Microsurgical anatomy and approaches to thalamic gliomas. Part 2: Maximal safe resection of thalamic gliomas improves outcomes. A single-center experience.

OBJECTIVE: As presented in Part 1 of this series, thalamic gliomas (TGs) are deep-seated, difficult-to-access tumors surrounded by vital neurovascular structures. Given their high operative morbidity, TGs have historically been considered inoperable lesions. Although maximal safe resection (MSR) has become the treatment standard for lobar and even deep-seated mediobasal temporal and insular gliomas, the eloquent location of TGs has precluded this management strategy, with biopsy and adjuvant treatment being the mainstay. The authors hypothesized that MSR can be achieved with low morbidity and mortality for TGs, thus resulting in improved outcomes. METHODS: A retrospective single-center study was performed on all TG patients from 2006 to 2020. Clinical, imaging, and pathology reports were obtained. Univariate and multivariate analyses were performed to determine prognostic variables. Case examples illustrate various approaches and the rationale for staging resections of more complex TGs. RESULTS: A total of 42 patients (26 males, 16 females), among them 12 pediatric (29%) cases, were included. Their mean age was 36.0 ± 21.4 (median 30, range 3-73) years. The median maximal tumor diameter was 45 (range 19-70) mm. Eighteen patients (43%) had a prior stereotactic needle tumor biopsy, with the ultimate diagnosis changed for 7 patients (39%) following microsurgical resection. The most common surgical approaches were transtemporal (29%), anterior interhemispheric transcallosal (29%), and superior parietal lobule (25%). Overall, the combined subtotal and gross-total resection rate was 95% (n = 40). Low-grade gliomas (LGGs; grades I and II) comprised one-third of the group, whereas half of the patients had glioblastoma multiforme. There were no operative mortalities. Although temporary postoperative motor deficits were observed in 12 patients (28.6%), all improved during the early postoperative period except 1 (2.4%), who had mild residual hemiparesis. Two patients required CSF diversion for hydrocephalus. The 2-year overall survival rate was 90% for LGG patients and 15% for high-grade glioma (HGG) patients. Multivariate analysis revealed that histological grade, age, and extent of resection were independent prognostic factors associated with survival. CONCLUSIONS: Management of TGs is challenging, with resection avoided by many, if not most, neurosurgeons, especially for HGGs. The results reported here demonstrate improved outcomes with resection, particularly in younger LGG patients. The authors therefore advocate for MSR for a select cohort of TG patients using carefully planned surgical approaches, contemporary intraoperative adjuncts, and meticulous microsurgical techniques.

Microsurgical anatomy and approaches to thalamic gliomas. Part 1: A cartography guide for navigating to the thalamus. Integrating 3D model rendering with anatomical dissections.

OBJECTIVE: The selection of appropriate microsurgical approaches to treat thalamic pathologies is currently largely subjective. The objective of this study was to provide a structured cartography map for surgical navigation to treat gliomas involving different surfaces of the thalamus. METHODS: Fifteen formalin-fixed, silicone-injected cadavers (30 sides) were dissected, and 10 adult brain specimens (20 sides) were used to illustrate thalamic microsurgical anatomy using the Klingler fiber dissection technique. Exposures and trajectories for the six most common microsurgical approaches were depicted using MR data from healthy subjects converted into surface-rendered 3D virtual brain models. Additionally, thalamic surfaces exposed with all six approaches were color mapped on the virtual 3D model and compared side-by-side in 360° views with previously reported microsurgical approaches. These 3D models were then used in conjunction with topographic data to guide cadaveric dissection steps. RESULTS: There are two general surgical routes to thalamic lesions: the subarachnoid transcisternal and transcortical routes. The transcisternal route consists of the following three approaches: 1) anterior interhemispheric transcallosal approach, which exposes the anterior and superior thalamus; 2) posterior interhemispheric transcallosal approach, which exposes the posterosuperior thalamus; and 3) supracerebellar infratentorial approach, which exposes the posteromedial cisternal thalamus and can be extended laterally to approach the posterolateral thalamus by cutting the tentorium. The three transcortical approaches are the 1) superior parietal lobule approach, which exposes the posterosuperior thalamus and is particularly advantageous in the setting of hydrocephalus; 2) transtemporal gyrus approach, which exposes the inferolateral thalamus; and 3) transsylvian transinsular approach, which exposes the lateral thalamus (slightly more superiorly and posteriorly) and is advantageous for pathologies extending laterally into the peduncle, lenticular nucleus, or insula. CONCLUSIONS: Microsurgical approaches to thalamic gliomas continue to be challenging. Nonetheless, safe and effective cisternal, ventricular, and cortical corridors can be developed with thoughtful planning, anatomical understanding, and knowledge of the advantages, risks, and limitations of each approach. In some cases, it is wise to combine these approaches with staged procedures, as the authors demonstrate in Part 2. In Part 1 of this two-part series, they discuss thalamic microsurgical anatomy and illustrate the trajectory and exposures of all six approaches to guide decision-making. Part 2 discusses their thalamic glioma microsurgical case series, which utilizes these microsurgical approaches.

Global Neurosurgery Advances From Trenches to Bedside: Lessons From Neurosurgical Care in War, Humanitarian Assistance, and Disaster Response.

INTRODUCTION: War has influenced the evolution of global neurosurgery throughout the past century. Armed conflict and mass casualty disasters (MCDs), including Humanitarian Assistance Disaster Relief missions, require military surgeons to innovate to meet extreme demands. However, the military medical apparatus is seldom integrated into the civilian health care sector. Neurosurgeons serving in the military have provided a pragmatic template for global neurosurgeons to emulate in humanitarian disaster responses. In this paper, we explore how wars and MCD have influenced innovations of growing interest in the resource-limited settings of global neurosurgery. METHODS: We performed a narrative review of the literature examining the influence of wars and MCD on contemporary global neurosurgery practices. RESULTS: Wartime innovations that influenced global neurosurgery include the development of triage systems and modernization with airlifts, the implementation of ambulance corps, early operation on cranial injuries in hospital camps near the battlefield, the use of combat body armor, and the rise of damage control neurosurgery. In addition to promoting task-shifting and task-sharing, workforce shortages during wars and disasters contributed to the establishment of the physician assistant/physician associate profession in the USA. Low- and middle-income countries (LMICs) face similar challenges in developing trauma systems and obtaining advanced technology, including neurosurgical equipment like battery-powered computed tomography scanners. These challenges-ubiquitous in low-resource settings-have underpinned innovations in triage and wound care, rapid evacuation to tertiary care centers, and minimizing infection risk. CONCLUSION: War and MCDs have catalyzed significant advancements in neurosurgical care both in the pre-hospital and inpatient settings. Most of these innovations originated in the military and subsequently spread to the civilian sector as military neurosurgeons and reservist civilian neurosurgeons returned from the battlefront or other low-resource locations. Military neurosurgeons have utilized their experience in low-resource settings to make volunteer global neurosurgery efforts in LMICs successful. LMICs have, by necessity, responded to challenges arising from resource shortages by developing innovative, context-specific care paradigms and technologies.

More Laboratory Simulations-Fewer Brain Complications: Prospects from the First Neurosurgery Laboratory in Iraq.

BACKGROUND: The intensive training requirements needed to achieve the requisiste microneurosurgical milestones makes proper training and skill acquisition a challenge to the novice neurosurgeon. This problem is compounded in low- and middle-income nations, where neurosurgery is subject to a myriad of human and financial resource constraints. A temporary solution may be provided by low-cost laboratories that are adaptive to local needs. METHODS: The "HOZ NeuroSurgery LAB" is a nonprofit facility dedicated to microneurosurgery education and skills training. The laboratory, established in June 2015, is housed at the Neurosurgery Teaching Hospital in Baghdad, Iraq. It operates under the motto "More Laboratory Simulation-Fewer Brain Complications.". The fundamental infrastructure of the facility consists of a relatively inexpensive microscope, indigenous locally created training equipment, and animal-based models. RESULTS: Since its inception, this lab has functioned as a hub for resident education and microneurosurgery service, in addition to contributing to the specialty's academic output in the nation. The lab is directly responsible for training 4 vascular neurosurgeons who are currently directing the nation's first organized neurovascular service. Also, it has delivered 53 microneurosurgery skills courses, coordinated 8 student neurosurgery elective cycles with a total of 532 participants, and published approximately 70 research articles. CONCLUSIONS: Our experience may serve as a model for other low- and middle-income countries interested in using the principle of "doing more with less" to overcome some of the challenges associated with microneurosurgery in these parts of the world.

Surgical Clipping of a Ruptured Distal Anterior Inferior Cerebellar Artery Aneurysm: A Technical Note.

Aneurysms of the distal anterior inferior cerebellar artery (AICA) are uncommon. They can present with subarachnoid hemorrhage (SAH), cerebellopontine angle syndrome, or a combination of the two. We describe the technique and nuances of microsurgical clipping of a ruptured distal AICA aneurysm using a retrosigmoid approach. After performing the craniotomy, the AICA was exposed in a distal to proximal fashion and the aneurysm and the proximal parent vessel were identified. After establishing proximal control, a clip was placed across the neck of the aneurysm to obliterate it while maintaining flow within the parent vessel. Finally, the flow within the parent vessel was confirmed and the final clip position was checked to ensure that it was not compressing any of the cranial nerves in the vicinity. The aneurysm was completely obliterated, and the parent vessel remained patent. Distal AICA aneurysms are rare and challenging to treat. The retrosigmoid approach is commonly used to treat these aneurysms. Careful planning, which includes studying the vascular anatomy and the aneurysm characteristics, and proficient execution of the procedure can increase the safety and improve outcomes of surgical clipping of these aneurysms.

Cerebellar mutism following head trauma: A case report and literature review.

BACKGROUND: Cerebellar mutism (CM) is defined as the lack of speech production, despite an intact state of consciousness and cognitive function, that happens secondary to a cerebellar insult. To the best of our knowledge, only five cases have thus far been described in the English literature. In this paper, we report the sixth incidence overall, which is also the first case of a CM associated with penetrating head injury. The relevant literature is reviewed and analyzed, our current knowledge of the neuroanatomical and functional relations is summarized, and potential future research endeavors are indicated. CASE DESCRIPTION: An 8-year-old girl was transferred to our hospital having had fallen on a rod that penetrated her neck behind the ear. An urgent computed tomography scan of the head revealed a right cerebellar contusion with surrounding edema. Three days later, she became mute but was still obeying commands. Repeat imaging showed a resolving cerebellar contusion with increased edema and mass effect. By day 9, she had uttered a few words. At 1-month follow-up, the child had regained normal speech. CONCLUSION: Posttraumatic CM is a rare and probably underreported condition with only six documented cases to date. Although it may well be on the same spectrum as postoperative CM, further understanding of the exact mechanism, clinical course, and prognosis of this entity is bound to significantly improve the recovery and quality of life of head trauma patients.

Remarkable Clinical Improvement Following Microsurgical Resection of Left Lingual Gyrus Cerebral Cavernous Malformation: A Case Report

Moyamoya disease is a chronic and unusual cerebrovascular disorder characterized by progressive stenosis and occlusion of the distal portions of internal carotid arteries and its main branches within the circle of Willis. Posterior circulation (vertebral and basilar arteries) may also be affected; however, this presentation is uncommon. As well as stenosis of the terminal portion of intracranial arteries, it is seen the development of a network of collateral vessels abnormally dilated at the base of the brain with an aspect of a "puff of smoke," whose term in Japanese is described as "moyamoya." The present study aims to report two consecutive cases of patients who presented to our service with different clinical manifestations. Further investigation with digital subtraction angiography showed a moyamoya pattern.

The spectrum of venous anomalies associated with atretic parietal cephaloceles: A literature review.

BACKGROUND: Parietal atretic cephalocele (PAC) is a small, subscalp lesion with underlying extracranial meningeal, neural, and glial tissues. In this paper, we analyze the related literature on the continuum of PAC-associated venous anomalies and report an exemplary case. METHODS: The PubMed Medline database was searched using the following search algorithm: (Atretic encephalocele) OR (Rudimentary meningocele,) OR (Atypical meningocele) OR (Meningocele manqué) OR (Meningeal heterotopia). Only papers detailing the venous anomalies associated with PACs have been included. RESULTS: A total of 30 papers in our search documented PAC-associated venous abnormalities. The overall number of cases reported was 68 (including our exemplary case). The most frequently identified associated venous anomaly was the presence of a "fenestrated superior sagittal sinus" recorded in 48.5% of cases (n = 33), followed closely by "persistent falcine sinus" in 47% (n = 32) and vertical embryonic positioning of the straight sinus (SS) in 44% (n = 30). The complete absence of a SS was reported in 39.7% (n = 27) and various anomalies of the Galenic system were reported in 26.8% of cases (n = 12). CONCLUSION: Although benign in nature, PACs are often a marker for the presence of complex and variable cerebral venous malformations, requiring extensive preoperative imaging workup for both the superficial and deep venous systems to obtain an accurate understanding of the anatomy of the venous system and guide surgical planning.

PubMed-indexed neurosurgical research productivity of Iraq-based neurosurgeons.

BACKGROUND: Research is a central component of neurosurgical training and practice and is increasingly viewed as a quintessential indicator of academic productivity. In this study, we focus on identifying the current status and challenges of neurosurgical research in Iraq. METHODS: An online PubMed Medline database search was conducted to identify all articles published by Iraq-based neurosurgeons between 2003 and 2020. Information was extracted in relation to the following parameters: authors, year of publication, author's affiliation, author's specialty, article type, article citation, journal name, journal impact factor, and topic. This data were then tabulated and analyzed. RESULTS: Between 2003 and 2021, a total of 52 PubMed indexed papers were published from Iraq. All publications have been clustered in the period of 2012-2020. From 2012 to 2016, only four papers were published, one per year. The number of publications increased from 2017 to 2021, with an average of 12 publications per year. The most common article type was "case reports" (n = 14). Neurotrauma (n = 10) and vascular neurosurgery (n = 10) were the two most common topics. Most of the studies came from the city of Bagdad (n = 46), with just nine studies coming from peripheral governorates. The Neurosurgery Teaching Hospital in Bagdad was the neurosurgery center with the highest research output (n = 38). CONCLUSION: The number of publications per year has been showing a, relatively, promising trend since 2012. However, to promote sustained growth in academic productivity, a strategic plan that acknowledges the political, financial, and health-system-related challenges are urgently needed.