Late meningitis and a nonabsorbable stent in recurrent Rathke's cleft cyst: illustrative case.

BACKGROUND: The management of recurrent Rathke's cleft cysts (RCCs) remains challenging. The off-label application of steroid-eluting bioabsorbable or nonabsorbable intracystic stents has been recently described. Early outcomes and complications of this treatment have been described as well, but long-term data are lacking. OBSERVATIONS: A 31-year-old woman who had undergone 3 prior transsphenoidal surgeries for recurrent RCC at other institutions was admitted for methicillin-susceptible Staphylococcus aureus meningitis. Five years earlier, a nonabsorbable stent had been placed in the cyst using a microsurgical transsphenoidal approach. RCC recurrence had been radiologically evident after 2 years but was clinically asymptomatic. Acute cerebrospinal fluid leakage and other causes of meningitis were ruled out; the stent was occluded. After antibiotic therapy and resolution of the meningitis, the patient underwent endoscopic removal of the catheter, excision of the cyst, and reconstruction with a nasoseptal flap. At the 18-month follow-up, she remained neurologically intact, under replacement therapy, and with no signs of recurrence. LESSONS: The authors report the first case of late meningitis due to a nonabsorbable stent positioned for the treatment of a recurrent RCC. Currently, data on the long-term outcomes, failure rates, and complications of stents for RCC are limited. https://thejns.org/doi/10.3171/CASE2477.

The oculomotor cistern and pituitary adenomas: anatomical and clinical study.

OBJECTIVE: The oculomotor cistern (OMC) is a meningeal cuff filled with CSF that contains the oculomotor nerve (cranial nerve [CN] III) at the level of the lateral wall of the cavernous sinus. Only a few studies have investigated the involvement of the OMC by pituitary adenomas (pituitary neuroendocrine tumors [PitNETs]), mainly with relatively small case series. The aim of this study was to perform a histomorphological description of the OMC and systematically analyze its involvement by PitNETs from radiological, clinical, and surgical perspectives. METHODS: Ten hemisellae from formalin-fixed specimens were studied with 3-µm sections. Digital image analysis software was used for morphological and quantitative assessments. Clinical, radiological, surgical, and histological data of patients undergoing endoscopic transsphenoidal surgery for PitNETs at the University of Brescia, Italy, between 2014 and 2021 were recorded. OMC involvement was graded as not compressed, compressed, and invaded. The same surgical team operated on all patients. RESULTS: The OMC had an elliptical shape with an average area of 3.1 mm2 and a length of 5.5 mm. No cisternal points of weakness were recognized in the histomorphological study. Of 315 patients, 246 had complete data: apoplexy and CN III palsy were documented in 6.9% and 8.5%, respectively. OMC compression and invasion were recorded in 106 (43.1%) and 23 (9.3%) patients. Significant associations between OMC involvement and PitNET dimensions (p < 0.001), Knosp grade (p < 0.001), preoperative oculomotor palsy (p < 0.001), Ki-67 percentage (p = 0.009), and recurrence/progression of residual tumor (p = 0.008) were found. A new postoperative CN III palsy was evident in 2%: transient in 4 cases, and persistent in 1 patient treated for a recurrent PitNET who experienced a local infection complication. Preoperative CN III palsy improved in 10 cases. CONCLUSIONS: Significant OMC involvement by PitNETs might be underrecognized, but it can be treated using the endoscopic transsphenoidal approach, and it affects patient outcomes.

Retroperitoneal schwannoma during pregnancy: A case report and practice-based overview.

The retroperitoneum is the rarest site for Schwannomas, tumors that originate from Schwann cells and usually present as benign, slowly growing masses. During pregnancy, the routine application of ultrasound for fetal assessment has led to an increased rate of detection of maternal asymptomatic masses, notably including the retroperitoneal ones. While most of these masses prove to be benign, it is imperative to consider the potential for malignancy. This report presents a rare case involving a woman diagnosed with bilateral adnexal cysts and a pre-sacral retroperitoneal mass during the first trimester of pregnancy. Surgical intervention was employed to remove ovarian tumors, and a biopsy was performed on the non-adnexal tumor to determine its nature. The histological examination revealed a bilateral borderline seromucinous tumor in the ovaries and identified a Schwannoma in the sacral mass. Despite the considerable size of the pre-sacral mass, which significantly impacted the patient's quality of life, successful measures were taken to achieve a near-term pregnancy, culminating in the delivery of a healthy baby. Subsequently the patient underwent neurosurgical treatment of the substantial pre-sacral Schwannoma. The discovery of a Schwannoma during pregnancy can evoke concerns among healthcare practitioners, touching upon potential malignancy risks, accelerated tumor growth, and impacts on fetal well-being. This paper provides a comprehensive, practice-based overview of these critical aspects.

Training models and simulators for endoscopic transsphenoidal surgery: a systematic review.

Endoscopic transsphenoidal surgery is a novel surgical technique requiring specific training. Different models and simulators have been recently suggested for it, but no systematic review is available. To provide a systematic and critical literature review and up-to-date description of the training models or simulators dedicated to endoscopic transsphenoidal surgery. A search was performed on PubMed and Scopus databases for articles published until February 2023; Google was also searched to document commercially available. For each model, the following features were recorded: training performed, tumor/arachnoid reproduction, assessment and validation, and cost. Of the 1199 retrieved articles, 101 were included in the final analysis. The described models can be subdivided into 5 major categories: (1) enhanced cadaveric heads; (2) animal models; (3) training artificial solutions, with increasing complexity (from "box-trainers" to multi-material, ct-based models); (4) training simulators, based on virtual or augmented reality; (5) Pre-operative planning models and simulators. Each available training model has specific advantages and limitations. Costs are high for cadaver-based solutions and vary significantly for the other solutions. Cheaper solutions seem useful only for the first stages of training. Most models do not provide a simulation of the sellar tumor, and a realistic simulation of the suprasellar arachnoid. Most artificial models do not provide a realistic and cost-efficient simulation of the most delicate and relatively common phase of surgery, i.e., tumor removal with arachnoid preservation; current research should optimize this to train future neurosurgical generations efficiently and safely.

The Extracellular Matrix in Glioblastomas: A Glance at Its Structural Modifications in Shaping the Tumoral Microenvironment-A Systematic Review.

BACKGROUND AND AIM: While many components of the ECM have been isolated and characterized, its modifications in the specific setting of GBMs have only been recently explored in the literature. The aim of this paper is to provide a systematic review on the topic and to assess the ECM's role in shaping tumoral development. METHODS: An online literature search was launched on PubMed/Medline and Scopus using the research string "((Extracellular matrix OR ECM OR matrix receptor OR matrix proteome) AND (glioblastoma OR GBM) AND (tumor invasion OR tumor infiltration))", and a systematic review was conducted in accordance with the PRISMA-P guidelines. RESULTS: The search of the literature yielded a total of 693 results. The duplicate records were then removed (n = 13), and the records were excluded via a title and abstract screening; 137 studies were found to be relevant to our research question and were assessed for eligibility. Upon a full-text review, 59 articles were finally included and were summarized as follows based on their focus: (1) proteoglycans; (2) fibrillary proteins, which were further subdivided into the three subcategories of collagen, fibronectin, and laminins; (3) glycoproteins; (4) degradative enzymes; (5) physical forces; (6) and glioma cell and microglia migratory and infiltrative patterns. CONCLUSIONS: Our systematic review demonstrates that the ECM should not be regarded anymore as a passive scaffold statically contributing to mechanical support in normal and pathological brain tissue but as an active player in tumor-related activity.

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.

A Comparative Analysis with Exoscope and Optical Microscope for Intraoperative Visualization and Surgical Workflow in 5-Aminolevulinic Acid-Guided Resection of High-Grade Gliomas.

BACKGROUND: The exoscope has been proposed as a valid tool in 5-aminolevulinic acid-guided resection of high-grade gliomas. However, it is not clear if, beyond ergonomics, the exoscope provides a real benefit over the optical microscope (OM). The aim of this study was to compare the exoscope with the OM in terms of surgical visualization and workflow in 5-aminolevulinic acid-guided brain surgery. METHODS: Surgical videos of patients diagnosed with histopathologically confirmed, Shinoda stage I, high-grade gliomas who underwent surgery in from January to April 2022 were studied. Visualization under a 5-aminolevulinic acid blue filter for vessels, parenchyma, surgical instruments, and fluorescence was categorized for both superficial and deep fields. The following data were also recorded: median number of switches between white light and blue filter, average duration per switch, and amount of work under blue filter. RESULTS: There were 5 surgeries performed under OM guidance and 5 performed under exoscope guidance. Under a blue filter, the exoscope was significantly better than the OM in visualizing vessels, parenchyma, and surgical instruments for both superficial and deep surgical fields. The median number of switches between blue and white light was lower compared with the OM. Both median switch duration and percentage of work under the blue filter were superior when using the exoscope. CONCLUSIONS: Within the limitations of a preliminary analysis, use of the exoscope in fluorescence-guided surgery for high-grade gliomas provided significant advantages in terms of visualization of the surgical field under a blue filter and linearity of surgical flow.

A supervised machine-learning algorithm predicts intraoperative CSF leak in endoscopic transsphenoidal surgery for pituitary adenomas.

BACKGROUND: Despite advances in endoscopic transnasal transsphenoidal surgery (E-TNS) for pituitary adenomas (PAs), cerebrospinal fluid (CSF) leakage remains a life-threatening complication predisposing to major morbidity and mortality. In the current study we developed a supervised ML model able to predict the risk of intraoperative CSF leakage by comparing different machine learning (ML) methods and explaining the functioning and the rationale of the best performing algorithm. METHODS: A retrospective cohort of 238 patients treated via E-TNS for PAs was selected. A customized pipeline of several ML models was programmed and trained; the best five models were tested on a hold-out test and the best classifier was then prospectively validated on a cohort of 35 recently treated patients. RESULTS: Intraoperative CSF leak occurred in 54 (22,6%) of 238 patients. The most important risk's predictors were: non secreting status, older age, x-, y- and z-axes diameters, ostedural invasiveness, volume, ICD and R-ratio. The random forest (RF) classifier outperformed other models, with an AUC of 0.84, high sensitivity (86%) and specificity (88%). Positive predictive value and negative predictive value were 88% and 80% respectively. F1 score was 0.84. Prospective validation confirmed outstanding performance metrics: AUC (0.81), sensitivity (83%), specificity (79%), negative predictive value (95%) and F1 score (0.75). CONCLUSIONS: The RF classifier showed the best performance across all models selected. RF models might predict surgical outcomes in heterogeneous multimorbid and fragile populations outperforming classical statistical analyses and other ML models (SVM, ANN etc.), improving patient management and reducing preventable morbidity and additional costs.

Multinodular plexiform tumors of major peripheral nerves: A practical overview.

BACKGROUND AND AIMS: Multinodular/plexiform schwannomas and neurofibromas of major nerves are rare: before surgery, differential diagnosis among these two uncommon variants is challenging. For both forms, surgical removal is recommended in case of progressive growth and worsening of neurological symptoms. Surgery has a higher risk of neurological damage than conventional schwannomas or neurofibromas. In literature, a comparison among these rare tumors is usually limited to the pathological aspect while specific surgical and clinical management indications are lacking. Cutaneous tumors of both forms arising from terminal peripheral nerves' branches might be treated by plastic surgeons while tumors of major nerves remain under neurosurgical competence. Here we report our recent neurosurgical experience on the matter, to furnish useful suggestions for the management of these tumors. METHOD: We analyzed the clinical, radiological, and pathological data in a consecutive case series of plexiform/multinodular nerve tumors operated at our institution in the last five years. RESULTS: In our series, neurofibroma type of plexiform tumors was more frequent than schwannoma type: two sporadic plexiform-multinodular schwannomas (patients 1, and 5) and three multinodular/plexiform Neurofibromatosis familial (Neurofibromatosis 1 / NF-1) (patients 2, 3, and 4). Surgery was complex when major nerves were involved. The early outcome appeared mostly related to the pre-surgical neurological conditions and histological grading. INTERPRETATION: Although sharing some features, multinodular-plexiform schwannomas and neurofibromas have consistent differences from the clinical, surgical and pathological points of view.

Craniovertebral Junction Transanasal and Transoral Approaches: Reconstruct the Surgical Pathways with Soft or Hard Tissue Endocopic Lines? This Is the Question.

A variety of pathological conditions may affect the clivus and the craniovertebral junction (CVJ). These include congenital disorders, chronic inflammation, neoplasms, infections, and posttraumatic conditions that could all result in CVJ compression and myelopathy Endoscopic-assisted procedures have been further developed for CVJ decompression and they have now become conventional approaches. The aims of the present study were:(1) to compare "radiological" and "surgical" nasoaxial lines (NAxLs); (2) to introduce an analogous radiological line as a predictor of the superior extension of the transoral approach (palatine inferior dental arch line (PIA); (3) to compare the "radiological" nasopalatine line (NPL) with the "surgical" NPL (SNPL) and surgical PIA (SPIA); (4) to compare "our" SNPL with the NAxL; and (5) to find possible radiological reference points to predict, preoperatively, the maximal extent of superior dissection for the transoral approach (SPIA).

Giant Basilar Artery Aneurysm Involving the Origin of Bilateral Posterior Cerebral and Superior Cerebellar Arteries: Neck Reconstruction with pCONus-Assisted Coiling.

Giant aneurysms of the basilar artery are rare and are frequently associated with obstructive hydrocephalus and brainstem compression. Treatment still remains a challenge both for neurosurgeons and for interventional neuroradiologists. Cases reported in the literature are anecdotal and, overall, their outcomes are poor. We present the case of a patient with a giant aneurysm of the basilar artery tip, involving the origin of both the posterior cerebral and superior cerebellar arteries, who underwent coiling and ventriculoperitoneal shunting for associated obstructive hydrocephalus. A pCONus ® stent (Phenox; Bochum, Germany) was detached with its petals opened over the ostia of the parent vessels, with the aim being to reconstruct the neck of the aneurysm and to preserve the flow in the parent vessel. Moreover, the presence of the stent was useful to maintain the coils within the dome of the aneurysm. The pCONus is a new neurovascular device that is also useful for treating cases of complex basilar artery aneurysms when the ostia of the parent vessel origin is at the level of the aneurysm neck.

CSF dynamics analysis in patients with post-traumatic ventriculomegaly.

OBJECTIVE: The management of post-traumatic ventriculomegaly (PTV) is controversial. This is due to the difficulty to determine whether PTV is related to an atrophic process or to a true "active" hydrocephalus. The purpose of this study is to analyze the CSF-dynamics in patients with PTV and, possibly, to identify parameters that correlate with prognosis. METHODS: 15 patients with PTV were treated following this protocol: 1-frontal ventriculostomy (with Rickham reservoir); 2-CSF-dynamics evaluation; 3-ventriculo-peritoneal shunt. CSF dynamics evaluation was based on an intraventricular infusion test (performed three to five days after ventriculostomy). Outflow Resistance (R-out) and Intracranial Elastance Index (EI, i.e. the reciprocal of intracranial compliance) were calculated. Patients were classified according to response to shunt into: 1-fast responders: rapid clinical improvement, i.e. within days/one month from surgery; 2-slow responders: patients presenting little clinical improvement occurring after months (despite neurorehabilitation); 3-non responders: no clinical improvement. RESULTS: Seven patients (46.7%) were classified as fast-responders, three patients were classified as slow-responders (20%) and five patients were classified as non-responders (33.3%). Opening CSF pressure was less than 15 mmHg for all patients. R-out (cut-off >10 mmHg/ml/min) had 100% sensitivity, 50% specificity, 100% negative predictive value and 63.6% positive predictive value. EI (cut-off value >0.3) had 100% specificity, 42.4% sensitivity, 100% positive predictive value and 66.7% negative predictive value. CONCLUSIONS: Based on these considerations, we can suggest that, for patients with normal pressure PTV, analysis of CSF dynamics could be of help in selecting patients for CSF-shunt. A combination of Intracranial Elastance and of R-out could help predicting shunt responsiveness.

Comparison of diagnostic accuracy between three different rules of interpreting high sensitivity troponin T results.

With the introduction of high sensitivity troponin-T (hs-TnT) assay, clinicians face more patients with 'positive' results but without myocardial infarction. Repeated hs-TnT determinations are warranted to improve specificity. The aim of this study was to compare diagnostic accuracy of three different interpretation rules for two hs-TnT results taken 6 h apart. After adjusting for clinical differences, hs-TnT results were recoded according to the three rules. Rule1: hs-TnT >13 ng/L in at least one determination. Rule2: change of >20 % between the two measures. Rule3: change >50 % if baseline hs-TnT 14-53 ng/L and >20 % if baseline >54 ng/L. The sensitivity, specificity and ROC curves were compared. The sensitivity analysis was used to generate post-test probability for any test result. Primary outcome was the evidence of coronary critical stenosis (CCS) on coronary angiography in patients with high-risk chest pain. 183 patients were analyzed (38.3 %) among all patients presenting with chest pain during the study period. CCS was found in 80 (43.7 %) cases. The specificity was 0.62 (0.52-0.71), 0.76 (0.66-0.84) and 0.83 (0.74-0.89) for rules 1, 2 and 3, respectively (P < 0.01). Sensitivity decreased with increasing specificity (P < 0.01). Overall diagnostic accuracy did not differ among the three rules (AUC curves difference P = 0.12). Sensitivity analysis showed a 25 % relative gain in predicting CCS using rule 3 compared to rule 1. Changes between two determinations of hs-TnT 6 h apart effectively improved specificity for CCS presence in high-risk chest pain patients. There was a parallel loss in sensitivity that discouraged any use of such changes as a unique way to interpret the new hs-TnT results.