Late Relapse of Previous Pulmonary Cryptococcosis With Symptoms Resembling Cerebral Infarction: A Case Report.

Cryptococcosis, an infection caused by Cryptococcus neoformans and Cryptococcus gattii, predominantly targets the central nervous system (CNS) in patients with AIDS but is not limited to this group. The disease can also occur in individuals with various immunosuppressive conditions, frequently involving the brain or lungs. Cryptococcal meningitis (CM) is the most common form of fungal meningoencephalitis, leading to intracerebral infections, cerebral infarction, or hydrocephalus. The clinical presentation of CM is nonspecific, and imaging features can vary significantly. This case report presents a patient with cerebral infarction, who was HIV-negative but had been on long-term cortisone therapy. Notably, the patient had a history of pulmonary cryptococcosis 15 years prior to cerebral involvement. When initially at our clinic, histology and culture results from brain biopsies were negative and the earlier pulmonary cryptococcosis history was unknown. Subsequently, cryptococcal antigen was detected in both serum and cerebrospinal fluid (CSF), and C. neoformans was cultivated from CSF. This case highlights the critical importance of maintaining a high index of suspicion for CM, particularly in patients with a history of previous cryptococcal infections, and it also demonstrates the possibility of false-negative brain biopsy results due to secondary vascular events associated with CM.

Muscarinic receptor drug trihexyphenidyl can alter growth of mesenchymal glioblastoma in vivo.

Glioblastoma (GBM) is the most commonly occurring and most aggressive primary brain tumor. Transcriptomics-based tumor subtype classification has established the mesenchymal lineage of GBM (MES-GBM) as cancers with particular aggressive behavior and high levels of therapy resistance. Previously it was show that Trihexyphenidyl (THP), a market approved M1 muscarinic receptor-targeting oral drug can suppress proliferation and survival of GBM stem cells from the classical transcriptomic subtype. In a series of in vitro experiments, this study confirms the therapeutic potential of THP, by effectively suppressing the growth, proliferation and survival of MES-GBM cells with limited effects on non-tumor cells. Transcriptomic profiling of treated cancer cells identified genes and associated metabolic signaling pathways as possible underlying molecular mechanisms responsible for THP-induced effects. In vivo trials of THP in immunocompromised mice carry orthotopic MES-GBMs showed moderate response to the drug. This study further highlights the potential of THP repurposing as an anti-cancer treatment regimen but mode of action and d optimal treatment procedures for in vivo regimens need to be investigated further.

Enlarged tumefactive perivascular, or Virchow-Robin, spaces and hydrocephalus: do we need to treat? Illustrative cases.

BACKGROUND: Perivascular spaces (PVSs) are spaces in brain parenchyma filled with interstitial fluid surrounding small cerebral vessels. Massive enlargements of PVSs are referred to as "giant tumefactive perivascular spaces" (GTPVSs), which can be classified into three types depending on their localization. These lesions are rare, predominantly asymptomatic, and often initially misinterpreted as cystic tumor formations. However, there are several reported cases in which GTPVSs have induced neurological symptoms because of their size, mass effect, and location, ultimately leading to obstructive hydrocephalus necessitating neurosurgical intervention. Presented here are three diverse clinical presentations of GTPVS. OBSERVATIONS: Here, the authors observed an asymptomatic case of type 1 GTPVS and two symptomatic cases of type 3 GTPVS, one causing local mass effect and the other hydrocephalus. LESSONS: GTPVSs are mostly asymptomatic lesions. Patients without symptoms should be closely monitored, and biopsy is discouraged. Hydrocephalus resulting from GTPVS necessitates surgical intervention. In these cases, third ventriculostomy, shunt implantation, or direct cyst fenestration are surgical options. For patients presenting with symptoms from localized mass effect, a thorough evaluation for potential neurosurgical intervention is imperative. Follow-up in type 3 GTPVS is recommended, particularly in untreated cases. Given the infrequency of GTPVS, definitive guidelines for neurosurgical treatment and subsequent follow-up remain elusive.

Concept of a fully-implantable system to monitor tumor recurrence.

Current treatment for glioblastoma includes tumor resection followed by radiation, chemotherapy, and periodic post-operative examinations. Despite combination therapies, patients face a poor prognosis and eventual recurrence, which often occurs at the resection site. With standard MRI imaging surveillance, histologic changes may be overlooked or misinterpreted, leading to erroneous conclusions about the course of adjuvant therapy and subsequent interventions. To address these challenges, we propose an implantable system for accurate continuous recurrence monitoring that employs optical sensing of fluorescently labeled cancer cells and is implanted in the resection cavity during the final stage of tumor resection. We demonstrate the feasibility of the sensing principle using miniaturized system components, optical tissue phantoms, and porcine brain tissue in a series of experimental trials. Subsequently, the system electronics are extended to include circuitry for wireless energy transfer and power management and verified through electromagnetic field, circuit simulations and test of an evaluation board. Finally, a holistic conceptual system design is presented and visualized. This novel approach to monitor glioblastoma patients is intended to early detect recurrent cancerous tissue and enable personalization and optimization of therapy thus potentially improving overall prognosis.

Extravascular optical coherence tomography of cerebral vessel walls in vivo.

PURPOSE: Evaluation of extravascular, microscope integrated OCT (iOCT) as an in vivo imaging modality of cerebral blood vessels and as an intraoperative imaging method. METHODS: Microscope integrated optical coherence tomography of major cerebral arteries (n = 13) and superficial sylvian veins (n = 5) and one incidental cerebral vasospasm (n = 1) in (n = 10) patients. Post procedural analysis of OCT volume scans, microscopic images and videos during the time of scan as well as measurements of the diameter of vessel walls and its layers with an accuracy of 7.5 µm. RESULTS: iOCT was feasible during vascular microsurgical procedures. In all scanned arteries a clear delineation of the physiological three layered vessel wall composition could be achieved. Pathological arteriosclerotic alterations of cerebral artery walls could precisely be demonstrated. Major superficial cortical veins conversely presented a mono layered composition. First in vivo measurements of vascular mean diameters were possible. Cerebral artery walls showed a diameter of 296 µm, tunica externa 78 µm, media 134 µm and interna 84 µm. CONCLUSION: For the first time the microstructural composition of cerebral blood vessels could be illustrated in vivo. Due to an outstanding spatial resolution a clear definition of physiological and pathological characteristics was possible. Therefore, microscope integrated optical coherence tomography holds promise for basic research in the field of cerebrovascular arteriosclerotic diseases and for intraoperative guidance during microvascular surgery.

Spinal Meningioma Surgery through the Ages-Single-Center Experience over Three Decades.

Background and Objectives: Spinal meningiomas, which are well characterized and are most frequently intradural extramedullary tumors, represent 25% of all intradural spinal tumors. The goal of this study was to compare the outcomes of surgically treated patients with spinal meningiomas in two time intervals with special emphasis on postoperative functional outcomes. Methods: Patients with spinal meningiomas admitted to our department between 1990 and 2020 were enrolled and divided into a historic cohort (HC; treated 1990−2007) and a current cohort (CC; treated 2008−2020). Patients' clinical data and surgical and radiological reports were retrospectively analyzed up to 5 years. Preoperative and postoperative neurological function were assessed using the modified McCormick Scale (mMCS). The Charlson Comorbidity Index (CCI) was used to evaluate the effect of comorbidities on the preoperative status and postoperative outcome. Results: We included 300 patients. Participants in the CC (n = 144) were significantly younger compared to those in the HC (n = 156), with twice as many patients <50 years of age (p < 0.001). The most common tumor location was the thoracic spine (n = 204). The median follow-up was 38.1 months (±30.3 standard deviation). A symptom duration until surgery <12 months was significantly associated with an earlier improvement in the mMCS (p = 0.045). In the CC, this duration was shorter and patients' neurological function at the first and last follow-ups was significantly better than for those in the HC (p < 0.001 for both). Conclusions: Our study results suggested that the impact of surgical management and postoperative rehabilitation on spinal meningioma patients' long-term neurological outcome has reached important milestones over the last decades. An earlier diagnosis led to earlier surgical treatment and improved patients' postoperative neurological recovery. Our results exposed that surgical therapy for spinal meningioma should be performed within 12 months after appearance of symptoms to achieve a better recovery.

Angiosarcoma on Top of a Meningioma Mimicking a Transosseous Meningioma: an Interdisciplinary Point of View.

Cutaneous angiosarcoma is a rare type of sarcoma with poor prognosis. Meningioma is the most frequent benign intracranial tumor. Despite the fact that meningiomas are mostly benign, bone and skin can be infiltrated. We report the rare case of an angiosarcoma on top of a meningioma with hyperostosis at exactly the same location mimicking a transosseous growth of a meningioma. An 84-year-old man presented with progressive swelling and ulcerous lesion of the forehead. The patient underwent surgery in an interdisciplinary setting together with a plastic surgeon, including resection of the intracranial tumor and infiltrated bone and skin. To the best of our knowledge, this is the only reported case of a meningioma and angiosarcoma in direct neighborhood. A preoperative biopsy of the skin tumor would have led initially to the correct diagnosis of an angiosarcoma and would have allowed a better planning of the operation and extent of resection.

Life and death of molecular subclones in recurrent meningioma: A case study.

Meningiomas are the most common primary intracranial tumors, of which atypical meningiomas account for ~ 20%. A loss of NF2 has been proven to be an initial step for meningioma development; however, the role of non-NF2 alterations is unknown. Here we report a case of an atypical meningioma with a NF2 splice donor mutation and four recurrences. Using a custom NGS panel, further complex heterogenic molecular alterations were discovered. At first, one subclone of the initial tumor showed an additional PIK3CA variant, most likely of no pathogenic relevance. Then, the first and second recurrences no longer harbored the PIK3CA variant and no tumor heterogeneity was found. The tumor-driving NF2 mutation persisted, however. The latest, third recurrence showed a remarkable genetic heterogeneity with multiple, additional non-NF2 variants and a pathogenic PIKC3A mutation. In detail, one subclone showed a SUFU and two SMARCE1 variants. Another, geographically separate tumor subclone, in contrast, showed several different non-NF2 variants in SMO, PIK3CA and SUFU. Most important, one of the newly acquired PIK3CA alterations in the kinase domain (L1006F) is likely to be an additional tumor-driving mutation, which activates the PI3K-AKT-mTOR pathway. The reported genetic heterogeneity in meningiomas has been addressed in only a few studies. Although some of the detected variants in our case are expected to have biochemical consequences, these consequences are usually not likely to promote tumor development, when taking into account the suggested role of the altered proteins in tumorigenic pathways. However, the occurrence of a single oncogenic missense mutation in a subclone of the third recurrence may indicate a clonal change towards enhanced aggressiveness. Taken together, our case supports the need to perform in-depth studies to clarify the role of non-NF2 mutations for meningioma growth and development.

A comparison of input devices for precise interaction tasks in VR-based surgical planning and training.

To exploit the potential of virtual reality (VR) in medicine, the input devices must be selected carefully due to their different benefits. In this work, input devices for common interaction tasks in medical VR planning and training are compared. Depending on the specific purpose, different requirements exist. Therefore, an appropriate trade-off between meeting task-specific requirements and having a widely applicable device has to be found. We focus on two medical use cases, liver surgery planning and craniotomy training, to cover a broad medical domain. Based on these, relevant input devices are compared with respect to their suitability for performing precise VR interaction tasks. The devices are standard VR controllers, a pen-like VR Ink, data gloves and a real craniotome, the medical instrument used for craniotomy. The input devices were quantitatively compared with respect to their performance based on different measurements. The controllers and VR Ink performed significantly better than the remaining two devices regarding precision. Qualitative data concerning task load, cybersickness, and usability and appropriateness of the devices were assessed. Although no device stands out for both applications, most participants preferred using the VR Ink, followed by the controller and finally the data gloves and craniotome. These results can guide the selection of an appropriate device for future medical VR applications.

Brain biopsy in patients with CLIPPERS syndrome: why and when.

CLIPPERS (chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids) is an inflammatory disorder of the central nervous system (CNS), predominantly involving the brainstem with a characteristic magnetic resonance imaging (MRI) appearance and clinical and radiological responsiveness to glucocorticosteroids. Yet diagnostic biomarkers are missing and other immune-mediated, (para-) infectious and malignant causes mimic CLIPPERS-like MRI presentations. We report the case of a 51-year-old male patient with CLIPPERS who repeatedly responded well to high-dose corticosteroids. After 7 months, however, treatment failed, and he had a biopsy-confirmed diagnosis of a CNS B-cell lymphoma. Clinical and MRI signs of CLIPPERS include a wide spectrum of differential diagnoses which often arise only later during the course of disease. Similar to the case presented here, delayed diagnosis and specific therapy may contribute to an unfavorable outcome. Hence, we propose that in the absence of other diagnostic markers, brain biopsy should be performed as early as possible in CLIPPERS patients.

A new amplicon-based gene panel for next generation sequencing characterization of meningiomas.

Meningiomas are the most frequent primary intracranial tumors. The considerable variety of histological subtypes has been expanded by the definition of molecular alterations, which can improve both diagnostic accuracy and determination of individual patient's outcome. According to the upcoming WHO classification of brain tumors, the in-time analysis of frequent molecular events in meningiomas may become mandatory to define meningioma subtypes. We have compiled a custom-made amplicon-based next generation sequencing (NGS) meningioma panel covering the most frequent known recurrent mutations in 15 different genes. In an unselected consecutive meningioma cohort (109 patients) analyzed over a period of 12 months, we detected mutations in 11 different genes, with most frequent alterations in NF2 (43%), AKT1E17K (15%), and TRAF7 (13%). In 39 tumors (36%), two different mutations were detected, with NF2 and SUFU (n = 5) and KLF4 and TRAF7 (n = 5) being the most frequent combinations. No alterations were found in POLR2A, CDKN2A, CDKN2B, and BAP1, and no homozygous CDKN2A/B deletion was detected. NF2 mutations were found in tumors of all WHO grades, whereas mutations in KLF4, TRAF7, and SMO were restricted to WHO grade I meningiomas. In contrast, SMARCE1 and TERT mutations were associated with WHO grade II meningiomas (according to the WHO classification 2016). The distribution of mutations across histological subtypes or tumor localization was in line with the existing literature, with typical combinations like KLF4K409Q /TRAF7 for secretory meningiomas and preferential skull base localization of meningiomas harboring SMO and AKT1E17K mutations. Thus, we present a custom-made NGS meningioma panel providing a time and cost-efficient reliable detection of relevant somatic molecular alterations in meningiomas suitable for daily routine.

VR-based training of craniotomy for intracranial aneurysm surgery.

PURPOSE: Intracranial aneurysms can be treated micro-surgically. This procedure involves an appropriate head position of the patient and a proper craniotomy. These steps enable a proper access, facilitating the subsequent steps. To train the access planning process, we propose a VR-based training system. METHOD: We designed and implemented an immersive VR access simulation, where the user is surrounded by a virtual operating room, including medical equipment and virtual staff. The patient's head can be positioned via hand rotation and an arbitrary craniotomy contour can be drawn. The chosen access can be evaluated by exposing the aneurysm using a microscopic view. RESULTS: The evaluation of the simulation took place in three stages: testing the simulation using the think-aloud method, conducting a survey and examining the precision of drawing the contour. Although there are differences between the virtual interactions and their counterparts in reality, the participants liked the immersion and felt present in the operating room. The calculated surface dice similarity coefficient, Hausdorff distance and feedback of the participants show that the difficulty of drawing the craniotomy is appropriate. CONCLUSION: The presented training simulation for head positioning and access planning benefits from the immersive environment. Thus, it is an appropriate training for novice neurosurgeons and medical students with the goal to improve anatomical understanding and to become aware of the importance of the right craniotomy hole.

AKT1E17K -mutated meningioma cell lines respond to treatment with the AKT inhibitor AZD5363.

AIMS: Meningiomas are the most frequent primary brain tumours. Recently, knowledge about the molecular drivers underlying aggressive meningiomas has been expanded. A hotspot mutation in the AKT1 gene (AKT1E17K ), which is found in meningiomas at the convexity and especially at the skull base, has been associated with earlier tumour recurrence. METHODS: Here, we analysed the effects of the AKT1E17K mutation and treatment response to the Akt inhibitor AZD5363 in transgenic meningioma cell clones and mouse xenografts modelling convexity or skull base meningiomas. RESULTS: We show that the AKTE17K mutation significantly enhances meningioma cell proliferation and colony size in vitro, resulting in significantly shortened survival times of mice carrying convexity or skull base AKT1E17K xenografts. Treatment of mutant cells or xenografts (150 mg/kg/d) with AZD5363 revealed a significant decrease in cell proliferation and colony size and a prolongation of mouse survival. Western blots revealed activation of AKT1 kinase (phosphorylation at Ser273 and Thr308) by the E17K mutation in human meningioma samples and in our in vitro and in vivo models. CONCLUSIONS: Our data suggest that AKT1E17K mutated meningiomas are a promising selective target for AZD5363.

Theranostic applications of optical coherence tomography in neurosurgery?

In light of our own experiences, we value the existing literature to critically point out possible "near" future applications of optical coherence tomography (OCT) as an intraoperative neurosurgical guidance tool. "Pub Med", "Cochrane Library", "Crossref Metadata Search", and "IEEE Xplore" databases as well as the search engine "Google Scholar" were screened for "optical coherence tomography + neurosurgery", "optical coherence tomography + intraoperative imaging + neurosurgery", and "microscope integrated optical coherence tomography + neurosurgery". n = 51 articles related to the use of OCT as an imaging technique in the field of neurosurgery or neurosurgical research. n = 7 articles documented the intraoperative use of OCT in patients. n = 4 articles documented the use of microscope-integrated optical coherence tomography as a neurosurgical guidance tool. The Results demonstrate that OCT is the first imaging technique to study microanatomy in vivo. Postoperative analysis of intraoperative scans holds promise to enrich our physiological and pathophysiological understanding of the human brain. No data exists to prove that OCT-guided surgery minimizes perioperative morbidity or extends tumor resection. But results suggest that regular use of microscope-integrated OCT could increase security during certain critical microsurgical steps like, e.g., dural dissection at cavernous sinus, transtentorial approaches, or aneurysm clip placement. Endoscopy integration could aid surgery in regions which are not yet accessible to real-time imaging modalities like the ventricles or hypophysis. Theranostic instruments which combine OCT with laser ablation might gain importance in the emerging field of minimal invasive tumor surgery. OCT depicts vessel wall layers and its pathologies uniquely. Doppler OCT could further visualize blood flow in parallel. These abilities shed light on promising future applications in the field of vascular neurosurgery.

Generation of an NFκB-Driven Alpharetroviral "All-in-One" Vector Construct as a Potent Tool for CAR NK Cell Therapy.

Immune cell therapeutics are increasingly applied in oncology. Especially chimeric antigen receptor (CAR) T cells are successfully used to treat several B cell malignancies. Efforts to engineer CAR T cells for improved activity against solid tumors include co-delivery of pro-inflammatory cytokines in addition to CARs, via either constitutive cytokine expression or inducible cytokine expression triggered by CAR recognition of its target antigen-so-called "T cells redirected for universal cytokine-mediated killing" (TRUCKs) or fourth-generation CARs. Here, we tested the hypothesis that TRUCK principles could be expanded to improve anticancer functions of NK cells. A comparison of the functionality of inducible promoters responsive to NFAT or NFκB in NK cells showed that, in contrast to T cells, the inclusion of NFκB-responsive elements within the inducible promoter construct was essential for CAR-inducible expression of the transgene. We demonstrated that GD2CAR-specific activation induced a tight NFκB-promoter-driven cytokine release in NK-92 and primary NK cells together with an enhanced cytotoxic capacity against GD2+ target cells, also shown by increased secretion of cytolytic cytokines. The data demonstrate biologically relevant differences between T and NK cells that are important when clinically translating the TRUCK concept to NK cells for the treatment of solid malignancies.

Frequency of actionable molecular drivers in lung cancer patients with precocious brain metastases.

Brain metastases frequently occur during the course of disease in patients suffering from lung cancer. Occasionally, neurological symptoms caused by brain metastases (BM) might represent the first sign of systemic tumor disease (so called precocious metastases), leading to the detection of the primary lung tumor. The biological basis of precocious BM is largely unknown, and treatment options are not well established for this subgroup of patients. Therefore, we retrospectively analyzed 33 patients (24 non-small cell lung cancer (NSCLC)), 9 small cell lung cancer (SCLC)) presenting with precocious BM focusing on molecular alterations potentially relevant for the tumor's biology and treatment. We found five FGFR1 amplifications (4 adenocarcinoma, 1 SCLC) among 31 analyzed patients (16.1%), eight MET amplifications among 30 analyzed tumors (7 NSCLC, 1 SCLC; 26.7%), three EGFR mutations within 33 patients (all adenocarcinomas, 9.1%), and five KRAS mutations among 32 patients (all adenocarcinomas; 15.6%). No ALK, ROS1 or RET gene rearrangements were detected. Our findings suggest that patients with precocious BM of lung cancer harbor EGFR mutations, MET amplifications or FGFR1 amplifications as potential targeted treatment options.

Definition and extraction of 2D shape indices of intracranial aneurysm necks for rupture risk assessment.

PURPOSE: Intracranial aneurysms are local dilations of brain vessels. Their rupture, as well as their treatment, is associated with high risk of morbidity and mortality. In this work, we propose shape indices for aneurysm ostia for the rupture risk assessment of intracranial aneurysms. METHODS: We analyzed 84 middle cerebral artery bifurcation aneurysms (27 ruptured and 57 unruptured) and their ostia, with respect to their size and shape. We extracted 3D models of the aneurysms and vascular trees. A semi-automatic approach was used to separate the aneurysm from its parent vessel and to reconstruct the ostium. We used known indices to quantitatively describe the aneurysms. For the ostium, we present new shape indices: the 2D Undulation Index (UI[Formula: see text]), the 2D Ellipticity Index (EI[Formula: see text]) and the 2D Noncircularity Index (NCI[Formula: see text]). Results were analyzed using the Student t test, the Mann-Whitney U test and a correlation analysis between indices of the aneurysms and their ostia. RESULTS: Of the indices, none was significantly associated with rupture status. Most aneurysms have an NCI[Formula: see text] below 0.2. Of the aneurysms that have an NCI[Formula: see text] above 0.5, only one is ruptured, which indicates that ruptured aneurysms often have a circular-shaped ostium. Furthermore, the ostia of ruptured aneurysms tend to have a smaller area, which is also correlated with the aneurysm's size. While also other variables were significantly correlated, strong linear correlations can only be seen between the area of the ostium with the aneurysm's volume and surface. CONCLUSION: The proposed shape indices open up new possibilities to quantitatively describe and compare ostia, which can be beneficial for rupture risk assessment and subsequent treatment decision. Additionally, this work shows that the ostium area and the size of the aneurysm are correlated. Further longitudinal studies are necessary to analyze whether stable and unstable aneurysms can be distinguished by their ostia.

Impact of acetylsalicylic acid (ASA) on postoperative hemorrhage in spinal lumbar surgery: Should preoperative ASA be discontinued for elective surgery?

OBJECTIVE: The application of acetylsalicylic acid (ASA) represents high evidence in the aging society due to primary and secondary prevention in cardiovascular disease and stroke. However, this presents a challenge for neurosurgeons in terms of preoperative and postoperative management of care. This study aimed to analyze the risk of bleeding by applying ASA before lumbar spinal surgery. METHODS: Retrospective analysis of medical records of 3051 patients was performed from 2008 to 2018 who underwent lumbar surgery at our institution. The risk of postoperative hemorrhage was compared in patients treated with ASA versus patients without ASA treatment. Additionally, the relationship between discontinuation of ASA preoperatively (≥7 days) or no previous history of ASA versus continuation with ASA (<7 days) on postoperative hemorrhage was analyzed. RESULTS: Postoperative hemorrhagic were observed in 2.1% (n = 63) of all lumbar operations. In 421 patients, the effect of ASA (<7 days) was still persistent at the time of surgery (ASA impact group). Of these, 12 (2.85%) patients had a hemorrhage. No significant differences were found in comparison to the No ASA impact group (p = 0.272). Sex (p = 0.003), hypertension (p = 0.015), recurrent surgery (p = 0.001) and use of hemostatic agents (p = 0.023) had a significant impact on postoperative hemorrhage. CONCLUSION: The continuation of ASA medication is not associated with increased risk of postoperative hemorrhage after spinal surgery. However, sex, hypertension, recurrent surgery and the use of hemostatic agents under continued ASA treatment were found to be associated with an increased risk of hemorrhage.

Impact of acetylsalicylic acid in patients undergoing cerebral aneurysm surgery - should the neurosurgeon really worry about it?

There has been an increase in the use of acetylsalicylic acid (ASA, Aspirin®) among patients with stroke and heart disease as well as in aging populations as a means of primary prevention. The potentially life-threatening consequences of a postoperative hemorrhagic complication after neurosurgical operative procedures are well known. In the present study, we evaluate the risk of continued ASA use as it relates to postoperative hemorrhage and cardiopulmonary complications in patients undergoing cerebral aneurysm surgery. We retrospectively analyzed 200 consecutive clipping procedures performed between 2008 and 2018. Two different statistical models were applied. The first model consisted of two groups: (1) group with No ASA impact - patients who either did not use ASA at all as well as those who had stopped their use of the ASA medication in time (> = 7 days prior to operation); (2) group with ASA impact - all patients whose ASA use was not stopped in time. The second model consisted of three groups: (1) No ASA use; (2) Stopped ASA use (> = 7 days prior to operation); (3) Continued ASA use (did not stop or did not stop in time, <7 days prior to operation). Data collection included demographic information, surgical parameters, aneurysm characteristics, and all hemorrhagic/thromboembolic complications. A postoperative hemorrhage was defined as relevant if a consecutive operation for hematoma removal was necessary. An ASA effect has been assumed in 32 out of 200 performed operations. A postoperative hemorrhage occurred in one out these 32 patients (3.1%). A postoperative hemorrhage in patients without ASA impact was detected and treated in 5 out of 168 patients (3.0%). The difference was statistically not significant in either model (ASA impact group vs. No ASA impact group: OR = 1.0516 [0.1187; 9.3132], p = 1.000; RR = 1.0015 [0.9360; 1.0716]). Cardiopulmonary complications were significantly more frequent in the group with ASA impact than in the group without ASA impact (p = 0.030). In this study continued ASA use was not associated with an increased risk of a postoperative hemorrhage. However, cardiopulmonary complications were significantly more frequent in the ASA impact group than in the No ASA impact group. Thus, ASA might relatively safely be continued in patients with increased cardiovascular risk and cases of emergency cerebrovascular surgery.

Microscope integrated optical coherence tomography of a cerebral arachnoid cyst: A new technique to increase intraoperative security.

PURPOSE: This technical note illustrates microscope integrated optical coherence tomography (iOCT) as an imaging technique to delineate concealed micro anatomical structures not displayable by conventional intraoperative imaging methods in the context of a cerebral arachnoid cyst. METHODS: iOCT was used for the first time to scan a cerebral arachnoid cyst in vivo. Scanning sites were defined at the outer membrane of the arachnoid cyst, the inner membrane at the temporal cortex as well as at the fenestration site to the basal cisterns - a point out of reach and resolution for conventional intraoperative imaging methods like e. g. ultrasound or neuroendoscopy. RESULTS: iOCT was feasible during microsurgical fenestration of an arachnoid cyst. A clear delineation of the arachnoid cyst membrane was possible. The differentiation of the arachnoid cyst membrane and underlying arachnoid barrier cell membrane was possible. Trans cystic scanning at the temporal cortex could delineate the content of the subarachnoid space like subarachnoid blood vessels, trabecular sytem and vessel wall morphology of a M4 middle cerebral artery branch. Scanning of the inner membrane of the arachnoid cyst at site of fenestration to the basal cisterns excluded underlying micro anatomical structures. CONCLUSION: This case demonstrates that iOCT achieved to delineate concealed micro anatomical structures which are occult to conventional intraoperative imaging methods. Further studies are necessary to value iOCT as a tool to improve intraoperative security.