Dissected Aorta Repair Through Stent Implantation trial: Canadian results

Objectives

We describe the Canadian results of the Ascyrus Medical Dissection Stent (AMDS), a novel partially uncovered aortic arch hybrid graft implanted antegrade during hypothermic circulatory arrest to promote true lumen expansion and enhance aortic remodeling.

Midterm Outcomes of the Dissected Aorta Repair Through Stent Implantation Trial

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Comprehensive assessment of aquatic community responses to a new anionic surfactant, high-solubility alkyl sulfate

High-solubility alkyl sulfate (HSAS) is a new anionic surfactant for use in consumer product applications that provides enhanced water solubility and improved water hardness tolerance. A comprehensive model stream ecosystem investigation was conducted to assess ecological and toxicological effects of HSAS on stream invertebrates. Model streams were dosed with HSAS for a period of 56 days following 56 days of colonization in a single-pass, flow-through system. Exposures were control and 9.1, 24.1, 64.0, 165.8, and 426.5 microg/L based on specific analytical detection methods. Benthic abundance on gravel substrates, drift, and insect emergence were assessed. Several taxonomically unrelated taxa were found sensitive to HSAS and formed the basis of toxicological conclusions. Abundance or biomass of a limpet (Ferrissea), a bivalve (Corbicula), flatworms (Turbellaria), and a mayfly (Stenonema) was reduced at concentrations ranging from 165.8 to 426.5 microg/L. Principal response curve analysis, a constrained form of principal components analysis, demonstrated consistency with univariate analyses and identified similar populations as being sensitive to HSAS. Comparison with historical studies from the same testing site, streams, and experimental design, but with structurally related alkyl sulfate and alkyl ethoxysulfate anionic surfactants, revealed several similar trends in response profiles at the population level for both tolerant and sensitive species. Based on the comprehensive nature of the study, strength of data trends, and demonstrated sensitivity of the aquatic communities contained in the experimental system, the no-observed-effect concentration for HSAS was concluded to be 64.0 microg/L. An application factor of 1 is justified for deriving a predicted no-effect concentration) for HSAS in aquatic systems.     

Impact of Obesity on Heart and Lung Transplantation: Does Pre-Transplant Obesity Affect Outcomes?

Increasing prevalence of obesity has led to a rise in the number of prospective obese heart and lung transplant recipients. The optimal management strategy of obese patients with end-stage heart and lung failure remains controversial. This review article discusses and provides a summary of the literature surrounding the impact of obesity on outcomes in heart and lung transplantation. Studies on transplant obesity demonstrate controversy in terms of morbidity and mortality outcomes and obesity pre-transplantation. However, the impact of obesity on outcomes seems to be more consistently demonstrated in lung rather than heart transplantation. The ultimate goal in heart and lung transplantation in the obese patient is to identify those at highest risk of complication that may warrant therapies to mitigate risk by addressing comorbid conditions.     

The role of competing mechanisms on Lck regulation

Immunologic Research - Lck is a Src-related protein tyrosine kinase that associates with CD4 and CD8 molecules and is essential to T cell development and T cell activation. Regulatory mechanisms of...     

Hybrid aortic arch and frozen elephant trunk reconstruction: bridging the gap between conventional and total endovascular arch repair

Introduction: Novel endovascular techniques hope to offer patients aortic arch repair with reduced morbidity compared to conventional arch surgery; however, current endovascular strategies remain challenged by the proximal seal zone, higher stroke rates, long-term durability and select anatomy. Hybrid arch repair offers patients a less invasive alternative that can treat more distal aorta than conventional arch repair yet still be performed via standard sternotomy.

Areas covered: This review will discuss the current evidence and future development of hybrid aortic arch and frozen elephant trunk reconstruction. Several approaches to hybrid arch repair are summarized, including the off-label use of thoracic endovascular stent-grafts and commercially manufactured hybrid grafts. Technical considerations and clinical outcomes with each approach will be addressed along with advantages and disadvantages.

Expert commentary: Hybrid arch repair will undergo continued refinement as our ability to provide a less-invasive alternative to conventional open arch repair grows. Evolution to allow for improved head vessel branch sizing, improved frozen elephant trunk deployment accuracy, monitoring to prevent paraplegia and utilization of intraoperative image guidance in hybrid operating rooms is necessary. The potential exists for hybrid approaches to arch pathology to completely supplant conventional surgery, while avoiding the potential deleterious complications of total endovascular repair.     

The Acute and Chronic Toxicity of Hexadecyl and Heptadecyl Sulfate to Aquatic Organisms

HSAS (high-solubility alkyl sulfate) is a new anionic surfactant composed predominantly of methyl and ethyl branched hexadecyl and heptadecyl sulfate. Effects of HSAS on a wide range of fish, algae, and invertebrates were investigated in conventional laboratory toxicity tests as well as in exposures conducted as part of an experimental stream model ecosystem study. For invertebrates and fish, C_16.7HSAS (average alkyl chain length 16.7) acute LC₅₀ values ranged from 0.23 (channel catfish) to 2.9 (Asiatic clam, Corbicula) mg/L in well and river waters. LC₅₀ values for those species tested in both waters were typically within a factor of 1.5 and all were within a factor of 2 of each other, suggesting bioavailability is similar in these waters. Chronic toxicity values ranged from 0.070 (fathead minnow) to 0.42 (amphipod, Hyalella) mg/L across fish and invertebrates with algal chronic toxicity values ranging from 0.5 (blue-green algae, Anabaena flos-aquae) to 7.8 (green algae, Scenedesmus) mg/L. The order of sensitivity to HSAS acute and chronic toxicity was fish = invertebrate > algae. Based on the chronic single species sensitivity distribution, the concentrations protective of 90 and 95% of species were estimated to be 0.058 and 0.036 mg/L, respectively. These compare well with the model ecosystem NOEC of 0.064 mg/L (Belanger et al. 2005).     

Lung transplantation from donors after circulatory death using portable ex vivo lung perfusion

BACKGROUND:

Donation after circulatory death is a novel method of increasing the number of donor lungs available for transplantation. Using organs from donors after circulatory death has the potential to increase the number of transplants performed.

METHODS:

Three bilateral lung transplants from donors after circulatory death were performed over a six-month period. Following organ retrieval, all sets of lungs were placed on a portable ex vivo lung perfusion device for evaluation and preservation.

RESULTS:

Lung function remained stable during portable ex vivo perfusion, with improvement in partial pressure of oxygen/fraction of inspired oxygen ratios. Mechanical ventilation was discontinued within 48 h for each recipient and no patient stayed in the intensive care unit longer than eight days. There was no postgraft dysfunction at 72 h in two of the three recipients. Ninety-day mortality for all recipients was 0% and all maintain excellent forced expiratory volume in 1 s and forced vital capacity values post-transplantation.

CONCLUSION:

The authors report excellent results with their initial experience using donors after circulatory death after portable ex vivo lung perfusion. It is hoped this will allow for the most efficient use of available donor lungs, leading to more transplants and fewer deaths for potential recipients on wait lists.