Cranio-Orbital Approach and Decompression of the Optic Nerves: A 2-Stage, 4-by-4-Step Approach to Improve Vision in Sellar and Parasellar Lesions.

BACKGROUND AND OBJECTIVES: Despite advances in cranial base techniques, surgery of the sellar and parasellar regions remains challenging because of complex neurovascular relationships. Lesions within this region frequently present with progressive visual deterioration caused by distortion and compression of the optic chiasm and nerves. In addition to the direct mass effect from mechanical forces acting on the optic apparatus, these lesions alter blood supply and reduce vascular perfusion, prompting surgical treatment to remove the lesion, alleviate compression, and improve blood flow to the optic nerve. We sought to describe a 2-stage, 4-by-4-step approach, broken down and described as a "four-by-four" technique for optic apparatus decompression and a wide approach to different sellar and parasellar lesions. METHODS: We describe the operative nuances and key anatomic points in the microsurgical removal of sellar and parasellar lesions. The technique is illustrated with examples of different cases with pre- and follow-up MRI imaging and a brief overview of visual outcomes. RESULTS: The described technique has been demonstrated in various lesions in 5 patients. Patients presented with bilateral visual loss in 4 (80.0%) cases and with unilateral visual loss in 1 (20.0%) case. Improvement in visual function was noted in all cases, confirmed with visual acuity and visual field testing. DISCUSSION: The transcranial approach ("from above") remains an important surgical option for patients with excellent exposure and visualization of the sellar and parasellar regions. It permits early access to the optic canal for careful microsurgical decompression and relaxation of the optic nerve to preserve and improve its microvascularization and ultimately vision. CONCLUSION: The authors augmented the 2-stage, 4-by-4-step technique of decompression with elaborate illustrations of diverse sellar and parasellar lesions to demonstrate the versatility of this approach.

Understanding Adult Central Nervous System Hemangioblastomas: A Systematic Review.

BACKGROUND: Adult hemangioblastomas (HBs) are rare World Health Organization central nervous system (CNS) grade 1 tumors, particularly affecting the posterior cranial fossa. They exhibit a gender bias, impacting men in their fifth and sixth decades of life and manifesting sporadically or as part of von Hippel Lindau disease. Understanding the intricacies of CNS HBs is crucial for clinical decision-making. METHODS: A systematic review of 576 articles was conducted following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. Eligibility criteria included 3189 adult cases of CNS HBs. Data on patient demographics, tumor characteristics, symptoms, treatment modalities, complications, and outcomes were systematically extracted and synthesized. RESULTS: The review revealed a heterogeneous demographic distribution, with a male predominance. The median age at diagnosis was 44.7 years. Cranial HBs were more commonly located in the infratentorial (73%) than supratentorial (27%) compartments. Spinal HBs were mostly located in the cervical spine (44.3%), followed by thoracic (36.7%) and lumbar spine (12%). Clinical symptoms varied by location, emphasizing the importance of anatomical considerations. Surgical intervention-total resection (82% of cases)-was the preferred treatment modality, while radiotherapy was less common. Histological examination and immunohistochemistry aided in accurate diagnosis. Complications were location-specific, with intracranial complications more common in infratentorial tumors. Overall, favorable outcomes were prevalent (78% of cases), with low mortality rates. CONCLUSIONS: Adult CNS HBs present with diverse characteristics and clinical manifestations. Surgical intervention remains the mainstay treatment; ongoing research into genetic and molecular mechanisms may enhance our understanding of tumor pathology and lead to improved management strategies in the future.

A brief history of neurosurgery in Bosnia and Herzegovina: historical vignette.

The modern period of neurosurgery in Bosnia and Herzegovina began with the first neurosurgical procedure performed by Dr. Karl Bayer in 1891 on 3 patients with depressed skull fractures and epilepsy. In 1956 the Department of Surgery in Sarajevo designated several beds specifically for a neurosurgical unit. A significant milestone in the history of neurosurgery in Bosnia and Herzegovina was the establishment of the Division of Neurosurgery at the Clinical Center University of Sarajevo in 1970. The first neurosurgeon to complete his training in Bosnia and Herzegovina was Dr. Faruk Konjhodzic. The first female neurosurgeon was Dr. Nermina Iblizovic. Presently, there are 7 neurosurgical departments in the country, located in Sarajevo, Tuzla, Zenica, Mostar, Banja Luka, Bihac, and Foca. The Association of Neurosurgeons in Bosnia and Herzegovina, founded in 2003, is a member of the European Association of Neurosurgical Societies and the World Federation of Neurosurgical Societies. The aim of this historical paper is to provide a concise chronology of important events and mention key individuals who have contributed to the development of modern neurosurgery in Bosnia and Herzegovina.

Cranio-Orbital Pretemporal Approach for Microsurgical Resection of Hypothalamic Rosette Forming Glioneuronal Tumor with Reversal of Preoperative Blindness: 2-Dimensional Operative Video.

The hypothalamic region is susceptible to involvement of several processes.1 Lesions in this region remain challenging for surgical access and treatment. Strategies include both endoscopic and microsurgical approaches.2 A cranio-orbital approach with extradural clinoidectomy and optic canal unroofing provides the necessary corridor to visualize and decompress the optic nerve/chiasm and remains an important tool in achieving complete tumor resection with favorable functional and visual outcomes.3-12 Endoscope assistance in transcranial surgery is well established, used to provide direct visualization of hidden adjacent tissues.13 A 25-year-old woman presented with headache and progressive visual loss to blindness (hand waving and light perception) on admission. Magnetic resonance imaging demonstrated a 28-mm-diameter tumor in the hypothalamic region with no significant postcontrast enhancement. She underwent right cranio-orbital craniotomy, extradural anterior clinoidectomy, and optic canal unroofing with a 2-mm high-speed diamond drill and copious irrigation. After ipsilateral falciform ligament release, the tumor capsule was coagulated, sharply opened, and resected in a piecemeal fashion. Endoscopic assistance warranted the removal of hidden parts and confirmed tumor removal. Histopathology and next-generation sequencing confirmed the diagnosis of rosette-forming glioneural tumor. Follow-up revealed gross total tumor removal on magnetic resonance imaging and complete recovery of visual function as per ophthalmologist examination. Rosette-forming glioneural tumors are considered rare and classified as World Health Organization grade I tumors usually found in the fourth ventricle.14 To our knowledge, we present the first operative video (Video 1) demonstrating the removal of rosette-forming glioneural tumor in the hypothalamic region with endoscopic assistance.

Spontaneous Bleeding in Vestibular Schwannoma in Patients on Oral Anticoagulant Therapy: Report of Two Cases and Review of Literature.

OBJECTIVE: Anticoagulant therapy is a risk factor for repeated intratumoral hemorrhage and acute enlargement of a vestibular schwannoma (VS) with neurological deficits. Therefore, we describe two cases of patients on oral anticoagulant therapy with intratumoral hemorrhage in which anticoagulant therapy prior to surgical resection was discontinued. We also discuss other similar cases from the literature since this is a rare event. CASE REPORTS: We described the two cases of intratumoral hemorrhage in acoustic neurinoma and conducted a literature review of similar cases of patients with intratumoral hemorrhage in acoustic neurinoma who were also on oral anticoagulants. Both patients presented with CN-VII palsy prior to surgery; both also fully re-covered after surgery except for hearing loss on the tumor side. Our literature review found 50 cases of VS (reported as vestibular schwannomas in the literature) with intratumoral hemorrhage. From this total, 11 patients used oral anticoagulant therapy with reported poor outcomes and high mortality; 9 of these 11 cases were reported in the past 20 years. The incidence is expected to rise due to increased use of anticoagulant therapy due to onset of atrial fibrillation, atherosclerosis, and thromboembolism from longer human lifespan. CONCLUSION: Anticoagulant therapy represents a risk factor for intratumoral hemorrhage and acute enlargement of VS tumor mass with neurological deficits.

A brief retrospective of the history of neurosurgery in Croatia.

The beginnings of neurosurgery in Croatia date to the end of the 19th century when Teodor Wickerhauser performed the first craniotomy in the country in 1886. Exactly 60 years later, in 1946, Danko Riessner founded a separate neurosurgical ward in Zagreb and is therefore considered the founder of Croatian neurosurgery. His main scientific contribution was a paper on the shifting of brain masses, published in 1939. The Department of Neurosurgery at the University of Zagreb was founded in 1974 as one of the first institutions of its kind in Southeast Europe. Finally, the Croatian Neurosurgical Society was founded in 1992 to promote the neurosurgical profession and science at the national level. This historical vignette aimed to provide a brief chronology of the most important events and notable people in the history of Croatian neurosurgery, as well as to commemorate its founders and highlight its development from the beginning to its current state of proficiency and expertise.

Cranioorbital Pretemporal Skull Base Approach with Anterior Clinoidectomy for Removal of Large Left Clinoid Meningioma: "Unwrapping" Encircled Internal Carotid Artery and Decompressing Optic Nerve: 2-Dimensional Operative Video.

Clinoidal meningiomas are meningiomas arising from or in the vicinity of the anterior clinoid process.1 Despite advanced microsurgical techniques, clinoidal meningiomas remain challenging.2 Extradural anterior clinoidectomy with optical unroofing remains an important tool in skull base surgery, which provides a safe operative corridor, facilitating greater extent of resection and enhancing overall outcome, particularly visual function.2-13 A 66-year-old woman presented with history of visual disturbances. Magnetic resonance imaging revealed a dural-based tumor consistent with a large left clinoidal meningioma, with tumor wrapping (encircling) around the left trunk and internal carotid artery (ICA) bifurcation, elevating the left middle cerebral artery M1 segment, and invading the left optic canal. Left cranio-orbital craniotomy with pretemporal exposure was used (Video 1).1,9 A high-speed diamond drill with irrigation completed the extradural anterior clinoidectomy and optical canal unroofing. Use of a 1-mm Kerrison rongeur should be done with utmost care. The tumor was unwrapped via meticulous piecemeal removal. Final dissection and ICA unwrapping was done when the tumor was debulked enough that dissecting it off the artery was safe and under less tension. Due to its obscurity, final decompression of the left optic nerve with incision and opening of the falciform ligament was performed at the end of the procedure.10 Postoperative neuro-ophthalmologic examination showed a grossly unchanged left visual field with some visual acuity improvement. Resection of tumor encircling the ICA has been described previously;14 however, to the best of our knowledge, this is the first video describing removal of a tumor surrounding the ICA (perfomed by senior author K.I.A.), essentially "unwrapping" the left ICA trunk and its bifurcation. The patient consented to publication.

Effect of Body Mass Index on Chiari Malformation 1 Tonsil Ectopia Length in Adults.

OBJECTIVE: Diagnosis of Chiari I malformation (CM-1) is based on measurements of the inferior extension of the cerebellar tonsils into the foramen magnum on cranial or cervical spine magnetic resonance imaging. Imaging may be obtained before the patient is referred to the neurosurgical specialist. The length of time raises questions about the possibility that body mass index (BMI) fluctuations could affect the measurement of ectopia length. However, previous literature on BMI and CM-1 has reported conflicting findings on BMI. METHODS: We conducted a retrospective chart review of 161 patients who were referred to a single neurosurgeon for CM-1 consultation. Patients with multiple recorded BMI values (n = 71) were compared to see if BMI changes correlated with changes in ectopia length. In addition, we compared and tested 154 recorded ectopia lengths from the patients (1 per patient) and patient BMI values with Pearson correlation and Welch t tests to determine if BMI changes either influenced or were associated with ectopia changes. RESULTS: For the 71 patients with multiple BMI values, change in ectopia length ranged from -4.6-9.8 mm but was not statistically significant (r = 0.019; P = 0.88). For the 154 measured ectopia lengths, changes in BMI did not correlate with ectopia length (P > 0.05). Likewise, differences in ectopia length between patients in normal, overweight, and obese categories were not statistically significant (|tstat| < |tcrit|, P > 0.05). CONCLUSIONS: In individual patients, we found that BMI and changes in BMI were not accompanied by changes in tonsil ectopia length.

Bibliometric Analysis of 6 Major European Neurosurgical Publications from 2011-2020 (part 3): a Comparative Metrics Review.

Background: We previously conducted bibliometric analysis of 6 North American neurosurgical journals. Objective: To perform a bibliometric analysis of 6 European neurosurgical journals to build on our previous studies. Methods: We searched Web of Science for articles published in Acta Neurochirurgica, British Journal of Neurosurgery, Child's Nervous System, Journal of Neurological Surgery Part A: Central European Neurosurgery, Journal of Neurosurgical Sciences, and Neurosurgical Review between 2011 and 2020. We analyzed bibliometric parameters related to total annual document distribution, author metrics, journal metrics, country and continental distribution, institution, keywords, and journal impact. Results: European countries provided the greatest contributions. Acta Neurochirurgica followed by Child's Nervous System published the greatest number of articles and had the highest h-index and number of citations. From 2018 to 2020, total documents increased 79.6%, original articles increased 86.5%, review articles increased 103.6%, citations increased 79.6%, number of publishing authors increased 72.1%, number of authors in multi-author documents increased 72.4%, and author's keywords and keywords plus increased 72.4% and 27.0%, respectively. The collaboration index decreased 5.3% from 4.49 to 4.25. Annual published documents and citations were lower for European journals versus North American journals. Conclusion: Several parameters of the European journals increased by 2020. One interesting finding is that growth for the 6 journals dramatically increased in the 2 years prior to the COVID-19 pandemic. While neurosurgeon free time during lockdowns may account for much of the increase in 2020, the trend began before this. Our analysis did not identify a cause for the pre-COVID increases.

Cranial Versus Cervical Spine Magnetic Resonance Imaging in Adult Chiari Malformation Type I Diagnostics: Is There a Difference in Tonsil Ectopia Length?

BACKGROUND: Chiari malformation type 1 (CM-1) diagnosis is based on measurement of the cerebellar tonsils on cranial or cervical spine magnetic resonance imaging (MRI). However, imaging parameters of cranial and cervical spine MRI could differ because spine MRI has greater resolution. METHODS: We conducted a retrospective chart review of 161 patients of a single neurosurgeon for adult CM-I consultation between February 2006 and March 2019. Patients were selected based on receiving both cranial and cervical spine MRI within a month of each other to determine tonsillar ectopia length for CM-1. Ectopias were measured to determine if differences in values were statistically significant. RESULTS: From the 161 total patients, 81 had cranial and cervical spine MRI for a total of 162 tonsil ectopia measurements (81 cranial and 81 spinal). Average ectopia length on a cranial MRI was 9.1 mm (±5.2 mm); average ectopia length on a spinal MRI was 8.9 mm (±5.3 mm). Average cranial and spinal MRI values were found to be <1 standard deviation apart. Two-tailed, nonequal variances t test determined that differences between the cranial and spinal ectopia measurements were insignificant (P = 0.2403). CONCLUSIONS: This study confirmed that the added resolution offered by spine MRI did not make better or more refined measurements over cranial MRI that could lead to measurement differences, which can instead be attributed to chance. Cranial and cervical spine MRI can be used to determine the degree of the tonsil ectopia.

An integrative survival analysis and a systematic review of the cerebellopontine angle glioblastomas.

Glioblastomas presenting topographically at the cerebellopontine angle (CPA) are exceedingly rare. Given the specific anatomical considerations and their rarity, overall survival (OS) and management are not discussed in detail. The authors performed an integrative survival analysis of CPA glioblastomas. A literature search of PubMed, Scopus, and Web of Science databases was performed per PRISMA guidelines. Patient data including demographics, clinical features, neuroimaging, management, follow-up, and OS were extracted. The mean age was 39 ± 26.2 years. The mean OS was 8.9 months. Kaplan-Meier log-rank test and univariate Cox proportional-hazards model identified hydrocephalus (log-rank, p = 0.034; HR 0.34; 95% CI 0.12-0.94; p = 0.038), chemotherapy (log-rank, p < 0.005; HR 5.66; 95% CI 1.53-20.88; p = 0.009), and radiotherapy (log-rank, p < 0.0001; HR 12.01; 95% CI 3.44-41.89; p < 0.001) as factors influencing OS. Hydrocephalus (HR 3.57; 95% CI 1.07-11.1; p = 0.038) and no adjuvant radiotherapy (HR 0.12; 95% CI 0.02-0.59; p < 0.01) remained prognostic on multivariable analysis with fourfold and twofold higher risk for the time-related onset of death, respectively. This should be considered when assessing the risk-to-benefit ratio for patients undergoing surgery for CPA glioblastoma.

Supratentorial Hemangioblastoma in Adults: A Systematic Review and Comparison of Infratentorial and Spinal Cord Locations.

BACKGROUND: Supratentorial hemangioblastomas are benign and highly vascularized neoplasms that appear most often in the spine and posterior cranial fossa. They can also be located in the supratentorial compartment of the brain. We conducted a systematic review of the literature to better understand the clinical insights of supratentorial hemangioblastoma in adults. METHODS: Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, the authors reviewed the English-language literature in the PubMed/MEDLINE database on supratentorial hemangioblastoma in adults, published in the past 40 years. We analyzed the differences between sporadic hemangioblastomas and hemangioblastomas associated with von Hippel-Lindau disease. In addition, we compared the characteristics of supratentorial hemangioblastomas with infratentorial and spinal cord locations. RESULTS: We reviewed 92 articles, describing 157 supratentorial hemangioblastomas in a total cohort of 148 adult patients. Most articles reporting supratentorial hemangioblastomas were published in the United States. Supratentorial hemangioblastomas occur more frequently in women than men. The median age at the time of diagnosis was 44.48 years. The sellar/parasellar region was the most commonly tumor location, while the most common morphological type was the solid type. Almost 80% of hemangioblastomas were completely resected; the outcome was favorable in more than 3 fourth of patients. CONCLUSIONS: Given their rarity, the literature on supratentorial hemangioblastomas is limited and based mostly on case reports. Complete surgical resection is the first choice of treatment and is associated with a good treatment outcome.

Cisternal, Falciform, and Optic Canal Decompression Influencing Optic Nerve Biomechanics: A Microsurgical Anatomic Study.

BACKGROUND: Questions remain regarding optic nerve (ON) physiology, mechanical compliance, and microvasculature, particularly surgical outcomes and atypical visual field defects associated with sellar/parasellar pathology (eg, tumors and aneurysms). OBJECTIVE: To study the microsurgical/histological anatomy of each ON segment and corresponding microvasculature, calculate area of optic-carotid space at each decompression stage, and measure ON tension before/after compression. METHODS: Five cadaveric heads (10 sides) underwent sequential dissection: (1) intradural (arachnoidal) ON dissection; (2) falciform ligament opening; (3) anterior clinoidectomy, optic canal decompression, and ON sheath release. At each step, we pulled the nerve superiorly/laterally with a force meter and measured maximal mobility/mechanical tension in each position. RESULTS: Cisternal ON microvasculature was more superficial and less dense vs the orbital segment. ON tension was significantly lower with higher mobility when manipulated superiorly vs lateromedially. Optic-carotid space significantly increased in size at each decompression stage and with ON mobilization both superiorly and laterally, but the increase was statistically significant in favor of upward mobilization. At decompression step, upward pull provided more space with less tension vs side pull. For upward pull, each step of decompression provided added space as did side pull. CONCLUSION: Opening the optic canal, falciform ligament, and arachnoid membrane decompresses the ON for safer manipulation and provided a wider optic-carotid surgical corridor to access sellar/parasellar pathology. When tailoring decompression, the ON should be manipulated superiorly rather than lateromedially, which may guide surgical technique, help prevent intraoperative visual deterioration, facilitate postoperative visual improvement, and help understand preoperative visual field deficits based on mechanical factors.

Adult Chiari Malformation Type I: Surgical Anatomy, Microsurgical Technique, and Patient Outcomes.

In this study, the authors summarize the current knowledge on epidemiology, demographics, risk factors, and prognostic factors that influence outcomes in patients with adult Chiari malformation type I (CM-I) who underwent posterior fossa decompression surgery with duraplasty. Furthermore, they describe the contribution of their research group to the field of adult CM-I treatment, including association of increased body mass index with severity of CM-I and syringomyelia, relevant surgical anatomy, and surgical technique of 270° microsurgical decompression of foramen magnum. The authors also report on common complications in the literature and describe techniques for prevention of complications.

CLINICAL AND SURGICAL CHARACTERISTICS OF POSTERIOR FOSSA TUMORS IN ADULTS - SINGLE-CENTER EXPERIENCE OF SURGICAL MANAGEMENT.

In contrast to tumors in children, between 6% and 20% of all brain tumors in adults arise solitary in the posterior cranial fossa. Given their rarity in adults, as well as the importance and complexity of their treatment, this paper reviews and discusses the clinical and surgical characteristics of such tumors. In a retrospective single-institution observational study, adult patients with posterior fossa tumors treated surgically over a ten-year period were analyzed. The characteristics observed were age and gender distribution, clinical symptoms, histopathologic tumor type, tumor size, location and extent of surgical resection, tumor recurrence and postoperative complications, as well as surgical outcome. Sixty-six patients who underwent surgical treatment were diagnosed with a tumor in the posterior fossa. The mean age was 63 years, and patients were evenly distributed by gender. The most common histopathologic type was metastatic tumor (59.1%), whereas meningioma was the most common primary brain tumor (16.6%) recorded. Most patients presented with vegetative and cerebellar symptoms in general and cranial nerve palsy, especially in the occurrence of vestibular schwannoma. In conclusion, posterior fossa tumors grow in a confined space and therefore may directly threaten vital centers in their immediate vicinity. Thus, it is crucial to schedule an appropriate surgical intervention as soon as possible, as it can significantly improve treatment outcome and prognosis of the disease. If possible, meticulous total tumor resection should be the treatment of choice. In the case of hydrocephalus, a ventriculoperitoneal shunt should be considered as an alternative surgical option after tumor resection.