Effect of Aneurysm and Patient Characteristics on Intracranial Aneurysm Wall Thickness

Background: The circle of Willis is a network of arteries allowing blood supply to the brain. Bulging of these arteries leads to formation of intracranial aneurysm (IA). Subarachnoid hemorrhage (SAH) due to IA rupture is among the leading causes of disability in the western world. The formation and rupture of IAs is a complex pathological process not completely understood. In the present study, we have precisely measured aneurysmal wall thickness and its uniformity on histological sections and investigated for associations between IA wall thickness/uniformity and commonly admitted risk factors for IA rupture.Methods: Fifty-five aneurysm domes were obtained at the Geneva University Hospitals during microsurgery after clipping of the IA neck. Samples were embedded in paraffin, sectioned and stained with hematoxylin-eosin to measure IA wall thickness. The mean, minimum, and maximum wall thickness as well as thickness uniformity was measured for each IA. Clinical data related to IA characteristics (ruptured or unruptured, vascular location, maximum dome diameter, neck size, bottleneck factor, aspect and morphology), and patient characteristics [age, smoking, hypertension, sex, ethnicity, previous SAH, positive family history for IA/SAH, presence of multiple IAs and diagnosis of polycystic kidney disease (PKD)] were collected.Results: We found positive correlations between maximum dome diameter or neck size and IA wall thickness and thickness uniformity. PKD patients had thinner IA walls. No associations were found between smoking, hypertension, sex, IA multiplicity, rupture status or vascular location, and IA wall thickness. No correlation was found between patient age and IA wall thickness. The group of IAs with non-uniform wall thickness contained more ruptured IAs, women and patients harboring multiple IAs. Finally, PHASES and ELAPSS scores were positively correlated with higher IA wall heterogeneity.Conclusion: Among our patient and aneurysm characteristics of interest, maximum dome diameter, neck size and PKD were the three factors having the most significant impact on IA wall thickness and thickness uniformity. Moreover, wall thickness heterogeneity was more observed in ruptured IAs, in women and in patients with multiple IAs. Advanced medical imaging allowing in vivo measurement of IA wall thickness would certainly improve personalized management of the disease and patient care.

Microsurgical clipping of middle cerebral artery aneurysms: complications and risk factors for complications

Objective Middle cerebral artery aneurysms (MCAas) with rupture and unruptured IAs are considered good candidates for microsurgery. The objective of the present study was to evaluate the risk of complications and the risk factors for microsurgical treatment of MCAas to better define the indications for microsurgery. Methods We conducted a retrospective cohort study based on data provided from three French tertiary neurosurgical units from January 1, 2013 to May 31, 2020. We first collected data on all the patients who required microsurgical treatment for MCAas. We evaluated the frequency of complications and finally searched for the risk factors for complications after microsurgery. Complications were defined as a composite criterion with the presence of one of the following: procedural-related death, symptomatic cerebral ischemia, impossible exclusion, incomplete exclusion, or (re)bleeding of the treated aneurysm and symptomatic surgical site hematoma. We then compared patients with and without complications using univariate and multivariate analyses. Results Between January 2013 and May 2020, 292 MCAas in 284 patients were treated. A total of 29 (9.9%) MCAas had a complication. The complications were as follows: symptomatic cerebral ischemia: 4.8%, aneurysm rebleeding: 0.3%, surgical site hematoma: 1.0%, impossible exclusion: 0.3%, and incomplete exclusion: 4.1%. However, severe complications, defined as death or a modified Rankin score (mRs) score ≥4 at 3 months, were infrequent and occurred in 7/292 patients (2.4%). In the multivariate analysis, independent risk factors for complications were the following: a ruptured aneurysm, a larger maximum IA size, a larger neck size, and arterial branches passing less than <1 mm from the IA neck or dome. Conclusions MCAa surgery is a safe procedure with a low rate of serious procedure-related complications and an excellent rate of occlusion. The risk factors for complications are a ruptured aneurysm, a larger IA, a larger neck size, and the presence of an “en passage” arterial branch less than 1 mm from the IA. In these cases, at least for factors that do not present a significant difficulty for EVT, such as the presence of an “en passage” artery or ruptured IA, EVT has to be more thoroughly discussed.

Patient and aneurysm factors associated with aneurysm recanalization after coiling

BackgroundOne limitation of the endovascular treatment of intracranial aneurysms is aneurysm recanalization. The Analysis of Recanalization after Endovascular Treatment of intracranial Aneurysm (ARETA) study is a prospective multicenter cohort study evaluating the factors associated with recanalization after endovascular treatment.MethodsThe current analysis is focused on patients treated by coiling or balloon-assisted coiling (BAC). Postoperative, mid-term vascular imaging, and evolution of aneurysm occlusion were independently evaluated by two neuroradiologists. A 3-grade scale was used for aneurysm occlusion (complete occlusion, neck remnant, and aneurysm remnant) and for occlusion evolution (improved, stable, and worsened). Recanalization was defined as any worsening of aneurysm occlusion.ResultsBetween December 2013 and May 2015, 16 French neurointerventional departments enrolled 1289 patients. A total of 945 aneurysms in 908 patients were treated with coiling or BAC. The overall rate of aneurysm recanalization at mid-term follow-up was 29.5% (95% CI 26.6% to 32.4%): 28.9% and 30.3% in the coiling and BAC groups, respectively. In multivariate analyses factors independently associated with recanalization were current smoking (36.6% in current smokers vs 24.5% in current non-smokers (OR 1.8 (95% CI 1.3 to 2.4); p=0.0001), ruptured status (31.9% in ruptured aneurysms vs 25.1% in unruptured (OR 1.5 (95% CI 1.1 to 2.1); p=0.006), aneurysm size ≥10 mm (48.8% vs 26.5% in aneurysms <10 mm (OR 2.6 (95% CI 1.8 to 3.9); p<0.0001), wide neck (32.1% vs 25.8% in narrow neck (OR 1.5 (95% CI 1.1 to 2.1); p=0.02), and MCA location (34.3% vs 28.3% in other locations (OR 1.5 (95% CI 1.0 to 2.1); p=0.04).ConclusionsSeveral factors are identified by the ARETA study as playing a role in aneurysm recanalization after coiling: current smoking, aneurysm status (ruptured), aneurysm size (≥10 mm), neck size (wide neck), and aneurysm location (middle cerebral artery). This finding has important consequences in clinical practice.Trial registration numberURL: http://www.clinicaltrials.gov; Unique Identifier: NCT01942512.

Abstract 1122‐000213: Presence of Blebs Associated with Reduced Aneurysm Wall Tension and Increased Wall Enhancement

Introduction : Aneurysm wall enhancement using high‐resolution vessel wall imaging (HR‐VWI) may provide new surrogate biomarkers for instability. Finite element analysis (FEA) paired with HR‐VWI can provide more insight into complex morphological features that ultimately lead to aneurysm growth and rupture. Methods : Unruptured intracranial aneurysms were reconstructed in 3D from CE‐MRA imaging. Shells were created assuming a uniform wall thickness of 86 μm and FEA was conducted with a 3rd order polynomial material model, assuming the wall to be isotropic, homogenous, and similar between subjects. The 95th percentile wall tension was defined as high wall tension to account for mesh artifacts. Low wall tension was identified from nodal values and verified on contour plots. Regions of high and low wall tension were characterized from contour plots. Aneurysms were measured and classified as enhancing (CR stalk ≥0.6) or non‐enhancing (CR stalk <0.6), using manual ROI measurements from 3T HR‐VWI T1 postcontrast imaging. Results : Of the twenty‐three aneurysms analyzed, fourteen were classified as enhancing (CR stalk ≥0.6) and nine as non‐enhancing. Enhancing aneurysms had a significantly higher 95th percentile wall tension (m = 0.89±0.32 N/cm) compared to non‐enhancing aneurysms (m = 0.48±0.10 N/cm, p<0.001). Wall enhancement remained a significant predictor of wall tension while accounting for the effects of aneurysm size (p = 0.046). High wall tension was consistently concentrated at the neck of the aneurysm, while low wall tension concentrated at the dome. (Figure 1). Aneurysms with blebs (N = 7) had significantly lower minimal wall tension (m = 0.13±0.02 N/cm) than those without (m = 0.21±0.10 N/cm, p = 0.033). Enhancing aneurysms had significantly higher minimal wall tensions (m = 0.23±0.10 N/cm), than non‐enhancing aneurysms (m = 0.13±0.02 N/cm, 0.003). Minimal wall tension was less strongly correlated with diameter and neck size (Spearman’s r = 0.564,0.378 respectively) than 95th percentile wall tension (Spearman’s r = 0.756, 0.541 respectively). Conclusions : Large and irregular aneurysms are subject to complex mechanical loading. The resultant stress concentrators may prompt the histological remodeling response observed in areas of growth, like the aneurysm neck. Low wall tension indicative of wall degradation in areas more prone to rupture colocalized with aneurysm wall enhancement and blebs.

TOUCH® Prosthesis for Thumb Carpometacarpal Joint Osteoarthritis: A Prospective Case Series

The dual mobility concept currently represents the newest generation of thumb carpometacarpal prostheses. The aim of this study was to evaluate the short-term outcomes of TOUCH® prosthesis. From September 2019 to July 2020, 40 prosthesis were implanted in 37 patients suffering from symptomatic stage III osteoarthritis. All included patients with a median age of 57.7 (IQR: 13.6) finished the systematic follow-up regimen (4, 8, 16 weeks, 6, and 12 months postoperatively). All parameters significantly improved (p < 0.0001) compared to the preoperative status. At 1 year follow-up, median DASH Scores decreased from 54 (IQR 22) to 12 (IQR 28) and pain levels improved from 8 (IQR 2) to 1 (IQR 2). Moreover, key-pinch strength increased from 3.8 (2.0) to 5.8 (2.5), while palmar abduction, radial abduction, and opposition also significantly improved. 35/37 patients were satisfied with the functional outcomes. We observed 10 complications, of which 6 were tendon-related issues, and 2 were due to an inappropriate choice of neck size. We could detect one dislocation but no evidence of cup loosening, tilting or subsidence in any patient. Despite the occurrence of some complications, we recommend implantation of this prosthesis type due to favorable clinical and radiological performance.

Value of 3D-DSA in the detection of intracranial aneurysms

Aim: To determine the value of three-dimensional (3D) digital subtraction angiography (DSA) in the detection of intracranial aneurysms and to compare 3D technique with DSA. Materials and Methods: A retrospective analysis of 50 patients with 60 intracranial aneurysms who underwent both conventional DSA and 3D-DSA for the evaluation of intracranial aneurysms was conducted. The presence of aneurysms, detection of aneurysmal neck, size, location, presence of additional and small aneurysms analyzed from the two protocols were compared. Results: Three-dimensional technique detected 54 aneurysms while conventional DSA detected 38 aneurysms. There was no correlation between aneurysm detection and aneurysm neck detection in the two technologies observed, but there was a difference in detection performance depending on the technology used. Three-dimensional technique detected 52 aneurysm necks while conventional DSA detected 24 aneurysm necks. There was a statistically significant and positive relationship between the detected size of the aneurysm using 3D technique and DSA technology. Three-dimensional technique detected 24 additional aneurysms while conventional DSA detected only six additional aneurysms. Conclusions: Three-dimensional technique are more successful in the detection of aneurysms, their necks and small aneurysms in comparison to digital subtraction angiography, but difference is not statistically significant. The size of the aneurysm statistically significant affects the aneurysm neck detection by conventional DSA.

Developing Neck Circumference Growth Reference Charts for Pakistani Children and Adolescents Using the Lambda-Mu-Sigma (LMS) and Quantile Regression Method

Objective: Neck circumference (NC) is currently used as an embryonic marker of obesity and its associated risks. But its use in clinical evaluations and other epidemiological purposes requires sex and age-specific standardized cut-offs which are still scarce for the Pakistani pediatric population. We therefore developed sex and age- specific growth reference charts for NC for Pakistani children and adolescents aged 2-18 years. Design: Cross-sectional multi-ethnic anthropometric survey (MEAS) study. Setting: Multan, Lahore, Rawalpindi and Islamabad. Participants: The dataset of 10,668 healthy Pakistani children and adolescents aged 2 to 18 years collected in MEAS were used. Information related to age, sex and NC were taken as study variables. The lambda-mu-sigma (LMS) and quantile regression (QR) methods were applied to develop growth reference charts for NC. Results: The 5th, 10th, 25th, 50th, 75th, 90th and 95th smoothed percentile values of NC were presented. The centile values showed that neck size increased with age in both boys and girls. During 8 and 14 years of age, girls were found to have larger NC than boys. A comparison of NC median (50th) percentile values with references from Iranian and Turkish populations reveals substantially lower NC percentiles in Pakistani children and adolescents compared to their peers in the reference population. Conclusion: The comparative results suggest that the uses of NC references of developed countries are inadequate for Pakistani children. A small variability between empirical centiles and centiles obtained by QR procedure recommends that growth charts should be constructed by QR as an alternative method.

REtrospective Multicenter INdian Study of Derivo Embolization Device (REMIND): Periprocedural Safety

Purpose: The treatment of aneurysms with characteristics such as complex morphology, fusiform, blister-like, wide neck, or large size has been revolutionized with the introduction of flow diverters. Though flow diverters have several advantages over coiling, they also have certain important disadvantages such as the lack of immediate protection against rupture, the risk of ischemic stroke, the need for antiplatelet therapy, and long latency for complete effect. The Derivo Embolization Device (DED) is a second-generation self-expanding device that is claimed to be less thrombogenic than conventional devices. We retrospectively evaluated the periprocedural safety and risks associated with the Derivo Embolization Device across 5 centers in India.Materials and Methods: This is a multicentric, retrospective, observational study of DED, conducted at 5 high volume endovascular therapy centers in India from May 2018 to June 2020. Periprocedural demographic, clinical, and angiographic data were collected from a retrospective review of patient charts.Results: A total of 96 patients, including 56 (58.3%) females, aged between 16–80 years (60±12.7 years) harboring 106 aneurysms were studied. Seven (7.3%) were noted to harbor multiple aneurysms: 6 had 3 aneurysms each, while 1 patient had 5 aneurysms. The following aneurysm characteristics were noted: average size, 9.8±8.2 mm; average neck size, 6.9±8.5 mm; wide-necked (>4mm), 63 (59.4%); giant (>25mm), 8 (7.5%); and anterior circulation location, 98 (92.5%). Eighteen (17%) of these were ruptured. Additional balloon angioplasty was performed in 5 (5.2%) patients. Intraprocedural problems were encountered in 3 (3.1%), of which only 1 had clinical implications, the device fish-mouthing with stent thrombosis resulting in a malignant middle cerebral artery territory infarction. The modified Rankin scale at 3 months was worse in 1 patient.Conclusion: DED is a newer generation flow diverter stent with a low periprocedural complication rate.

Gaussian Process Based Model to Optimize Additively Manufactured Powder Microstructures From Phase Field Modeling

A persistent problem in the selective laser sintering process is to maintain the quality of additively manufactured parts, which can be attributed to the various sources of uncertainty. In this work, a two-particle phase-field microstructure model has been analyzed. The sources of uncertainty as the two input parameters were surface diffusivity and inter-particle distance. The response quantity of interest (QOI) was selected as the size of the neck region that develops between the two particles. Two different cases with equal and unequal sized particles were studied. It was observed that the neck size increased with increasing surface diffusivity and decreased with increasing inter-particle distance irrespective of particle size. Sensitivity analysis found that the inter-particle distance has more influence on variation in neck size than that of surface diffusivity. The machine learning algorithm Gaussian Process Regression was used to create the surrogate model of the QOI. Bayesian Optimization method was used to find optimal values of the input parameters. For equal-sized particles, optimization using Probability of Improvement provided optimal values of surface diffusivity and inter-particle distance as 23.8268 and 40.0001, respectively. The Expected Improvement as an acquisition function gave optimal values 23.9874 and 40.7428, respectively. For unequal sized particles, optimal design values from Probability of Improvement were 23.9700 and 33.3005, respectively, while those from Expected Improvement were 23.9893 and 33.9627, respectively. The optimization results from the two different acquisition functions seemed to be in good agreement.

Physical Conditioning Strategies for the Prevention of Concussion in Sport: a Scoping Review

Background Concussion in sports has received a great deal of media attention and may result in short and longer-lasting symptoms, especially in adolescents. Although significant strides have been made in the identification and management of concussion, less is known about the primary prevention of this condition. The aims of this scoping review are to (1) summarize the current research of physical conditioning strategies to reduce or prevent concussion incidence in individuals participating in sport, especially adolescents, and (2) to identify gaps in the knowledge base. Our research question was what is known from the existing literature about physical preparation strategies to reduce or prevent concussion in adult and adolescent sports? Methods Three literature searches were conducted by information officers at two universities at six-month intervals, using five electronic databases (PubMed; WorldCat.org; Mendeley; EBSCOHost and Ovid MEDLINE). To increase the search range, subject experts were consulted and articles and reference lists were hand searched. A scoping review methodology identified eligible studies that analyzed physical preparation techniques on modifiable physical risk factors in athletes to reduce the incidence of concussion. The PRISMA-ScR checklist guided the reporting of the findings. Results A total of 1414 possible articles were identified, after duplicates removed, and articles analyzed against the inclusion and exclusion criteria, only 9 articles qualified for analysis. Two articles were found from studying reference lists. Thus, a total of 11 articles were included in the final evaluation for the purposes of this study. Data are reported from mostly adolescent subjects participating in nine different sports from three countries. Findings are presented with specific reference to previously recognized modifiable risk factors of concussion which include neck strength, neck size, cervical stiffness, type of sport, and pre-activity exercises. Conclusions There is limited research examining the physical preparation of athletes, especially in adolescents, to reduce or prevent concussion, and conflicting evidence in the few small sample studies that were identified. This scoping review identifies the research gap for a potentially vital modifiable risk factor, notably in the physical preparation of children and adolescents to reduce or prevent sports-related concussion.