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.

Editorial Commentary: Stronger and Faster Suture Configuration—But Is It Better? Challenges of Surgical Innovation in the Modern Era

When evaluating the characteristics of a new surgical technique, it is important to consider practical effects of the technique on clinical practice, as it would be inappropriate to advocate for cost-prohibitive or excessively time-consuming methods, even if biomechanically superior. The Krackow stitch has long been considered the gold standard for suture-graft fixation; potential limitations with this technique include the risk of needle sticks to the surgical team and the time required to perform the stitch. A new proprietary method (SpeedTrap, DePuy-Mitek, Raynham, MA) offers a significantly faster solution with equivalent or better biomechanics; however, elongation of the suture-graft construct is still a concern, and the cost effectiveness remains unclear. Regardless, we are fortunate to be practicing in an era when we can have great appreciation for the problem-solving innovations of surgeons who practiced in prior decades as well as witness the continued effort to optimize clinical outcomes now and in the future.     

Agreement between blood draw techniques for assessing platelet activation by flow cytometry

It is widely believed that assays of platelet activation are susceptible to preanalytical variables related to blood draw technique. We assessed platelet activation by whole blood flow cytometry and investigated the effects of: (1) drawing blood into vacuum tubes or manually aspirated syringes, and (2) discarding the first drawn blood sample (discard tube). Platelet P-selectin expression and platelet-monocyte complexes were measured by flow cytometry under both basal conditions and following stimulation with 0.1, 1, or 10 µM ADP. Bland-Altman plots demonstrated agreement between results for vacuum tube and syringe-aspirated samples with an a priori-defined clinically relevant agreement limit of 5%. Agreement of results was also observed between discard tube and second draw samples for both vacuum-driven and manually aspirated blood. We conclude that a vacuum tube or a manually-aspirated syringe can be used when assessing platelet activation by flow cytometry and that there is no need for a discard tube.     

Clinical Course of Patients With Worsening Heart Failure With Reduced Ejection Fraction

Background

Epidemiology of patients with worsening heart failure and reduced ejection fraction (HFrEF) in the real-world setting is not well described.

Use of a convolutional neural network and quantitative ultrasound for diagnosis of fatty liver

Quantitative ultrasound (QUS) was used to classify rabbits that were induced to have liver disease by placing them on a fatty diet for a defined duration and/or periodically injecting them with CCl₄. The ground truth of the liver state was based on lipid liver percents estimated via the Folch assay and hydroxyproline concentration to quantify fibrosis. Rabbits were scanned ultrasonically in vivo using a SonixOne scanner and an L9-4/38 linear array. Liver fat percentage was classified based on the ultrasonic backscattered radiofrequency (RF) signals from the livers using either QUS or a 1-D convolutional neural network (CNN). Use of QUS parameters with linear regression and canonical correlation analysis demonstrated that the QUS parameters could differentiate between livers with lipid levels above or below 5%. However, the QUS parameters were not sensitive to fibrosis. The CNN was implemented by analyzing raw RF ultrasound signals without using separate reference data. The CNN outputs the classification of liver as either above or below a threshold of 5% fat level in the liver. The CNN outperformed the classification utilizing the QUS parameters combined with a support vector machine in differentiating between low and high lipid liver levels (i.e., accuracies of 74% versus 59% on the testing data). Therefore, although the CNN did not provide a physical interpretation of the tissue properties (e.g., attenuation of the medium or scatterer properties) the CNN had much higher accuracy in predicting fatty liver state and did not require an external reference scan.     

Impact of Spinal Manipulation on Lower Extremity Motor Control in Lumbar Spinal Stenosis Patients: A Small-Scale Assessor-Blind Randomized Clinical Trial

ObjectiveThe purpose of this study was to quantify the impact of a single lumbar spinal manipulation (SM) intervention on the leg movement performance of degenerative lumbar spinal stenosis (LSS) patients in a small-scale registered randomized clinical trial.MethodsParticipants with LSS (n = 14) were tested at baseline for pain, lumbar range of motion, and behavioral or kinematic motor performance (using an established Fitts’ Law foot-pointing task), then underwent covariate adaptive randomization to receive SM or no intervention. Postintervention all dependent measures were repeated. Experimenters were blinded to patient group allocation. University ethics board approval was attained.ResultsFor the primary outcome movement time, there was no significant difference between groups. As predicted by Fitts’ Law, all participants had longer movement times as task difficulty increased. Secondary kinematic outcomes yielded no significant between-group differences. Consistent with Fitts’ Law, kinematic measures changed significantly with task difficulty. Pairwise comparisons revealed the kinematic variables were more adversely affected by greater movement amplitudes than target size changes. No exploratory differences in pain or lumbar range of motion were observed.ConclusionChanges in motor performance were not observed in this chronic pain population after a single SM intervention compared with a control group. Given the sample size, the study may have been underpowered to detect meaningful differences. Fitts’ Law was observed for the lower extremity–pointing task for an LSS population and may provide an objective measure of motor performance.