Mapping the circle of Trolard: A holistic view of its role in neurosurgical practice, anatomical perspectives and clinical applications.

Introduction: An anatomical structure that resembles the circle of Willis, the circle of Trolard is generated in the basal cistern and travels around the midbrain in a roundabout manner, passing adjacent to the lateral side of the cerebral peduncle. Research question: The primary objective of this article is to provide neurosurgeons with a comprehensive understanding of Trolard's circle, emphasizing its anatomical features and clinical significance. Material and methods: A comprehensive evaluation of the available literature pertaining to the venous circle of Trolard was conducted by conducting searches in the PubMed, Web of Science, and Scopus databases. In the present overview, the terminologies "venous circle of Trolard," "basal venous circle," and "basal vein of Rosenthal" were employed. Results: Upon doing a comprehensive examination of the existing literature and primary sources pertaining to the venous circle of Trolard, it was discovered that an only six studies had been conducted on this particular subject matter. We made observations regarding the anatomical characteristics of the subject and engaged in a discussion regarding their prospective applications and importance within the context of neurosurgical procedures. Discussion and conclusion: The scarcity of research on these structures is attributed to the challenges associated in studying them in vivo. Through directing focus towards these structures, our aim is to stimulate further investigation into their potential involvement in a range of neurological and neurosurgical disorders.

Cortical incisions and transcortical approaches for intra-axial and intraventricular lesions: A scoping review.

Background: Transcortical approaches, encompassing various surgical corridors, have been employed to treat an array of intraparenchymal or intraventricular brain pathologies, including tumors, vascular malformations, infections, intracerebral hematomas, and epileptic surgery. Designing cortical incisions relies on the lesion location and characteristics, knowledge of eloquent functional anatomy, and advanced imaging such as tractography. Despite their widespread use in neurosurgery, there is a noticeable lack of systematic studies examining their common lobe access points, associated complications, and prevalent pathologies. This scoping review assesses current evidence to guide the selection of transcortical approaches for treating a variety of intracranial pathologies. Methods: A scoping review was conducted using the PRISMA-ScR guidelines, searching PubMed, EMBASE, Scopus, and Web of Science. Studies were included if ≥5 patients operated on using transcortical approaches, with reported data on clinical features, treatments, and outcomes. Data analysis and synthesis were performed. Results: A total of 50 articles encompassing 2604 patients were included in the study. The most common primary pathology was brain tumors (60.6%), particularly gliomas (87.4%). The transcortical-transtemporal approach was the most frequently identified cortical approach (70.48%), and the temporal lobe was the most accessed brain lobe (55.68%). The postoperative course outcomes were reported as good (55.52%), poor (28.38%), and death (14.62%). Conclusion: Transcortical approaches are crucial techniques for managing a wide range of intracranial lesions, with the transcortical-transtemporal approach being the most common. According to the current literature, the selective choice of cortical incision and surgical corridor based on the lesion's pathology and anatomic-functional location correlates with acceptable functional outcomes.

A case that encapsulates the challenges of being a neurosurgeon in war-torn countries: Perspectives from Iraq.

Background: The provision of healthcare services in Iraq has been negatively affected by a lack of resources, strained healthcare infrastructure, and low patient socioeconomic status. This paper describes a case of multiple intracranial aneurysms (MIAs) that highlight the challenges of practicing vascular neurosurgery in Iraq. Case Description: A 57-year-old female presented with sudden-onset severe headache, photophobia, and drowsiness and was diagnosed with subarachnoid hemorrhage in the basal cistern. Despite international guidelines recommending urgent treatment for suspected ruptured intracranial aneurysms, the patient's healthcare team in Babylon advised against a CT angiogram (CTA). The patient's family took responsibility for transferring her to a private facility for a CTA, which showed four aneurysms. Due to financial constraints, the family opted for open surgery, during which a ruptured aneurysm was found and successfully managed. The remaining two aneurysms were monitored with serial follow-up imaging. Conclusion: The case highlights the challenges of practicing vascular neurosurgery in Iraq and the impact of financial constraints on the management of MIA. It emphasizes the need for increased resources and expertise in the country's healthcare system to provide optimal care for patients with life-threatening conditions.

A Systematic Review and Meta-Analysis of 3-Dimensional Morphometric Parameters for Cerebral Aneurysms.

BACKGROUND: Imaging modalities with increased spatial resolution have allowed for more precise quantification of cerebral aneurysm shape in 3-dimensional (3D) space. We conducted a systematic review and meta-analysis to assess the correlation of individual 3D morphometric measures with cerebral aneurysm rupture status. METHODS: Two independent reviewers performed a PRISMA (preferred reporting items of systematic reviews and meta-analysis)-guided literature search to identify articles reporting the association between 3D morphometric measures of intracranial aneurysms and rupture status. RESULTS: A total of 15,122 articles were identified. After screening, 39 studies were included. We identified 17 3D morphometric measures, with 11 eligible for the meta-analysis. The meta-analysis showed a significant association with rupture status for the following measures: nonsphericity index (standardized mean difference [SMD], 0.66; 95% confidence interval [CI], 0.53-0.79; P < 0.0001; I2 = 55.2%), undulation index (SMD, 0.55; 95% CI, 0.26-0.85; P = 0.0017; I2 = 68.1%), ellipticity index (SMD, 0.53; 95% CI, 0.29-0.77; P = 0.0005; I2 = 70.8%), volume (SMD, 0.18; 95% CI, 0.02-0.35; P = 0.0320; I2 = 82.3%), volume/ostium ratio (SMD, 0.43; 95% CI, 0.16-0.71; P = 0.0075; I2 = 90.4%), elongation (SMD, -0.94; 95% CI, -1.12 to -0.76; P = 0.0005; I2 = 0%), flatness (SMD, -0.87; 95% CI, -1.04 to -0.71; P = 0.0005; I2 = 0%), and sphericity (SMD, -0.62; 95% CI, -1.06 to -0.17; P = 0.0215; I2 = 67.9%). A significant risk of publication bias was estimated for the ellipticity index (P = 0.0360) and volume (P = 0.0030). CONCLUSIONS: Based on the results of a meta-analysis containing 39 studies, the nonsphericity index, undulation index, elongation, flatness, and sphericity demonstrated the most consistent correlation with rupture status.

Surgical resection of pericallosal tuberculoma through contralateral approach: A case report.

Background: Pericallosal tuberculoma, a rare form of intracranial tuberculoma, affects the corpus callosum and results from tuberculosis (TB), a bacterial infection that can cause a myriad of symptoms. Diagnosing this condition can be challenging but can be confirmed through imaging studies and biopsy. Treatment involves a combination of antitubercular medications and surgical removal of the lesion if it is in a critical location or causing significant symptoms. This article describes the surgical management and imaging characteristics approach to a patient with intracranial tuberculoma. Case Description: A 17-year-old female with a history of TB meningitis nine years ago presented with one week of recurrent seizures and mild third nerve palsy, later diagnosed as a tuberculoma of the corpus callosum through radiological imaging and biopsies. A total surgical resection of the lesion was performed using a contralateral interhemispheric frontal parasagittal approach. The patient went under observation and suitable follow-up plans. Conclusion: Surgical management can effectively treat cerebral granulomas and improve neurological deficits in patients with recurring TB. Despite the possibility of complications, the benefits of such measures are highlighted in this case, suggesting that surgical intervention can be a viable option for achieving optimal outcomes in these patients.

Flow Diverters with Surface Modification in Patients with Intracranial Aneurysms: A Systematic Review and Meta-Analysis.

BACKGROUND: Flow diverters with surface modification (FDSM) are increasingly being used in the treatment of intracranial aneurysms (ANs). We aimed to evaluate the effectiveness and safety across different devices and antiplatelet therapies using a systematic review and meta-analysis. METHODS: A systematic review was performed to identify original studies of ≥10 patients with intracranial ANs treated with FDSM from database inception through August 2023. Primary effectiveness outcome was the rate of complete AN occlusion at follow-up ≥6 months. Safety outcomes included ischemic stroke, hemorrhage, and in-stent thrombosis, and were stratified by FDSM devices and antiplatelet therapies. Certainty of evidence was evaluated following the Grading of Recommendations, Assessment, Development, and Evaluations approach. RESULTS: Twenty-seven studies were included, yielding 2161 patients with 2373 ANs. A total of 70.5% of the ANs were located on the internal carotid artery (ICA). Total 10.3% were acutely ruptured. The complete AN occlusion rate was 72.3% at follow-up ≥6 months. Sensitivity analysis in the ICA AN cohort yielded comparable occlusion rates between Pipeline Flex Embolization Device-Shield (80.4%) and Phenox-hydrophilic polymer-coated (77.5%, P = 0.54), but a lower 66.2% rate for Flow Redirection Endoluminal Device-X (P = 0.02). The rate of in-stent thrombosis and stenosis tended to be higher in Phenox-hydrophilic polymer-coated (3.4%) and Flow Redirection Endoluminal Device-X (4.3%) versus Pipeline Flex Embolization Device-Shield (0.8%, P = 0.05). CONCLUSIONS: FDSM were safe with satisfactory effectiveness for intracranial ANs. More specific investigations are warranted to explore their performance in ANs beyond the ICA and optimal antiplatelet therapy.

Occipital artery: Anatomical variations and neurosurgical applications.

Background: The occipital artery (OA) is a branch of the external carotid artery. It gives rise to several cutaneous, muscular, and meningeal branches to supply different anatomical areas. The implication of OA in the neurosurgical field is well-established in the literature. Our aim in this study is to draw a complete picture of the anatomical variations and neurosurgical applications of the OA. Methods: A literature review was conducted in Google Scholar and PubMed to review the studies discussing OA, its anatomical variation, and neurosurgical applications. Results: We identified 29 articles that discuss the anatomical variations and neurosurgical applications of the OA. Certain variables are used to describe the surgical anatomy of OA. We also discussed certain applications of OA and its importance in neurosurgical bypass, embolization, and aneurysms. Conclusion: Comprehending the anatomy of the OA is crucial for neurosurgeons to safely and effectively perform procedures such as bypass and embolization. In addition, knowledge of the anatomical variations of the OA can help surgeons anticipate potential challenges and tailor their approach accordingly.

Supraorbital artery: Anatomical variations and neurosurgical applications.

Background: The supraorbital artery (SOA) originates from the ophthalmic artery in a superomedial aspect of the orbit, exiting through the supraorbital groove to emerge onto the forehead. The SOA has important neurosurgical considerations regarding different approaches and bypasses. The SOA is poorly described in the standard anatomical textbooks. Therefore, we present this article to describe the anatomical variations of the SOA and their implications on the neurosurgical field. Methods: We conducted a literature review in PubMed and Google Scholar databases to review the existing literature describing the SOA anatomy and its neurosurgical applications. Results: While reading the available articles and original works regarding SOA, we identified 22 studies that discuss the SOA. We noticed the anatomical variations of the SOA in terms of origin, course, diameter, branches, depth, and distance in relation to the midline and vertical glabellar line. We also discussed certain applications of SOA and its importance in neurosurgical approaches, bypass, photoplethysmography, aneurysms, and reconstruction of cranial fossa defects. Conclusion: The variable anatomy of the SOA has a paramount impact on performing different neurosurgical approaches. Therefore, cadaveric studies of the SOA are important to explore potential methods for the preservation of the artery in different neurosurgical applications.

The Enigma of the Impervious Nobel Prize for Neurosurgeons.

The Nobel Prize, which has been highly esteemed since its establishment in 1901, carries significant status within the scientific community. The Nobel Prize in Physics, Chemistry, Medicine, and Economics has long been recognized for its recognition of significant scientific contributions. However, the Nobel Prize in Physiology or Medicine holds a distinct significance due to its direct association with advancements in human health. The subject of neurosurgery, which encompasses both clinical and academic domains, has witnessed remarkable developments; nonetheless, it has not yet been awarded a Nobel Prize. The objective of this investigation is to elucidate the factors contributing to the enigmatic nature of this recognition and propose feasible techniques that can be implemented to achieve it.

Methods of Hemostasis in Cranial Neurosurgery: An Anatomy-Based Stepwise Review.

BACKGROUND: Hemostasis is crucial in preventing hemorrhage during cranial neurosurgical procedures and maintaining visualization of the surgical field. There is significant variation in the availability of hemostatic methods across different settings and hemostatic techniques are being continuously developed over the decades of practicing neurosurgery. The aim of this article is to provide an outline of the potential methods to achieve hemostasis based on the sequential operative anatomy of a cranial operation. METHODS: A systematic review was conducted following the PRISMA guidelines. The PubMed database was searched from inception of the database to July 18, 2023. A total of 64 studies were identified fulfilling predefined inclusion criteria, and the risk of bias was assessed using the Joanna Briggs Institute checklists. RESULTS: Seventy-one hemostatic agents, techniques, tools, and devices were identified, which were then categorized according to the operative phase for which they are indicated. Nine operative anatomic targets were addressed in the sequence in which they are involved during a cranial procedure. For each anatomic target, the following number of hemostatic techniques/agents were identified: 11 for scalp, 3 for periosteum, 10 for skull bone, 11 for dura mater, 9 for venous sinuses, 5 for arteries, 6 for veins, 12 for brain parenchyma, and 4 for cerebral ventricles. CONCLUSIONS: Depending on the phase of the surgery and the anatomic structure involved, the selection of the appropriate hemostatic method is determined by the source of bleeding. Surgeon awareness of all the potential techniques that can be applied to achieve hemostasis is paramount, especially when faced with operative nuances and difficult-to-control bleeding during cranial neurosurgical procedures.

Peritrigeminal Safe Entry Zone Access to Anterolateral Pons Using the Presigmoid Retrolabyrinthine Suprameatal Approach: A Cadaveric Morphometric Study.

BACKGROUND AND OBJECTIVES: Access to the anterolateral pontine lesions can be achieved through the peritrigeminal and supratrigeminal safe entry zones using Kawase, retrosigmoid, or translabyrinthine approaches. However, these approaches entail shallow extensive dissection, tangential access, and compromise vestibulocochlear function. We aimed to investigate infratentorial presigmoid retrolabyrinthine approach to access pontine lesions through the peritrigeminal zone. METHODS: We performed 10 presigmoid retrolabyrinthine suprameatal approach dissections in 5 cadaveric heads. Anatomic-radiological characteristics and variations were evaluated. Six morphometric parameters were measured and analyzed to predict surgical accessibility. RESULTS: The pontine infratrigeminal area was accessible in all patients. The mean exposed area of the anterolateral pontine surface was 98.95 cm 2 (±38.11 cm 2 ). The mean length of the exposed trigeminal nerve was 7.9 cm (±2.9 cm). Preoperative anatomic-radiological parameters may allow to select patients with favorable anatomy that offers appropriate surgical accessibility to the anterior pontine cavernoma through a presigmoid retrolabyrinthine corridor. CONCLUSION: Anterolateral pontine lesions can be accessed through a minimally invasive infratentorial presigmoid retrolabyrinthine approach by targeting the infratrigeminal safe entry zone. Further clinical studies should be conducted to evaluate the viability of this technique for treating these complex pathologies in real clinical settings.

Effectiveness of Mentorships and Early Exposure in Neurosurgery.

BACKGROUND: Mentorship programs are crucial for continuous medical education, improving personal confidence, knowledge, and skills, and have been associated with staff retention and overall career satisfaction. However, there are limited studies evaluating the effectiveness of mentorship programs in neurosurgery. The study aims to evaluate the effectiveness of mentorship programs in neurosurgery, focusing on knowledge and skill development, personal growth, and networking opportunities. METHODS: A cross-sectional study was conducted during the 9th Hoz Neurosurgery Mentorship Program, involving 175 participants from 16 countries. Precourse and postcourse surveys assessed participants' neurosurgical knowledge, research experience, personal abilities, and acknowledgment of neurosurgical subspecialties. RESULTS: Of the participants, 89% were from Iraq, with the remaining from various countries. Most participants were medical students in their early years. The average neurosurgical knowledge score increased from 35.29/60 precourse to 38.4/60 postcourse. The total passing percentage increased from 71% precourse to 86% postcourse. Prior to the program, 87% of participants had not participated in research projects, and 69% had not presented at scientific meetings. Feedback from the postcourse survey highlighted personal development, leadership, teamwork, public speaking skills, and ethical and moral aspects of being a neurosurgeon. CONCLUSIONS: Mentorship programs are effective in advancing the skills and capabilities of medical students, junior residents, and physicians. Evaluation of their effectiveness should consider not only scientific knowledge but also practical capabilities, personal growth, and critical thinking development. Free-of-charge programs with diverse participants and overall effectiveness make such experiences unique compared to other mentorship opportunities.

A case series of gyrus rectus arteriovenous malformation: Clinical characteristics, angioarchitecture, microsurgical treatment, and outcome.

Background: Gyrus rectus arteriovenous malformation (AVM) is one of the intricate pathologies that can lead to gyrus rectus hematoma. However, there is a paucity of research on this topic. This case series aims to delineate the characteristics of gyrus rectus AVMs, their outcomes, and treatment strategies. Methods: We enrolled five cases of gyrus rectus AVM that presented to the Neurosurgery Teaching Hospital in Baghdad, Iraq. Patients with the presence of gyrus rectus AVM were analyzed according to the demographic data, clinical status, radiological imaging, and outcome. Results: Of the total cases enrolled, all five cases were ruptured at the presentation. Most of the AVMs had arterial feeders from the anterior cerebral artery (80%) and superficial venous drainage through the anterior third of the superior sagittal sinus occurred in four cases (80%). Two of the cases were classified as Spetzler-Martin grade 1 AVMs, two were grade 2, and one was grade 3. With regard to the modified Rankin Score (mRS), four of them had a score of 0 after observation for 30, 18, 26, and 12 months, respectively, while one patient had an mRS score of 1 after 28 months of observation. All five cases presented with seizure and were all treated by surgical resection. Conclusion: To the best of our knowledge, this is the second report documenting the features of gyrus rectus AVMs and the first one from Iraq. Further, research into gyrus rectus AVMs is required to help better characterize and enhance our knowledge on the outcomes of such lesions.

Supraorbital keyhole approach for paraclinoid aneurysms clipping: A case series with literature review.

Background: Paraclinoid aneurysms (PcAs) are challenging aneurysms due to the complexity of their relation to the surrounding bony and neurovascular structures. Although over the past decade, their management strategy has shifted from transcranial to endovascular approaches; here, we try to revolve around a subcategory to which minimal invasive supraorbital keyhole (SOK) surgery is feasible depending on specific radiological criteria with a literature review. Methods: A group of unruptured PcAs was managed surgically, with a subset that was clipped through the SOK approach. They were selected by preoperative simulation images using 3D computed tomography (CT) angiography (CTA). We also conducted an extensive literature review based on a database available on PubMed and Google Scholar, the yielded cases from the literature review plus our cases were analyzed according to six parameters including their size, location, dome direction, need for clinoidectomy and proximal cervical control, and surgical outcome. Results: From February 2009 to August 2022, 49 cases of unruptured PcAs were managed by clipping, and of these, four cases were clipped by the SOK approach, in addition, four cases were yielded through the literature review. The sizes of the PcAs ranged from 3 to 8 mm. Their location fluctuated from anterior to the superomedial wall and their domes pointed superiorly except for one which points posteriorly. Six of eight cases required anterior clinoidectomy, the outcome was uneventful. Conclusion: A subset of unruptured PcAs are amenable to SOK with criteria such as unruptured small aneurysm (<10 mm) and projected superiorly. These characteristics can be determined preoperatively using CTA.

Bilateral basal ganglia hemorrhage: a systematic review of etiologies, management strategies, and clinical outcomes.

Bilateral basal ganglia hemorrhages (BBGHs) represent rare accidents, with no clear standard of care currently defined. We reviewed the literature on BBGHs and analyzed the available conservative and surgical strategies. PubMed, Scopus, Web of Science, and Cochrane were searched following the PRISMA guidelines to include studies reporting patients with BBGHs. Clinical characteristics, management, and outcomes were analyzed. We included 64 studies comprising 75 patients, 25 (33%) traumatic and 50 (67%) non-traumatic. Traumatic cases affected younger patients (mean age 35 vs. 46 years, p=0.014) and males (84% vs. 71%, p=0.27) and were characterized by higher proportion of normal blood pressures at admission (66% vs. 13%, p=0.0016) compared to non-traumatic cases. Most patients were comatose at admission (56%), with a mean Glasgow Coma Scale (GCS) score of 7 and a higher proportion of comatose patients in the traumatic than in the non-traumatic group (64% vs. 52%, p=0.28). Among the traumatic group, motor vehicle accidents and falls accounted for 79% of cases. In the non-traumatic group, hemorrhage was most associated with hypertensive or ischemic (54%) and chemical (28%) etiologies. Management was predominantly conservative (83%). Outcomes were poor in 56% of patients with mean follow-up of 8 months. Good recovery was significantly higher in the traumatic than in the non-traumatic group (48% vs. 17%, p=0.019). BBGHs are rare occurrences with dismal prognoses. Standard management follows that of current intracerebral hemorrhage guidelines with supportive care and early blood pressure management. Minimally invasive surgery is promising, though substantial evidence is required to outweigh the potentially increased risks of bilateral hematoma evacuation.

Transcanal Transpromontorial Approaches to the Internal Auditory Canal: A Systematic Review.

OBJECTIVE: Exclusive endoscopic (EETTA) and expanded (ExpTTA) transcanal transpromontorial approaches have shown promising results for treating internal auditory canal (IAC) lesions. We reviewed the literature to answer the question: "Do EETTA and ExpTTA achieve high rates of complete resection and low rates of complications in treating patients with IAC pathologies?" DATA SOURCES: PubMed, EMBASE, Scopus, Web of Science, and Cochrane were searched. REVIEW METHODS: Studies reporting EETTA/ExpTTA for IAC pathologies were included. Indications and techniques were discussed and meta-analyzed rates of outcomes and complications were obtained with random-effect model meta-analyses. RESULTS: We included 16 studies comprising 173 patients, all with non-serviceable hearing. Baseline FN function was mostly House-Brackmann-I (96.5%; 95% CI: 94.9-98.1%). Most lesions were vestibular/cochlear schwannomas (98.3%; 95% CI: 96.7-99.8%) of Koos-I (45.9%; 95% CI: 41.3-50.3%) or II (47.1%; 95% CI: 43-51.1%). EETTA was performed in 101 patients (58.4%; 95% CI: 52.4-64.3%) and ExpTTA in 72 (41.6%; 95% CI: 35.6-47.6%), achieving gross-total resection in all cases. Transient complications occurred in 30 patients (17.3%; 95% CI: 13.9-20.5%), with meta-analyzed rates of 9% (95% CI: 4-15%), comprising FN palsy with spontaneous resolution (10.4%; 95% CI: 7.7-13.1%). Persistent complications occurred in 34 patients (19.6%; 95% CI: 17.1-22.2%), with meta-analyzed rates of 12% (95% CI: 7-19%), comprising persistent FN palsy in 22 patients (12.7%; 95% CI: 10.2-15.2%). Mean follow-up was 16 months (range, 1-69; 95% CI: 14.7-17.4). Post-surgery FN function was stable in 131 patients (75.8%; 95% CI: 72.1-79.5%), worsened in 38 (21.9%; 95% CI: 18.8-25%), and improved in 4 (2.3%; 95% CI: 0.7-3.9%), with meta-analyzed rates of improved/stable response of 84% (95% CI: 76-90%). CONCLUSION: Transpromontorial approaches offer newer routes for IAC surgery, but their restricted indications and unfavorable FN outcomes currently limit their use. Laryngoscope, 133:2856-2867, 2023.