[ESTABLISHING A NEW TEAM FOR ENDOSCOPIC ENDONASAL SKULL BASE SURGERY: THE LEARNING CURVE FROM BASIC TO ADVANCED COMPLEXITY LEVEL].

INTRODUCTION: Establishing a new team for endoscopic endonasal skull base surgeries (EES) requires a period of adjustment. Our team was established 4 years ago and consists of surgeons with previous experience. Our objective was to examine the learning curve associated with the establishment of such a team. METHODS: All patients who underwent EES between January 2017 and October 2020 were reviewed. The first 40 patients were defined as the 'early group' and the last 40 as the 'late group'. Data was retrieved from electronic medical records and surgical videos. Study groups were compared in terms of the level of surgical complexity, (II to V according to EES complexity level scale; level I cases were excluded), surgical outcome and complication rate. RESULTS: 'Early group' cases and 'late group' cases were operated on in 25 and 11 months, respectively. Complexity level II surgeries, which mainly included pituitary adenomas, were the most common in both groups (77.5% and 60%, respectively); of these, functional adenomas and reoperations were more common in the 'late group'. The rate of advanced complexity surgeries (III - V) was higher in the 'late group' (40% vs. 22.5%); level V surgeries were performed only in the 'late group'. No significant differences were observed in terms of surgical outcomes or complications; postoperative cerebrospinal fluid (CSF) leaks were less common in the 'late group' (2.5% vs. 7.5%). CONCLUSIONS: Our findings indicate that the establishment of a new EES team, even if it includes experienced skull base surgeons, is associated with a learning curve, which requires about 40 cases.

[COMPARISON OF HIGH GAMMA ELECTROCORTICOGRAPHY AND DIRECT CORTICAL STIMULATION MAPPING OF CORTICAL FUNCTION IN AWAKE CRANIOTOMY: INITIAL EXPERIENCE].

INTRODUCTION: The use of intraoperative electrical cortical stimulation (ECS) to map function is the standard of care in modern neurosurgery. Recently, high gamma electrocorticography (hgECOG) mapping has had encouraging results. In this study we aim to compare hgECOG and fMRI with ECS for motor and language mapping. METHODS: We retrospectively evaluated medical records of patients who underwent awake surgery for tumor resection between January 2018 and December 2021. The first 10 consecutive patients who underwent ECS and hgECOG for mapping of motor and language functions were defined as the study group. Pre- and intra-operative imaging and electrophysiology data were used for analysis. RESULTS: ECS and hgECOG motor mapping demonstrated functional motor areas in 71.4% and 85.7% of patients, respectively. All motor areas identified with ECS were also demonstrated using hgECOG. In 2 patients, hgECOG-based mapping demonstrated motor areas not demonstrated with ECS but present in preoperative fMRI imaging. Of the 15 hgECOG tasks performed for language mapping, the findings of 6 (40%) were in accordance with the ECS mapping. Two (13.3%), showed language areas that were demonstrated using ECS and in addition, showed areas that were not. Four mappings (26.7%) showed language areas that were not demonstrated using ECS. In 3 mappings (20%), the functional areas identified by ECS were not demonstrated by hgECOG. CONCLUSIONS: Intraoperative hgECOG for mapping of motor and language functions provide a fast and reliable method without the risk of stimulation-induced seizures. Further studies are needed to assess functional outcome of patients undergoing hgECOG-guided tumor resection.

[INTRAOPERATIVE ELECTROPHYSIOLOGY MAPPING OF CORTICAL FUNCTION: A BRIEF HISTORY AND EVOLVING ALTERNATIVE].

INTRODUCTION: Multiple studies have demonstrated that the improved extent of resection for patients with glioma is associated with improved survival. The use of intraoperative electrophysiology cortical mapping to demonstrate function became a standard of care in modern neurosurgery and an indispensable tool to achieve the goal of maximal safe resection in tumor surgery. In this study, we review the brief history of intraoperative electrophysiology cortical mapping from the first cortical mapping study back in 1870 to the innovative tool of broad gamma cortical mapping used today.

Comparison of matched formalin-fixed paraffin embedded and fresh frozen meningioma tissue reveals bias in proteomic profiles.

Tissue biopsies are most commonly archived in a paraffin block following tissue fixation with formaldehyde (FFPE) or as fresh frozen tissue (FFT). While both methods preserve biological samples, little is known about how they affect the quantifiable proteome. We performed a 'bottom-up' proteomic analysis (N = 20) of short and long-term archived FFPE surgical samples of human meningiomas and compared them to matched FFT specimens. FFT facilitated a similar number of proteins assigned by MetaMorpheus compared with matched FFPE specimens (5378 vs. 5338 proteins, respectively (p = 0.053), regardless of archival time. However, marked differences in the proteome composition were apparent between FFPE and FFT specimens. Twenty-three percent of FFPE-derived peptides and 8% of FFT-derived peptides contained at least one chemical modification. Methylation and formylation were most prominent in FFPE-derived peptides (36% and 17% of modified FFPE peptides, respectively) while, most of phosphorylation and iron modifications appeared in FFT-derived peptides (p < 0.001). A mean 14% (± 2.9) of peptides identified in FFPE contained at least one modified Lysine residue. Importantly, larger proteins were significantly overrepresented in FFT specimens, while FFPE specimens were enriched with smaller proteins.

Sphenoorbital meningioma: surgical series and design of an intraoperative management algorithm.

Current surgical removal of sphenoorbital meningiomas (SOM) mainly aims at reduction of proptosis and restoration of visual function; some stages of the surgical technique are controversial. In this study, we aim to present a surgical decision-making algorithm for SOM. A retrospective study of 27 patients who underwent resection of SOM in our center (2005-2014) was conducted. The primary outcomes evaluated were postoperative visual function and radiological exophthalmos. In our study, clinical proptosis was the most common presenting sign (92%), followed by visual loss (37%). Our surgical algorithm includes (1) extracranial stage; (2) extradural stage, including removal of the anterior clinoid process only in cases of tumor invasion (22% of our cases); (3) intradural stage; (4) intraorbital stage, including opening of the periorbita only in the presence of resectable intraorbital tumor; and (5) reconstruction, including rigid orbital reconstruction only if the periorbita was violated (22%) and placement of a fat graft in the epidural space in most cases (85%). Complete tumor resection was achieved in 51.8%. The extent of resection was limited mainly due to invasion to the cavernous sinus (61.5%) and the superior orbital fissure (84%). Surgery achieved significant visual improvement in 80% and exophthalmos reduction in 77% of the patients. Preoperative visual deficit (P = 0.0001) and optic canal involvement (P = 0.04) appeared to predict postoperative improvement of visual function. Surgical complications were mainly transient cranial nerve deficits. Based on our results, we concluded that the proposed surgical algorithm leads to successful visual, cosmetic, and oncologic outcomes.

Initial experience with a robotically operated video optical telescopic-microscope in cranial neurosurgery: feasibility, safety, and clinical applications.

OBJECTIVE The move toward better, more effective optical visualization in the field of neurosurgery has been a focus of technological innovation. In this study, the authors' objectives are to describe the feasibility and safety of a new robotic optical platform, namely, the robotically operated video optical telescopic-microscope (ROVOT-m), in cranial microsurgical applications. METHODS A prospective database comprising patients who underwent a cranial procedure between April 2015 and September 2016 was queried, and the first 200 patients who met the inclusion criteria were selected as the cohort for a retrospective chart review. Only adults who underwent microsurgical procedures in which the ROVOT-m was used were considered for the study. Preoperative, intraoperative, and postoperative data were retrieved from electronic medical records. The authors address the feasibility and safety of the ROVOT-m by studying various intraoperative variables and by reporting perioperative morbidity and mortality, respectively. To assess the learning curve, cranial procedures were categorized into 6 progressively increasing complexity groups. The main categories of pathology were I) intracerebral hemorrhages (ICHs); II) intraaxial tumors involving noneloquent regions or noncomplex extraaxial tumors; III) intraaxial tumors involving eloquent regions; IV) skull base pathologies; V) intraventricular lesions; and VI) cerebrovascular lesions. In addition, the entire cohort was evenly divided into early and late cohorts. RESULTS The patient cohort comprised 104 female (52%) and 96 male (48%) patients with a mean age of 56.7 years. The most common pathological entities encountered were neoplastic lesions (153, 76.5%), followed by ICH (20, 10%). The distribution of cases by complexity categories was 11.5%, 36.5%, 22%, 20%, 3.5%, and 6.5% for Categories I, II, II, IV, V, and VI, respectively. In all 200 cases, the surgical goal was achieved without the need for intraoperative conversion. Overall, the authors encountered 3 (1.5%) major neurological morbidities and 6 (3%) 30-day mortalities. Four of the 6 deaths were in the ICH group, resulting in a 1% mortality rate for the remainder of the cohort when excluding these patients. None of the intraoperative complications were considered to be attributable to the visualization provided by the ROVOT-m. When comparing the early and late cohorts, the authors noticed an increase in the proportion of higher-complexity surgeries (Categories IV-VI), from 23% in the early cohort, to 37% in the late cohort (p = 0.030). In addition, a significant reduction in operating room setup time was demonstrated (p < 0.01). CONCLUSIONS The feasibility and safety of the ROVOT-m was demonstrated in a wide range of cranial microsurgical applications. The authors report a gradual increase in case complexity over time, representing an incremental acquisition of experience with this technology. A learning curve of both setup and execution phases should be anticipated by new adopters of the robot system. Further prospective studies are required to address the efficacy of ROVOT-m. This system may play a role in neurosurgery as an integrated platform that is applicable to a variety of cranial procedures.

Surgical resection of skull-base chordomas: experience in case selection for surgical approach according to anatomical compartments and review of the literature.

BACKGROUND: Chordoma is a rare bony malignancy known to have a high rate of local recurrence after surgery. The best treatment paradigm is still being evaluated. We report our experience and review the literature. We emphasize on the difference between endoscopic and open craniotomy in regard to the anatomical compartment harboring the tumor, the limitations of the approaches and the rate of surgical resection. METHOD: We retrospectively collected all patients with skull-base chordomas operated on between 2004 and 2014. Detailed radiological description of the compartments being occupied by the tumor and the degree of surgical resection is discussed. RESULTS: Eighteen patients were operated on in our facility for skull-base chordoma. Seventeen endoscopic surgeries were done in 15 patients, and 7 craniotomies were done in 5 patients. The mean age was 48.9 years (±19.8 years). When reviewing the anatomical compartments, we found that the most common were the upper clivus (95.6%) and lower clivus (58.3%), left cavernous sinus (66.7%) and petrous apex (∼60%). Most of the patients had intradural tumor involvement (70.8%). In all craniotomy cases, there was residual tumor in multiple compartments. In the endoscopic cases, the most difficult compartments for total resection were the lower clivus, and lateral extensions to the petrous apex or cavernous sinus. CONCLUSIONS: Our experience shows that the endoscopic approach is a good option for midline tumors without significant lateral extension. In cases with very lateral or lower extensions, additional approaches should be added trying to achieve complete resection.

Surgical management of spontaneous cerebrospinal fluid leakage through temporal bone defects--case series and review of the literature.

Increasing numbers of cases of idiopathic cerebrospinal fluid (CSF) leakage through temporal bone defects (TBD) have been recently reported, mainly in otolaryngologic journals. Those cases are referred to as spontaneous temporal bone encephaloceles (TBE). Three surgical approaches have been advocated for this condition: the transmastoid approach (TMA), the middle cranial fossa approach (MCFA), or a combination of both. We conducted a retrospective study of all 11 consecutive patients who underwent 12 middle cranial fossa craniotomies for the treatment of CSF leakage through TBD in our institution between 2011 and 2014. Neurosurgical and otologic data were collected from the patients' records. Nine of our cases had an idiopathic etiology. No CSF leaks recurred during an average follow-up of 19.5 months. There was one case of a postoperative expressive aphasia with complete recovery in a few weeks. A systematic literature search was conducted for all studies addressing the treatment of spontaneous TBE between 1986 and 2013. It revealed a trend favoring the use of the MCFA approach over the TMA approach, with an acceptable risk of less than 5% for craniotomy-related complications. We concluded that MCFA is an effective and safe technique for the repair of CSF leakage through TBD. A high percentage of complete resolution with a low complication rate can be achieved with this surgical technique.

Management and outcome of recurrent adult craniopharyngiomas: an analysis of 42 cases with long-term follow-up.

OBJECTIVE The treatment of recurrent and residual craniopharyngiomas is challenging. In this study the authors describe their experience with these tumors and make recommendations on their management. METHODS The authors performed an observational study of adult patients (≥ 18 years) with recurrent or residual craniopharyngiomas that were managed at their tertiary center. Retrospective data were collected on demographics and clinical, imaging, and treatment characteristics from patients who had a minimum 2-year follow-up. Descriptive statistics were used and the data were analyzed. RESULTS There were 42 patients (27 male, 15 female) with a mean age of 46.3 ± 14.3 years. The average tumor size was 3.1 ± 1.1 cm. The average time to first recurrence was 3.6 ± 5.5 years (range 0.2-27 years). One in 5 patients (8/42) with residual/recurrent tumors did not require any active treatment. Of the 34 patients who underwent repeat treatment, 12 (35.3%) had surgery only (transcranial, endoscopic, or both), 9 (26.5%) underwent surgery followed by adjuvant radiation therapy (RT), and 13 (38.2%) received RT alone. Eighty-six percent (18/21) had a gross-total (n = 4) or near-total (n = 14) resection of the recurrent/residual tumors and had good local control at last follow-up. One of 5 patients (7/34) who underwent repeat treatment had further treatment for a second recurrence. The total duration of follow-up was 8.6 ± 7.1 years. The average Karnofsky Performance Scale score at last follow-up was 80 (range 40-90). There was 1 death. CONCLUSIONS Based on this experience and in the absence of guidelines, the authors recommend an individualized approach for the treatment of symptomatic or growing tumors. This study has shown that 1 in 5 patients does not require repeat treatment of their recurrent/residual disease and can be managed with a "scan and watch" approach. On the other hand, 1 in 5 patients who had repeat treatment for their recurrence in the form of surgery and/or radiation will require further additional treatment. More studies are needed to best characterize these patients and predict the natural history of this disease and response to treatment.

Visual deterioration during pregnancy due to skull base tumors compressing the optic apparatus.

Intracranial tumors may rapidly enlarge during pregnancy. When the tumor abuts the optic apparatus, tumor growth may cause visual deterioration. The decisions regarding the management of these tumors should take into consideration visual function, fetal and maternal safety, and the ability for total resection of the tumor. The objective of the study was to describe our experience and to establish principles for management of intracranial tumors compressing the optic apparatus that present during pregnancy or in the early post partum period. A retrospective case-series review was conducted. Women who presented with visual deterioration either during pregnancy or in the early post partum period due to an intracranial tumor were included. Neurosurgical and obstetrical data were collected from the patients' hospital files and outpatient clinic records. Between 2005 and 2011, nine pregnant women with visual deterioration were diagnosed and treated. Of them, four underwent a neurosurgical procedure during pregnancy. Of the five patients who underwent surgery for tumor resection after delivery, three required urgent cesarean section either due to acute visual deterioration or obstetrical reasons. There was no maternal or fetal mortality and a good overall neonatal outcome was achieved. Improvement in visual acuity and visual fields was achieved in all patients. Postoperative complications included two cases of CSF leak, which resolved after treatment. Visual deterioration during pregnancy due to tumors that compress the optic apparatus requires treatment by a multi-disciplinary team. Surgery is well tolerated by mother and fetus during early and midpregnancy; thus, in cases where visual deterioration is detected, delay of surgery is not justified.

Critical appraisal of endovascular treatment of brain arteriovenous malformation using Onyx in a series of 92 consecutive patients.

BACKGROUND: The introduction of Onyx has led us to adopt a new treatment approach for brain arteriovenous malformation (AVM), using endovascular embolization with Onyx as the first line treatment with a curative intent. The aim of the present report is to evaluate our results using this strategy, with special emphasis on angiographic characteristics affecting treatment risks and success rates. METHODS: From October 2006 to December 2009, 92 consecutive patients harboring brain AVM were treated with Onyx during 177 procedures. RESULTS: Endovascular treatments were completed in 68 out of 92 patients. Median number of procedures was two. Complete obliteration using embolization exclusively was achieved in 25 patients, resulting in a 37 % cure rate in patients who concluded treatments (25/68), and 27 % in the cohort. In Spetzler-Martin grades 1 & 2 AVMs, complete obliteration was achieved in 48 % of the cases. Complete obliteration rates were significantly higher in lesions with superficial big feeding arteries. There were 15 bleeding complications during 177 embolization sessions (8.4 % per procedure); seven cases resolved in less than 3 months. Permanent disability rate was 6.5 %; mortality rate was 2.2 %. Bleeding was related to the use of the microcatheter/guidewire in six cases and to the use of the embolization material in nine, the amount of Onyx injected was significantly higher in those nine cases. CONCLUSIONS: Embolization of brain AVM using Onyx and detachable tip microcatheters results in a relatively high rate of complete obliteration. Angioarchitecture of the lesion can predict treatment success. Higher amounts of Onyx injected per session increase the bleeding risk.

Treatment of intra-cranial aneurysms with the SILK flow diverter: 2 years' experience with 28 patients at a single center.

BACKGROUND: Flow diverters are recently developed stent-like endovascular devices developed to treat complex and non-coilable aneurysms. SILK is a type of flow diverter that has been used for nearly 3 years. Only sparse data about it are available. We would like to share our experience with this device. METHODS: Twenty-eight patients were treated with SILK from October 2008 to October 2010. Thirty-one treatment sessions were performed for 32 aneurysms using 31 SILKs. Twenty have been treated with SILK only and eight with SILK and adjuvant stents. Twenty-six (86%) patients performed cross-sectional imaging (MRA/CTA) for follow-up. Eighteen (64%) patients had follow-up brain angiography. RESULTS: In all patients the SILK could be deployed. No case of early or late aneurysmal rupture was noted. Five patients (17.8%) developed immediate clinical complications, which were permanent in three (10.7%). All the complications occurred in patients harboring aneurysms larger than 15 mm. In two other patients, occlusion of the SILK was noted with no clinical deficit. A complete or near-complete aneurysmal occlusion was found in brain angiography or cross-sectional imaging follow-up in 83.3% of the patients. CONCLUSIONS: SILK is a relatively simple device to use, with a low rate of technical and clinical complications and a high short-term aneurysmal occlusion rate. In aneurysms smaller than 15 mm, the results are excellent. Results are also encouraging in the larger aneurysms, taking into consideration their complexity. The device characteristics and mainly its drawbacks must be well known by the users.

The Role of 3D Tractography in Skull Base Surgery: Technological Advances, Feasibility, and Early Clinical Assessment with Anterior Skull Base Meningiomas.

Objective The aim of this study is to determine feasibility of incorporating three-dimensional (3D) tractography into routine skull base surgery planning and analyze our early clinical experience in a subset of anterior cranial base meningiomas (ACM). Methods Ninety-nine skull base endonasal and transcranial procedures were planned in 94 patients and retrospectively reviewed with a further analysis of the ACM subset. Main Outcome Measures (1) Automated generation of 3D tractography; (2) co-registration 3D tractography with computed tomography (CT), CT angiography (CTA), and magnetic resonance imaging (MRI); and (3) demonstration of real-time manipulation of 3D tractography intraoperatively. ACM subset: (1) pre- and postoperative cranial nerve function, (2) qualitative assessment of white matter tract preservation, and (3) frontal lobe fluid-attenuated inversion recovery (FLAIR) signal abnormality. Results Automated 3D tractography, with MRI, CT, and CTA overlay, was produced in all cases and was available intraoperatively. ACM subset : 8 (44%) procedures were performed via a ventral endoscopic endonasal approach (EEA) corridor and 12 (56%) via a dorsal anteromedial (DAM) transcranial corridor. Four cases (olfactory groove meningiomas) were managed with a combined, staged approach using ventral EEA and dorsal transcranial corridors. Average tumor volume reduction was 90.3 ± 15.0. Average FLAIR signal change was -30.9% ± 58.6. 11/12 (92%) patients (DAM subgroup) demonstrated preservation of, or improvement in, inferior fronto-occipital fasciculus volume. Functional cranial nerve recovery was 89% (all cases). Conclusion It is feasible to incorporate 3D tractography into the skull base surgical armamentarium. The utility of this tool in improving outcomes will require further study.

The Outcome of Intracranial Meningioma Surgery in Octogenarians: Matched Cohort Study.

BACKGROUND: Previous studies compared outcomes of intracranial meningioma surgery in octogenarians with outcomes in younger patients without accounting for different tumor locations and sizes. The aim of the current study was to evaluate outcomes of intracranial meningioma surgery in octogenarians taking into account patient preoperative status and comorbidities as well as tumor properties. METHODS: The study cohort included all octogenarian patients who underwent elective craniotomies for intracranial meningiomas during 2008-2020 and patients <70 years old in the same time period matched for tumor size, tumor location, and preoperative Karnofsky scale score. Each group comprised 31 patients. Postoperative complications were divided into systemic, neurological, and wound related. Mortality and long-term complications were evaluated at 6-month follow-up. RESULTS: Mean age of patients was 82.6 ± 2.6 years for the study group and 57.9 ± 9.9 years for the control group (P < 0.0001). Two octogenarians (6.5%) died within 30 days after elective craniotomy compared with none in the younger group (P = 0.49). Mortality rates at 6 months were comparable between the 2 groups (12.9% vs. 3.2%, P = 0.35). There was no significant difference in overall postoperative complications between the octogenarian and control groups (77.4% vs. 74.2%, P = 0.77). American Society of Anesthesiologists score was the single predictor for any postoperative complications (odds ratio = 2.219, 95% confidence interval 1.024-4.811, P = 0.04). CONCLUSIONS: This study found no excess mortality or morbidity in octogenarians compared with younger patients. The American Society of Anesthesiologists score rather than age is a significant risk factor for overall morbidity and mortality following intracranial meningioma surgery in octogenarians.

When a Root Is the Cause of Infection.

BACKGROUND: Sinorhizobium meliloti is a phytobacterium found in the root nodules of plants, where it is involved in fixing nitrogen for delivery to the roots in exchange for a photosynthate carbon source. There have been no reported cases of S. meliloti infection in humans. We conducted a retrospective review of clinical records and diagnostic tests. CASE DESCRIPTION: An 81-year-old woman who presented to the emergency department with a 1-day history of progressive decline in her level of consciousness following a head injury and deep scalp laceration. Her medical history was significant for a ventriculoperitoneal shunt due to normal pressure hydrocephalus. Imaging studies revealed hydrocephalus and a tear in the shunt catheter. Cerebrospinal fluid analysis was not suggestive for meningitis. Cerebrospinal fluid culture revealed an unfamiliar organism, identified as S. meliloti following sequencing of its entire genome, which was considered a contaminant. The patient subsequently developed peritonitis, and the same pathogen was detected in the peritoneal fluid, suggesting distal shunt infection. Symptoms resolved after shunt removal and antibiotic treatment. Thorough history taking revealed that the patient had fallen and struck her head against a flowerpot. CONCLUSIONS: S. meliloti is a phytopathogen that should not be easily disregarded as a contaminant when isolated from human sterile fluids or tissues. Aggressive management including removal of infected hardware, if present, is required to ensure resolution of infection. It emphasizes the importance of thorough history taking.

An Anatomically-Based Endoscopic Endonasal Model to Navigate the Anterior Ventral Skull Base.

BACKGROUND: Endoscopic endonasal approaches to access the sellar and parasellar regions are challenging in the face of anatomical variations or pathologic conditions. We propose an anatomically-based model including the orbitosellar line (OSL), critical oblique foramen line (COFL), and paramedial anterior line (PAL) facilitating safe, superficial-to-deep dissection triangulating upon the medial opticocarotid recess. METHODS: Five cadaveric heads were dissected to systematically expose the OSL, COFL, and PAL, illustrated with image guidance. Application of the coordinate system and a 6-step dissection sequence is described. RESULTS: The coordinate system consists of 1) the OSL, connecting a) the anterior orbital point, junction of the anterior buttress of the middle turbinate with the agger nasi region, located 34.3 ± 0.9 mm above the intersection of the vertical plane of the lacrimal crest, and the orthogonal plane of the maxillo-ethmoidal suture; b) the posterior orbital point, junction of the optic canal with the lamina papyracea, located 4 ± 0.7 mm below the posterior ethmoidal artery; and c) the medial opticocarotid recess; 2) COFL (15 ± 2.8 mm), connecting the palatovaginal canal, vidian canal, and foramen rotundum; and 3) PAL (39 ± 0.06 mm), connecting the vidian canal with the posterior ethmoidal artery. CONCLUSIONS: OSL, COFL, and PAL form an anatomically-based model for the systematic exposure when accessing the parasellar and sellar regions. Preliminary anatomical data suggest that this model may be of value when normal anatomy is distorted by pathology or anatomic variations.

Tuberculum sellae meningiomas: a systematic review of transcranial approaches in the endoscopic era.

INTRODUCTION: With the advent of skull base endoscopy, tuberculum sellae meningiomas (TSMs) are currently operated both from the traditional transcranial (TC) route as well as the extended endonasal endoscopic trasns-sphenoidal approach (EETS). The aim of this study was to conduct a systematic review of TSMs excised via the TC route in the modern era when the EETS excision is gaining popularity. EVIDENCE ACQUISITION: We performed a systematic review in the medical literature following the PRISMA guidelines. A medical librarian retrieved a list of 3443 articles published from 2006-2016 from the Medline, Embase and Cochrane Central databases. Two of the authors independently screened for titles and abstracts and excluded 3340 of them. We reviewed the full text of the remaining 103 articles and included in our analysis 31 that met the following inclusion criteria: 1) 5 or more cases reported; and 2) report of the extent of resection, visual outcomes and complications specifically for TSMs were documented. EVIDENCE SYNTHESIS: Thirty-one articles were selected for this systematic review with a total number of 983 patients with TSM. The mean age was 54.1±4.6 years, 75% of them being female. The follow-up was 43.9±20.7 months. The mean tumor diameter was 27.8±4.9 mm. Gross total resection was achieved in 84% while subtotal or near total resection was 14%. Vision improved, worsened and remained unchanged in 65.5%, 10.4%, and 24.7% respectively. The CSF leak rate was 3.4%. Transient or permanent pituitary dysfunction was reported in 6.9% of patients. There was a vascular injury in 5.1% of the patients with the majority (4.3%) being symptomatic. The recurrence rate was 3.8% and mortality 1.1%. CONCLUSIONS: In the past decade, the ETTS excision of TSMs has gained popularity and in some centers has become the approach of choice. However the TC route still remains the most common approach for most TSMs meningiomas and for the majority of neurosurgeons. The evolution of transcranial surgery including the use of minimally invasive techniques, such as endoscope-assisted transcranial resection are associated with relatively high resection rates and improved visual outcomes with low morbidity and mortality. A direct comparison with TS approaches was not done for the purpose of this review analysis. Given the limited availability and heterogeneity of comparative observational studies, a meta-analysis was deemed inappropriate.

Endoscopic management of Esthesioneuroblastoma: Our experience and review of the literature.

During the last two decades evolution of the endoscopic endonasal approaches (EEA) has offered the option of minimally invasive techniques in the management of esthesioneuroblastomas (ENB), either as endoscope assisted cranial resection or as pure endoscopic procedures. This study presents the use of pure EEA in the management of ENB in our center, along with a literature review. We retrospectively reviewed the clinical, radiology and pathology records of patients with ENB treated during the period July 2006 to January 2016. During the above period, ten patients with ENB were treated using pure EEA. The mean age was 47.5 years. The gender distribution was: eight males, two females. The most common presenting symptoms were nasal obstruction and discharge or epistaxis (8/10). The mean duration of symptoms was 1.5 years. All patients had preoperative confirmation of ENB by biopsy. Five patients received neoadjuvant radiation and four underwent postoperative radiation. One patient did not receive any radiotherapy and no patient received chemotherapy. Gross total resection was achieved in all patients and intraoperative microscopically negative surgical margins achieved in 9/10 (90%). No major intraoperative complications occurred. The most common postoperative complication was nasal infection. Cerebrospinal fluid leak was noted in one patient. During the follow-up period of 6-120 months (mean 74.8) two cases of neck lymph node recurrence were observed. No deaths due to the disease occurred during the follow-up period. Pure EEA offer excellent results in the management of ENB. Neoadjuvant radiation treatment is promising although more studies need to establish its role.

Reanalyzing the "far medial" (transcondylar-transtubercular) approach based on three anatomical vectors: the ventral posterolateral corridor.

Endoscopic endonasal access to the jugular foramen and occipital condyle - the transcondylar-transtubercular approach - is anatomically complex and requires detailed knowledge of the relative position of critical neurovascular structures, in order to avoid inadvertent injury and resultant complications. However, access to this region can be confusing as the orientation and relationships of osseous, vascular, and neural structures are very much different from traditional dorsal approaches. This review aims at providing an organizational construct for a more understandable framework in accessing the transcondylar-transtubercular window. The region can be conceptualized using a three-vector coordinate system: vector 1 represents a dorsal or ventral corridor, vector 2 represents the outer and inner circumferential anatomical limits; in an "onion-skin" fashion, key osseous, vascular, and neural landmarks are organized based on a 360-degree skull base model, and vector 3 represents the final core or target of the surgical corridor. The creation of an organized "global-positioning system" may better guide the surgeon in accessing the far-medial transcondylar-transtubercular region, and related pathologies, and help understand the surgical limits to the occipital condyle and jugular foramen - the ventral posterolateral corridor - via the endoscopic endonasal approach.

Endoscopic Endonasal Reconstructive Methods to the Anterior Skull Base.

The success of expanded endoscopic endonasal approaches (EEAs) to the anterior skull base, sellar, and parasellar regions has been greatly aided by the advancement in reconstructive techniques. In particular, the pedicled vascularized flaps have been developed and effectively cover skull base defects of varying sizes with a significant reduction in postoperative CSF leaks. There are two aims to this review: (1) We will provide our current, simplified reconstruction algorithm. (2) We will describe, in detail, the relevant anatomy, indications/contraindications, and surgical technique, with a particular emphasis on the nasoseptal flap (NSF). The inferior turbinate flap (ITF), middle turbinate flap (MTF), pericranial flap (PCF), and temporoparietal fascial flap (TPFF) will also be described. The NSF should be the primary option for reconstruction of majority of skull base defects following endonasal endoscopic surgery. In general, for the planum, cribriform, and upper two-thirds of the clivus, the NSF is ideal. For the lower-third of the clivus, the NSF may not be adequate and may require additional reconstructive options. Although limited in reach or more technically challenging, these reconstructive flaps should still be considered and kept in the surgical algorithm.