Single versus multiple reoperations for recurrent intracranial meningiomas.

PURPOSE: To identify the risk factors and management of the multiple recurrences and reoperations for intracranial meningiomas. METHODS: Data of a neurosurgical series of 35 patients reoperated on for recurrent intracranial meningiomas were reviewed. Analyzed factors include patient age and sex, tumor location, extent of resection, WHO grade, Ki67-MIB1 and PR expression at initial diagnosis, time to recurrence; pattern of regrowth, extent of resection, WHO grade and Ki67-MIB1 at first recurrence were also analyzed. All these factors were stratified into two groups based on single (Group A) and multiple reoperations (Group B). RESULTS: Twenty-four patients (69%) belonged to group A and 11 (31%) to group B. The age < 65 years, male sex, incomplete resection at both initial surgery and first reoperation, and multicentric-diffuse pattern of regrowth at first recurrence are risk factors for multiple recurrences and reoperations. In group B, the WHO grade and Ki67-MIB1 increased in further recurrences in 54% and 64%, respectively. The time to recurrence was short in 7 cases (64%), whereas 4 patients (36%) further recurred after many years. Eight patients (73%) are still alive after 7 to 22 years and 2 to 4 reoperations. CONCLUSION: The extent of resection and the multicentric-diffuse pattern of regrowth at first recurrence are the main risk factors for multiple recurrences and reoperations. Repeated reoperations might be considered even in patients with extensive recurrent tumors before the anaplastic transformation occurs. In such cases, even partial tumor resections followed by radiation therapy may allow long survival in good clinical conditions.

Open-door extended endoscopic transorbital technique to the paramedian anterior and middle cranial fossae: technical notes, anatomomorphometric quantitative analysis, and illustrative case.

OBJECTIVE: The superior eyelid endoscopic transorbital approach (SETOA) provides a direct and short minimally invasive route to the anterior and middle skull base. Nevertheless, it uses a narrow corridor that limits its angles of attack. The aim of this study was to evaluate the feasibility and potential benefits of an "extended" conservative variant of the "standard" endoscopic transorbital approach-termed "open-door"-to enhance the exposure of lesions affecting the paramedian aspect of the anterior and middle cranial fossae. METHODS: First, the authors described the technical nuances of the open-door extended transorbital approach (ODETA). Next, they documented its morphometric advantages over standard SETOA. Finally, they provided a clinical-anatomical application to demonstrate enhanced exposure and better angles of attack to treat lesions occupying the paramedian anterior and middle cranial fossae. Five adult cadaveric specimens (10 sides) initially underwent standard SETOA and then extended open-door SETOA (ODETA to the paramedian anterior and middle fossae). The adjunct of hinge-orbitotomy, through three surgical steps and straddling the frontozygomatic suture, converted conventional SETOA to its extended open-door variant. CT scans were performed before dissection and uploaded to the neuronavigation system for quantitative analysis. The angles of attack on the axial plane that addressed four key landmarks, namely the tip of the anterior clinoid process (ACP), foramen rotundum (FR), foramen ovale (FO), and trigeminal impression (TI), were calculated for both operative techniques and compared. RESULTS: Hinge-orbitotomy of the extended open-door SETOA resulted in several surgical, functional, and esthetic advantages: it provided wider axial angles of attack for each of the target points, with a gain angle of 26.68° ± 1.31° for addressing the ACP (p < 0.001), 29.50° ± 2.46° for addressing the FR (p < 0.001), 19.86° ± 1.98° for addressing the FO (p < 0.001), and 17.44° ± 2.21° for addressing the lateral aspect of the TI (p < 0.001), while hiding the skin scar, avoiding temporalis muscle dissection, preserving flap vascularization, and decreasing the rate of bone infection and degree of orbital content retraction. CONCLUSIONS: The extended open-door technique may be specifically suited for selected patients affected by paramedian anterior and middle fossae lesions, with prevalent anteromedial extension toward the anterior clinoid, the foremost compartment of the cavernous sinus and FR and not completely controlled with the pure endoscopic transorbital approach.

Neuroanatomical photogrammetric models using smartphones: a comparison of apps.

OBJECTIVES: A deep knowledge of the surgical anatomy of the target area is mandatory for a successful operative procedure. For this purpose, over the years, many teaching and learning methods have been described, from the most ancient cadaveric dissection to the most recent virtual reality, each with their respective pros and cons. Photogrammetry, an emergent technique, allows for the creation of three-dimensional (3D) models and reconstructions. Thanks to the spreading of photogrammetry nowadays it is possible to generate these models using professional software or even smartphone apps. This study aims to compare the neuroanatomical photogrammetric models generated by the two most utilized smartphone applications in this domain, Metascan and 3D-Scanner, through quantitative analysis. METHODS: Two human head specimens (four sides) were examined. Anatomical dissection was segmented into five stages to systematically expose well-defined structures. After each stage, a photogrammetric model was generated using two prominent smartphone applications. These models were then subjected to both quantitative and qualitative analysis, with a specific focus on comparing the mesh density as a measure of model resolution and accuracy. Appropriate consent was obtained for the publication of the cadaver's image. RESULTS: The quantitative analysis revealed that the models generated by Metascan app consistently demonstrated superior mesh density compared to those from 3D-Scanner, indicating a higher level of detail and potential for precise anatomical representation. CONCLUSION: Enabling depth perception, capturing high-quality images, offering flexibility in viewpoints: photogrammetry provides researchers with unprecedented opportunities to explore and understand the intricate and magnificent structure of the brain. However, it is of paramount importance to develop and apply rigorous quality control systems to ensure data integrity and reliability of findings in neurological research. This study has demonstrated the superiority of Metascan in processing photogrammetric models for neuroanatomical studies.

Posterolateral approaches to the thoracic spine for calcific disc herniation: is wider exposure always better?

OBJECTIVE: To compare the costotransversectomy (CTV) and transpedicular (TP) approaches versus the transfacet (TF) approach for the surgical treatment of calcific thoracic spine herniations (cTDH), in terms of surgical and clinical outcomes. BACKGROUND: Surgical approaches for cTDH are debated. Anterior approaches are recommended, while posterolateral approaches are preferred for non-calcific, paramedian, and lateral hernias. Currently, there is limited evidence about the superiority of a more invasive surgical approach, such as CTV or TP, over TF, a relatively less invasive approach, in terms of neurological outcome, pain, and surgical complications, for the treatment of cTDH. METHODS: A retrospective, observational, monocentric study was conducted on patients who underwent posterolateral thoracic approaches for symptomatic cTDH, between 2010 and 2023, at our institute. Three groups were drafted, based on the surgical approach used: TF, TP, and CTV. All procedures were assisted by intraoperative CT scan, spinal neuronavigation, and intraoperative neuromonitoring. Analyzed factors include duration of surgery, amount of bone removal, intraoperative blood loss, CSF leak, need of instrumentation for iatrogenic instability, degree of disc herniation removal, myelopathy recovery. Afterwards, a statistical analysis was performed to investigate the bony resection of the superior posterior edge of the vertebral soma. The primary outcome was the partial or total herniation removal. RESULTS: This study consecutively enrolled 65 patients who underwent posterolateral thoracic surgery for cTDH. The TF approach taking the least, and the CTV the longest time (p < 0.01). No statistical difference was observed between the three mentioned approaches, in terms of intraoperative blood loss, dural leakage, post-resection instrumentation, total herniation removal, or myelopathy recovery. An additional somatic bony resection was successful in achieving total herniation removal (p < 0.01), and the extent of bony resection was directly proportional to the extent of hernia removal (p < 0.01). CONCLUSIONS: No statistically significant differences were highlighted between the TP, TF, and CTV regarding the extent of cTDH removal, the postoperative complications, and the neurological improvement. The described somatic bone resection achieved significant total herniation removal and was directly proportional to the preop against postop anteroposterior diameter difference.

Impact of deep brain stimulation therapy on the vertebral sagittal balance in Parkinson's disease patients.

Parkinson's disease (PD) is characterized by cardinal motor signs: 4-6 Hz resting tremor, rigidity, and bradykinesia. In addition, 3-18% of PD patients have camptocormia, an abnormal forward flexion of the thoracolumbar spine, which may have a negative impact on patients' quality of life. Different possible treatments have been suggested for such a condition, but no one is resolutive. This study aims to define the possible impact of DBS, with selective targeting on the dorsal-lateral region of the STN, on the sagittal balance of patients affected by PD. Among all patients that have undergone DBS procedures in our institution, we selected eight subjects, four females and four males, with selective targeting on the dorsal-lateral region of the subthalamic nucleus (STN) because of camptocormia and other severe postural changes. Radiological assessments of spinal balance parameters before surgery and at 6 and 12 months postoperatively were carried out. Comparison of preoperative and postoperative spine X-ray data showed a statistically significant improvement in dorsal kyphosis angle (D-Cobb) 12 months after the operation. Deep brain stimulation with selective targeting of the dorsal lateral part of the STN may induce changes of the posture in patients with Parkinson's disease 12 months after the operation, which appears to improve in this small sample size, but larger observational and controlled trials would be required to confirm this observation.

Meningiomas of the rolandic region: risk factors for motor deficit and role of intra-operative monitoring.

OBJECTIVE: Meningiomas of the rolandic region are associated to high risk of postoperative motor deficits. This study discusses the factors affecting motor outcome and recurrences from the analysis of a monoinstitutional case series and eight studies from a literature review. METHODS: Data of 75 patients who underwent surgery for meningioma of the rolandic region were retrospectively reviewed. The analyzed factors included tumor location and size, clinical presentation, magnetic resonance imaging (MRI) and surgical findings, brain-tumor interface, extent of resection, postoperative outcome and recurrence. Eight studies from literature on rolandic meningiomas treated with or without intraoperative monitoring (IOM) were reviewed with the aim to define the impact of IOM on the extent of resection and motor outcome. RESULTS: Among the 75 patients of the personal series, the meningioma was on the brain convexity in 34 (46%), at the parasagittal region in 28 (37%) and at the falx in 13 (17%). The brain-tumor interface was preserved in 53 cases (71%) at MRI and in 56 (75%) at surgical exploration. Simpson grade I resection was obtained in 43% of patients, grade II in 33%, grade III in 15% and grade IV in 9%. The motor function worsened postoperatively in 9 among 32 cases with preoperative deficit (28%) and in 5 among 43 with no preoperative deficit (11.5%); definitive motor deficit was evidenced in overall series at follow-up in 7 (9.3%). Patients with meningioma with lost arachnoid interface had significant higher rates of worsened postoperative motor deficit (p = 0.01) and seizures (p = 0.033). Recurrence occurred in 8 patients (11%). The analysis of the 8 reviewed studies (4 with and 4 without IOM) shows in the group without IOM higher rates of Simpson grades I and II resection (p = 0.02) and lower rates of grades IV resection (p = 0.002); no significant differences in postoperative immediate and long-term motor deficits were evidenced between the two groups. CONCLUSIONS: Data from literature review show that the use of IOM does not affect the postoperative motor deficit Therefore, its role in rolandic meningiomas resection remains to be determined and will be defined in further studies.

The anterolateral triangle as window on the foramen lacerum from transorbital corridor: anatomical study and technical nuances.

OBJECTIVE: Neurosurgical indications for the superior eyelid transorbital endoscopic approach (SETOA) are rapidly expanding over the last years. Nevertheless, as any new technique, a detailed knowledge of the anatomy of the surgical target area, the operative corridor, and the specific surgical landmark from this different perspective is required for a safest and successful surgery. Therefore, the aim of this study is to provide, through anatomical dissections, a detailed investigation of the surgical anatomy revealed by SETOA via anterolateral triangle of the middle cranial fossa. We also sought to define the relevant surgical landmarks of this operative corridor. METHODS: Eight embalmed and injected adult cadaveric specimens (16 sides) underwent dissection and exposure of the cavernous sinus and middle cranial fossa via superior eyelid endoscopic transorbital approach. The anterolateral triangle was opened and its content exposed. An extended endoscopic endonasal trans-clival approach (EEEA) with exposure of the cavernous sinus content and skeletonization of the paraclival and parasellar segments of the internal carotid artery (ICA) was also performed, and the anterolateral triangle was exposed. Measurements of the surface area of this triangle from both surgical corridors were calculated in three head specimens using coordinates of its borders under image-guide navigation. RESULTS: The drilling of the anterolateral triangle via SETOA unfolds a space that can be divided by the course of the vidian nerve into two windows, a wider "supravidian" and a narrower "infravidian," which reveal different anatomical corridors: a "medial supravidian" and a "lateral supravidian," divided by the lacerum segment of the ICA, leading to the lower clivus, and to the medial aspect of the Meckel's cave and terminal part of the horizontal petrous ICA, respectively. The infravidian corridor leads medially into the sphenoid sinus. The arithmetic means of the accessible surface area of the anterolateral triangle were 45.48 ± 3.31 and 42.32 ± 2.17 mm2 through transorbital approach and endonasal approach, respectively. CONCLUSION: SETOA can be considered a minimally invasive route complementary to the extended endoscopic endonasal approach to the anteromedial aspect of the Meckel's cave and the foramen lacerum. The lateral loop of the trigeminal nerve represents a reliable surgical landmark to localize the lacerum segment of the ICA from this corridor. Nevertheless, as any new technique, a learning curve is needed, and the clinical feasibility should be proven.

The feasibility of three port endonasal, transorbital, and sublabial approach to the petroclival region: neurosurgical audit and multiportal anatomic quantitative investigation.

PURPOSE: The petroclival region represents the "Achille's heel" for the neurosurgeons. Many ventral endoscopic routes to this region, mainly performed as isolated, have been described. The aim of the present study is to verify the feasibility of a modular, combined, multiportal approach to the petroclival region to overcome the limits of a single approach, in terms of exposure and working areas, brain retraction and manipulation of neurovascular structures. METHODS: Four cadaver heads (8 sides) underwent endoscopic endonasal transclival, transorbital superior eyelid and contralateral sublabial transmaxillary-Caldwell-Luc approaches, to the petroclival region. CT scans were obtained before and after each approach to rigorously separate the contribution of each osteotomy and subsequentially to build a comprehensive 3D model of the progressively enlarged working area after each step. RESULTS: The addition of the contralateral transmaxillary and transorbital corridors to the extended endoscopic endonasal transclival in a combined multiportal approach provides complementary paramedian trajectories to overcome the natural barrier represented by the parasellar and paraclival segments of the internal carotid artery, resulting in significantly greater area of exposure than a pure endonasal midline route (8,77 cm2 and 11,14 cm2 vs 4,68 cm2 and 5,83cm2, extradural and intradural, respectively). CONCLUSION: The use of different endoscopic "head-on" trajectories can be combined in a wider multiportal extended approach to improve the ventral route to the most inaccessible petroclival regions. Finally, by combining these approaches and reiterating the importance of multiportal strategy, we quantitatively demonstrate the possibility to reach "far away" paramedian petroclival targets while preserving the neurovascular structures.

Management of the skull base invasion in spheno-orbital meningiomas.

BACKGROUND: The tumor invasion of the skull base structures is very frequent in spheno-orbital meningiomas. The aim of the present study is to evaluate the invasion rate of skull base structures and the best surgical approach and management. METHODS: The surgical series of 80 spheno-orbital meningiomas was reviewed. The tumors were classified according to the intraorbital location with respect to the optic nerve axes into three types: I-lateral: II-medial; III-diffuse. The invasion of the orbital apex, optic canal, superior orbital fissure, anterior clinoid, ethmoid-sphenoid sinuses, and infratemporal fossa was evaluated. The rate and extension of involvement of these structures was correlated with the intraorbital location and the surgical approach. The preoperative ophtalmological symptoms and signs and their outcome were also evaluated. RESULTS: Proptosis was found in 79 patients (97%), variable decrease of the visual function in 47 patients (59%), and deficits of the eye movements in 28(35%). The invasion of the optic canal (74%), superior orbital fissure (65%), anterior clinoid (60%), and orbital apex (59%) was more frequently found, whereas the tumor extension into the ethmoid-sphenoid sinuses (4%) and infratemporal fossa (4%) was rare. Types II and III meningiomas showed significantly higher involvement of the skull base structures than type I ones, which only had 15% invasion of the optic canal. Remission or significant improvement of the visual function occurred postoperatively in 24 among 47 cases (51%), with a higher rate for type I meningiomas vs. other types (p = 0.021, p = 0.019) and worsening in 7 (15%). CONCLUSIONS: Spheno-orbital meningiomas growing in the lateral orbital compartment show no involvement of the skull base structures excepting the optic canal as compared to those growing medially or diffusely. The surgical resection of tumor invading the skull base structures should be more extensive as possible, but the risk of optic and oculomotor deficits must be avoided.

Malignant intraventricular meningioma: literature review and case report.

Malignant intraventricular meningiomas (IVMs) are very rare with only a few reported cases. A midline search up to December 2020 selected 40 articles for a total of 65 patients. The inclusion criteria were series and case reports in English language, as well as papers written in other languages, but with abstracts written in English. Malignant IVMs at the first diagnosis (group A, 50 patients) and those with anaplastic transformation from previous WHO grades I and II tumors (group B, 15 patients) were separately analyzed. The unique personal case among 1285 meningiomas (0.078%) is also added. Malignant IVMs mainly occur in women (61%) with a median age of 45 years and are mainly located in the lateral ventricle (93%) and trigonal region (74%), with no cases in the fourth ventricle. Irregular borders (80%), heterogeneous enhancement (83%), and perilesional edema (76%) are the most frequent radiological findings. The histology was mainly pure anaplastic (85%), whereas papillary (7%), rhabdoid (5%), and mixed forms (3%) are very rare. The CSF spread was found in 60% of the cases. The prognosis is very dismal, with an overall median survival of 17.5 months after surgery for the anaplastic forms. Malignant IVMs at initial diagnosis (group A) show better overall survival (25 months) than those occurring from anaplastic transformation of lower grade tumors (group B) (10.1 months).