESCRIPTION: We present four cases of lesions in the posterior incisural space that was treated with a retractorless interhemispheric transtentorial approach. Two patients were previously seen at another institution for a falcotentorial meningioma. We resected the meningiomas with a parietal-occipital interhemispheric transtentorial approach with no neurological deficits. A third patient presented with a large superior vermian hemangioblastoma with a steep angle of the tentorium. The fourth patient had a large upper vermian metastatic lesion with progressive enlargement, which was refractory to radiation treatments and chemotherapy, and we achieved partial resection. Postoperative visual function was completely preserved in all patients. CONCLUSION: A carefully executed retractorless interhemispheric approach in select cases is an effective option to reduce morbidity and prevent visual complications when removing lesions in the posterior tentorial incisure.

Microsurgical Technique for Basilar Apex Aneurysm Clipping: Two-Dimensional Video.

We present the case of a 57-year-old female with hypertension, current smoker status, and recent headaches. Imaging studies showed an unruptured 8-mm basilar apex wide neck aneurysm located 4 mm above posterior clinoid (Figure 1) with a 3-mm anterior communicant artery aneurysm. No contraindications were encountered for endovascular treatment, although after we evaluated endovascular and surgical options, surgical clipping was considered also a safe and favorable option based on anterior projection of aneurysm, height of the basilar artery bifurcation, small and elongated posterior communicant artery, and available space between posterior clinoid and basilar artery (4 mm). The presence of a second aneurysm increased the patient's interest in a more definitive treatment, as we mentioned the possibility of its treatment if considered safe intraoperatively. A cranio-orbito-zygomatic craniotomy, anterior clinoidectomy, and sylvian fissure dissection was performed with electrophysiology monitoring. The exposure was enhanced by sphenoparietal sinus ligation, and the anterior clinoidectomy allowed working spaces at optic-carotid and carotid-oculomotor spaces for Liliequist membrane dissection, without need for posterior clinoid removal (Figure 2). Brief temporary clipping at basilar trunk below superior cerebellar arteries at perforating free zone was performed. Two clips were applied, obliterating adequately the aneurysm respecting perforating vessels. After the basilar apex aneurysm clipping, we proceeded in a standard fashion to clip the additional anterior communicant artery aneurysm. Micro-Doppler and intraoperative angiogram confirmed aneurysm exclusion and patent parent vessels (Video 1). The patient developed minimal ptosis due to partial right oculomotor nerve palsy that recovered completely in 2 weeks; otherwise, her neurologic exam was normal. At 1-year follow up, computed tomography angiography showed complete aneurysm exclusion.