Systematic Review on Endovascular Access to Intracranial Arteries for Mechanical Thrombectomy in Acute Ischemic Stroke.

Purpose: In acute ischemic stroke for large vessel occlusions, delayed or failed access to intracranial occlusions has a negative impact on procedural and clinical outcomes. The aim of this review is to identify and quantify access failures and challenges in mechanical thrombectomy.

Methods: A systematic literature review of PubMed and Scopus databases from January 2014 to October 2020 was performed.

The impact of compliance on Stage 2 uni-ventricular heart circulation: An experimental assessment of the Bidirectional Glenn.

The Bidirectional Glenn (BDG) or cavopulmonary connection is typically undertaken to volume unload the single ventricle in an effort to preserve ventricular and atrioventricular valve function. The geometry of this surgical palliation has been shown to influence the fluid energy loss as well as the distribution of flow that enters through the superior vena cava. In-vitro and in-silico studies to date have been performed on rigid wall models, while this investigation looks at the impact of flexible thin walled models versus rigid walls.

An in-vitro evaluation of the flow haemodynamic performance of Gore-Tex extracardiac conduits for univentricular circulation.

Objective(s): The Fontan procedure is a common palliative intervention for sufferers of single ventricle congenital heart defects that results in an anastomosis of the venous return to the pulmonary arteries called the total cavopulmonary connection (TCPC). In patients with palliated single ventricular heart defects, the Fontan circulation passively directs systemic venous return to the pulmonary circulation in the absence of a functional sub-pulmonary ventricle. Therefore, the Fontan circulation is highly dependent on favourable flow and energetics, and minimal energy loss is of great importance.

An in vitro assessment of atrial fibrillation flow types on cardiogenic emboli trajectory paths.

Atrial fibrillation is the most significant contributor to thrombus formation within the heart and is responsible for 45% of all cardio embolic strokes, which account for approximately 15% of acute ischemic strokes cases worldwide. Atrial fibrillation can result in a reduction of normal cardiac output and cycle length of up to 30% and 40%, respectively. A total of 240 embolus analogues were released into a thin-walled, patient-specific aortic arch under normal (60 embolus analogues) and varying atrial fibrillation (180 embolus analogues) pulsatile flow conditions.

Investigation of the Hemodynamics Influencing Emboli Trajectories Through a Patient-Specific Aortic Arch Model.

Background and Purpose- Cardiogenic emboli account for 15% to 20% of acute ischemic stroke cases worldwide. However, the chance of such emboli, of varying sizes, causing a stroke under various flow types has not been evaluated. Methods- A patient-specific aortic arch model was fabricated from a medical image dataset of a 77-year-old male case, with atrial fibrillation and distal occlusion of the right M1 vessel.

Embolus Analog Trajectory Paths Under Physiological Flowrates Through Patient-Specific Aortic Arch Models.

Atrial fibrillation (AF) is the most common irregular heartbeat among the world's population and is a major contributor to cardiogenic embolisms and acute ischemic stroke (AIS). However, the role AF flow plays in the trajectory paths of cardiogenic emboli has not been experimentally investigated. A physiological simulation system was designed to analyze the trajectory patterns of bovine embolus analogs (EAs) (n = 720) through four patient-specific models, under three flow conditions: steady flow, normal pulsatile flow, and AF pulsatile flow.

The Mechanical Characterisation of Bovine Embolus Analogues Under Various Loading Conditions.

Embolus Analogues (EAs) can provide understanding of the mechanical characteristics of blood clots of cardiac origin. Bovine EAs (n = 29) were fabricated with varying concentrations of thrombin (0-20 NIHU/ml blood). Histological staining confirmed that EA composition compared sufficiently with human samples reported in literature.

Validation of the Strain Assessment of a Phantom of Abdominal Aortic Aneurysm: Comparison of Results Obtained From Magnetic Resonance Imaging and Stereovision Measurements.

Predicting aortic aneurysm ruptures is a complex problem that has been investigated by many research teams over several decades. Work on this issue is notably complex and involves both the mechanical behavior of the artery and the blood flow. Magnetic resonance imaging (MRI) can provide measurements concerning the shape of an organ and the blood that flows through it.

Systematic Review and Patient-Level Meta-analysis of the Streamliner Multilayer Flow Modulator in the Management of Complex Thoracoabdominal Aortic Pathology.

Purpose: To examine the safety and short-term efficacy of the Streamliner Multilayer Flow Modulator (SMFM) in the management of patients with complex thoracoabdominal aortic pathology who are unfit for alternative interventions.

Methods: Biomedical databases were systematically searched for articles published between 2008 and 2015 on the SMFM. A patient-level meta-analysis was used to evaluate aneurysm-related survival.

Comparison of the strain field of abdominal aortic aneurysm measured by magnetic resonance imaging and stereovision: a feasibility study for prediction of the risk of rupture of aortic abdominal aneurysm.

The prediction of the risk of rupture of abdominal aortic aneurysm (AAA) is a complex problem. Currently the criteria to predict rupture of abdominal aortic aneurysms are aneurysm diameter and growth rates. It is generally believed that study of the wall strain distribution could be helpful to find a better decision criterion for surgery of aortic aneurysms before their rupture.

The influence of computational assumptions on analysing abdominal aortic aneurysm haemodynamics.

The variation in computational assumptions for analysing abdominal aortic aneurysm haemodynamics can influence the desired output results and computational cost. Such assumptions for abdominal aortic aneurysm modelling include static/transient pressures, steady/transient flows and rigid/compliant walls. Six computational methods and these various assumptions were simulated and compared within a realistic abdominal aortic aneurysm model with and without intraluminal thrombus.

An in vitro assessment of the cerebral hemodynamics through three patient specific circle of Willis geometries.

The Circle of Willis (CoW) is a complex pentagonal network comprised of fourteen cerebral vessels located at the base of the brain. The collateral flow feature within the circle of Willis allows the ability to maintain cerebral perfusion of the brain. Unfortunately, this collateral flow feature can create undesirable flow impact locations due to anatomical variations within the CoW.

An experimental investigation of the hemodynamic variations due to aplastic vessels within three-dimensional phantom models of the circle of Willis.

A complete circle of Willis (CoW) is found in approximately 30-50% of the population. Anatomical variations, such as absent or surgically clamped vessels, can result in undesirable flow patterns. These can affect the brain's ability to maintain cerebral perfusion and the formation of cerebral aneurysms.

Hemodynamic variations due to spiral blood flow through four patient-specific bifurcated stent graft configurations for the treatment of abdominal aortic aneurysms.

Endovascular repair is now a recognised procedure for treating abdominal aortic aneurysms. However, post-operative complications such as stent graft migration and thrombus may still occur. To assess these complications numerically, the correct input boundary conditions, which include the full human aorta with associated branching, should be included.

In vitro evaluation of the effects of intraluminal thrombus on abdominal aortic aneurysm wall dynamics.

The optimum time to treat abdominal aortic aneurysms (AAAs) still remains an uncertain issue. The decision to intervene does not take in account the effects that wall curvature, intraluminal thrombus (ILT) properties and thickness have on rupture. The role of ILT in aneurysm dynamics and rupture has been controversial.

[Management of adult abdominal pain in the Emergency Room].

Abdominal pain is a commonplace reason for surgical consultation in the emergency department and is the the most common symptom which the digestive surgeon on-call must evaluate. He must understand the pathophysiologic basis of visceral pain and referred pain in order to appreciate its diverse manifestations. Abdominal pain can stem from many causes intestinal and non-intestinal, medical and surgical.

3-D numerical simulation of blood flow through models of the human aorta.

A Spiral Computerized Tomography (CT) scan of the aorta were obtained from a single subject and three model variations were examined. Computational fluid dynamics modeling of all three models showed variations in the velocity contours along the aortic arch with differences in the boundary layer growth and recirculation regions. Further down-stream, all three models showed very similar velocity profiles during maximum velocity with differences occurring in the decelerating part of the pulse.

Effects of flat, parabolic and realistic steady flow inlet profiles on idealised and realistic stent graft fits through Abdominal Aortic Aneurysms (AAA).

Computational fluid dynamics modelling of bifurcated stent grafts positioned across Abdominal Aortic Aneursysms (AAAs) is influenced significantly by the boundary conditions and geometry. To assess these influencing factors, simulations using three different steady inlet profiles and two geometries were run. The steady velocity inlet profiles (flat, parabolic and realistic) were used as input boundary conditions with a constant pressure outlet for each model.

A mathematical model to predict the in vivo pulsatile drag forces acting on bifurcated stent grafts used in endovascular treatment of abdominal aortic aneurysms (AAA).

Endovascular treatment of abdominal aortic aneurysms (AAA) is a promising new alternative to the traditional surgical repair. However, the endovascular approach suffers problems such as stent graft migration, endoleaks and stent mechanism breakage. Fatigue failure is believed to be the major cause of stent graft migration and device breakage.

[Antibiotic prophylaxis in surgery of the esophagus].

Surgery of oesophagus carcinoma is a long and major procedure. Perioperative radiochemotherapy is often required. Therefore many factors favour the occurrence of local and general postoperative infection, justifying an antibiotic prophylaxis directed against oesophageal and gastric flora.

Clinical evaluation of the CORDIS vascular access port systems: a multicenter study.

Two non-metallic vascular access port systems, the Multipurpose Access Port (MPAP) and Miniport, developed by CORDIS S.A., France, have been evaluated clinically in 78 cancer patients.

[Hereditary deficiency of antithrombin III, protein C and protein S. A study of 31 patients from 8 unrelated families].

The families of eight unrelated patients were studied with regard to a hereditary deficiency in antithrombin III (ATIII), protein C, or protein S. These deficiencies were recognized in the course of investigations for deep-vein thrombosis (DVT) in the eight patients. A group of 31 individuals (patients and family members), mostly less than 40-year-old was explored.

[Biological criteria for the evaluation of prophylactic treatment with a low molecular weight heparin (Kabi 2165)].

Efficacy of a low molecular weight heparin (Kabi 2165) was compared with that of non-fractionated heparin in the prevention of abdominal surgery postoperative venous thrombosis by means of a double-blind randomized trial in 79 patients. Determination of D. dimers in these patients allowed assessment of specificity of this assay for detection of postoperative venous thrombosis.