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.

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.

Quality of life in patients with unruptured intracranial aneurysms treated conservatively, before and after occlusion. A single center cohort study

Introduction

Rupture of intracranial aneurysms is the most frequent cause of subarachnoid hemorrhage and is associated with high morbidity. Recommendations for preventive treatment of unruptured aneurysms (UIAs) remain controversial due to inconsistent data on their natural history and the risks associated with treatment. The awareness of being diagnosed with one or more UIAs can provoke feelings of anxiety and psychosocial distress. Therefore, the impact of management on a patients' health perception and quality of life (QoL) is an essential factor to be considered in the treatment decision-making process.

Objective

The aim of this study was to assess and compare QoL in patients diagnosed with one or more UIAs depending on their treatment as well as their pre- or postoperative status.

Material and methods

Demographic and clinical data as well as results of the 15D quality of life (15D QoL) questionnaire of 189 patients were prospectively collected and retrospectively analyzed. Patients were categorized into different subgroups, depending on their treatment modalities (conservative, microsurgery or endovascular treatment) and their pre- or postoperative status at the time of completion of the questionnaire. Statistical analysis was performed to compare the different subgroups.

Results

Conservatively treated patients had similar mean 15D QoL scores as preoperative patients. Despite an initial postoperative QoL reduction and a trend towards recovery and even an improvement of QoL in the long term after UIA occlusion, neither clinically relevant nor statistically significant differences between preoperative and postoperative mean 15D QoL scores were observed.

Conclusions

Health-related QoL does not significantly change after treatment of UIAs when compared to the preoperative period. Further studies are needed to confirm long-term postoperative quality of life changes as well as treatment-related influencing factors on patients' quality of life.

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.

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.

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.

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.

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.

Phase I-II Study of Prone Hypofractionated Accelerated Breast and Nodal Intensity Modulated Radiation Therapy

PURPOSE/OBJECTIVE(S)

In patients (pts) with breast cancer, prone radiation therapy (RT) has been shown to reduce heart and lung dose which may decrease late toxicity. Routinely used for whole breast irradiation, its use to treat regional lymph nodes (LNs) is not widespread.

MATERIALS/METHODS

In this phase I-II study, pts treated with partial mastectomy or mastectomy with 1-5 pathologically involved LNs underwent whole breast or post-mastectomy RT plus regional nodal irradiation using IMRT to the supraclavicular and level III axillary LNs. Pts who underwent sentinel LN biopsy (SLNB) alone (no axillary dissection) had the level I and II axillary LNs included in the RT field. 40.5Gy in 15 daily 2.7Gy fractions with daily concomitant 0.5Gy tumor bed boost was prescribed. Normal tissue dose constraints included heart V5Gy<5%, ipsilateral lung V10Gy<20%, contralateral lung V5Gy<15%, ipsilateral brachial plexus (BP) maximal dose (Dmax)<43Gy, spinal cord Dmax≤37.5Gy, spinal cord + 0.5cm Dmax<41Gy, thyroid contralateral lobe Dmax<16Gy, esophagus V30Gy<50% and Dmax≤40.5Gy. The primary endpoints were dosimetric feasibility and incidence of >grade 2 acute toxicity according to CTCAE, v3.0. The secondary endpoint was late toxicity. Exploratory outcomes were local recurrence, disease free survival (DFS), and overall survival (OS).

RESULTS

Between January 2011 to December 2016, 97 pts with stage IB-IIA breast cancer were enrolled. 66 pts underwent partial mastectomy and 31 pts underwent mastectomy. 16 pts had SLNB alone. 33% (95% CI: 23.8%, 43.3%) met all protocol dose constraints. Heart, contralateral lung, spinal cord and esophagus V30Gy constraints were met by all pts. The ipsilateral lung constraint was met in 95% (95% CI: 88.6%, 98.4%) of plans with a mean V10Gy of 9.44% (SD: 6.08). The BP Dmax constraint was exceeded in 31.6% (95% CI: 22.4%, 41.9%) of plans with a mean increase of 2.86 Gy (SD: 7.92 Gy) over target. The esophageal Dmax<40.5Gy constraint was exceeded in 6 plans with an increase in 0.74 Gy (SD: 0.46 Gy) over target. There were no grade 3 acute toxicities meeting the primary toxicity endpoint. Common acute low-grade toxicities by pt included fatigue (grade 1: 54 [56%]; grade 2: 2 [2%]), esophagitis (grade 1: 8 [8%]; grade 2: 2 [2%]), dermatitis (grade 1: 81 [84%]; grade 2: 6 [6%]). At median and maximum follow up of 8.02 (IQR: 3.31) and 13.3 years, respectively, there were 2 local recurrences (2.1%). DFS and OS were 86.6% (95% CI: 78.2%, 92.7%) and 90.7% (95% CI: 83.1%, 95.7%), respectively. The incidence of pts with maximum grade 1, 2 and 3 late toxicities were 39 (40%), 14 (14%), and 2 (2%), respectively. The maximum grade late toxicities included 1 grade 3 retraction and 2 grade 3 asymmetries. There was no brachial plexopathy or pneumonitis.

CONCLUSION

Patients treated with prone hypofractionated hybrid breast/chest wall tangents and IMRT to the regional LNs demonstrate excellent dosimetry to the heart, lungs and spinal cord, minimal acute and late toxicity and excellent clinical outcomes. PMID: 26723552.

Characterization of Objective Skin Color Changes during and after Breast and Chest Wall Radiotherapy and Correlation with Radiation-Induced Skin Toxicity in Breast Cancer Patients, Including Patients with Skin of Color

PURPOSE/OBJECTIVE(S)

Radiation dermatitis (RD) is common among women undergoing breast and chest wall radiotherapy (RT); however, existing scales to assess the severity of RD are subjective and do not account for variability in skin of color (SOC). For instance, the Common Terminology Criteria for Adverse Events (CTCAE) criteria do not include hyperpigmentation in the grading scale. There is data indicating worse RD in African American and Hispanic patients; however, the rate and severity in SOC remains unknown given the lack of data using objective measures of RD. Spectrophotometry is one method to quantify the appearance of color by measuring spectral characteristics without the bias associated with subjective clinical scoring. We present a phase I prospective non-therapeutic clinical trial to objectively define SOC at baseline and evaluate spectrophotometric skin changes during and after breast or chest wall RT in parallel with physician-graded RD using CTCAE criteria. We hypothesize that there will be greater discrepancy between physician graded RD and objective measures of RD in patients with SOC in whom hyperpigmentation will be undercaptured by physician-grading. This is the first study intending to correlate SOC with objective changes after RT as a reliable indicator of RD. We offer a novel system for evaluating RD that is applicable to SOC.

MATERIALS/METHODS

A total of 60 patients with localized breast cancer (stage 0-III) undergoing conventional whole breast or chest wall RT (50Gy/ 25 fx), hypofractionated whole breast RT (40.5Gy/15 fx) or ultrahypofractionated partial breast RT (6Gy x5), with or without regional nodal RT were enrolled. 3 skin color readouts using the Commission International de l'Eclairage 3D color system (l*, a*, b*) were measured within the radiation field using a spectrophotometer at baseline, once weekly during RT, 10 days post RT, 4 weeks and 12 months post RT. The spectrophotometer is a non-invasive, hand-held device that is used in the clinic room with no additional equipment or setup requirements. Data is automatically exported to a spreadsheet organized by timepoint and patient. The l* axis is a gray scale (0 = black, 100 = white) correlating with skin pigmentation and the a* axis describes red and green values correlating with erythema. The primary objective is to evaluate the changes from baseline in skin color readouts in the quadrant of tumor location during and after RT based on fractionation. The secondary objective is to evaluate changes within and across groups defined by baseline skin color. Exploratory objectives include evaluating the association of baseline color readouts and changes after RT with acute and late grade > 2 clinician-rated skin and subcutaneous tissue effects according to the CTCAE, v5.0, physician graded cosmesis and clinical interventions to treat RD, such as use of topical steroids and oral analgesics. As of January 2023, we have enrolled 100% of the planned patients.

RESULTS

To be determined.

CONCLUSION

To be determined. Clinical Study Identifier: S22-00192.

A Phase II, Randomized, Double Blind, Placebo Controlled Study of the Safety and Efficacy of a Caffeine-Based Antifibrosis Cream in Patients with Breast Cancer Undergoing Radiation Therapy

PURPOSE/OBJECTIVE(S)

Radiation induced fibrosis (RIF) is a common long term adverse event in patients undergoing post-mastectomy radiation therapy (PMRT) which can cause capsular contracture, implant loss, and reconstruction complications in women with implant-based breast reconstruction. At a molecular level, adenosine is a driver of RIF. Preclinical data have shown that pharmacologic blockade of the adenosine A2A Receptor (A2AR) in mice as well as an A2AR knockout mouse model prevented skin fibrosis associated with radiation injury. Caffeine is an A2AR antagonist which has been shown to block the development of hepatic fibrosis in liver disease patients. We present a phase II placebo controlled clinical trial to evaluate whether a caffeine-based cream can prevent RIF and thus reduce the rates of reconstructive complications in patients with tissue expander-based reconstruction requiring PMRT.

MATERIALS/METHODS

Women ≥ 18 years old with breast carcinoma stage 0-III status post mastectomy with tissue expander-based reconstruction who require PMRT to the chest wall +/- the regional nodes are being enrolled. The target accrual is 60 patients. Boost field to the chest wall, scar and/or nodal region is allowed. Patients with inflammatory breast cancer or those requiring skin bolus are excluded. Prior to starting radiation, patients will be randomized to placebo vs. caffeine cream and they will be instructed to apply the cream twice a day starting on the first day of radiation treatment and continuing daily for the duration of radiation until the removal of tissue expanders. The primary study endpoint is reconstructive complications requiring rehospitalization or reoperation by 2 years post radiation including reconstructive failure with or without reconstruction. A safety endpoint of grade ≥ 2 acute radiation dermatitis will also serve as a co-primary endpoint. Secondary endpoints are wound infection/cellulitis, hematoma, seroma, threatened exposure, wound dehiscence, implant leakage, rupture, and or deflation, and capsular contracture that do not meet criteria for the primary endpoint. Clinician rated cosmesis, local recurrence, regional recurrence, distant metastasis and survival up to 4 years are additional secondary endpoints. Exploratory endpoint includes the use of shear wave elastography (SWE) as a potential tool to quantitatively measure post irradiation fibrosis. Correlative aims include assessing epidermal thickness and fat layer thickness from tissue obtained at time of implant exchange for association with the development of fibrosis. The primary efficacy endpoint will be estimated using Kaplan Meier methods from date of randomization. Treatment comparisons will be based on a 2-sided log rank chi-square test and the hazard ratio will be estimated with 95% confidence intervals. The study started accruing in 12/2019 and is estimated to end by 04/2024. As of January 2023, 67% (40/60 patients) of the planned patients have been enrolled.

RESULTS

To be determined.

CONCLUSION

To be determined.

Benefit of Advanced 3D DSA and MRI/CT Fusion in Neurovascular Pathology

Digital subtraction angiography provides excellent spatial and temporal resolution; however, it lacks the capability to depict the nonvascular anatomy of the brain and spinal cord.A review of the institutional database identified five patients in whom a new integrated fusion workflow of cross-sectional imaging and 3D rotational angiography (3DRA) provided important diagnostic information and assisted in treatment planning. These included two acutely ruptured brain arteriovenous malformations (AVM), a small superficial brainstem AVM after radiosurgery, a thalamic microaneurysm, and a spine AVM, and fusion was crucial for diagnosis and influenced further treatment.Fusion of 3DRA and cross-sectional imaging may help to gain a deeper understanding of neurovascular diseases. This is advantageous for planning and providing treatment and, most importantly, may harbor the potential to minimize complication rates. Integrating image fusion in the work-up of cerebrovascular diseases is likely to have a major impact on the neurovascular field in the future.

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.

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%).

CONCLUSION

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.

Successful weaning versus permanent cerebrospinal fluid diversion after aneurysmal subarachnoid hemorrhage: post hoc analysis of a Swiss multicenter study

OBJECTIVE

Acute hydrocephalus is a frequent complication after aneurysmal subarachnoid hemorrhage (aSAH). Among patients needing CSF diversion, some cannot be weaned. Little is known about the comparative neurological, neuropsychological, and health-related quality-of-life (HRQOL) outcomes in patients with successful and unsuccessful CSF weaning. The authors aimed to assess outcomes of patients by comparing those with successful and unsuccessful CSF weaning; the latter was defined as occurring in patients with permanent CSF diversion at 3 months post-aSAH.

METHODS

The authors included prospectively recruited alert (i.e., Glasgow Coma Scale score 13-15) patients with aSAH in this retrospective study from six Swiss neurovascular centers. Patients underwent serial neurological (National Institutes of Health Stroke Scale), neuropsychological (Montreal Cognitive Assessment), disability (modified Rankin Scale), and HRQOL (EuroQol-5D) examinations at < 72 hours, 14-28 days, and 3 months post-aSAH.

RESULTS

Of 126 included patients, 54 (42.9%) developed acute hydrocephalus needing CSF diversion, of whom 37 (68.5%) could be successfully weaned and 17 (31.5%) required permanent CSF diversion. Patients with unsuccessful weaning were older (64.5 vs 50.8 years, p = 0.003) and had a higher rate of intraventricular hemorrhage (52.9% vs 24.3%, p = 0.04). Patients who succeed in restoration of physiological CSF dynamics improve on average by 2 points on the Montreal Cognitive Assessment between 48-72 hours and 14-28 days, whereas those in whom weaning fails worsen by 4 points (adjusted coefficient 6.80, 95% CI 1.57-12.04, p = 0.01). They show better neuropsychological recovery between 48-72 hours and 3 months, compared to patients in whom weaning fails (adjusted coefficient 7.60, 95% CI 3.09-12.11, p = 0.02). Patients who receive permanent CSF diversion (ventriculoperitoneal shunt) show significant neuropsychological improvement thereafter, catching up the delay in neuropsychological improvement between 14-28 days and 3 months post-aSAH. Neurological, disability, and HRQOL outcomes at 3 months were similar.

CONCLUSIONS

These results show a temporary but clinically meaningful cognitive benefit in the first weeks after aSAH in successfully weaned patients. The resolution of this difference over time may be due to the positive effects of permanent CSF diversion and underlines its importance. Patients who do not show progressive neuropsychological improvement after weaning should be considered for repeat CT imaging to rule out chronic (untreated) hydrocephalus.

Impact of Very Small Aneurysm Size and Anterior Communicating Segment Location on Outcome after Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Very small anterior communicating artery aneurysms (vsACoA) of <5 mm in size are detected in a considerable number of patients with aneurysmal subarachnoid hemorrhage (aSAH). Single-center studies report that vsACoA harbor particular risks when treated.

OBJECTIVE

To assess the clinical and radiological outcome(s) of patients with aSAH diagnosed with vsACoA after aneurysm treatment and at discharge.

METHODS

Information on n = 1868 patients was collected in the Swiss Subarachnoid Hemorrhage Outcome Study registry between 2009 and 2014. The presence of a new focal neurological deficit at discharge, functional status (modified Rankin scale), mortality rates, and procedural complications (in-hospital rebleeding and presence of a new stroke on computed tomography) was assessed for vsACoA and compared with the results observed for aneurysms in other locations and with diameters of 5 to 25 mm.

RESULTS

This study analyzed n = 1258 patients with aSAH, n = 439 of which had a documented ruptured ACoA. ACoA location was found in 38% (n = 144/384) of all very small ruptured aneurysms. A higher in-hospital bleeding rate was found in vsACoA compared with non-ACoA locations (2.8 vs 2.1%), especially when endovascularly treated (2.1% vs 0.5%). In multivariate analysis, aneurysm size of 5 to 25 mm, and not ACoA location, was an independent risk factor for a new focal neurological deficit and a higher modified Rankin scale at discharge. Neither very small aneurysm size nor ACoA location was associated with higher mortality rates at discharge or the occurrence of a peri-interventional stroke.

CONCLUSION

Very small ruptured ACoA have a higher in-hospital rebleeding rate but are not associated with worse morbidity or mortality.

Quality of Life After Poor-Grade Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Poor-grade aneurysmal subarachnoid hemorrhage (aSAH) is associated with high mortality and poor disability outcome. Data on quality of life (QoL) among survivors are scarce because patients with poor-grade aSAH are underrepresented in clinical studies reporting on QoL after aSAH.

OBJECTIVE

To provide prospective QoL data on survivors of poor-grade aSAH to aid clinical decision making and counseling of relatives.

METHODS

The herniation World Federation of Neurosurgical Societies scale study was a prospective observational multicenter study in patients with poor-grade (World Federation of Neurosurgical Societies grades 4 & 5) aSAH. We collected data during a structured telephone interview 6 and 12 months after ictus. QoL was measured using the EuroQoL - 5 Dimensions - 3 Levels (EQ-5D-3L) questionnaire, with 0 representing a health state equivalent to death and 1 to perfect health. Disability outcome for favorable and unfavorable outcomes was measured with the modified Rankin Scale.

RESULTS

Two hundred-fifty patients were enrolled, of whom 237 were included in the analysis after 6 months and 223 after 12 months. After 6 months, 118 (49.8%) patients were alive, and after 12 months, 104 (46.6%) patients were alive. Of those, 95 (80.5%) and 89 (85.6%) reached a favorable outcome with mean EQ-5D-3L index values of 0.85 (±0.18) and 0.86 (±0.18). After 6 and 12 months, 23 (19.5%) and 15 (14.4%) of those alive had an unfavorable outcome with mean EQ-5D-3L index values of 0.27 (±0.25) and 0.19 (±0.14).

CONCLUSION

Despite high initial mortality, the proportion of poor-grade aSAH survivors with good QoL is reasonably large. Only a minority of survivors reports poor QoL and requires permanent care.

Right ventricular and left ventricular diameters are independent predictors of death or cardiopulmonary resuscitation in intermediate and high-risk pulmonary embolisms

Background

Increased right ventricular (RV) dilation measured by the ratio of RV diameter (RVD) to left ventricular (LV) diameter (LVD) (RV:LV) is associated with pulmonary embolism (PE) severity and mortality. Data regarding the individual contributions of RVD and LVD are limited.

Purpose

To examine RVD and LVD as independent contributors to death or need for cardiopulmonary resuscitation (CPR) in intermediate- or high-risk PEs treated with surgical or catheter-based strategies

Methods

We measured basal RVD and LVD on presenting transthoracic echocardiograms (TTE) using the diastolic 4-chamber view on 127 PEs managed with surgical embolectomy (n=95, 75%), extracorporeal membrane oxygenation (n=23, 18%), or catheter-directed embolectomy (n=9, 7%) for intermediate- (64%) or high-risk (36%) PE (based on European Society of Cardiology criteria) between 2005 and 2022. The primary outcome was the composite of death (n=2) or survivors requiring CPR (n=10).

Results

A total of 127 patients were analyzed. Subjects were 57±14 years, 38% women, BMI 34±8. Mean RVD and LVD were 4.4±0.9 cm and 3.9±0.8 cm respectively. All presented with severe RV dysfunction on TTE and elevated cardiac biomarkers (Troponin-I or B-type natriuretic peptide). Mean RV:LV was 1.2±0.3 (range 0.7 to 2.8). Using logistic regression, higher RV:LV was associated with increased odds of death or CPR (odds ratio (OR) 15 [95% confidence interval (CI): 2.5, 82] per 1-unit increase, p=0.002. RV:LV &gt;1.2 was the cutoff most associated with death or CPR, OR 7.2 [95% CI: 1.5, 34.5], p=0.01. Increasing RVD [OR 3.8 (95% CI: 1.1, 12.8), p=0.03] and decreasing LVD [OR 4.9 (95% CI: 1.3, 16.9), p=0.02] were independent predictors of death or CPR. RVD &gt;5.0 cm (OR 5.9 [95% CI: 1,5, 23.2], p 0.01) and LVD &lt;3.6 cm (OR 7.0 [95% CI: 1.7, 27.9], p=0.006) were the cutoff values most associated with the primary outcome. These cutoff values remained significant predictors even after adjustment for body surface area. Other parameters or RV size and function (diastolic area, systolic area and fractional area change) did not predict death or CPR. All of the subjects meeting the primary outcome had high-risk PE.

Discussion

In addition to RV:LV greater than 1.2, RVD and LVD were independently associated with death or CPR among high- or intermediate risk PEs. The independent contribution of declining LVD on PE mortality is a novel finding and highlights PE associatient LV pathophysiology (hyperdynamic and underfilled) antecedent to hemodynamic collapse. PE literature focuses on RV dilation as a predictor of PE mortality. LVD may represent a useful measure to risk stratify PE patients and predict hemodynamic decompensation.

Funding Acknowledgement

Type of funding sources: None.

Exploring Novel Innovation Strategies to Close a Technology Gap in Neurosurgery: The HORAO Crowdsourcing Campaign (Preprint)

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.

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.

Longitudinal neuropsychological assessment after aneurysmal subarachnoid hemorrhage and its relationship with delayed cerebral ischemia: a prospective Swiss multicenter study

OBJECTIVE

While prior retrospective studies have suggested that delayed cerebral ischemia (DCI) is a predictor of neuropsychological deficits after aneurysmal subarachnoid hemorrhage (aSAH), all studies to date have shown a high risk of bias. This study was designed to determine the impact of DCI on the longitudinal neuropsychological outcome after aSAH, and importantly, it includes a baseline examination after aSAH but before DCI onset to reduce the risk of bias.

METHODS

In a prospective, multicenter study (8 Swiss centers), 112 consecutive alert patients underwent serial neuropsychological assessments (Montreal Cognitive Assessment [MoCA]) before and after the DCI period (first assessment, < 72 hours after aSAH; second, 14 days after aSAH; third, 3 months after aSAH). The authors compared standardized MoCA scores and determined the likelihood for a clinically meaningful decline of ≥ 2 points from baseline in patients with DCI versus those without.

RESULTS

The authors screened 519 patients, enrolled 128, and obtained complete data in 112 (87.5%; mean [± SD] age 53.9 ± 13.9 years; 66.1% female; 73% World Federation of Neurosurgical Societies [WFNS] grade I, 17% WFNS grade II, 10% WFNS grades III-V), of whom 30 (26.8%) developed DCI. MoCA z-scores were worse in the DCI group at baseline (-2.6 vs -1.4, p = 0.013) and 14 days (-3.4 vs -0.9, p < 0.001), and 3 months (-0.8 vs 0.0, p = 0.037) after aSAH. Patients with DCI were more likely to experience a decline of ≥ 2 points in MoCA score at 14 days after aSAH (adjusted OR [aOR] 3.02, 95% CI 1.07-8.54; p = 0.037), but the likelihood was similar to that in patients without DCI at 3 months after aSAH (aOR 1.58, 95% CI 0.28-8.89; p = 0.606).

CONCLUSIONS

Aneurysmal SAH patients experiencing DCI have worse neuropsychological function before and until 3 months after the DCI period. DCI itself is responsible for a temporary and clinically meaningful decline in neuropsychological function, but its effect on the MoCA score could not be measured at the time of the 3-month follow-up in patients with low-grade aSAH with little or no impairment of consciousness. Whether these findings can be extrapolated to patients with high-grade aSAH remains unclear. Clinical trial registration no.: NCT03032471 (ClinicalTrials.gov).

Herniation World Federation of Neurosurgical Societies Scale Improves Prediction of Outcome in Patients With Poor-Grade Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Favorable outcomes are seen in up to 50% of patients with World Federation of Neurosurgical Societies (WFNS) grade V aneurysmal subarachnoid hemorrhage. Therefore, the usefulness of the current WFNS grading system for identifying the worst scenarios for clinical studies and for making treatment decisions is limited. We previously modified the WFNS scale by requiring positive signs of brain stem dysfunction to assign grade V. This study aimed to validate the new herniation WFNS grading system in an independent prospective cohort.

METHODS

We conducted an international prospective multicentre study in poor-grade aneurysmal subarachnoid hemorrhage patients comparing the WFNS classification with a modified version-the herniation WFNS scale (hWFNS). Here, only patients who showed positive signs of brain stem dysfunction (posturing, anisocoric, or bilateral dilated pupils) were assigned hWFNS grade V. Outcome was assessed by modified Rankin Scale score 6 months after hemorrhage. The primary end point was the difference in specificity of the WFNS and hWFNS grading with respect to poor outcomes (modified Rankin Scale score 4-6).

RESULTS

Of the 250 patients included, 237 reached the primary end point. Comparing the WFNS and hWFNS scale after neurological resuscitation, the specificity to predict poor outcome increased from 0.19 (WFNS) to 0.93 (hWFNS) (McNemar, P<0.001) whereas the sensitivity decreased from 0.88 to 0.37 (P<0.001), and the positive predictive value from 61.9 to 88.3 (weighted generalized score statistic, P<0.001). For mortality, the specificity increased from 0.19 to 0.93 (McNemar, P<0.001), and the positive predictive value from 52.5 to 86.7 (weighted generalized score statistic, P<0.001).

CONCLUSIONS

The identification of objective positive signs of brain stem dysfunction significantly improves the specificity and positive predictive value with respect to poor outcome in grade V patients. Therefore, a simple modification-presence of brain stem signs is required for grade V-should be added to the WFNS classification.

REGISTRATION

URL: https://clinicaltrials.gov; Unique identifier: NCT02304328.

Spontaneous Intracranial Hypotension Without CSF Leakage-Concept of a Pathological Cranial to Spinal Fluid Shift

Objective: Spontaneous intracranial hypotension (SIH) is typically caused by CSF leakage from a spinal dural tear, a meningeal diverticulum, or a CSF venous fistula. However, some patients present with classic orthostatic symptoms and typical intracranial imaging findings without evidence of CSF leakage despite repeated diagnostic work-up. This article aims to elaborate a hypothesis that would explain a pathologically increased orthostatic shift of CSF from the cranial to the spinal compartment in the absence of a CSF leak.

Medical Hypothesis: The symptoms of SIH are caused by a decrease in intracranial CSF volume, intracranial hypotension, and downward displacement of intracranial structures. A combination of pathologically increased spinal compliance, decreased intracranial CSF volume, low CSF outflow resistance, and decreased venous pressure might result in a pathological orthostatic cranial-to-spinal CSF shift. Thus, in rare cases, intracranial hypotension may occur in the absence of CSF leakage from the dural sac.

Conclusion: We propose a pathophysiological concept for the subgroup of SIH patients with typical cranial imaging findings and no evidence of CSF leakage. In these patients, reducing the compliance or the volume of the spinal compartment seems to be the appropriate therapeutic strategy.

Anesthesia modality does not affect clinical outcomes of intra-arterial vasodilator treatment in patients with symptomatic cerebral vasospasms

Background: Delayed cerebral ischemia and cerebral vasospasm remain the leading causes of poor outcome in survivors of aneurysmal subarachnoid hemorrhage. Refractory cerebral vasospasms can be treated with endovascular vasodilator therapy, which can either be performed in conscious sedation or general anesthesia. The aim of this study is to compare the effect of the anesthesia modality on long-term clinical outcomes in patients undergoing endovascular vasodilator therapy due to cerebral vasospasm and hypoperfusion.

Methods: Modified Rankin Scale (mRS) scores were retrospectively analyzed at time of discharge from the hospital and six months after aneurysmal subarachnoid hemorrhage. Additionally, National Institutes of Health Stroke Scale (NIHSS) was assessed 24 hours before, immediately before, immediately after, and 24 hours after endovascular vasodilator therapy, and at discharge and six months. Interventional parameters such as duration of intervention, choice and dosage of vasodilator and number of arteries treated were also recorded.

Results: A total of 98 patients were included in this analysis and separated into patients who had interventions in conscious sedation, general anesthesia and a mix of both. Neither mRS at discharge nor at six months showed a significant difference for functionally independent outcomes (mRS 0-2) between groups. NIHSS before endovascular vasodilator therapy was significantly higher in patients receiving interventions in general anesthesia but did not differ anymore between groups six months after the initial bleed.

Conclusion: This study did not observe a difference in outcome whether patients underwent endovascular vasodilator therapy in general anesthesia or conscious sedation for refractory cerebral vasospasms. Hence, the choice should be made for each patient individually.

OPERA tau neutrino charged current interactions

The OPERA experiment was designed to discover the vτ appearance in a vμ beam, due to neutrino oscillations. The detector, located in the underground Gran Sasso Laboratory, consisted of a nuclear photographic emulsion/lead target with a mass of about 1.25 kt, complemented by electronic detectors. It was exposed from 2008 to 2012 to the CNGS beam: an almost pure vμ beam with a baseline of 730 km, collecting a total of 1.8·1020 protons on target. The OPERA Collaboration eventually assessed the discovery of vμ→vτ oscillations with a statistical significance of 6.1 σ by observing ten vτ CC interaction candidates. These events have been published on the Open Data Portal at CERN. This paper provides a detailed description of the vτ data sample to make it usable by the whole community.

Development of a Complication- and Treatment-Aware Prediction Model for Favorable Functional Outcome in Aneurysmal Subarachnoid Hemorrhage Based on Machine Learning

BACKGROUND

Current prognostic tools in aneurysmal subarachnoid hemorrhage (aSAH) are constrained by being primarily based on patient and disease characteristics on admission.

OBJECTIVE

To develop and validate a complication- and treatment-aware outcome prediction tool in aSAH.

METHODS

This cohort study included data from an ongoing prospective nationwide multicenter registry on all aSAH patients in Switzerland (Swiss SOS [Swiss Study on aSAH]; 2009-2015). We trained supervised machine learning algorithms to predict a binary outcome at discharge (modified Rankin scale [mRS] ≤ 3: favorable; mRS 4-6: unfavorable). Clinical and radiological variables on admission ("Early" Model) as well as additional variables regarding secondary complications and disease management ("Late" Model) were used. Performance of both models was assessed by classification performance metrics on an out-of-sample test dataset.

RESULTS

Favorable functional outcome at discharge was observed in 1156 (62.0%) of 1866 patients. Both models scored a high accuracy of 75% to 76% on the test set. The "Late" outcome model outperformed the "Early" model with an area under the receiver operator characteristics curve (AUC) of 0.85 vs 0.79, corresponding to a specificity of 0.81 vs 0.70 and a sensitivity of 0.71 vs 0.79, respectively.

CONCLUSION

Both machine learning models show good discrimination and calibration confirmed on application to an internal test dataset of patients with a wide range of disease severity treated in different institutions within a nationwide registry. Our study indicates that the inclusion of variables reflecting the clinical course of the patient may lead to outcome predictions with superior predictive power compared to a model based on admission data only.

Education, Healthy Ageing and Vaccine Literacy

Importance and Objective: The Covid pandemic is a timely opportunity to try to broaden our understanding of the links between education and health literacy and explore the vaccine-decision process with a view to identifying interventions that will positively influence vaccine uptake.

EVIDENCE

Health and vaccine literacy encompass people's knowledge, motivation, and competence to access, understand, appraise and apply health information in order to make judgements and take decisions in everyday life concerning health care, disease prevention and health promotion.

FINDINGS

Appropriate vaccine communication, which depends greatly on personal and contextual determinants, as well as on societal and environmental circumstances, is essential to reassure people about vaccine efficacy, safety, and possible side effects. However, vaccine confidence is not solely a question of trust in the vaccine's efficacy, safety. and individual protective benefit of vaccination. It also encompasses the mechanism(s) of vaccine activity, immunization schedules, organization and trust in the healthcare system that promotes and delivers the vaccines, and at what costs. When healthcare professionals as science brokers of vaccine knowledge attempt to increase vaccine knowledge and confidence, they must adjust their communication to the educational or health literacy level of their intended audience. Even if their messages are apparently clear and simple, they absolutely need to verify that they are properly understood.

RELEVANCE

Specific vaccine communication training appears essential to increase vaccine communication skills among healthcare providers. Moreover, further randomized controlled studies are warranted to improve vaccine empowerment among different populations, from a variety of educational backgrounds.

Incidence and Outcome of Aneurysmal Subarachnoid Hemorrhage: The Swiss Study on Subarachnoid Hemorrhage (Swiss SOS)

BACKGROUND AND PURPOSE

The purpose of this study was to assess nationwide incidence and outcomes of aneurysmal subarachnoid hemorrhage (aSAH). The Swiss SOS (Swiss Study on Subarachnoid Hemorrhage) was established in 2008 and offers the unique opportunity to provide this data from the point of care on a nationwide level.

METHODS

All patients with confirmed aneurysmal subarachnoid hemorrhage admitted between January 1, 2009 and December 31, 2014, within Switzerland were recorded in a prospective registry. Incidence rates were calculated based on time-matched population data. Admission parameters and outcomes at discharge and at 1 year were recorded.

RESULTS

We recorded data of 1787 consecutive patients. The incidence of aneurysmal subarachnoid hemorrhage in Switzerland was 3.7 per 100 000 persons/y. The number of female patients was 1170 (65.5%). With a follow-up rate of 91.3% at 1 year, 1042 patients (58.8%) led an independent life according to the modified Rankin Scale (0-2). About 1 in 10 patients survived in a dependent state (modified Rankin Scale, 3-5; n=185; 10.4%). Case fatality was 20.1% (n=356) at discharge and 22.1% (n=391) after 1 year.

CONCLUSIONS

The current incidence of aneurysmal subarachnoid hemorrhage in Switzerland is lower than expected and an indication of a global trend toward decreasing admissions for ruptured intracranial aneurysms. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT03245866.

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.

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.

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.

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.