A quantitative comparative surgical analysis of the endoscopic transorbital approach and frontotemporal-orbitozygomatic approach for extradural exposure of the cavernous sinus.

OBJECTIVE: Recently, the endoscopic superior eyelid transorbital approach (SETA) has emerged as a potential alternative to access the cavernous sinus (CS). Several previous studies have attempted to quantitatively compare the traditional open anterolateral skull base approaches with transorbital exposure; however, these comparisons have been limited to the area of exposure provided by the bone opening and trajectory, and fail to account for the main avenues of exposure provided by subsequent requisite surgical maneuvers. The authors quantitatively compare the surgical access provided by the frontotemporal-orbitozygomatic (FTOZ) approach and the SETA following applicable periclinoid surgical maneuvers, evaluate the surgical exposure of key structures in each, and discuss optimal approach selection. METHODS: SETA and FTOZ approaches were performed with subsequent applicable surgical maneuvers on 8 cadaveric heads. The lengths of exposure of cranial nerves (CNs) II-VI and the cavernous internal carotid artery; the areas of the space accessed within the supratrochlear, infratrochlear, and supramaxillary (anteromedial) triangles; the total area of exposure; and the angles of attack were measured and compared. RESULTS: Exposure of the extradural CS was comparable between approaches, whereas access was significantly greater in the FTOZ approach compared with the SETA. The lengths of extradural exposure of CN III, V1, V2, and V3 were comparable between approaches. The FTOZ approach provided marginally increased exposure of CNs IV (20.9 ± 2.36 mm vs 13.4 ± 3.97 mm, p = 0.023) and VI (14.1 ± 2.44 mm vs 9.22 ± 3.45 mm, p = 0.066). The FTOZ also provided significantly larger vertical (44.5° ± 6.15° vs 18.4° ± 1.65°, p = 0.002) and horizontal (41.5° ± 5.40° vs 15.3° ± 5.06°, p < 0.001) angles of attack, and thus significantly greater surgical freedom, and provided significantly greater access to the supratrochlear (p = 0.021) and infratrochlear (p = 0.007) triangles, and significantly greater exposure of the cavernous internal carotid artery (17.2 ± 1.70 mm vs 8.05 ± 2.37 mm, p = 0.001). Total area of exposure was also significantly larger in the FTOZ, which provided wide access to the lateral wall of the CS as well as the possibility for intradural access. CONCLUSIONS: This is the first study to quantitatively identify the relative advantages of the FTOZ and transorbital approaches at the target region following requisite surgical maneuvers. Understanding these data will aid in selecting an optimal approach and maneuver set based on target lesion size and location.

What really matters for returning to work after breast cancer? A 6-month exploratory study.

Return to work (RTW) after breast cancer (BC) may significantly impact on women recovery and quality of life. Literature hightlighed several factors associated to RTW after BC but there is still some concern about prognostic factors influencing work resumption after BC treatments. The present study aims to explore which baseline factors are associated with RTW at 6-month after BC surgery. The participants in this 6-month prospective study were 149 patients who underwent breast cancer-related surgery and accessed an Oncology Clinic for cancer therapy from March 2017 to December 2019 in Northern Italy. Participants filled in a battery of questionnaires at baseline, and they were asked whether they had returned to work at 6-month follow-up. Psychological measurements included job stress (Job Content Questionnaire), work engagement (Utrecht Work Engagement Scale), quality of life (World Health Organization Quality of Life- BREF), anxiety and depression (Hospital Anxiety and Depression Scale), resilience (Connor - Davidson Resilience Scale - 10 item) and personal expectations about RTW (ad-hoc single item). Moreover, sociodemographic, clinical, and work-related data were collected. Independent t-test and Chi-square test were used for comparisons among variables; logistic regression model was used to explore predictors of RTW. A total of 73.9 percent returned to work at6-month after surgery. In the multivariate model, chemiotherapy (B = -1.428; SE = 0.520) and baseline women's expectations about their RTW (B = -0.340; DS = 0.156) were significant predictors of RTW. These results suggest that careful individual clinical and psychological screening of risk factors at baseline can prevent from occupational disability and long sickness absence.

The complete anterior petrosectomy: an expanded extended-middle fossa approach with removal of the infratrigeminal petrous apex and drilling of the lateral clivus.

Intradural exposure in the extended middle fossa anterior transpetrosal approach is traditionally limited to the inferior petrosal sinus inferomedially. Expanding bone removal of the petrous apex around the petrous internal carotid artery (ICA), underneath the trigeminal ganglion/mandibular nerve, and into the lateral component of the clivus can significantly expand the limits of this approach beyond the inferior petrosal sinus and allows for exposure of the midline structures, aspects of the contralateral inferior clival region, and, when high riding, the vertebrobasilar junction. To date, no descriptive techniques for drilling into the lateral clivus in this approach have been published. The authors provide a detailed stepwise description of their complete anterior petrosectomy, in use at their institution, that involves skeletonization of the posteromedial petrous ICA, gentle elevation of the trigeminal ganglion/mandibular nerve, removal of the infratrigeminal petrous apex, and two techniques for drilling into the lateral clivus along the petroclival fissure. These techniques provide a direct and unobstructed corridor to the midpetroclival region and ventral brainstem with greater maneuverability and enhanced control of the midline structures, which is especially useful for resection of petroclival meningiomas, chondrosarcomas, and giant vascular lesions of the mid- and upper basilar artery and its proximal branches.

Trends and age-period-cohort effect on dental caries prevalence from 2008 to 2019 among Brazilian preschoolers.

This study aimed to evaluate trends in the prevalence of dental caries in preschool children and associated factors considering different time variations. This is a time series study performed using data from three cross-sectional studies with pre-school children from southern Brazil in 2008, 2013 and 2019. This children group was born between the years of 2003 to 2018. Dental caries was evaluated by decayed, missing and filled deciduous teeth (dmft index). Demographic, socioeconomic, behavioural and psychosocial variables were also collected. Chi-square test for trends and a hierarchical age-period-cohort (HAPC) analysis using multilevel Poisson regression model for testing the associations between predictor variables and dental caries experience were used. A total of 1,644 pre-school children participated in all surveys. There was a significant difference in caries experience considering all APC effects. The prevalence of dental caries was 25.0% in 2008, 16.3% in 2013, and 19.4% in 2019 (p < 0.01) and no statistical difference was observed. An age effect showed that older children were more likely to experience dental caries. Considering the cohort effect, there is a significant difference between the generations, mainly between 2003 and 2018. Household income, use of dental services, and parent's perception of child oral health were associated with dental caries experience no matter the time variation. Despite recent declines in dental caries prevalence among preschool children, caries levels increased with age and social inequalities persisted through the years, indicating a need of reviewing the policies to reduce the burden of this oral disease.

Access to carbonyl compounds via the electroreduction of N-benzyloxyphthalimides: Mechanism confirmation and preparative applications.

A method to access carbonyl compounds using reductive conditions was evaluated via electrochemical reduction of their corresponding N-benzyloxyphthalimide derivatives (NBOPIs). The mechanism of this originally reported electrochemical reaction was proposed based on DFT calculation and is experimentally confirmed herein, contrasting simulated and experimental cyclic voltammetry data. The reaction scope studied in a preparative scale and using redox sensitive functional groups showed good selectivity and tolerance toward oxidation under the reaction conditions with a moderate to good yield (50-71%). Nevertheless, some restrictions with reducible functional groups, like benzyl-brominated and nitro-aromatic derivatives, were observed. The present approach can be considered a self-sustainable electrochemical catalysis for the synthesis of aromatic carbonylic compounds passing through anion radical intermediates produced by a cathodic reaction.

Trends and age-period-cohort effect on dental caries prevalence from 2008 to 2019 among Brazilian preschoolers

Abstract This study aimed to evaluate trends in the prevalence of dental caries in preschool children and associated factors considering different time variations. This is a time series study performed using data from three cross-sectional studies with pre-school children from southern Brazil in 2008, 2013 and 2019. This children group was born between the years of 2003 to 2018. Dental caries was evaluated by decayed, missing and filled deciduous teeth (dmft index). Demographic, socioeconomic, behavioural and psychosocial variables were also collected. Chi-square test for trends and a hierarchical age-period-cohort (HAPC) analysis using multilevel Poisson regression model for testing the associations between predictor variables and dental caries experience were used. A total of 1,644 pre-school children participated in all surveys. There was a significant difference in caries experience considering all APC effects. The prevalence of dental caries was 25.0% in 2008, 16.3% in 2013, and 19.4% in 2019 (p < 0.01) and no statistical difference was observed. An age effect showed that older children were more likely to experience dental caries. Considering the cohort effect, there is a significant difference between the generations, mainly between 2003 and 2018. Household income, use of dental services, and parent's perception of child oral health were associated with dental caries experience no matter the time variation. Despite recent declines in dental caries prevalence among preschool children, caries levels increased with age and social inequalities persisted through the years, indicating a need of reviewing the policies to reduce the burden of this oral disease.

Does bullying due to oral conditions influence cigarette smoking in adolescents? A structural equation modeling.

This study aimed to explore the pathways that can influence cigarette smoking among adolescents. This population-based cohort followed a random sample of 12-year-old adolescents from southern Brazil for 6 years. Regular cigarette smoking was assessed through a self-reported question, previously used in the Brazilian National Survey of Scholar Health. We also gathered data on bullying, dental caries at baseline, incidence of caries, sex, friend network, and Sense of Coherence (SOC). Socioeconomic and demographic characteristics were also collected. Structural equation modeling was used to evaluate the pathways. Of the 1,134 adolescents examined at baseline, 768 were re-evaluated (67.7% retention rate). The prevalence of smoking was 37.6%. This prevalence was directly affected by low SOC (SC: -0.14, p < 0.01), low household income (SC: -0.12, p < 0.01), and male sex (SC: 0.15, p < 0.01). Presence of dental caries at baseline indirectly influenced the occurrence of dental bullying at follow-up via the incidence of dental caries (SC: 0.01, p < 0.05). Dental bullying indirectly influenced cigarettes consumption via SOC (SC: 0.62, p < 0.05). Friend network also indirectly influenced the consumption of cigarettes via SOC (SC: 0.32, p < 0.05). Psychosocial factors influence adolescent cigarette consumption through its higher direct and indirect effects (via bullying). In addition, behavioral, sociodemographic, and clinical factors also influence the occurrence of smoking.

Occurrence of Neofusicoccum parvum Causing Canker and Branch Dieback of European Hazelnut in Maule Region, Chile.

The European hazelnut (Corylus avellana) is an important fruit crop cultivated in Chile, with over 17,000 ha planted (46%) in the Maule region, central Chile. During a routine orchard survey in seasons 2020-2021 and 2021-2022, in the Maule region, canker and dieback symptoms were observed in two commercial orchards of European hazelnut cv. Tonda Di Giffoni in San Rafael (8-year-olds) and Linares (15-year-olds), with an incidence between 10% and 36%, respectively, based on external symptoms. Twenty symptomatic branches exhibiting cankers, reduced vigor, wilting, twig death, and dieback, were collected. A cross-section of diseased branches revealed mostly brown V or U-shaped cankers of hard consistency. Branches were cut, and pieces of cankers were surface sterilized in 96% ethanol for 3 s and briefly flamed. Small pieces of wood (5 mm2) from the edge of cankered tissues were placed on Potato Dextrose Agar (2% PDA) amended with 0.1% Igepal CO-630 and incubated at 25°C for five days in the dark (Díaz and Latorre 2014). Pure cultures were obtained by transferring a hyphal tip from growing colonies to fresh PDA media. Eight pure cultures (NP-Haz01 to NP-Haz08) developed dark to olive-brown fast-growing colonies with scarce aerial mycelium after seven days at 25°C on PDA under near-UV light. These isolates showed a dark-olive color on the reverse side of Petri dishes and developed abundant, aggregated, and dark-brown globose pycnidia after 21 days at 25°C. Conidia were hyaline, aseptate, ellipsoidal, densely granulate, externally smooth, and thin-walled dark, that measured (9.5-) 15.5 ±1.2 (-17.3) x (5.1-) 7.2 ± 0.6 (-9.1) µm (n = 30), with a length/width ratio of 2.15. These isolates were tentatively identified morphologically as Neofusicoccum sp. Molecular identification was performed using ITS1/ITS4, Bt2a/Bt2b and EF1-728F/EF1-986R primers of the internal transcribed spacer (ITS1-5.8S-ITS2) region, a portion of the beta-tubulin (BT) and part of the translation elongation factor (EF1-) genes, respectively (Dissanayake et al. 2015). A MegaBlast search in GenBank showed a 99% similarity to isolate CMW9081, the ex-type of Neofusicocum parvum (Pennycook & Samuels) Crous, Slippers & A.J.L. Phillips. The sequences were added to GenBank (OR393855 to OR393857 for ITS; OR400688 to OR400690 for BT; OR400691 to OR400693 for EF1-). Pathogenicity of three isolates (NP-Haz02, NP-Haz04, NP-Haz09) was studied on freshly made pruning wounds on attached branches of 3-year-old and one-year-old of European hazelnut cv. Tonda Di Giffoni in the San Rafael field. Fifteen pruning wounds were inoculated with 40 µL conidial suspension (105 conidia/mL) of each isolate of N. parvum. Sterile distilled water was used as a control treatment (n=15 branches) for branches of 3-year-olds and one-year-olds. Both pathogenicity tests were repeated once. Attached branches of 3-year-olds (6 months of incubation) and one-year-olds (4 months of incubation), developed necrotic streaks and cankers with a mean length of 33 to 82 mm and 25 to 51 mm, respectively. No necrotic streaks were observed in the branches treated with water. Neofusicoccum parvum was reisolated only from symptomatic tissues of inoculated branches, and morphological and molecularly (EF1-) identified, thus fulfilling Koch's postulates. Previously, other Botryosphaeriaceae spp. as Diplodia coryli (Guerrero and Pérez 2012) and D. mutila (Moya-Elizondo et al. 2023) have been obtained from canker and dieback of hazelnut in Chile. Recently, N. parvum was reported causing nut rot in hazelnuts in Italy (Wagas et al. 2022). To our knowledge, this is the first report of N. parvum causing canker and branch dieback of hazelnut trees in Chile and worldwide.

Dihydrolevoglucosenone (Cyrene™), a new possibility of an environmentally compatible solvent in synthetic organic electrochemistry.

Dihydrolevoglucosenone (DLG or Cyrene™) solvent is a green dipolar solvent produced from cellulose waste. Different studies have demonstrated that it can successfully replace dipolar solvents, such as N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMA) and N-methylpyrrolidinone (NMP), in a variety of chemical reactions. In this paper, the first application of DLG in organic electrosynthesis is described, with results of its use in the electrochemical reduction of benzophenone derivatives (ca. E = -1.75 V vs. Ag/AgCl), as a greener alternative to other dipolar solvents with environmental concerns. Conductivity measurements show that the solvent presents conductivity and viscosity limitations that can be overcome by using EtOH as a cosolvent. The DLG/EtOH mixture resulted in a convenient solvent to carry out galvanostatic electroreductions of starting materials that exhibit high potential value. Furthermore, the reaction pathway (1e- or 2e-) was found to be dependent on the supporting electrolyte used; TBABF4 favored 2e- reduction to the corresponding alcohol (52-85%), whereas LiClO4 promoted C-C pinacolic coupling (47-70%).

Metaresearch study highlights the gender gap in randomized controlled trials in dentistry.

BACKGROUND AND OBJECTIVES: This study aimed to assess the gender gap in randomized controlled trials (RCTs) in dentistry in terms of authorship, collaborations, metrics, funding and reporting of good research practice and transparecy. METHODS: The search was performed in PubMed for RCTs restricted to English texts in the dental field, indexed from 12/31/2016 to 12/31/2021. Two reviewers screened the studies in line with the eligibility criteria. A total of 844 articles were included. The name and gender of authors, citation metrics, funding, reporting of characteristics of good research practice and transparency were extracted. We considered "collaboration between authors" when the corresponding author was different from the first author. RESULTS: The proportion of women as first authors was 46.56% and 40.12% for corresponding authors. The analysis showed that when a woman is the corresponding author, the probability of the first author also being a woman is 57% higher compared to the first author being a man. For "protocol registration" and "data sharing," the prevalence of reporting was higher when women were first authors. CONCLUSION: A gender gap in dentistry RCTs was identified and related to the participation of women as first and corresponding authors and the collaboration between authors.

Exploring the use of preprints in dentistry.

OBJECTIVE: This study aims to assess the use, impact, and dissemination of preprints in dentistry. METHODS: This is a meta-research study with a cross-sectional design. We included preprints published in dentistry, regardless of the year of publication. Searches were performed in the medRxiv.org and Preprints.org platforms and restricted to English. One researcher extracted the data, and another researcher verified data consistency. The following data were extracted: year of publication, country of the corresponding author, number of abstract and full-text views and downloads, Altmetric attention score, whether the preprint was mentioned in other servers such as Twitter and Publons, number of mentions in other servers, number of citations in the Dimensions database, and whether the preprint had already been published in a peer-reviewed journal. If already published, we extracted the journal's impact factor (JCR 2021) and the number of citations in the Dimensions database. We conducted a descriptive analysis of the extracted characteristics and explored relationships between metrics using the Spearman correlation. RESULTS: We identified 276 preprints. Most of the studies were published between 2020 and 2022 (n = 229), especially those from ten countries. The most-cited preprint and published article are the same study. Only the correlation between the number of preprint citations and peer-reviewed article citations in the Dimensions database showed a large positive association (Spearman's rho = 0.5809). CONCLUSION: Preprints gained popularity over the last several years due to the COVID-19 pandemic and reached a larger audience, especially on platforms such as Twitter. CLINICAL SIGNIFICANCE: Preprint publishing allows faster dissemination of science for the benefit of society.

Quantitative analysis of external carotid artery bypass donor vessels by recipient and approach.

INTRODUCTION: Utilization an in-situ pedicle of the external carotid artery (ECA) as an arterial donor can allow for the successful augmentation or replacement of flow to a large vascular territory. We propose a mathematical model for quantitatively analyzing and grading the suitability of donor and recipient bypass vessels based on a set of anatomical and surgical variables in order to predict which pair has the greatest possibility for success. Using this method, we analyze all of the potential donor-recipient pairs for each ECA donor vessel-including the superficial temporal (STA), middle meningeal (MMA), and occipital (OA) arteries. METHODS: The ECA pedicles were dissected in frontotemporal, middle fossa, subtemporal, retrosigmoid, far lateral, suboccipital, supracerebellar, and occipital transtentorial approaches. For each approach, every potential donor-recipient pair was identified, and donor length and diameter were measured as well as depth of field, angle of exposure, ease of proximal control, maneuverability, and length and diameter of the recipient segment. Anastomotic pair scores were determined by adding the weighted donor and recipient. RESULTS: The best overall anastomotic pairs were OA-vertebral artery (V3, 17.1) and STA-insular (M2, 16.3) and STA-sylvian (M3, 15.9) segments of the middle cerebral artery. Other strong anastomotic combinations were OA- telovelotonsillar (15) and OA- tonsilomedullary (14.9) segments of the posterior inferior cerebellar artery, and MMA-lateral pontomesencephalic segment of the superior cerebellar artery (14.2). CONCLUSIONS: This novel model for anastamotic pair scoring can serve as a useful clinical tool for selecting the optimal donor, recipient, and approach combination that can help facilitate a successful bypass.

First Report of Pantoea agglomerans Causing a Leaf Blight and Bulb Rot of Onion in Chile.

Onion (Allium cepa L) is an important vegetable crop in Chile with 3.675 ha (ODEPA, www.odepa.gob.cl). Since 2017, a series of symptoms has been increasingly observed, mainly in mature bulbs which include water-soaked lesions on mature leaves and external and central cataphylls, which evolve to necrotic lesions and rot, reducing yields and affecting the postharvest life. As the season progresses over 90% incidence has been estimated in severely affected fields. Symptomatic plants were collected for disease identification in summer (February 2022) in Santa Cruz, O´Higgins, Chile, (34º41'32"S and 71º27'17"W). Isolations were done on semi-selective OEM medium (Zaid et al. 2012) and isolated colonies were transferred and maintained on King's B (KB) medium. Colonies on OEM medium were yellow slightly green in the center, circular to irregular shape, elevated, smooth margin, and mucoid texture (Tho et al. 2015). On KB medium colonies were yellow cream, slightly darker in the center, with smooth margins and circular or slightly irregular. Two isolates (CHS B3, CHS B1), obtaining in three different onion fields, were further identified by PCR amplification of partial 16S rRNA using primers 27F/1492R (Frank et al., 2008). The resulting sequencing were deposited in GenBank under accession numbers OP934962.1 and OP934961.1. A BLAST search of GenBank showed that these sequences exhibited 99,89 to 100 % nucleotides similarities with multiple Pantoea agglomerans sequences. Three isolates were used to test pathogenicity on detached cataphylls and onion plants tests in the laboratory and greenhouse, respectively. Cataphylls (n=10) were surface disinfected with 2% NaOCl for 2 min, placed in sterile Petri dishes, and injected with 50 µL (106 UFC/mL) inoculum suspension with the aid of a hypodermic syringe. Cataphylls were incubated in humid chamber at 22 + 2ºC for 14 days. Additionally, three-month-old onion plants (n=10), growing in pod, were inoculated by injecting leaves with 1 mL inoculum suspension (106 UFC/mL). Plant were incubated under greenhouse for 30 days to 28ºC. An equal number of cataphylls and onion plants, injected with sterile water, were left as controls. Water soaked lesions on inoculated cataphylls appeared five days after inoculation. While onions plants develop water soaked lesion 1- 4 days after inoculation. Blight and bulb rot were observed only on inoculated plants. Symptoms were identical to those previously observed in the field. Reisolations were accomplished for 100% of the inoculated cataphylls and leaves fulfilling Koch's postulates (Biochemical characterization and PCR amplification of partial 16S rRNA). Previously, Pectobacterium carotovorum was reported causing a similar disease in Chile (Acuña 2008). However, to our knowledge this is the first report of P. agglomerans causing onion leaf blight and bulb rot in O'Higgins Region, Chile. In agreement with other reports (De Armas et al. 2015, Tho et al. 2015), leaf blight and bulb has been a very aggressive disease in Chile. These results do not exclude the possibility that other Pantoea species (Armas et al. 2015) may be involved in the leaf blight and bulb rot of onions.

Prognostic Role of Pathological Complete Response in Early Stage Epithelial Solid Tumors.

Neoadjuvant chemotherapy was originally designed to convert inoperable cancer. Nowadays, this concept has expanded since it can also offer the possibility to evaluate markers of response such as pathological complete response (pCR) with possible implications in long-term prognostic outcomes. A substantial body of literature tried to evaluate the ability of pCR to fulfill the conditions required to establish a preliminary endpoint, such as pCR, as a surrogate for the final endpoint, the overall survival (OS) but no systematic reviews have been performed yet. In this review we systematically analyzed the prognostic role of pCR in various cancers (breast, gastro-oesophageal, rectal, ovarian, bladder, lung) in which neoadjuvant treatment is a standard of care, evaluating articles published in the English language of phase III or phase II randomized controlled trials and meta-analyses. Since the continue development of immunotherapy in earlier stage, it has also been considered the impact of tumor-infiltrating lymphocyte on pCR.

Anterolateral Routes to the Skull Base-The Frontotemporal Approaches and Exposure of the Sellar and Parasellar Regions.

Surgical approaches to the sellar and parasellar regions are highly challenging due to the densely packed nature of the traversing neurovasculature. The frontotemporal-orbitozygomatic approach offers a wide angle of exposure for the management of lesions involving the cavernous sinus, parasellar region, upper clivus, and adjacent neurovascular structures. It combines the pterional approach with different osteotomies that remove the superior and lateral walls of the orbit and zygomatic arch. Extradural exposure and preparation of the periclinoid region, whether as initial preparation for a combined intraextradural approach to deep-seated skull base targets or as the main avenue of surgical exposure, can substantially enlarge surgical corridors and minimize the need for brain retraction in this very confined microsurgical space. We provide a stepwise description of how we perform the fronto-orbitozygomatic approach and an associated series of surgical maneuvers and techniques that can be utilized in a variety of anterior and anterolateral approaches, either alone or in combination, to tailor exposure to a given lesion. These techniques are not limited to traditional skull base approaches and represent a valuable addition to every neurosurgeon's armamentarium as enhancements to common surgical approaches.

Transpetrosal Routes to the Skull Base-Anterior and Posterior Transpetrosal Approaches.

The extended middle fossa approach with anterior petrosectomy, or anterior transpetrosal approach, is a highly effective and direct approach to difficult-to-access petroclival tumors and basilar artery aneurysms. This surgical approach exposes a significant window of the posterior fossa dura between the mandibular nerve, internal auditory canal, and petrous internal carotid artery, below the level of the petrous ridge, and provides an unobstructed view of the middle fossa floor to the upper half of the clivus and petrous apex, without requiring removal of the zygoma. The posterior transpetrosal approaches, including the perilabyrinthine, translabyrinthine, and transcochlear approaches, provide direct and wide exposure of the cerebellopontine angle and posterior petroclival region. The translabyrinthine approach is commonly used for the removal of acoustic neuromas and other lesions of the cerebellopontine angle. We provide a stepwise description of how we perform these approaches and how to combine and extend them in order to achieve transtentorial exposure.

Posterolateral Routes to the Skull Base, Craniocervical Junction, and Jugular Foramen-The Far Lateral Transcondylar Approach and Combined Transpetrosal Transcervical Approaches.

The far lateral approach provides wide surgical access to the lower third of the clivus, pontomedullary junction, and anterolateral foramen magnum and rarely requires craniovertebral fusion. The most common indications for this approach are posterior inferior cerebellar artery and vertebral arteryaneurysms, brainstem cavernous malformations, and tumors anterior to the lower pons and medulla, including meningiomas of the anterior foramen magnum, schwannomas of the lower cranial nerves, and intramedullary tumors at the craniocervical junction. We provide a stepwise description of how we perform the far lateral approach, as well as how to combine the far lateral approach with other skull base approaches, including the subtemporal transtentorial approach, for lesions involving the upper clivus; the posterior transpetrosal approach, for lesions involving the cerebellopontine angle and/or petroclival region; and/or lateral cervical approaches, for lesions involving the jugular foramen or carotid sheath regions.

Tailored Surgical Access to the Cavernous Sinus and Parasellar Region: Assessment of Cavernous Sinus Entry Corridors and the Periclinoid and Pericavernous Surgical Maneuvers.

BACKGROUND: Lesions involving the cavernous sinus (CS) represent some of the most challenging pathologies of the skull base owing to the dense traversing and surrounding neurovasculature. Extradural exposure and preparation of this region, whether as initial preparation for a combined intra-extradural approach or as the main avenue of surgical exposure, can enlarge surgical corridors and minimize the need for brain retraction in this very confined space. We provide a detailed assessment of the entry corridors to the CS that are available within each approach, the surgical exposure and freedom provided by each of these corridors, and demonstrate how extradural and intradural preparation of these corridors can be used to widen the available working space and facilitate surgery. METHODS: Pterional, frontotemporal-orbital, frontotemporal-orbitozygomatic, frontotemporal-zygomatic, perilabyrinthine transtentorial, and endoscopic transnasal transsphenoidal approaches were performed on cadaveric heads to access the perisellar and CS regions. Periclinoid maneuvers (extradural cutting of the meningo-orbital band, anterior clinoidectomy, unroofing of the optic canal, opening of the superior orbital fissure, displacement of the extra-annular structures, opening of the annulus of Zinn, and interdural dissection), pericavernous maneuvers (intradural cutting of the distal dural ring, mobilization of the supraclinoid internal carotid artery, opening of the oculomotor porus, and mobilization of cranial nerve (CN) III), peritrigeminal extensions (extradural mobilization of CN V2 [maxillary] and/or V3 [mandibular]), and other surgical maneuvers were performed and evaluated. The CS was divided into 8 anatomical compartments and 9 entry corridors were described, and exposure and freedom were assessed accordingly. RESULTS: Intradurally, the standard unextended pterional, frontotemporal-orbital, and frontotemporal orbitozygomatic transsylvian approaches provided access solely to the parasellar entry corridor into the superior wall of the CS. Expanding these approaches with extradural periclinoid maneuvers allowed for subsequent application of the intradural pericavernous maneuvers and enlargement of the parasellar corridor and exposure of the carotid cave. Extradurally, the frontotemporal-orbital approach could be expanded via application of periclinoid maneuvers, which provided access to the anterior portions of the main lateral wall entry corridors. The frontotemporal-orbitozygomatic approach could also be expanded with periclinoid maneuvers to provide extradural access to all 6 lateral wall entry corridors. The extradural frontotemporal-zygomatic approach only provided exposure following interdural dissection, which allowed for access to the inferolateral entry corridors into the lateral wall. Extradural peritrigeminal extension in the frontotemporal-orbitozygomatic and frontotemporal-zygomatic approaches allows for enlargement of the supramaxillary and pre- and postmandibular corridors. The perilabyrinthine approach to the posterior wall was enlarged with opening of Dorello's canal and the endoscopic transnasal transsphenoidal approach was enlarged with opening of the optic canal. CONCLUSIONS: Targeted extradural preparation optimizes exposure and significantly improves access to deep-seated targets by enhancing surgical maneuverability through the unlocking of neurovascular structures and widening of surgical corridors without the need for additional brain retraction.