Aneurysm dome and vessel pressure measurements with coiling, stent assisted coiling and flow diversion.

Background: Variability in long-term endovascular treatment outcomes for intracranial aneurysms has prompted questions regarding the effects of these treatments on aneurysm hemodynamics. Endovascular techniques disrupt aneurysmal blood flow and shear, but their influence on intra-aneurysmal pressure remains unclear. A better understanding of aneurysm pressure effects may aid in predicting outcomes and guiding treatment decisions.

Application of 3D printing to create an in vitro aneurysm rupture model.

Currently available benchtop (in vitro) aneurysm models are inadequate for testing the efficacy of endovascular device treatments. Specifically, current models do not represent the mechanical instability of giant aneurysms (defined as aneurysms with 25 mm in height or width) and do not predictably rupture under simulated physiological conditions. Hence, in vitro aneurysm models with biomechanically relevant material properties and a predictable rupture timeframe are needed to accurately assess the efficacy of new medical device treatment options.

Development of physiologically relevant synthetic thrombus for use in visual analysis of in vitro mechanical thrombectomy device testing.

Background: Ischemic stroke is a leading cause of death and significant long-term disability worldwide. Mechanical thrombectomy is emerging as a standard treatment for eligible patients. As clinical implementation of stent retrieval and aspiration thrombectomy increases, there is a need for physiologically relevant in vitro device efficacy testing.

Large, Wide-Neck, Side-Wall Aneurysm Treatment in Canines Using NeuroCURE: A Novel Liquid Embolic.

Background: Untreated intracranial aneurysms can rupture and result in high rates of morbidity and mortality. Although there are numerous approved endovascular aneurysm treatment devices, most require dual anti-platelet therapy, are minimally biocompatible, or are prone to recanalization. Neurovascular Controlled Uniform Rapid Embolic (NeuroCURE) is an innovative polymer gel material with long-term stability, biocompatibility, and hemocompatibility developed for the treatment of large, wide-neck aneurysms.

Definitions of intracranial aneurysm size and morphology: A call for standardization.

Background: Intracranial aneurysms (IAs) are classified based on size (maximal dome diameter) as well as additional parameters such as neck diameter and dome-to-neck ratio (DNR). The neurosurgical literature includes a wide variety of definitions for both IA size and neck classifications. Standardizing the definitions of IA size and wide-neck classifications would help eliminate inconsistencies and potential misunderstandings of aneurysm morphology and rupture risk.

Application of nondestructive mechanical characterization testing for creating in vitro vessel models with material properties similar to human neurovasculature.

Vessel models are a first step in developing endovascular medical devices. However, these models, often made from glass or silicone, do not accurately represent the mechanical properties of human vascular tissue, limiting their use to basic training and proof-of-concept testing. This study outlines methods to quantify human vascular tissue mechanical properties and synthetic biomaterials for creating representative vessel models.

Application of a rabbit-elastase aneurysm model for preliminary histology assessment of the PPODA-QT liquid embolic.

Background: PPODA-QT is a novel liquid embolic under development for the treatment of cerebral aneurysms. We sought to test the rabbit-elastase aneurysm model to evaluate the tissue response following PPODA-QT embolization.

Methods: Experimental elastase-induced aneurysms were created in fourteen New Zealand White Rabbits.

Quantifying the mechanical and histological properties of thrombus analog made from human blood for the creation of synthetic thrombus for thrombectomy device testing.

Background: Untreated ischemic stroke can lead to severe morbidity and death, and as such, there are numerous endovascular blood-clot removal (thrombectomy) devices approved for human use. Human thrombi types are highly variable and are typically classified in qualitative terms - 'soft/red,' 'hard/white,' or 'aged/calcified.' Quantifying human thrombus properties can accelerate the development of thrombus analogs for the study of thrombectomy outcomes, which are often inconsistent among treated patients.

In vivo embolization of lateral wall aneurysms in canines using the liquid-to-solid gelling PPODA-QT polymer system: 6-month pilot study.

Object: Over the past 20 years, endovascular embolization has become the preferred method of treating cerebral aneurysms. While there are many embolic devices on the market, none is ideal. In this study the authors investigated the use of a liquid-to-solid gelling polymer system-that is, poly(propylene glycol) diacrylate and pentaerythritol tetrakis (3-mercaptopropionate) (PPODA-QT)-to embolize in vivo aneurysms over a 6-month period.

Preliminary investigation of calcium alginate gel as a biocompatible material for endovascular aneurysm embolization in vivo.

Objective: We sought to expand our assessment of calcium alginate as an embolic agent in an aneurysm model in swine that survived from 30 to 90 days. The objective of this study was to assess the biocompatibility and stability of calcium alginate in aneurysms in vivo.

Methods: Ten models were created from a venous pouch sutured to the carotid artery, simulating flow to a side-wall aneurysm.

Carbonic anhydrase XIV deficiency produces a functional defect in the retinal light response.

Members of the carbonic anhydrase (CA) family play an important role in the regulation of pH, CO(2), ion, and water transport. CA IV and CA XIV are membrane-bound isozymes expressed in the eye. CA IV immunostaining is limited to the choriocapillaris overlying the retina, whereas CA XIV is expressed within the retina in Müller glial cells and retinal pigment epithelium.

Calcium alginate gel as a biocompatible material for endovascular arteriovenous malformation embolization: six-month results in an animal model.

Objective: We sought to expand our assessment of calcium alginate as an embolic agent in an animal model of a cerebral arteriovenous malformation (AVM). The objective of this study was to assess the long-term biocompatibility and stability of calcium alginate in AVM swine models that survived from 1 to 6 months.

Methods: The swine model included a carotid-jugular anastomosis to redirect flow to the rete mirabile (RM), thereby simulating flow to an AVM.

In vivo assessment of calcium alginate gel for endovascular embolization of a cerebral arteriovenous malformation model using the Swine rete mirabile.

Objective: We sought to assess the stability of calcium alginate as an embolic agent in an animal model of a cerebral arteriovenous malformation (AVM). Swine cerebral AVM models were used to test the injectability, radiographic visualization, mechanical stability, and biocompatibility of calcium alginate as an occlusive agent.

Methods: The swine cerebral AVM model included a carotid-to-jugular anastomosis to increase flow to the rete mirabile (RM), thereby simulating the pressure gradient and shunted blood flow of an AVM.

Flow properties of liquid calcium alginate polymer injected through medical microcatheters for endovascular embolization.

The flow properties of liquid calcium alginate injections were investigated for application in endovascular embolization. Alginate shear properties were assessed with a rheometer and a controlled injection system. The experimental results were used to model the flow properties and predict alginate's flow characteristics within various medical microcatheter delivery systems.