The Oculomotor Cistern and Its Role in the Management of Pituitary Lesions: An Anatomical, Radiographic, and Clinical Scoping Review

Background: The oculomotor cistern (OMC) is a cerebrospinal fluid space bound by meningeal layers that surrounds the oculomotor nerve as it crosses the oculomotor triangle to reach the lateral wall of the cavernous sinus at the level of the anterior clinoid process. Although several anatomical and radiological studies are available, its anatomy and relationship with pituitary adenomas (PAs) are still matter of discussion. Objective: The aim of the study is to provide an updated and focused overview of the OMC, highlighting the different perspectives and descriptions from anatomical, radiological, and clinical points of view. Methods: A scoping review was conducted up to 29th October 2022, according to PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews) criteria. PubMed, Web of Science, Scopus databases, and correlated citations were investigated. Results: Of the 562 records identified, 22 were included in the present analysis. There were 13, 5, and 4 anatomo-surgical, radiological, and clinical studies, respectively. Though there is general consensus on its definition, data are variable on different features of OMC. Defects or absence of dural layers adjacent to the oculomotor nerve were described in only 4 papers. The transition from meningeal to neural layers is still unclear. PAs with OMC involvement are poorly studied and have unique clinical characteristics. To date, 21 patients have been described; the reported prevalence of OMC involvement by PAs ranges from 4.1% to 14.6%. Conclusions: Clarifying the OMC features with further systematic studies may not only broaden theoretical knowledge but also have implications on endoscopic transnasal pituitary surgery

Pituitary adenomas and invasiveness from anatomo-surgical, radiological, and histological perspectives: A systematic literature review

Invasiveness in pituitary adenomas has been defined and investigated from multiple perspectives, with varying results when its predictive value is considered. A systematic literature review, following PRISMA guidelines, was performed, searching PubMed and Scopus databases with terms that included molecular markers, histological, radiological, anatomical and surgical data on invasiveness of pituitary adenomas. The results showed that differing views are still present for anatomical aspects of the sellar region that are relevant to the concept of invasiveness; radiological and histological diagnoses are still limited, but might improve in the future, especially if they are related to surgical findings, which have become more accurate thanks to the introduction of the endoscope. The aim is to achieve a correct distinction between truly invasive pituitary adenomas from those that, in contrast, present with extension in the parasellar area through natural pathways. At present, diagnosis of invasiveness should be based on a comprehensive analysis of radiological, intraoperative and histological findings

The “candy wrapper” of the pituitary gland: a road map to the parasellar ligaments and the medial wall of the cavernous sinus

Purpose: The anatomy of the medial wall of the cavernous sinus (MWCS) and parasellar ligaments (PLs) has acquired increasing importance in endoscopic endonasal (EE) surgery of the cavernous sinus (CS), including resection of the MWCS in functioning pituitary adenomas (FPAs). Although anatomical studies have been published, it represents a debated topic due to their complex morphology. The aim is to offer a description of the PLs that originate from the MWCS and reach the lateral wall of the cavernous sinus (LWCS), proposing the “candy wrapper” model. The relationships between the neurovascular structures and histomorphological aspects were investigated. Methods: Forty-two CSs from twenty-one human heads were studied. Eleven specimens were used for EE dissection; five underwent a microscopic dissection. Five specimens were used for histomorphological analysis. Results: Two groups of PLs with a fan-shaped appearance were encountered. The anterior group included the periosteal ligament (55% sides) and the carotico-clinoid complex (100% sides), formed by the anterior horizontal and the carotico-clinoid ligaments. The posterior group was formed by the posterior horizontal (78% sides), and the inferior hypophyseal ligament (34% sides). The periosteal ligament originated inferiorly from the MWCS, reaching the periosteal dura. The anterior horizontal ligament was divided in a superior and inferior branch. The superior one continued as the carotid-oculomotor membrane, and the inferior branch reached the CN VI. The carotico-clinoid ligament between the middle and anterior clinoid was ossified in 3 sides. The posterior horizontal ligament was related to the posterior genu and ended at the LWCS. The inferior hypophyseal ligament followed the homonym artery. The ligaments related to the ICA form part of the adventitia. Conclusion: The “candy wrapper” model adds further details to the previous descriptions of the PLs. Understanding this complex anatomy is essential for safe CS surgery, including MWCS resection for FPAs

Microsurgical transcranial approaches to the posterior surface of petrosal portion of the temporal bone: quantitative analysis of surgical volumes and exposed areas

Different microsurgical transcranial approaches (MTAs) have been described to expose the posterior surface of the petrous bone (PPB). A quantitative, anatomical comparison of the most used MTAs, for specific areas of the PPB, is not available. Anatomical dissections were performed on five formalin-fixed, latex-injected cadaver heads (10 sides). Six MTAs were analyzed: Kawase approach (KWA), retrosigmoid approach (RSA), retrosigmoid approach with suprameatal extension (RSAS), retrolabyrinthine approach (RLA), translabyrinthine approach (TLA), and transcochlear approach (TCA). Surgical volumes and exposed areas of each approach were quantified with a dedicated neuronavigation system (ApproachViewer, part of GTx-Eyes II, University Health Network, Toronto, Canada) and adjuvant software (ITK-SNAP and Autodesk Meshmixer 3.5). Areas and volumes were compared using linear mixed models. TCA provided the best exposure of Trautmann’s triangle and the retromeatal, suprameatal, meatal, and premeatal regions. RSAs provided the best exposure of the inframeatal region, with RSAS gaining significant exposure of the suprameatal region. KWA had the highest surgical volume, and RLA the lowest. Transpetrosal approaches offer the widest exposure of PPB proportionally to their invasiveness. Retrosigmoid approaches, which get to the studied region through a postero-lateral path, are paramount for the exposure of the inframeatal and suprameatal region and, given the adequate exposure of the remaining PPB, represent an effective approach for the cerebellopontine angle (CPA). These anatomical findings must be considered with approach-related morbidity and the pathological features in order to choose the most appropriate approach in clinical practice

Aggressive PitNETs and Potential Target Therapies: A Systematic Review of Molecular and Genetic Pathways

Recently, advances in molecular biology and bioinformatics have allowed a more thorough understanding of tumorigenesis in aggressive PitNETs (pituitary neuroendocrine tumors) through the identification of specific essential genes, crucial molecular pathways, regulators, and effects of the tumoral microenvironment. Target therapies have been developed to cure oncology patients refractory to traditional treatments, introducing the concept of precision medicine. Preliminary data on PitNETs are derived from preclinical studies conducted on cell cultures, animal models, and a few case reports or small case series. This study comprehensively reviews the principal pathways involved in aggressive PitNETs, describing the potential target therapies. A search was conducted on Pubmed, Scopus, and Web of Science for English papers published between 1 January 2004, and 15 June 2023. 254 were selected, and the topics related to aggressive PitNETs were recorded and discussed in detail: epigenetic aspects, membrane proteins and receptors, metalloprotease, molecular pathways, PPRK, and the immune microenvironment. A comprehensive comprehension of the molecular mechanisms linked to PitNETs’ aggressiveness and invasiveness is crucial. Despite promising preliminary findings, additional research and clinical trials are necessary to confirm the indications and effectiveness of target therapies for PitNETs

Do neurosurgeons follow the guidelines? A world-based survey on severe traumatic brain injury

BACKGROUND: Traumatic brain injury (TBI) is going to be the third-leading cause of death worldwide, according to the WHO. Two european surveys suggested that adherence to brain trauma guidelines is poor. No study has compared compliance between low- (LMICs) and high-income (UHICs) countries. Hence, this study aimed to investigate differences in the management of severe TBI patients, comparing low- and high-income, and adherence to the BTF guidelines. METHODS: a web-based survey was spread through the global Neuro foundation, different neurosurgical societies, and social media. RESULTS: a total of 803 neurosurgeons participated: 70.4 from UHICs and 29.6% from LMICs. Hypertonic was administered as an early measure by the 73% and 65% of the responders in LMICs and UHICs, respectively (P=0.016). an invasive intracranial pressure monitoring was recommended by the 66% and 58% of the neurosurgeons in LMICs and UHICs, respectively (P<0.001). antiseizure drugs (P<0.001) were given most frequently in LMICs as, against recommendations, steroids (87% vs. 61% and 86% vs. 81%, respectively). in the LMICs both the evacuation of the contusion and decompressive craniectomy were performed earlier than in UHICs (30% vs. 17% with P<0.001 and 44% vs. 28% with P=0.006, respectively). In the LMICs, the head CT control was performed mostly between 12 and 24 hours from the first imaging (38% vs. 23%, P<0.001). CONCLUSIONS: The current Guidelines on TBI do not always fit to both the resources and circumstances in different countries. Future research and clinical practice guidelines should reflect the greater relevance of TBI in low resource settings

Do neurosurgeons follow the guidelines? A world-based survey on severe traumatic brain injury

BACKGROUND: Traumatic brain injury (TBI) is going to be the third-leading cause of death worldwide, according to the WHO. Two european surveys suggested that adherence to brain trauma guidelines is poor. No study has compared compliance between low- (LMICs) and high-income (UHICs) countries. Hence, this study aimed to investigate differences in the management of severe TBI patients, comparing low- and high-income, and adherence to the BTF guidelines. METHODS: a web-based survey was spread through the global Neuro foundation, different neurosurgical societies, and social media. RESULTS: a total of 803 neurosurgeons participated: 70.4 from UHICs and 29.6% from LMICs. Hypertonic was administered as an early measure by the 73% and 65% of the responders in LMICs and UHICs, respectively (P=0.016). an invasive intracranial pressure monitoring was recommended by the 66% and 58% of the neurosurgeons in LMICs and UHICs, respectively (P<0.001). antiseizure drugs (P<0.001) were given most frequently in LMICs as, against recommendations, steroids (87% vs. 61% and 86% vs. 81%, respectively). in the LMICs both the evacuation of the contusion and decompressive craniectomy were performed earlier than in UHICs (30% vs. 17% with P<0.001 and 44% vs. 28% with P=0.006, respectively). In the LMICs, the head CT control was performed mostly between 12 and 24 hours from the first imaging (38% vs. 23%, P<0.001). CONCLUSIONS: The current Guidelines on TBI do not always fit to both the resources and circumstances in different countries. Future research and clinical practice guidelines should reflect the greater relevance of TBI in low resource settings