Brain aneurysms and arteriovenous malformations: advancements and emerging treatments in endovascular embolization

BACKGROUND AND PURPOSE: Brain aneurysms and vascular malformations can cause cerebral hemorrhages, with devastating consequences for the patients and their families. Since the development of microcatheters and materials used for endovascular embolization, we have witnessed a rapid advancement in the technology and in the number or patients treated with this approach. The aim of this review is to survey recent data relevant to new technologies and emerging treatment strategies in these areas. SUMMARY OF REVIEW: Clinical trials assessing the safety and efficacy of coil embolization for cerebral aneurysms were based on the use of bare platinum, helical coils. Since then, endovascular operators have been testing and using new materials such as bioactive coils, expandable coils, and complex-shaped coils. Based on the data so far obtained, third and fourth generation coil designs are rapidly emerging and will be ready for clinical application in the near future. Balloon- and stent-assisted coil embolization is enabling the treatment of complex, large-neck aneurysms and the vascular reconstruction of lesions previously considered not treatable. New open- and closed-cell designs allow the navigation and deployment of stents in extremely tortuous vessels. With regards to the embolization of vascular malformations, it is possible to safely navigate microcatheters and microwires through very small arteries previously considered not accessible. In addition, embolization materials such as n-butyl cyanoacrylate and ethylene-vinyl alcohol copolymer are now routinely injected to safely reduce or obliterate large and complex arteriovenous malformations and fistulae. CONCLUSIONS: Advancements in technology are rapidly improving the endovascular approach to the treatment of cerebral aneurysms and arteriovenous malformations

Role of laparoscopy in the diagnosis and management of benign adnexal masses

Background: Adnexal masses are frequent findings in women of all age groups. It consists of the ovaries, fallopian tubes and uterine ligaments. Women can present with various gynaecological complaints and adnexal masses could be detected while examining and investigating for these complaints. The aim was to study the role of laparoscopy in diagnosis and management of benign adnexal masses.Methods: The study was conducted on 48 women of reproductive age group. Per speculum examination was done and PAP smear was taken before bimanual examination was done. A complete per vaginum examination was done and the adnexal mass was assessed for its size, side, consistency, laterality and tenderness. Laparoscopy was done to confirm preoperative diagnosis and appropriate procedure done depending on diagnosis.Results: Pain in the lower abdomen was the commonest chief complaint seen in 87.5% cases. 41.67% cases were suspected to have endometriosis while on laparoscopy it was seen in 47.92%, 33.33% were suspected to have ovarian cyst which decreased to 25% on laparoscopy, ectopic pregnancy in 16.67% cases both pre-operative and on laparoscopic examination and tubo-ovarian mass in 8.33% cases pre-operatively and 2.08% on laparoscopy.Conclusions: This study has shown that if proper preoperative evaluation was done, author can select the appropriate patients for laparoscopic approach

Clinical profile of patients with pelvic adnexal masses

Background: Adnexal masses are frequent findings in women of all age groups. It consists of the ovaries, fallopian tubes and uterine ligaments. Women can present with various gynaecological complaints and adnexal masses could be detected while examining and investigating for these complaints. Aim was to study the clinical profile of women in reproductive age group presented with adnexal masses.Methods: The study comprised of 48 women of reproductive age group. Per speculum examination was done and PAP smear was taken before bimanual examination was done.A complete per vaginum examination was done and the adnexal mass was assessed for its size, side, consistency, laterality and tenderness.Results: Pain in the lower abdomen was the commonest chief complaint seen in 87.5% cases. Out of these, majority i.e.66.67% had chronic pelvic pain and 23% had pain of less than 1-month duration which were cases of ectopic pregnancy. 41.67% cases were suspected to have endometriosis,33.33% were suspected to have ovarian cyst, followed by ectopic pregnancy in 16.67% cases and tubo-ovarian mass in 8.33% cases.Conclusions: The present study shows that if proper preoperative evaluation is done, we can select the appropriate patients for laparoscopic approach

Effectiveness of mechanical endovascular thrombectomy in a model system of cerebrovascular occlusion

BACKGROUND AND PURPOSE: A number of thrombectomy devices are currently undergoing clinical evaluation; meanwhile, various novel devices are under investigation. The aims of this study were to quantify flow restoration and the particle size distribution of the effluent pursuant to MET in an in vitro occlusion model. MATERIALS AND METHODS: The model system was composed of 3 elements: an ICA/MCA replica, a clot model with mechanical properties similar to those of thrombi found in patients at risk of stroke, and a pulsatile flow loop. Different thrombectomy mechanisms including mechanical retrieval, aspiration, and waveguide induced cavitation were used. The efficacy end points were recanalization rate and amount of flow restoration. The risk of the embolic shower was assessed to evaluate device safety. RESULTS: The recanalization rates were the following: Merci, 67%; Solitaire, 100%; Penumbra, 83%; Enterprise, 17%; and the waveguide, 0%. In experiments in which recanalization was achieved, the amount of flow restoration for the Merci, Solitaire, and Enterprise devices was 100%, 92%, and 86%, respectively. The mean sizes of generated small and large clot fragments were between 23 and 37 and 215 and 285 mum, respectively, depending on the device used. The Merci device generated the fewest number of large fragments compared with the Penumbra system (P \u3c .05) and Solitaire (not significant). CONCLUSIONS: The risk of embolic shower was influenced by the mechanism of action for the thrombectomy device. Clinically reported recanalization rates for the Solitaire, Penumbra, and Merci devices were nearly identical in this model system, suggesting that this model may provide a predictive tool for preclinical evaluation of MET

A Spectral Theory of Neural Prediction and Alignment

The representations of neural networks are often compared to those of biological systems by performing regression between the neural network responses and those measured from biological systems. Many different state-of-the-art deep neural networks yield similar neural predictions, but it remains unclear how to differentiate among models that perform equally well at predicting neural responses. To gain insight into this, we use a recent theoretical framework that relates the generalization error from regression to the spectral bias of the model activations and the alignment of the neural responses onto the learnable subspace of the model. We extend this theory to the case of regression between model activations and neural responses, and define geometrical properties describing the error embedding geometry. We test a large number of deep neural networks that predict visual cortical activity and show that there are multiple types of geometries that result in low neural prediction error as measured via regression. The work demonstrates that carefully decomposing representational metrics can provide interpretability of how models are capturing neural activity and points the way towards improved models of neural activity.Comment: First two authors contributed equally. To appear at NeurIPS 202

Linear Classification of Neural Manifolds with Correlated Variability

Understanding how the statistical and geometric properties of neural activations relate to network performance is a key problem in theoretical neuroscience and deep learning. In this letter, we calculate how correlations between object representations affect the capacity, a measure of linear separability. We show that for spherical object manifolds, introducing correlations between centroids effectively pushes the spheres closer together, while introducing correlations between the spheres' axes effectively shrinks their radii, revealing a duality between neural correlations and geometry. We then show that our results can be used to accurately estimate the capacity with real neural data.Comment: 6 pages and 5 figures in main text. 11 pages and 1 figure in supplementary materia

Techniques in distal access of wide-necked giant intracranial aneurysms during treatment with flow diversion

BACKGROUND: Accessing the normal distal vessel in treatment of wide-necked giant intracranial aneurysms with flow diversion can be difficult. CASE DESCRIPTION: Through illustrative cases, the authors present several useful techniques in distal access of wide-necked giant aneurysms during flow diversion treatment. Obtaining an optimal projection that separates the outflow limb from the aneurysm is most critical. Each of the three techniques described enabled the distal access to giant intracranial aneurysms during treatment with flow diversion. CONCLUSION: The looped-around technique, balloon-assisted technique, and retrograde access are valuable strategies in crossing the aneurysm if direct distal access cannot be obtained

A study of maternal outcome in first trimester bleeding

Background: The outcome of first trimester vaginal bleeding is a matter of debate. Vaginal bleeding is common and potentially alarming symptom in early pregnancy. First trimester bleeding is a common occurrence. It has been estimated to occur in 15-25% of all pregnant women. Objective of this study was to evaluate the various maternal outcomes in women with first trimester bleeding.Methods: This prospective observational study was conducted in the postgraduate department of obstetrics and gynecology, SMGS Hospital, Government Medical College, Jammu, Jammu and Kashmir, India. The study included 200 pregnant women presented with first trimester bleeding. All the women were followed prospectively till delivery and early postpartum period for various outcomes such as preterm delivery, PROM, PPROM, anemia, oligohydramnios, placental abruption, placenta previa and postpartum hemorrhage.Results: Out of 200 patients studied, 19% patients aborted. Ectopic and molar pregnancy was seen in 5% and 1.5% patients respectively. Out of 74.5% patients who continued pregnancy, maternal complications included anemia (52%), PROM (14.09%), oligohydramnios (6.71%), placenta previa (5.37%), PPH (4.03%), PPROM (2.68%), preeclampsia (2.01%), gestational hypertension (1.34%), abruption and post-datism (0.67% each).Conclusions: From the results of this study, it can be concluded that first trimester bleeding can be a predicting factor in terms of mother and infant consequences of pregnancy and it is necessary to increase the knowledge of pregnant women in this regard for closer care