Sodium bicarbonate as a local adjunctive agent for limiting platelet activation, aggregation, and adhesion within cardiovascular therapeutic devices.

Cardiovascular therapeutic devices (CTDs) remain limited by thrombotic adverse events. Current antithrombotic agents limit thrombosis partially, often adding to bleeding. The Impella® blood pump utilizes heparin in 5% dextrose (D5W) as an internal purge to limit thrombosis.

Sodium bicarbonate alters protein stability and blood coagulability in a simulated Impella purge gap model.

Background: The Impella® microaxial blood pumps utilize purge fluid containing heparin to prevent biofouling of internal surfaces. Purge fluid interfaces with blood or blood components at two notable internal locations: (1) 5-8 μm radial gap ("Radial Gap" or "Gap 1") between the motor shaft and bearing, a site accessible by blood proteins or small molecules; and (2) 100 μm axial gap ("Axial Gap" or "Gap 2") between the impeller rotor and bearing, the site of mixing with larger circulating blood components. Despite its efficacy, heparin in the purge fluid complicates overall patient anticoagulation management.

Multifocal Cryoballoon Ablation for Eradication of Barrett's Esophagus-Related Neoplasia: A Prospective Multicenter Clinical Trial.

Introduction: Ablation of Barrett's esophagus (BE) is the preferred approach for the treatment of neoplasia without visible lesions. Limited data on cryoballoon ablation (CBA) suggest its potential clinical utility. We evaluated the safety and efficacy of CBA in a multicenter study of patients with neoplastic BE.

Hemolysis associated with Impella heart pump positioning: In vitro hemolysis testing and computational fluid dynamics modeling.

Introduction: Short-term mechanical circulatory support devices provide temporary hemodynamic support in heart failure and are increasingly used to enable recovery or as a bridge to decision. Blood damage with mechanical circulatory support devices is influenced by many factors, including the magnitude and duration of shear stress and obstruction to blood flow. This study aimed to evaluate the effects of the Impella CP heart pump positioning on hemolysis using in vitro hemolysis testing and computational fluid dynamics modeling.

CDX-2 Expression in Esophageal Biopsies Without Goblet Cell Intestinal Metaplasia May Be Predictive of Barrett's Esophagus.

Background: CDX-2 is a nuclear homeobox transcription factor not normally expressed in esophageal and gastric epithelia, reported to highlight intestinal metaplasia (IM) in the esophagus. Pathological absence of goblet cells at initial screening via hematoxylin and eosin (HE) and alcian blue (AB) staining results in patient exclusion from surveillance programs.

Aims: This study aimed to determine whether non-goblet cell IM, as defined by CDX-2 positivity, can be considered to be a precursor to Barrett's esophagus (BE).

Incidence of Esophageal Adenocarcinoma and Causes of Mortality After Radiofrequency Ablation of Barrett's Esophagus.

Background & Aims: Radiofrequency ablation (RFA) is commonly used to treat Barrett's esophagus (BE). We assessed the incidence of esophageal adenocarcinoma (EAC) after RFA, factors associated with the development of EAC, and EAC-specific and all-cause mortality.

Methods: We collected data for outcomes of patients who underwent RFA for BE from July 2007 through July 2011 from US multicenter RFA Patient Registry.

Treatment of chronic radiation proctopathy with radiofrequency ablation (with video).

Background: Chronic radiation proctopathy (CRP) is a common sequela occurring even many years after pelvic radiation. Current ablative therapies for bleeding ectatic vessels have the potential for deep tissue injury leading to ulcerations, perforation, and fistulas. Radiofrequency ablation (RFA) therapy avoids deep tissue injury and is a promising treatment for CRP.

In-vitro calcification study of polyurethane heart valves.

Tri-leaflet polyurethane heart valves have been considered as a potential candidate in heart valve replacement surgeries. In this study, polyurethane (Angioflex(®)) heart valve prostheses were fabricated using a solvent-casting method to evaluate their calcification resistance. These valves were subjected to accelerated life testing (continuous opening and closing of the leaflets) in a synthetic calcification solution.

Effects of fluid flow shear rate and surface roughness on the calcification of polymeric heart valve leaflet.

Surface defects, blood flow shear rates and mechanical stresses are contributing factors in the calcification process of polymeric devices exposed to the blood flow. A number of experiments were performed to evaluate the effect of surface defects such as roughness and cracks and flow shear rate on the calcification process of a polyurethane material used in the design of prosthetic heart valves. Results showed that polyurethane surface gets calcified and the calcification is more pronounced at the lower shear rates.

Prior fundoplication does not improve safety or efficacy outcomes of radiofrequency ablation: results from the U.S. RFA Registry.

Background: Ongoing gastroesophageal reflux may impair healing and re-epithelialization after radiofrequency ablation (RFA) of Barrett's esophagus (BE). Because prior fundoplication may improve reflux control, our aim was to assess the relationship between prior fundoplication and the safety/efficacy of RFA.

Methods: We assessed the U.

Effect of pulsatile blood flow on thrombosis potential with a step wall transition.

It is well known that thrombus can be formed at stagnation regions in blood flow. However, studies of thrombus formation have typically focused on steady state flow. We hypothesize that pulsating flow may reduce persistent stagnation at the sites of low shear stress by decreasing exposure time.

In vitro and computational thrombosis on artificial surfaces with shear stress.

Implantable devices in direct contact with flowing blood are associated with the risk of thromboembolic events. This study addresses the need to improve our understanding of the thrombosis mechanism and to identify areas on artificial surfaces susceptible to thrombus deposition. Thrombus deposits on artificial blood step transitions are quantified experimentally and compared with shear stress and shear rate distributions using computational fluid dynamics (CFD) models.