scholarly journals In vivo cerebral aneurysm models

2019 ◽  
Vol 47 (1) ◽  
pp. E20 ◽  
Author(s):  
John W. Thompson ◽  
Omar Elwardany ◽  
David J. McCarthy ◽  
Dallas L. Sheinberg ◽  
Carlos M. Alvarez ◽  
...  
Keyword(s):  
Cerebral Aneurysm ◽  
Surgical Techniques ◽  
Cerebral Aneurysms ◽  
Aneurysm Rupture ◽  
Large Animal ◽  
Pharmacological Interventions ◽  
Large Animal Models ◽  
First Line Therapy ◽  
Endovascular Devices

Cerebral aneurysm rupture is a devastating event resulting in subarachnoid hemorrhage and is associated with significant morbidity and death. Up to 50% of individuals do not survive aneurysm rupture, with the majority of survivors suffering some degree of neurological deficit. Therefore, prior to aneurysm rupture, a large number of diagnosed patients are treated either microsurgically via clipping or endovascularly to prevent aneurysm filling. With the advancement of endovascular surgical techniques and devices, endovascular treatment of cerebral aneurysms is becoming the first-line therapy at many hospitals. Despite this fact, a large number of endovascularly treated patients will have aneurysm recanalization and progression and will require retreatment. The lack of approved pharmacological interventions for cerebral aneurysms and the need for retreatment have led to a growing interest in understanding the molecular, cellular, and physiological determinants of cerebral aneurysm pathogenesis, maturation, and rupture. To this end, the use of animal cerebral aneurysm models has contributed significantly to our current understanding of cerebral aneurysm biology and to the development of and training in endovascular devices. This review summarizes the small and large animal models of cerebral aneurysm that are being used to explore the pathophysiology of cerebral aneurysms, as well as the development of novel endovascular devices for aneurysm treatment.

scholarly journals Review: Tissue Engineering of Small-Diameter Vascular Grafts and Their In Vivo Evaluation in Large Animals and Humans

Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 713
Author(s):  
Shu Fang ◽  
Ditte Gry Ellman ◽  
Ditte Caroline Andersen
Keyword(s):  
Animal Models ◽  
Vascular Grafts ◽  
Small Diameter ◽  
Large Animal ◽  
Large Animal Models ◽  
Graft Outcome ◽  
Limited Success ◽  
Large Animals

To date, a wide range of materials, from synthetic to natural or a mixture of these, has been explored, modified, and examined as small-diameter tissue-engineered vascular grafts (SD-TEVGs) for tissue regeneration either in vitro or in vivo. However, very limited success has been achieved due to mechanical failure, thrombogenicity or intimal hyperplasia, and improvements of the SD-TEVG design are thus required. Here, in vivo studies investigating novel and relative long (10 times of the inner diameter) SD-TEVGs in large animal models and humans are identified and discussed, with emphasis on graft outcome based on model- and graft-related conditions. Only a few types of synthetic polymer-based SD-TEVGs have been evaluated in large-animal models and reflect limited success. However, some polymers, such as polycaprolactone (PCL), show favorable biocompatibility and potential to be further modified and improved in the form of hybrid grafts. Natural polymer- and cell-secreted extracellular matrix (ECM)-based SD-TEVGs tested in large animals still fail due to a weak strength or thrombogenicity. Similarly, native ECM-based SD-TEVGs and in-vitro-developed hybrid SD-TEVGs that contain xenogeneic molecules or matrix seem related to a harmful graft outcome. In contrast, allogeneic native ECM-based SD-TEVGs, in-vitro-developed hybrid SD-TEVGs with allogeneic banked human cells or isolated autologous stem cells, and in-body tissue architecture (IBTA)-based SD-TEVGs seem to be promising for the future, since they are suitable in dimension, mechanical strength, biocompatibility, and availability.

A Systematic Review of the Tensile Biomechanical Properties of the Neonatal Brachial Plexus

2021 ◽  
Author(s):  
Virginia Orozco ◽  
Rachel Magee ◽  
Sriram Balasubramanian ◽  
Anita Singh
Keyword(s):  
Brachial Plexus ◽  
Biomechanical Properties ◽  
Large Animal ◽  
Comprehensive Overview ◽  
Related Factors ◽  
Large Animal Models ◽  
Biomechanical Responses ◽  
Biomechanical Parameters ◽  
Injury Outcomes

Abstract Brachial plexus birth injury has a reported incidence of 1 to 4 per 1000 live births. During complicated deliveries, neonatal, maternal, and other birth-related factors can cause over-stretching or avulsion of the neonatal brachial plexus leading to injury. Understanding biomechanical responses of the neonate brachial plexus when subjected to stretch can offer insight into the injury outcomes while guiding the development of preventative maneuvers that can help reduce the occurrence of neonatal brachial plexus injuries. This review article aims to offer a comprehensive overview of existing literature reporting biomechanical responses of the brachial plexus, in both adults and neonates, when subjected to stretch. Despite the discrepancies in the reported biomechanical properties of the brachial plexus, the studies confirm the loading rate and loading direction dependency of the brachial plexus tissue. Future studies, possibly in vivo, that utilize clinically-relevant neonatal large animal models can provide translational failure values of the biomechanical parameters for the neonatal brachial plexus when subjected to stretch.

scholarly journals Association between Circle of Willis Configuration and Rupture of Cerebral Aneurysms

Medicina ◽  
2019 ◽  
Vol 55 (7) ◽  
pp. 338
Author(s):  
Stojanović ◽  
Kostić ◽  
Mitić ◽  
Berilažić ◽  
Radisavljević
Keyword(s):  
Cerebral Aneurysm ◽  
Intracranial Hemorrhage ◽  
Lower Incidence ◽  
Cerebral Aneurysms ◽  
Aneurysm Rupture ◽  
Circle Of Willis ◽  
Type B ◽  
Brain Aneurysms

Background and Objectives: Intracranial hemorrhage caused by the rupture of brain aneurysms occurs in almost 10 per 100,000 people whereas the incidence of such aneurysms is significantly higher, accounting for 4–9%.Linking certain factors to cerebral aneurysm rupture could help in explaining the significantly lower incidence of their rupture compared to their presence. The aim of this study is to determine the association between the corresponding circle of Willis configurations and rupture of cerebral aneurysms. Materials and Methods: A group of 114 patients treated operatively for aruptured cerebral aneurysm and a group of 56 autopsied subjects were involved in the study. Four basic types of the circle of Willis configurations were formed—two symmetric types A and C, and two asymmetric types B and D. Results: A statistically significantly higher presence of asymmetry of the circle of Willis was determined in the group of surgically-treated subjects (p = 0.001),witha significant presence of asymmetric Type B in this group (p < 0.001). The changeson the A1 segment in the group of surgically-treated subjects showed a statistically significant presence compared to the group of autopsied subjects (p = 0.001). Analyzing the presence of symmetry of the circle of Willis between the two groups, that is, the total presence of symmetric types A and C, indicated their statistically significant presence in the group of autopsied patients (p < 0.001). Conclusions: Changes such as hypoplasia or aplasia of A1 and the resulting asymmetry of the circle of Willis directly affect the possibility of the rupture of cerebral aneurysms. Detection of the corresponding types of the circle of Willis after diagnostic examination can be the basis for the development of a protocol for monitoring such patients.

Evaluation of Cerebral Aneurysm Stent Performance in a Subject-Specific Computational Model

2010 ◽  
Author(s):  
Timothy J. Gundert ◽  
John F. LaDisa
Keyword(s):  
United States ◽  
Blood Flow ◽  
Computational Model ◽  
Cerebral Aneurysm ◽  
Cerebral Aneurysms ◽  
The United States ◽  
Flow Stagnation ◽  
Subject Specific ◽  
Endovascular Devices ◽  
Saccular Aneurysms

Rupture of cerebral aneurysms is the second leading cause of stroke in the United States [1]. Altered hemodynamics is thought to play a role in the progression and subsequent rupture of aneurysms. Blood flow into an aneurysm can be occluded by surgically clipping the aneurysm or using endovascular devices, such as stents or coils. In saccular aneurysms, coiling alone may be a sufficient method of inducing flow stagnation in the aneurysm, causing thrombosis and preventing rupture. When treating wide-necked aneurysms, stenting is often used in conjunction with coiling to prevent the migration of coils. Many investigators have studied the ability of a stent-only treatment to favorably alter flow in aneurysms [2, 3].

scholarly journals Consequences of mitral valve prolapse on chordal tension: Ex vivo and in vivo studies in large animal models

2011 ◽  
Vol 142 (6) ◽  
pp. 1585-1587 ◽  
Author(s):  
Mathieu Granier ◽  
Morten O. Jensen ◽  
Jesper L. Honge ◽  
Alain Bel ◽  
Philippe Menasché ◽  
...  
Keyword(s):  
Mitral Valve ◽  
Animal Models ◽  
Mitral Valve Prolapse ◽  
Ex Vivo ◽  
In Vivo Studies ◽  
Large Animal ◽  
Large Animal Models

Size is the Most Important Predictor of Aneurysm Rupture Among Multiple Cerebral Aneurysms: Post Hoc Subgroup Analysis of Unruptured Cerebral Aneurysm Study Japan

Neurosurgery ◽  
2017 ◽  
Vol 82 (6) ◽  
pp. 864-869 ◽  
Author(s):  
Masaaki Shojima ◽  
Akio Morita ◽  
Hirofumi Nakatomi ◽  
Shinjiro Tominari
Keyword(s):  
Cerebral Aneurysm ◽  
Cerebral Aneurysms ◽  
Aneurysm Rupture ◽  
Ruptured Aneurysm ◽  
Clinical Value ◽  
Total Cohort ◽  
Unruptured Cerebral Aneurysm ◽  
Specific Factors ◽  
Unruptured Cerebral Aneurysms ◽  
Post Hoc

Abstract BACKGROUND Multiple cerebral aneurysms are encountered in approximately 15% to 35% of patients harboring unruptured cerebral aneurysms. It would be of clinical value to determine which of them is most likely to rupture. OBJECTIVE To characterize features of the ruptured aneurysm relative to other concomitant fellow aneurysms in patients with multiple cerebral aneurysms. METHODS From a total of 5720 patients who were prospectively registered in the Unruptured Cerebral Aneurysm Study in Japan, a subgroup of patients with multiple cerebral aneurysms who developed subarachnoid hemorrhage was extracted for this post hoc analysis. Intrapatient comparisons of each aneurysm were carried out using aneurysm-specific factors such as size, location, and shape to identify predictors of rupture among the fellow aneurysms in a patient with multiple cerebral aneurysms. RESULTS Twenty-five patients with 62 aneurysms were identified from the total cohort of 5720 patients. With the distinctiveness in size, which means the aneurysm was the single largest among the multiple aneurysms, the ruptured aneurysm in each case was discriminated from the other coexisting aneurysms with a sensitivity of 0.76 and specificity of 0.86. CONCLUSION Our results suggest that the largest aneurysm is likely to rupture among coexisting aneurysms in a patient with multiple cerebral aneurysms.

scholarly journals Predicting Cerebral Aneurysm Rupture by Gradient Boosting Decision Tree using Clinical, Hemodynamic, and Morphological Information

10.29007/jjwt ◽  
2020 ◽  
Author(s):  
Toshiyuki Haruhara ◽  
Hideto Ohgi ◽  
Masaaki Suzuki ◽  
Hiroyuki Takao ◽  
Takashi Suzuki ◽  
...  
Keyword(s):  
Blood Vessel ◽  
Cerebral Aneurysm ◽  
Cerebral Aneurysms ◽  
Prediction Method ◽  
Preventive Treatment ◽  
Aneurysm Rupture ◽  
Gradient Boosting ◽  
Machine Learning Model ◽  
The Individual ◽  
Shape Data

Stroke is a serious cerebrovascular condition in which brain cells die due to an abrupt blockage of arteries supplying blood and oxygen or when a blood vessel bursts or ruptures and causes bleeding in the brain. Because the onset of stroke is very sudden in most people, prevention is often difficult. In Japan, stroke is one of the major causes of death and is associated with high medical costs; these problems are exacerbated by the aging population. Therefore, stroke prediction and treatment are important. The incidence of stroke may be avoided by preventive treatment based on the patient’s risk of stroke. However, since judging the risk of stroke onset is largely dependent upon the individual experience and skill of the doctor, a highly accurate prediction method that is independent of the doctor’s experience and skills is necessary. This study focuses on a predictive method for subarachnoid hemorrhage, which is a type of stroke. LightGBM was used to predict the rupture of cerebral aneurysms using a machine learning model that takes clinical, hemodynamic and morphological information into account. This model was used to analyze samples from 338 cerebral aneurysm cases (35 ruptured, 303 unruptured). Simulation of cerebral blood-flow was used to calculate the hemodynamic features while the surface curvature was extracted from the 3D blood-vessel-shape data as morphological features. This model yielded a sensitivity of 0.77 and a specificity of 0.83.

scholarly journals Adult Canine Intestinal Derived Organoids: A Novel In Vitro System for Translational Research in Comparative Gastroenterology

2018 ◽  
Author(s):  
Lawrance Chandra ◽  
Dana C Borcherding ◽  
Dawn Kingsbury ◽  
Todd Atherly ◽  
Yoko M Ambrosini ◽  
...  
Keyword(s):  
Animal Models ◽  
Translational Research ◽  
Three Dimensional ◽  
Metabolic Imaging ◽  
Large Animal ◽  
Large Animal Models ◽  
Molecular Features ◽  
Naturally Occurring

AbstractBackgroundLarge animal models, such as the dog, are increasingly being used over rodent models for studying naturally occurring diseases including gastrointestinal (GI) disorders. Dogs share similar environmental, genomic, anatomical, and intestinal physiologic features with humans. To bridge the gap between currently used animal models (e.g. mouse) and humans, and expand the translational potential of the dog model, we developed a three dimensional (3D) canine GI organoid (enteroid and colonoid) system. Organoids have recently gained interest in translational research as this model system better recapitulates the physiological and molecular features of the tissue environment in comparison with two-dimensional cultures.ResultsOrganoids were propagated from isolation of adult intestinal stem cells (ISC) from whole jejunal tissue as well as endoscopically obtained duodenal, ileal and colonic biopsy samples of healthy dogs and GI cases, including inflammatory bowel disease (IBD) and intestinal carcinomas. Intestinal organoids were comprehensively characterized using histology, immunohistochemistry, RNA in situ hybridization and transmission electron microscopy, and organoids mimicked the in vivo tissue environment. Physiological relevance of the enteroid system was defined using functional assays such as Optical Metabolic Imaging (OMI), the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) function assay, and Exosome-Like Vesicles (EV) uptake assay, as a basis for wider applications of this technology in basic, preclinical and translational GI research.ConclusionsIn summary, our findings establish the canine GI organoid systems as a novel model to study naturally occurring intestinal diseases in dogs and humans. Furthermore, canine organoid systems will help to elucidate host-pathogen interactions contributing to GI disease pathogenesis.

scholarly journals Large Animal Models of an In Vivo Bioreactor for Engineering Vascularized Bone

2018 ◽  
Vol 24 (4) ◽  
pp. 317-325 ◽  
Author(s):  
Banu Akar ◽  
Alexander M. Tatara ◽  
Alok Sutradhar ◽  
Hui-Yi Hsiao ◽  
Michael Miller ◽  
...  
Keyword(s):  
Animal Models ◽  
Large Animal ◽  
Large Animal Models ◽  
Vascularized Bone
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