Laser speckle contrast imaging versus microvascular Doppler sonography in aneurysm surgery: A prospective study.

Objective: This study aimed to compare microvascular Doppler sonography (MDS) and laser speckle contrast imaging (LSCI) for assessing vessel patency and aneurysm occlusion during microsurgical clipping of intracranial aneurysms. Methods: MDS and LSCI were used after clip placement during six neurovascular procedures including six patients, and agreement between the two techniques was assessed. LSCI was performed in parallel or right after MDS evaluation. The Doppler response was assessed through listening while flow in the LSCI videos was evaluated by three blinded neurovascular surgeons after the surgery. Statistical analysis determined the agreement between the techniques in assessing flow in 18 regions of interest (ROIs). Results: Agreement between MDS and LSCI in assessing vessel patency was observed in 87 % of the ROIs. LSCI accurately identified flow in 93.3 % of assessable ROIs, with no false positive or negative measurements. Three ROIs were not assessable with LSCI due to motion artifacts or poor image quality. No complications were observed. Conclusions: LSCI demonstrated high agreement with MDS in assessing vessel patency during microsurgical clipping of intracranial aneurysms. It provided continuous, real-time, full-field imaging with high spatial resolution and temporal resolution. While MDS allowed evaluation of deep vascular regions, LSCI complemented it by offering unlimited assessment of surrounding vessels.

Training Performance Assessment for Intracranial Aneurysm Clipping Surgery Using a Patient-Specific Mixed-Reality Simulator: A Learning Curve Study.

BACKGROUND AND OBJECTIVES: The value of simulation-based training in medicine and surgery has been widely demonstrated. This study investigates the introduction and use of a new mixed-reality neurosurgical simulator in aneurysm clipping surgery, focusing on the learning curve and performance improvement. METHODS: Five true-scale craniotomy head models replicating patient-specific neuroanatomy, along with a mixed-reality simulator, a neurosurgical microscope, and a set of microsurgical instruments and clips, were used in the operation theater to simulate aneurysm microsurgery. Six neurosurgical residents participated in five video-recorded simulation sessions over 4 months. Complementary learning modalities were implemented between sessions. Thereafter, three blinded analysts reported on residents' use of the microscope, quality of manipulation, aneurysm occlusion, clipping techniques, and aneurysm rupture. Data were also captured regarding training time and clipping attempts. RESULTS: Over the course of training, clipping time and number of clipping attempts decreased significantly (P = .018, P = .032) and the microscopic skills improved (P = .027). Quality of manipulation and aneurysm occlusion scoring improved initially although the trend was interrupted because the spacing between sessions increased. Significant differences in clipping time and attempts were observed between the most and least challenging patient models (P = .005, P = .0125). The least challenging models presented higher rates of occlusion based on indocyanine green angiography evaluation from the simulator. CONCLUSION: The intracranial aneurysm clipping learning curve can be improved by implementing a new mixed-reality simulator in dedicated training programs. The simulator and the models enable comprehensive training under the guidance of a mentor.

Cortical perfusion measurements with laser speckle contrast imaging during adenosine induced cardiac arrest for aneurysm clipping: a case report.

Adenosine induced cardiac arrest (AiCA) is one of the methods used to facilitate microsurgical aneurysm clipping by providing more visibility and less pressure in the aneurysmal sac and neighboring vessels. We report the use of laser speckle contrast imaging (LSCI) during AiCA to monitor the changes in pulsation and perfusion on the cortical surface during adenosine induced cardiac arrest for aneurysm clipping surgery. Application of this technology for perfusion monitoring may improve workflow and surgical guidance and provide valuable feedback continuously throughout the procedure. ClinicalTrials.gov identifier: NCT0502840.

Intracranial Aneurysm "Clip Anchoring": Technical Note.

Clip slippage and displacement during or after intracranial aneurysm surgery is associated with morbidity and can be detrimental. We report the usage of concomitant aneurysm clips and artery clips aiming to avoid this complication in a patient undergoing elective aneurysm surgical clipping.

Patient-reported symptomatology and its course in spontaneous intracranial hypotension - Beware of a chameleon.

OBJECTIVE: Although orthostatic headache is the hallmark symptom of spontaneous intracranial hypotension (SIH), patients can present with a wide range of different complaints and thereby pose a diagnostic challenge for clinicians. Our aim was to describe and group the different symptoms associated with SIH and their course over time. METHODS: We retrospectively surveyed consecutive patients diagnosed and treated for SIH at our institution from January 2013 to May 2020 with a specifically designed questionnaire to find out about their symptomatology and its course. RESULTS: Of 112 eligible patients, 79 (70.5%) returned the questionnaire and were included in the analysis. Of those, 67 (84.8%) reported initial orthostatic headaches, whereas 12 (15.2%) denied having this initial symptom. All except one (98.7%) patients reported additional symptoms: most frequently cephalic pressure (69.6%), neck pain (68.4%), auditory disturbances (59.5%), nausea (57%), visual disturbances (40.5%), gait disturbance (20.3%), confusion (10.1%) or sensorimotor deficits (21.5%). Fifty-seven (72.2%) patients reported a development of the initial symptoms predominantly in the first three months after symptom onset. Age and sex were not associated with the symptomatology or its course (p > 0.1). CONCLUSION: Although characteristic of SIH, a relevant amount of patients present without orthostatic headaches. In addition, SIH can manifest with non-orthostatic headaches at disease onset or during the course of the disease. Most patients report a wide range of associated complaints. A high degree of suspicion is crucial for an early diagnosis and targeted treatment.

Intraoperative Laser Speckle Contrast Imaging to Assess Vessel Flow in Neurosurgery: A Pilot Study.

BACKGROUND AND OBJECTIVES: Laser speckle contrast imaging (LSCI) has emerged as a promising tool for assessment of vessel flow during neurosurgery. We aimed to investigate the feasibility of visualizing vessel flow in the macrocirculation with a new fully microscope-integrated LSCI system and assess the validity and objectivity of findings compared with fluorescence angiography (FA). METHODS: This is a single-center prospective observational study enrolling adult patients requiring microsurgical treatment for brain vascular pathologies or brain tumors. Three independent raters, blinded toward findings of FA, reviewed regions of interest (ROIs) placed in exposed vessels and target structures. The primary end point was the validity of LSCI for assessment of vessel flow as measured by the agreement with FA. The secondary end point was objectivity, measured as the inter-rater agreement of LSCI findings. RESULTS: During 18 surgical procedures, 23 observations using FA and LSCI were captured simultaneously. Using LSCI, vessel flow was assessable in 62 (86.1%) and not assessable in 10 (13.9%) ROIs. The agreement between LSCI and FA was 86.1%, with an agreement coefficient of 0.85 (95% CI: 0.75-0.94). Disagreement between LSCI and FA was observed in the 10 ROIs that were not assessable. The agreement between ROIs that were assessable using LSCI and FA was 100%. The inter-rater agreement of LSCI findings was 87.9%, with an agreement coefficient of 0.86 (95% CI: 0.79-0.94). CONCLUSION: Fully microscope-integrated LSCI is feasible and has a high potential for clinical utility. Because of its characteristics, LSCI can be viewed as a full-field visual micro-Doppler that can be used as a complementary method to FA for assessing vessel flow during neurosurgery. Despite technical limitations related to the early development phase of the fully microscope-integrated system, we demonstrated reasonable validity and objectivity of findings compared with FA. Further research and refinement of the system may enhance its value in neurosurgical applications.

Anterior Lumbar Interbody Fusion in Elderly Patients: Peri- and Postoperative Complications and Clinical Outcome.

BACKGROUND: Anterior lumbar interbody fusion (ALIF) is an effective surgical technique for treating various lumbar pathologies, but its use in elderly patients is controversial. Data concerning complications and effectiveness are sparse. We investigated peri- and postoperative complications, radiographic parameters, and clinical outcome in elderly patients. METHODS: Patients ≥65 years who underwent ALIF between January 2008 and August 2020 were included in the study. All surgeries were performed through a retroperitoneal approach. Clinical and surgical data as well as radiologic parameters were collected prospectively and analyzed retrospectively. RESULTS: A total of 39 patients were included; the mean age was 72.6 (±6.3) years (range: 65-90 years); and the mean American Society of Anesthesiologists (ASA) risk classification was 2.3 (±0.6). A laceration of the left common iliac vein was the only major complication recorded (2.6%). Minor complications occurred in 20.5% of patients. Fusion rate was 90.9%. Reoperation rate at the index level was 12.8 and 7.7% in adjacent segments. The multidimensional Core Outcome Measures Index (COMI) improved from 7.4 (±1.4) to 3.9 (±2.7) after 1 year and to 3.3 (±2.6) after 2 years. Oswestry disability index (ODI) improved from 41.2 (±13.7) to 20.9 (±14.9) after 1 year and to 21.5 (±18.8) after 2 years. Improvements of at least the minimal clinically important change score of 2.2 and 12.9 points in the ODI and COMI after 2 years were noted in 75 and 56.3% of the patients, respectively. CONCLUSION: With careful patient selection, ALIF is safe and effective in elderly patients.

Exploring Novel Innovation Strategies to Close a Technology Gap in Neurosurgery: HORAO Crowdsourcing Campaign.

BACKGROUND: Scientific research is typically performed by expert individuals or groups who investigate potential solutions in a sequential manner. Given the current worldwide exponential increase in technical innovations, potential solutions for any new problem might already exist, even though they were developed to solve a different problem. Therefore, in crowdsourcing ideation, a research question is explained to a much larger group of individuals beyond the specialist community to obtain a multitude of diverse, outside-the-box solutions. These are then assessed in parallel by a group of experts for their capacity to solve the new problem. The 2 key problems in brain tumor surgery are the difficulty of discerning the exact border between a tumor and the surrounding brain, and the difficulty of identifying the function of a specific area of the brain. Both problems could be solved by a method that visualizes the highly organized fiber tracts within the brain; the absence of fibers would reveal the tumor, whereas the spatial orientation of the tracts would reveal the area's function. To raise awareness about our challenge of developing a means of intraoperative, real-time, noninvasive identification of fiber tracts and tumor borders to improve neurosurgical oncology, we turned to the crowd with a crowdsourcing ideation challenge. OBJECTIVE: Our objective was to evaluate the feasibility of a crowdsourcing ideation campaign for finding novel solutions to challenges in neuroscience. The purpose of this paper is to introduce our chosen crowdsourcing method and discuss it in the context of the current literature. METHODS: We ran a prize-based crowdsourcing ideation competition called HORAO on the commercial platform HeroX. Prize money previously collected through a crowdfunding campaign was offered as an incentive. Using a multistage approach, an expert jury first selected promising technical solutions based on broad, predefined criteria, coached the respective solvers in the second stage, and finally selected the winners in a conference setting. We performed a postchallenge web-based survey among the solvers crowd to find out about their backgrounds and demographics. RESULTS: Our web-based campaign reached more than 20,000 people (views). We received 45 proposals from 32 individuals and 7 teams, working in 26 countries on 4 continents. The postchallenge survey revealed that most of the submissions came from single solvers or teams working in engineering or the natural sciences, with additional submissions from other nonmedical fields. We engaged in further exchanges with 3 out of the 5 finalists and finally initiated a successful scientific collaboration with the winner of the challenge. CONCLUSIONS: This open innovation competition is the first of its kind in medical technology research. A prize-based crowdsourcing ideation campaign is a promising strategy for raising awareness about a specific problem, finding innovative solutions, and establishing new scientific collaborations beyond strictly disciplinary domains.

3D-Printed Head Model in Patient's Education for Micro-Neurosurgical Aneurysm Clipping Procedures.

BACKGROUND: Computed tomography (CT), Magnetic resonance imaging (MRI), and 3D reconstruction from Digital Subtraction Angiography (DSA) are currently used in clinical consultations for patients diagnosed with intracranial aneurysms; however, they have limitations in helping patients understand the disease and possible treatments. This study investigates the use of a 3D-printed model of the patients' neurosurgical anatomy and vascular pathology as an educational tool in outpatient clinics. METHODS: A 3D-printed model of a middle cerebral artery aneurysm was created for use during patient consultations to discuss microsurgical treatment of unruptured cerebral aneurysms. In total, 38 patients and 5 neurosurgeons were included in the study. After the consultation, the patients and neurosurgeons received a questionnaire to assess the effectiveness of the 3D-printed model as an educational tool. RESULTS: The 3D model improved the patients' understanding of the diagnosis, the aneurysm's relationship to the parent artery; the treatment process as well as the risks if left untreated. The patients found the 3D model to be an interesting tool (97%). The neurosurgeons were satisfied with the 3D-printed model as a patient encounter tool, they found the model effective during consultation (87%) and better than the conventional education tools used during consultations (97%). CONCLUSIONS: Using a 3D model improves communication, enhances the patient's understanding of the pathology and its treatment and potentially facilitates the informed consent process in patients undergoing intracranial aneurysm surgery.

Bleeding Risk of Cerebral Cavernous Malformations in Patients on Statin and Antiplatelet Medication: A Cohort Study.

BACKGROUND: Statin medication has been identified as a potential therapeutic target for stabilizing cerebral cavernous malformations (CCMs). Although increasing evidence suggests that antiplatelet medication decreases the risk of CCM hemorrhage, data on statin medication in clinical studies are scarce. OBJECTIVE: To assess the risk of symptomatic CCM-related hemorrhage at presentation and during follow-up in patients on statin and antiplatelet medication. METHODS: A single-center database containing patients harboring CCMs was retrospectively analyzed over 41 years and interrogated for symptomatic hemorrhage at diagnosis, during follow-up, and statin and antiplatelet medication. RESULTS: In total, 212 of 933 CCMs (22.7%), harbored by 688 patients, presented with hemorrhage at diagnosis. Statin medication was not associated with a decreased risk of hemorrhage at diagnosis (odds ratio [OR] 0.63, CI 0.23-1.69, P = .355); antiplatelet medication (OR 0.26, CI 0.08-0.86, P = .028) and combined statin and antiplatelet medication (OR 0.19, CI 0.05-0.66; P = .009) showed a decreased risk. In the antiplatelet-only group, 2 (4.7%) of 43 CCMs developed follow-up hemorrhage during 137.1 lesion-years compared with 67 (9.5%) of 703 CCMs during 3228.1 lesion-years in the nonmedication group. No follow-up hemorrhages occurred in the statin and the combined statin and antiplatelet medication group. Antiplatelet medication was not associated with follow-up hemorrhage (hazard ratio [HR] 0.7, CI 0.16-3.05; P = .634). CONCLUSION: Antiplatelet medication alone and its combination with statins were associated with a lower risk of hemorrhage at CCM diagnosis. The risk reduction of combined statin and antiplatelet medication was greater than in patients receiving antiplatelet medication alone, indicating a possible synergistic effect. Antiplatelet medication alone was not associated with follow-up hemorrhage.

Continuous hemodynamics monitoring during arteriovenous malformation microsurgical resection with laser speckle contrast imaging: case report.

AVM surgery is challenging due to progressive and often unforeseeable flow changes during its resection which involve both the AVM and the surrounding brain tissue. Hence, accurate monitoring of blood flow is crucial to minimize complications and improve outcomes. The following case report illustrates the usefulness of complimentary non-invasive tools that can provide real time blood flow assessment. We present a case demonstrating the application of laser speckle contrast imaging (LSCI) in evaluating vessel flow dynamics during AVM surgery. A 30-year-old female presented with sudden headaches, nausea, vomiting, and vertigo. Emergency imaging revealed a ruptured cerebellar AVM necessitating surgical intervention. LSCI was integrated into the surgical workflow, providing continuous visualization of relative cerebral blood flow (rCBF) of vessels surrounding the AVM. Before AVM resection, LSCI measurements revealed the arterialized vasculature supplying the AVM nidus; measurements after AVM resection showed significant hemodynamic changes including normal flow in the initially arterialized AVM draining veins and adjacent arterial branches. LSCI also detected blood flow alterations during temporary occlusion, enabling assessment of downstream vascular regions. In conclusion, we provide an example supporting the utility of LSCI for real-time hemodynamic monitoring during AVM resection surgery. LSCI offers non-invasive, continuous, and immediate blood flow information, complementing conventional imaging methods like indocyanine green angiography. Additionally, our findings suggest that LSCI has the potential to provide a non-invasive means of identifying the specific superficial vessel branches or cortical areas that receive blood supply from a particular vessel.

Risk Factors for Postoperative Cerebrospinal Fluid Leakage After Intradural Spine Surgery.

OBJECTIVE: Well-defined risk factors for cerebrospinal fluid leakage (CSFL) after intradural spine surgery are scarce in the literature. The aim of the present study was to identify patient- and surgery-related risk factors and the incidence of CSFL. METHODS: For the present retrospective cohort study, we identified consecutive patients who had undergone intradural spine surgery between 2009 and 2021 at our department. The primary endpoint was the incidence of clinically or radiologically proven CSFL. The effects of the clinical and surgical factors on the occurrence of CSFL were analyzed. RESULTS: A total of 375 patients (60.3% women; mean age, 54 ± 16.5 years) were included. Of the 375 patients, 30 (8%) had experienced postoperative CSFL and, thus, a significantly greater risk of wound healing disorders (odds ratio [OR], 24.9; 95% confidence interval [CI], 9.3-66.7) and surgical site infections (OR, 8.4; 95% CI, 2.6-27.7; P < 0.01 for each). No patient-related factors were associated with the development of CSFL. Previous surgery at the index level correlated significantly with the occurrence of postoperative CSFL (OR, 2.76; 95% CI, 1.1-6.8; P = 0.03) on multivariate analysis. Furthermore, patients with intradural tumors tended to have a greater risk of CSFL (OR, 2.3; 95% CI, 0.9-5.8; P = 0.07). Surgery-related factors did not influence the occurrence of CSFL. Surgery on the thoracic spine had resulted in a significantly lower postoperative CSFL rate compared with surgery on the cervical or lumbar spine (OR, -2.5; 95% CI, 1.3-4.9; P = 0.02). CONCLUSIONS: Our study found no modifiable risk factors for preventing CSFL after intradural spine surgery. Patients with previous surgery at the index level had a greater risk of CSFL. The occurrence of CSFL resulted in significantly more wound healing disorders and surgical site infections, necessitating further therapy.

Current state of social media utilization in neurosurgery amongst European Association of Neurosurgical Societies (EANS) member countries.

BACKGROUND: Social Media (SoMe) is becoming increasingly used in the medical community, and its use has been related with academic productivity. However, utilization of SoMe in the European neurosurgical community has not been assessed systematically. METHODS: An online search was undertaken to discover SoMe accounts of (1) national and related neurosurgical societies listed on the EANS website, (2) neurosurgical journals present on EANS website, (3) neurosurgery centers within EANS member countries, as listed on their website. SoMe accounts of Facebook, Twitter, YouTube, and Instagram were searched for journals and societies, and Twitter, Instagram, and Facebook for neurosurgery departments. The number of likes/followers/subscribers was recorded. RESULTS: Five (31%) neurosurgery journals had a SoMe presence. The highest number of followers, likes, and tweets was found for JNNP, and Journal of Neurological Surgery Part B had the most subscribers and video views. SoMe usage was identified for 11 national (28.2%) and 2 multi-national neurosurgical societies. From these, the French Society of Neurosurgery had the largest number of Facebook followers (> 2800) and Likes (> 2700), the Society of British Neurological Surgeons had the largest number of Twitter followers (> 2850), whereas EANS overall had the most followers on Twitter > 5100 and Facebook > 5450. A total of 87 SoMe neurosurgery center accounts were found on either Facebook, Instagram or Twitter, for 64 of 1000 centers (6.4%) in 22 of 40 different countries (55%). Of these 67% (n = 43/64) arose from 6 countries (England, Germany, Italy, Romania, Turkey, Ukraine). There were more Facebook accounts (n = 42) than Instagram accounts (n = 23) or Twitter accounts (n = 22). CONCLUSION: SoMe use amongst neurosurgical societies and departments in Europe is very limited. From our perspective, explanations are lacking for the correlated numbers to the market shares of SoMe in the respective countries. Further research, including a survey, to follow up on this important topic should be undertaken among EANS members.

Absence of pontine perforators in vertebrobasilar dolichoectasia on ultra-high resolution cone-beam computed tomography.

BACKGROUND: Vertebrobasilar dolichoectasia (VBDE) is a rare type of non-saccular intracranial aneurysm, with poor natural history and limited effective treatment options. Visualizing neurovascular microanatomy in patients with VBDE has not been previously reported, but may yield insight into the pathology, and provide important information for treatment planning. OBJECTIVE: To carry out a retrospective analysis of ultra-high resolution cone-beam computed tomography (UHR-CBCT) in patients with fusiform basilar aneurysms, visualizing neurovascular microanatomy of the posterior circulation with a special focus on the pontine perforators. METHODS: UHR-CBCT was performed in seven patients (mean age 59 years; two female) with a VBDE, and in 14 control patients with unrelated conditions. RESULTS: The mean maximum diameter of the fusiform vessel segment was 28 mm (range 19-36 mm), and the mean length of the segment was 39 mm (range 15-50 mm). In all patients with VBDE, UHR-CBCT demonstrated an absence of perforating arteries in the fusiform arterial segment and a mean of 3.7 perforators arising from the unaffected vessel segment. The network of interconnected superficial circumferential pontine arteries (brainstem vasocorona) were draping around the aneurysm sac. In controls, a mean of 3.6, 2.5, and 1.2 perforators were demonstrated arising from the distal, mid-, and proximal basilar artery, respectively. CONCLUSIONS: The absence of pontine perforators in the fusiform vessel segment of VBDE is counterbalanced by recruitment of collateral flow from pontine perforators arising from the unaffected segment of the basilar artery, as well as collaterals arising from the anterior inferior cerebellar artery/posterior inferior cerebellar artery and superior cerebellar artery. These alternative routes supply the superficial brainstem arteries (brainstem vasocorona) and sustain brainstem viability. Our findings might have implications for further treatment planning.

Somatosensory Evoked Potential and Transcranial Doppler Monitoring to Guide Shunting in Carotid Endarterectomy.

OBJECTIVE: Clamping of the internal carotid artery (ICA) during carotid endarterectomy (CEA) is a critical step. In our neurosurgical department, CEAs are performed with transcranial Doppler (TCD) and somatosensory evoked potential (SEP) monitoring with a 50% flow velocity/amplitude decrement warning criteria for shunting. The aim of our study was to evaluate our protocol with immediate neurologic deficits after surgery for the primary end point. METHODS: This is a single-center retrospective cohort study of symptomatic and asymptomatic ICA stenosis patients from January 2012 to June 2015. Only those cases in which CEA was performed with both modalities (TCD and SEP) were included. The Mann-Whitney U test was applied to evaluate TCD and SEP ratios based on immediate postoperative neurologic deficits. RESULTS: A total of 144 patients were included, 120 (83.3%) with symptomatic ICA stenosis. The primary end point was met by six patients (4.2%); all of them were patients with a symptomatic ICA stenosis. The stroke and death rate was 1.4%. Ratios of SEP amplitudes demonstrated significant differences between patients with and without an immediate postoperative neurologic deficit at the time of ICA clamping (p = 0.005), ICA clamping at 10 minutes (p = 0.044), and ICA reperfusion (p = 0.005). Ratios of TCD flow velocity showed no significant difference at all critical steps. CONCLUSION: In this retrospective series of simultaneous TCD and SEP monitoring during CEA surgery of predominantly symptomatic ICA stenosis patients, the stroke and death rate was 1.4%. SEP seemed to be superior to TCD in predicting the need for an intraoperative shunt and for predicting temporary postoperative deficits. Further prospective studies are needed.

Exploring Novel Funding Strategies for Innovative Medical Research: The HORAO Crowdfunding Campaign.

BACKGROUND: The rise of the internet and social media has boosted online crowdfunding as a novel strategy to raise funds for kick-starting projects, but it is rarely used in science. OBJECTIVE: We report on an online crowdfunding campaign launched in the context of the neuroscience project HORAO. The aim of HORAO was to develop a noninvasive real-time method to visualize neuronal fiber tracts during brain surgery in order to better delineate tumors and to identify crucial cerebral landmarks. The revenue from the crowdfunding campaign was to be used to sponsor a crowdsourcing campaign for the HORAO project. METHODS: We ran a 7-week reward-based crowdfunding campaign on a national crowdfunding platform, offering optional material and experiential rewards in return for a contribution toward raising our target of Swiss francs (CHF) 50,000 in financial support (roughly equivalent to US $50,000 at the time of the campaign). We used various owned media (websites and social media), as well as earned media (press releases and news articles) to raise awareness about our project. RESULTS: The production of an explanatory video took 60 hours, and 31 posts were published on social media (Facebook, Instagram, and Twitter). The campaign raised a total of CHF 69,109. Approximately half of all donations came from donors who forwent a reward (CHF 28,786, 48.74%); the other half came from donors who chose experiential and material rewards in similar proportions (CHF 14,958, 25.33% and CHF 15,315.69, 25.93%, respectively). Of those with an identifiable relationship to the crowdfunding team, patients and their relatives contributed the largest sum (CHF 17,820, 30.17%), followed by friends and family (CHF 9288, 15.73%) and work colleagues (CHF 6028, 10.21%), while 43.89% of funds came from donors who were either anonymous or had an unknown relationship to the crowdfunding team. Patients and their relatives made the largest donations, with a median value of CHF 200 (IQR 90). CONCLUSIONS: Crowdfunding proved to be a successful strategy to fund a neuroscience project and to raise awareness of a specific clinical problem. Focusing on potential donors with a personal interest in the issue, such as patients and their relatives in our project, is likely to increase funding success. Compared with traditional grant applications, new skills are needed to explain medical challenges to the crowd through video messages and social media.

Visualization of White Matter Fiber Tracts of Brain Tissue Sections With Wide-Field Imaging Mueller Polarimetry.

Identification of white matter fiber tracts of the brain is crucial for delineating the tumor border during neurosurgery. A custom-built Mueller polarimeter was used in reflection configuration for the wide-field imaging of thick sections of fixed human brain and fresh calf brain. The maps of the azimuth of the fast optical axis of linear birefringent medium reconstructed from the experimental Mueller matrix images of the specimen by applying a non-linear data compression algorithm showed a strong correlation with the silver-stained sample histology image, which is the gold standard for ex-vivo brain fiber tract visualization. The polarimetric maps of fresh calf brain tissue demonstrated the same trends in the depolarization, the scalar retardance and the azimuth of the fast optical axis as seen in fixed human brain tissue. Thus, label-free imaging Mueller polarimetry shows promise as an efficient intra-operative modality for the visualization of healthy brain white matter fiber tracts, which could improve the accuracy of tumor border detection and, ultimately, patient outcomes.

Indocyanine green videoangiography for recipient vessel stratification in superficial temporal artery-middle cerebral artery bypass surgery.

OBJECTIVE: In superficial temporal artery-middle cerebral artery (STA-MCA) bypass surgery, recipient vessel properties are likely one of the main reasons for bypass failure. In daily practice, most surgeons select the recipient with the largest diameter. However, selection of the ideal recipient remains debatable because there are no objective selection criteria if multiple potential recipients exist. Here, the authors assessed the benefit of using indocyanine green videoangiography (ICG-VA) to optimize recipient vessel selection in patients undergoing STA-MCA bypass surgery for hemodynamic compromise. METHODS: All patients who had undergone STA-MCA bypass procedures with pre- and postanastomosis ICG-VA between 2010 and 2019 were eligible for inclusion in this study. The primary bypass surgeon was blinded to the preanastomosis ICG-VA. Preanastomosis white-light and ICG-VA images were compared to determine the identifiability of potential recipient vessels and pathological flow patterns. After completion of the anastomosis, a second (postanastomosis) ICG-VA image was used to analyze the flow increase within the chosen recipient based on the vessel diameter, initial recipient blood flow, initial sequence of appearance on ICG-VA, initial blood flow direction within the recipient, and orientation of the bypass graft. ICG-VA, FLOW 800, and intraoperative white-light images, as well as demographic, clinical, and radiographic patient data, were retrospectively analyzed by a clinician who was not directly involved in the patients' care. RESULTS: Sixty patients underwent 65 STA-MCA bypass procedures with pre- and postanastomosis ICG-VA. The ICG-VA permitted identification of a significantly higher number of potential recipient vessels (median 4, range 1-9) than the white-light images (median 2, range 1-5; p < 0.001), with detection of pathological flow patterns in 20% of all procedures. No association was found between the diameter and blood flow within potential recipients (Spearman r = 0.07, p = 0.69). After bypass grafting, the highest flow increase was noted in recipients with an initially low flow (p < 0.01), a late appearance (p < 0.01), and an initially retrograde flow direction (p = 0.02). Interestingly, flow increase was not significantly influenced by the recipient diameter (p = 0.09) or graft orientation (p = 0.44). CONCLUSIONS: ICG-VA facilitates identification of potential recipient vessels and detection of pathological flow patterns. Recipients with an initially low flow, a late appearance, and a retrograde flow seem to bear the highest potential for flow increase, possibly due to a higher hemodynamic need for revascularization.

Augmented Reality in Superficial Temporal Artery to Middle Cerebral Artery Bypass Surgery: Technical Note.

BACKGROUND: Augmented reality (AR) applied to surgery refers to the virtual superimposition of computer-generated anatomical information on the surgical field. AR assistance in extracranial-intracranial (EC-IC) bypass revascularization surgery has been reported to be a helpful technical adjunct. OBJECTIVE: To describe our experience of using AR in superficial temporal artery to middle cerebral artery (STA-MCA) bypass surgery with the additional implementation of new technical processes to improve the safety and efficacy of the procedure. METHODS: Data sets from preoperative imaging were loaded and fused in a single 3-dimensional matrix using the neuronavigation system. Anatomical structures of interest (the STA, a selected M4 branch of the MCA, the middle meningeal artery [MMA], and the primary motor cortex [PMC]) were segmented. After the registration of the patient and the operating microscope, the structures of interest were projected into the eyepiece of the microscope and superimposed onto the patient's head, creating the AR surgical field. RESULTS: AR was shown to be useful in patients undergoing EC-IC bypass revascularization, mostly during the following 4 surgical steps: (1) microsurgical dissection of the donor vessel (STA); (2) tailoring the craniotomy above the recipient vessel (M4 branch of the MCA); (3) tailoring the craniotomy to spare the MMA; and (4) tailoring the craniotomy and the anastomosis to spare the PMC. CONCLUSION: AR assistance in EC-IC bypass revascularization is a versatile technical adjunct for helping surgeons to ensure the safety and efficacy of the procedure.

Surgical workflow for fully navigated high sacral amputation in sacral chordoma.

The method of choice for treatment of sacral chordomas is en bloc tumor removal via sacrectomy or sacral amputation in varying degrees depending on the initial tumor extent. Besides local tumor control, the preservation of neurological function is equally important to minimize postoperative bladder and bowel dysfunction. Removal of sacral tumors is complicated by the complex regional anatomy of the pelvis and the surrounding visceral and retroperitoneal structures. We aim to describe the surgical workflow for a fully navigated high sacral amputation facilitated by integration of an intraoperative computed tomography (iCT)-based spinal navigation system. An iCT-based spinal navigation system (AIRO® CT scanner, Brainlab AG, Feldkirchen, Germany) was used to perform intraoperative navigation with an image-guidance system and infrared tracking camera (BrainLab CurveTM, Brainlab AG, Feldkirchen, Germany) in combination with the spinal navigation set by Brainlab (Brainlab AG, Feldkirchen, Germany) to perform a fully navigated high sacral amputation. We demonstrate the successful implementation of iCT-based spinal navigation during high sacral amputation and the key advantages of this technique throughout the surgery. iCT-based spinal navigation is a useful complementing technique for en bloc high sacral amputations that renders the surgery safer and more accurate.